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Participatory research on workers' health
SC. Sci. Med. Vol. 34, No. 6. pp. 603-613, 1992 Printed in Great Britain. All rights reserved
PARTICIPATORY
Copyright
RESEARCH
ON WORKERS’
0277-9536192 S5.00 + 0.00 r% 1992 Pergamon Press plc
HEALTH
ASA CRISTINALAURELL,MARIANONORIEGA,SUSANAMARTINEZand JORGEVILLEGAS Master Program of Social Medicine, Department of Health Care, Autonomous Metropolitan University Xochimilco, Mexico City, Mexico Abstract-The concern for workers’ health has increased in Latin America during the last decade both on the part of research institutions and trade unions. A special emphasis has been given to active participation of workers not just in the transformation of working conditions to improve health but also in generation of knowledge. This paper presents an action oriented participatory research methodology based on a collective questionnaire that permits the recollection of data on characteristics of the labour process, risks and health damage. A comparison between the information on risks, health damage and the relationship risksdamage obtained with this methodology and those of an individual questionnaire applied at the same steel factory shows that the results produced are very similar. In view of these findings it is concluded that the participatory methodology has some important advantages over traditional methodologies since it provides qualitative information on the labour process, a precise picture of the main risks and how they are produced and semi-quantitative data on health damage, and at the same time, generates a process of consciousness and organization among workers that enables them to promote health oriented action. Key words-occupational
health, participatory research, Latin America, steel workers
with a collective and preventive orientation. However, despite the fact that this methodology was used in a large number of studies in Italy during the seventies [4] its results were never compared with those of studies using traditional scientific research techniques. The objective of this paper is to make such a confrontation, or validation, between the results of two phases of a study carried out at the same workplace; the first using a collective questionnaire methodology based on the Workers’ Model and the second based on traditional methodology. The study was made at a steel factory in Mexico during the period 1985 to 1988 in collaboration with the local union (Local 271 of the National Miners’ Union).
1. INTRODUmION
During the last 15 years studies on workers’ health and efforts to improve it have increased considerably in a relevant number of Latin American countries [ 11. Furthermore, part of the research in this field has been greatly influenced by the school of Latin American social medicine [l] that emphasizes on the social nature of the process of health-disease and assigns a central role to workers in the production of knowledge and not just in the transformation of working conditions to promote health. This has led some researchers to the search for participatory research methodologies that facilitate the construction of studies leading to an integral comprehension of work related health problems and which, at the same time, promote consciousness raising and organization among workers taking into account existing conditions, i.e. the circumstances under which workers act and the type of intervention that is sought. Such a methodology should at least include the following characteristics: be accessible to groups of organized workers, produce reliable information on risks and health damage, be action oriented and based on epidemiological and preventive criteria. In this context the so-called Italian Workers’ Model [2] has attracted great interest [3] since it permits analysis of the labour process, risks and related health problems by means of a procedure that mobilizes workers’ collective experience and transforms it into systematized knowledge. In addition, part of its results are specific proposals for action Address reprint requests to: Dr Asa Cristina Laurel1 Apartado postal 70-212, 04510 Mexico DF, Mexico. SSM 34,&a
2. ON THE METHODOLOGY (a) The collective questionnaire
The methodology used in the first phase of the research project at the steel industry is a modified version of the Workers’ Model [2]. The modifications were based on a critical analysis of its content that included both its theoretical assumptions and the characteristics of the information recollected [S]. The main changes referred to the theoretical assumptions since the Workers’ Model presents workers’ ‘experience’ as the only source of knowledge concerning reality; a conception that excludes the need to validate it against knowledge generated with other procedures; i.e. the Workers’ Model maintains an implicitly phenomenological position with the assumption that only ‘what is lived is real’. Our collective questionnaire, on the contrary, is structured according to a previously elaborated conception of the nature of the relationship between work and
603
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ASA CRISTINALAURELLel al.
health [6]. Based on this conception the elements relevant to study were established before starting the research. Thus, it guarantees the recollection of the necessary information in order to make a significant reconstruction of the relationship between work and health. Nevertheless, our collective questionnaire preserves various aspects of the Workers’ Model and is therefore based on the recognition of the possibility to mobilize and systematize workers’ experience of working conditions and their impact on health and to translate it into exact knowledge concerning the reality of the workplace. The condition, however, is that it is structured according to a theoretical conception that allows us to distinguish circumstantial from essential facts. In order to have access to this knowledge a ‘homogeneous group’ is formed, i.e. a group of workers that share the same working conditions and have a basic organization that allows it to act efficiently. The homogeneous group-with IO-12 members--collectively resolves the questionnaire with a procedure called ‘consentual validation’, which means that only the information recognized as correct by all group members is registered. The group discussions allow us to produce the necessary information and, at the same time, enable the workers to structure a common body of knowledge as a result of the confrontation between their individual experiences. The questionnaire covers five broad themes: the characteristics of the labour process, its risks or loads, the health damage they provoke, the existing health protective measures and those proposed by the workers to protect and promote health. Concerning each of these themes the collective questionnaire poses a series of ‘questions or discussion themes’ [7]. That is, it points out which problems to treat in order to orient the discussion while leaving sufficient margins so that the workers’ perception is not restrained by closed questions. The information gathered with the collective questionnaire has two main characteristics. On one hand, it is intentionally related to the group of workers and not to individuals, and, on the other, it is mainly qualitative. However, it allows for an estimation of the magnitude or intensity of the risks, the proportion of workers exposed, and also the proportion of workers that has experienced a specific health damage. The first part of the collective questionnaire is related to the labour process and gathers information on the place of the department in the global process-particularly with respect to its organizing segments-the flow scheme of the department, its spatial organization and its subsegments. These elements provide an initial approach to the transformations and transfer of the working object, to the instruments of work, to the type and number of workers and to the characteristics of their tasks and work relations. Subsequently the working object(s) and raw materials, the instruments of work and the division and
organization of work are analyzed in depth. With the discussion of these ‘themes’ the homogeneous group makes a reconstruction of the dynamic of the labour process. The reconstruction and analysis of the labour process is the starting point for the second part of the collective questionnaire with reference to the work risks or loads. In the questionnaire they are arranged in a manner similar to the ‘risk groups’ of the Workers’ Model given that it is convincingly argued that they synthesize workers’ representation of this aspect of the factory [2]. Thus, the first group-composed of elements that can be identified inside and outside the factory-includes physical hazards like temperature, humidity, ventilation, noise, vibration and illumination. The second grouyomposed of elements typical to the factory-include mainly chemical hazards such as dust, fibers, smoke, gas, solvents, vapors but also radiation. The third group-composed of elements related to the use of the body-include physiological work loads like heavy work and working positions. Each of these risks are analyzed to determine whether or not they constitute a problem; how they are generated, i.e. the relationship to the work object and instruments and the conditions of the installations; approximate intensity and duration; the most critical spots or the workers with the highest exposure and the manner in which the organization and division of labour affect its magnitude and time of exposure. The fourth risk group--composed of elements that cause tension or mental fatigue-includes the psychological load. In our collective questionnaire these are more developed than in the Workers’ Model and incorporate elements of the LEST Method [8] and the studies of Gardell-Frankenheauser [9] but seen in relationship to the group of workers and not to the individual worker. This group includes elements such as shift work, double shifts; work perceived as dangerous; emergencies; working speed; isolation, degree of control over working instruments and tasks; monotony and repetitiveness; characteristics of supervision, etc. Although the psychological loads are most directly related to organization and division of work, they also express imperatives of machinery and working objects. Once these risks have been detected it is necessary to estimate their intensity and distribution among workers according to their tasks. The fifth risk group, that is not included in the original Workers’ Model, includes the elements that might cause accidents. Once the labour process and its hazards and loads have been reconstructed the questionnaire proceeds to study health damage-understood as disorders and diseases-related to each of the risk groups. It is emphasized that both diseases and disorders are of interest since the two taken together give a more integral understanding of the process of worker wear and tear. For each type of health damage the approximate proportion of workers that experiences it is
Participatory research on workers’ health registered together with its seriousness. The reason for discussing damage in relation to each of the risk groups is that it allows clarification, on the one hand, the specific relationship between risks and damage and, on the other, the complexity of causal relations. The last part of the collective questionnaire is dedicated to mapping existing health protective measures and to the formulation of workers’ proposals for the elimination of risks and the improvement of health. Thus, this part is the principal support for action. (6) The methodology of the second phase The second phase of the study was carried out in order to produce the necessary information for validating the results of the collective questionnaire. An individual questionnaire and some special studies were applied to a probabilistic sample of 17% of the 5400 workers. Fifteen percent of the sample did not respond which is considered acceptable given the practical difficulties of the study. The individual questionnaire contained the following items: personal data; working history; present work situation; level of exposure to physical, chemical, physiological, psychological and mechanical risks; interrogation of symptoms of chronic and repetitive acute disorders and two scales of self-response (Cornell Medical Index and the Yoshitake scale). The study was restricted to chronic and repetitive acute disorders/diseases since it was considered that these could be related to work. The integration of the diagnosis was done on the basis of the interrogation of symptoms and the scales with pre-established criteria. The special studies practiced on all the workers of the sample were spirometry; audiometry (if the results suggested auditive fatigue the test was repeated after 12-24 hr of rest from work); blood sample; two measures of blood pressure; height and weight. Complementary studies were made to a part of the sample with the following criteria: chest X-ray on workers with symptoms suggestive of respiratory disease in the questionnaire and/or pathological changes in spirometry and/or 7 years or more of exposure to dust; eye examination performed by a ophthalmologist to those with symptoms suggestive of eye diseases in the questionnaire. The data processing was done with a microcomputer. Contrary to the information produced in the first phase of the study with the collective questionnaire, the data of the second phase refers to individuals and is in this sense quantitative. A limitation of the methodology of the second phase is that it only captures the characteristics of the labour processin terms of its risks thus excluding the possibility to reconstruct its complex dynamics. (c) The validation of the collective questionnaire methodology In order to validate the participatory methodology, the data of the second phase of the study was used as
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the parameter against which the results of the collective questionnaire are compared. Nevertheless, it is convenient to comment on the procedure because it oversimplifies the methodological problem involved. In fact it would be more adequate to compare the two sets of data analyzing: on the one hand, in which aspects the results of the different methodologies coincide and, on the other, in which aspects the results differ. Consequently it would be possible to determine which of the two gives a better understanding of the significative phenomena. Furthermore, it is necessary to point out two problems that interfere with the validation as it was done. The first relates to the nature of the object of study-health-as an objective-subjective phenomenon and involves conceptual and methodological questions. It could thus be questioned legitimately if the health-disease process could be understood dissociating its objective components from the subjective ones and if the method of choice is the objective test. A second point of interest is more technical since it concerns what, how and when a phenomenon is best measured. Neither of these problems is solved in this study however it is worth taking them into account in the interpretation of results since they allow for a richer analysis. The validation is done in the first place with information from the individual and collective questionnaires but the results of the special examinations are also included. With this information it is possible to analyze health damage (diseases/disorders), hazards or loads (risks) and the relationship risks-health. The information of the collective questionnaire on the labour process and protective measures is excluded since these items were not studied in the second phase of the study. Given the qualitative and semi-quantitative nature of the information gathered with the collective questionnaire, it was not possible to apply the standard methods used for validation. Therefore, the procedure employed is to make a qualitative and semi-quantitative comparison between the two sets of data (profiles) which allowed, on the one hand, to check the correspondence between the different profiles and, on the other, obtain an estimate of the order of magnitude of each of its components.
3. RESULTS OF THE VALIDATION
(a) Profiles of health damage
Table 1 shows the profiles of health damage constructed with information from the collective and individual questionnaires. The profile resulting from the collective questionnaire is qualitative and rank ordered by the approximate proportion of workers for whom the diseases/disorders is reported. Given that it is based on the accumulated health experience
ASA CRISTINALAURELL er al.
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Table I. Comparison between the profiles of health damage by collective and individual auestionnaires Questionnaire Disorders/diseases Shift work syndrome: gastritis, fatigue and sleeping disorders Irritative eye disease Acute and chronic upper respiratory diseases Nervousness, irritability Back disorders Joint diseases Skin diseases Hearing loss C.N.S. symptoms: (dizziness, nausea, vomiting, blurred vision, somnolence) Varicose veins, hernia Diabetes Kidney stone Tuberculosis of lung Skin cancer Brain cancer Myocardial infarction Stomach infections Other infections Anemia All other causes
Collective’
lndividu#
Majority Majority
66.7 60. I
Majority More than half More than half More than half Close to half Close to half
55.8 34.7 19.0 10.8 56.2 34.5
Close to half Less than half Few Few Few one case one case one case
31.2 15.4 6. I I.9 0.7
21.9 6.4 2.5 6.4
‘Proportion of workers that suffer from the disease/disorder. “Rate per 100 workers. Source: Elaboration from collective and individual questionnaires.
of the group, it refers not just to active workers but also to those who might have left work. The profile based on the data of the individual questionnaire expresses the diseases/disorders of active workers in rates per 100. As can be observed in Table 1 the two different methodologies reach the same results in terms of the qualitative profile of health damage and also show similarities in the frequency of the disorders/diseases. Thus in the coilective questionnaire profile the most frequent disorders are shift work syndrome, irritative eye diseases and acute repetitive and chronic upper respiratory diseases. This pattern is the same in the individual questionnaire profile with rates of 66.7, 60.6 and 55.8 per 100 workers. The pathology identified by the collective questionnaire with an intermediate frequency presents in the results of the individual questionnaire rates between 15 and 30 per 100, with exception of skin diseases with a rate of 56.3 and joint diseases with a rate of 10.8 per 100. The diseases identified as infrequent by the collective questionnaire also show the lowest rates in the individual questionnaire. These findings suggest that workers conceive health damage as a subjective-objective phenomenon and thus do not use exclusively medical criteria in its identification but also the degree of ‘suffering’ they experience or the extent to which the disorders interfere with their working capacity. The disorders that present those characteristics, then, are perceived more strongly by the workers even if they are medically ill defined. This would explain why this type of disorders are more frequently reported in the collective ques-
tionnaire. This would be the case, for instance, of joint diseases that in the individual questionnaire were diagnosed with a strict medical criteria while simple joint ache was reported in the collective questionnaire as a disorder. Conversely certain types of pathology are underestimated in the collective questionnaire since they are not perceived as relevant by the workers as, for instance, would be the case of skin diseases. It was also found that very serious diseases and those with a low prevalence are not satisfactorily registered by neither of the questionnaires which shows the necessity to work with special research designs to study them. Nevertheless, the collective questionnaire has some advantage over the individual one because it gives clues to what are the serious diseases given that the accumulated experience of the group tends to retain those cases and report them even if the sick workers have already left work. Examples of this are the cases of myocardial infarction and cancer that were reported. The individual questionnaire was designed to detect chronic and acute repetitive diseases/disorders related or not to work and registers certain pathologies such as infections and anemia that do not appear in the results of the collective questionnaire which was designed to register only work-related diseases/disorders. This shows that the workers discriminate well between work-related problems and those that are not related to work even if they are frequent such as infections. In order to deepen the analysis of the profile of health damage resulting from the two types of questionnaires the same procedure of validation was repeated for seven departments of the plant typical of its different labour processes. The comparison between the two profiles for each of the different departments confirmed the findings of the general profiles of health damage. The special examinations performed in the second phase of the study show results similar to those of the individual and collective questionnaires. In the eye examination chronic irritative eye diseases were found at a rate of 68.4 per 100; i.e. higher than the rate detected in the individual questionnaire and similar to the estimation of the collective one that a majority of workers suffer from this problem. The audiometries showed a rate of crippling hearing loss, using the strictest medical criteria [IO], of 4.5 per 100 workers; a figure that increases to 15.8 including severe but not crippling hearing loss according to the same criteria. Summing all audiometries, that show changes typical of exposure to industrial noise, a rate of 41.8 per 100 was found: the rate found in the individual questionnaire, 34.5, ranks between the rates of those with severe hearing loss and those showing the changes typical of industrial noise. The estimation of the collective questionnaire that close to half of the workers suffer from hearing
Participatory
research
loss coincides with the data on audiometries with industrial noise changes. The X-rays showed a rate of 5.3 per 100 with pneumoconiosis that increases to 10.6 including all radiological lung pathologies. This figure is not comparable to the one of the collective questionnaire given that the method does not distinguish particular diagnosis. However, is wellknown that there is not an exact coincidence between the radiological and clinical diagnosis. (b) Risk profiles The second item validated between the two questionnaires was the risk profiles (combinations of risks-hazards and loads-haracteristic of a working area). This validation, however, involves some difficulties due to the fact that the two methodologies are based on different conceptions. Thus, in the collective questionnaire risks are analyzed in direct relation to the labour process, its space and the group of workers. This implies that its analytical logic is qualitative and centered on how hazards are produced and their place in the labour process. This contrasts with the individual questionnaire that is necessarily centered on individual workers and their jobs. The importance of a particular hazard or load, then, is derived from the number of workers exposed and its intensity. It is not possible to compare immediately the two forms of measuring the importance of a hazard or load which affects the procedure of validation. This limitation should be borne in mind when comparing the two profiles. The comparison between the results of the two questionnaires shows that the general risk profiles are qualitatively similar but that there are some differences with respect to the importance of each of the hazards or loads. As can be observed in Table 2 those hazards considered to affect ‘all’ workers in the collective questionnaire (heat, noise and dust) also present very high percentages in the individual questionnaire. However, the coincidence is not that clear with respect to the hazards or loads that the homogeneous groups considered to affect the ‘majority’ or ‘few’ or ‘very few’ workers. Thus among the physical hazards humidity and illumination seem to be overestimated in the collective questionnaire. Nevertheless the major discrepancies are observed concerning the psychological loads related to emergencies, sustained attention, monotony, confusing orders and punishments are underestimated collecive questionnaire. It is interesting to note that the greatest discrepancies between the two methodologies are related to the risks that have the highest subjective content since it indicates that the individual perception in these cases is different than the one that results from a collective discussion. Finally the hazards of risk groups V tend to be underestimated which probably is due to the fact that the group discussion was oriented to detect principally the problems of group I-IV.
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Table 2. Comparison between risks profiles reported in the collective and individual questionnaires Questionnaire Collective’ IndividuaP Risk group Physical hazards: Noise Health Lack of ventilation Humidity Poor illumination Chemical hazards: Dust Welding fumes Coke gas Solvents Oven gas Quartz Tar Physiological loads: Forced working positions Heavy physical work Psychological loads: Shift work Dangerous work Double shifts Tight supervision Emergencies Sustained attention Monotony Confusing orders Too much work High speed Isolation Punishments Mechanical hazards: Unsafe electrical installations Unsafe machinery Unsafe floors __ _ . Unsate
tools
Exposed workers
88.8
Intensity’ d or e
All All Majority Majority Majority
82.3 51.0 36.1 33.5
19.6 73.2 45.6 27.0 21.7
All Majority Majority Majority Few Few Few
82.0 49.8 44.8 42.5 30.5 26. I 21.1
75.1 35.0 31.9 29.9 19.4 21.3 12.9
Majority Majority
60.5 59.6
49.7 48.8
Majority Majority Majority Majority Few FCW Few FCW Few Few Few Very few
75.4 12.2 52.9 50.8 69.3 64.9 56.9 42.1 38.4 33.1 20.6 53.7
49.5 46.2 44.1 50.0 31.3 31.4 33.7 52.7 37.5 38.3 24.6 52. I
Majority Majority Few
89.8 89.5 94.1 75.1
42.1 14.2 60.4 54. I
tew
‘Proportion of workers exposed. “Percentage of exposedworkers with respect to all workers. ‘Percentage of workers that consider the problem very seriou& or seriouZ with respect to all exposed workers. Data from the individual questionnaire. Source: Elaboration from collective and individual questionnaires.
The analysis of the general risk profiles was complemented repeating the same procedure with the profiles for seven departments of the plant typical of its different labour processes. These comparisons essentially confirmed the findings of the general risk profiles. Thus the hazards and loads identified are almost always the same in the collective and individual questionnaires and the discrepancies found concern the number of workers exposed. Moreover the coincidence tends to be greater with respect to the more ‘objective’ hazards than with respect to those that are more ‘subjective’, i.e. the psychological loads. As in the case of health damage these discrepancies seem to be related to the different nature of the two questionnaires given that the collective one rests more heavily on the subjective experience of workers than the individual one. (c) The relationship ‘risks-health damages’
The third aspect of the collective questionnaire that was validated is the relationship between risks and
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ASA CRISTINA LAURELL Ed al. Table 3. Comparison
between physical hazards and related health damage in the collective and individual questionnaire by years of work Time worked 7 or more years
+++ Notie : Hearing loss Nervousness: Irritability Anxiety Depression Headache Hear : Dehydration Headache Chronic irritation eye disease Upper resp. diseases’ Nervousness: Irritability
Anxiety Depression Skin diseases Joint ache Varicose veins Kidney stone
Less than 7 years
Magnitude of the problem + +++ ++ (rate per 100 workers)
++
+
_
45.3
30.4
25.0
28.6
25. I
Il.4
6.3
8.3
36.3 24.3 21.0 40.7
23.2 13.4 9.8 33.9
II.4 Il.4 2.3 25.0
32. I 8.9 12.5 25.0
23.5 14.5 I I.2 29.6
18.6 8.6 7.1 24.5
25.0 3.1 3.1 21.9
I I.1 II.1 II.1 22.2
59.2 32.4 72.8 61.0
19.0 30.4 63.3 49.4
15.2 28.3 60.9 45.7
4.2 24.2 65.3 41.1
50.7 26. I 56.0 50.0
14.4 30.8 47. I 50.0
10.7 21.4 42.9 50.0
2.0 12.3 42.9 29.6
36.2
31.6
26. I
20.0
23.9
21.2
18.4 15.2
21.7 19.6
10.5 9.5
12.7 14.2
14.4 7.7
17.9 3.6
14.3
23.0 19.2 65.3 16.4 2.8 3.3
55.1 10.8 1.9 2.5
58.7 17.4 4.3 -
60.0 12.4 6.3 4.2
47.8 5.2 -
55.8 I.9 0.9 1.9
7.1 28.6 7.1 -
6.1 2.0 53.1 6.1 -
Source: Elaboration from collective and individual questionnaires. ‘Chronic and acute repetitive (more than three times in I2 months).
diseases/disorders. In an action oriented research methodology, this aspect is particularly important since it is the basis for setting priorities for health protective action. When this relationship is discussed with the homogeneous group, it is stressed that a single risk could produce different disorders/diseases and also that a specific disorder/disease could be associated to more that one risk. In order to validate this part of the collective questionnaire we used the data of the individual questionnaire resulting from crossing the information on risks with the corresponding diagnosis. Thus Tables 3-7 are based on the relationship of ‘riskshealth damage’ identified by the homogeneous groups and the data on the same relationships found in the individual questionnaire expressed in rates per 100. In the analysis, the years worked at the factory are taken into account as an indicator of the time of exposure.* As can be seen in Table 3 the homogeneous groups related noise with hearing loss, nervousness and headache. In the data of the individual questionnaire this relationship is only verified totally with respect to anxiety and headache in workers who have worked 7 or more years at the plant with rates that increase when the level of exposure goes up. *One could object to the use of years worked at the factory as an indicator of ‘time of exposure’ with the argument that the information on risks refers to-the moment when the questionnaire was applied. Nevertheless the system of promotion employed at the steel plant implies that workers do not move from one department to another and therefore the risks typical of a specific department are the same over time for each worker.
With respect to hearing loss there is a gradient in relation to the seriousness of exposure to noise that is however inconsistent with regard to the groups with little or no exposure. Similar behavior is found for headache among workers with less than 7 years at the plant. This pattern does not invalidate the riskhealth damage relationships identified by the workers-that are well-known-given that it is compatible with the fact that low levels of noise are not pathogenic. The audiometry data show a similar pattern since workers with long working experience and severe or regular exposure to noise have a significantly higher frequency of the audiometric changes typical of exposure to industrial noise than those with little or no exposure. The data of the individual questionnaire with regard to the types of ‘nervousness’ [except anxiety among workers with more than 7 years of work) show a consistent pattern among workers that report noise as a problem but inconsistent among those who do not report it. i.e. As can be observed in Table 3 the groups with severe exposure to noise present much higher rates for these disorders than the groups with little exposure but those who report no exposure also have high rates. However, if the workers with no exposure to noise but with a high psychological load are excluded the expected gradient is re-established. In the collective questionnaire workers associated dehydration, headache, chronic irritative eye diseases, upper respiratory diseases, nervousness, skin diseases, joint ache, varicose veins and kidney stone with exposure to heat (see Table 3). The results of the individual questionnaire confirm these relationships with regard to dehydration for all workers and to headache, chronic irritative eye diseases, upper
Participatory
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Table 4. Comparison between chemical hazards and related health damage in the collective and individual questionnaire by years of work Time worked 7 or more years +++ Solvents and vapors: C.N.S. symptoms Headache Skin diseases Dusts: Upper resp. diseases Lower resp. diseases Skin diseases Chronic irritative Eye diseases Welding fumes: Upper resp. diseases Bronchitis Chronic irritative Eye diseases C.N.S. symptoms Headache Source: Elaboration
Less than 7 years
+ +++ ++ (Rate per 100 workers)
+
-
46.3 46.3 70.5
28.9 42. I 63.1
23.1 35.4 69.2
29.2 29.2 51.7
47.8 41.3 67.4
22.6 16.1 58.1
30.0 27.5 37.5
23.3 30.2 47.7
60.8 12.2 65.8
50.0 a.9 54.5
48.6 4.8 64.9
44.8 I.9 56.2
51.8 5.4 51.8
53.8 2.6 40.4
40.9 63.6
36.3 2.6 49.1
71.4
65.2
70.3
62.1
57.3
51.9
31.8
46.0
62.8 6.6
53.4 II.0
41.0 2.7
49.1 4.4
49.2 4.6
48.9 2.2
44.1 -
41.8 I.8
73.5 50.4 48.8
78.1 28.8 38.4
71.8 28.2 35.9
61.4 26.0 29.7
56.9 43.1 41.5
66.7 26.1 24.4
52.9 14.7 29.4
41.2 23.6 26.7
from collective and individual questionnaires.
diseases for workers with 7 or more years of work. The eye examinations, also, confirm the association between high exposure to heat and chronic irritative eye diseases. In the group of ‘nervousness’ irritability is the only mental disorder that shows a consistent pattern in relation to the magnitude of heat exposure. The associations, identified by the homogeneous groups, between heat and skin diseases, varicose veins, joint ache, and kidney stone are not verified by the data from the individual questionnaire (see Table 3). For skin diseases this inconsistency could be explained by the fact that there are many other work environment hazards that provoke these diseases. In the case of joint ache, as was mentioned above, the criteria used in the individual and collective questionnaires were quite different. Finally it seems that the inconsistency between the two methodologies regarding kidney stones and varicose veins could be explained by their low prevalence. The diseases/disorders identified as related to exposure to solvents and vapors by the homogeneous groups were C.N.S. symptoms (dizziness, nausea, vomiting, blurred vision, somnolence), headache and skin diseases (see Table 4). These relationships are verified by the results of the individual questionnaire for the groups with high exposure. It is interesting to note that headache as a single symptom shows a clear gradient with levels of exposure among workers with 7 or more years at the plant but not among those with less than 7 years since it coincides with the obcervation in the groups discussion that prolonged exposure to solvents tend to make the problem chronic. As a supporting fact concerning the magnitude of the problems caused by exposure to solvents and their vapors, it was found that 4.6% of blood samples show toxic granulation in the differential count even if specific diseases were not found. respiratory
++
According to the collective questionnaire, exposure to dust is associated with upper and lower respiratory diseases, chronic irritative eye diseases and skin diseases (see Table 4). The results of the individual questionnaire confirm this association with respect to upper respiratory diseases among all workers and lower respiratory diseases among workers with 7 years or more at the factory. This finding is consistent with the fact that the latter have a longer latency than the upper respiratory diseases. The chest X-rays confirm this interpretation since there is almost no pathology in the group with less than 7 years while among workers with long work experience there is a marked difference between those exposed to dust and those who are not. As can be observed in Table 4 the irritative eye diseases show a relatively consistent pattern in relation to the intensity of exposure to dust. Nevertheless, it should be considered that there are other work environmental hazards related to these disorders. In addition the eye examination showed a significantly higher frequency of these diseases among workers who reported dust as a severe problem. The skin diseases do not show a clear relationship to the exposure to dust. This is probably due to the fact that it needs to be associated with other hazards as, for example, heat. This assumption was confirmed by the analysis of those that are exposed to dust and heat that show high rates of skin diseases. The collective questionnaire reported as related to exposure to welding fumes upper respiratory diseases and bronchitis, chronic irritative eye diseases and C.N.S. symptoms including headache. The results of the individual questionnaire confirm the association with upper respiratory diseases. Concerning the rest of the disorders, rather than a gradient there is a threshold response among workers with high or high to regular exposure to welding fumes. In the special
610
ASA CRISTINALAIJRELLet al. Table
5. Comparison
between
physiological individual
loads
and
questionnaire
related
health
Time 7 or more
++
+
and
7 years
of the problem +++
per
100 workers)
++
+
-
work:
Backache
29.8
27.5
20.0
14.6
25.9
12.1
3.5
5.1
7.3
3.9
7.4
I.1
31.0
20.7
22.0
16.7
14.1
3.2
3.6
8.0
2.0
I
Hernia
Forced or uncomfortable
working position
Backache Varicose
the collective
Less than
(rate
Heavy physical
m
worked
Years Magnitude
+++
damage
by years of work
veins
5.7
14.7
-
-
: Il.3
-
-
12.5 -
15.3 0.8
Nervousness: Irritability
34.
33.6
34.0
26.4
37.0
21.7
17.5
Anxiety
23.0
23.6
24.0
12.7
16.7
19.6
7.5
5.3
Depression
23.0
17.1
12.0
12.2
II.1
18.5
7.5
3.1
39.7
33.6
20.0
23.4
25.9
23.9
30.0
23.7
Headache Source:
Elaboration
from
collective
and individual
studies this pattern was confirmed for eye diseases but not in the chest X-rays. In relation to the problems associated to heavy physical work the results of the collective and individual questionnaires coincide concerning back disorders as can be observed in Table 5. The relationship is not confirmed for hernia in the individual questionnaire despite the fact that it is well-known. This question might be explained by the low prevalence of the disorder. The homogeneous groups identified forced or uncomfortable (including immobility) working positions as associated to backache, varicose veins, nervousness and headache. The results of the individual questionnaire verify this association with regards to backache and, partially, nervousness and headache but not to varicose veins. Again, the low prevalence of varicose veins might explain this finding. In the collective questionnaire shift work was identified as one of the working conditions that provokes more health problems. It was related to gastritis, nervousness, sleeping disorders, headache, irritative eyes diseases and also weight loss and family problems. In this respect the individual questionnaire shows a similar pattern among workers with 7 years Table
6. Comparison
in the collective
between
shift work
and individual
and related
questionnaires Time
7 or more Shift
Gastritis
Less than Shift
worker No (rate
damage of work
worked
years
Yes
health
by years
worker
Yes
per
7 years
No
100 workers)
37.5
23. I
37.2
40.8
34.2 22.4
26.2 16.2
21.3 9.3 -.
21.6 14.4
Nervousness: Irritability Anxiety Depression
19.5
12.2
7.7
12.0
Sleep disorders
37.5
23.1
26.2
24.0
Headache
32.7
25.8
26.8
22.4
Eye irritation
67.3
67.6
53.6
44.0
Weight
loss*
Familv
oroblems’
Source:
Elaboration
‘Information
from
not recollected
collective
and
-I
individual
in the individual
questionnaires.
questionnaire.
15.3
questionnaires.
or more at the factory except in relation to eye disorders, that was not confirmed in the ophthalmological study either. However, there is no clear pattern among workers with less than 7 years of exposure. These results do not invalidate the observation of the workers on the health effects of shift work since it was verified for an important group. In an epidemiological perspective the finding is interesting since some studies on shift work [l I] show, on the one hand, that the related disorders become chronic and irreversible only after many years of exposure and, on the other, that the most vulnerable workers-some 20%-leave work because of these disorders, a finding that was verified in the present study. The homogeneous groups pointed out a series of elements of the labour process that provoke prolonged tension among which the most important are dangerous working situations, tight supervision, double shifts (16 hr), emergencies, monotony, sustained attention, confused orders and punishments. The disorders and diseases they related to this tension were nervousness, chronic fatigue, sleeping disorders, gastritis, hypertension, ischemic heart disease and diabetes. In order to validate these observations a score of tension was elaborated based on the sum of the qualifications (o-4) of each of the psychological loads. As can be observed in Table 7 the results of the individual questionnaire verify the relationships identified by the homogeneous groups. Among workers with 7 or more years at the factory all the disorders associated to prolonged tension show a clear gradient in relation to the level of exposure to tension. The differences between the rates of the groups are even more significant than with respect to the other risks since those of the groups with severe problems can be 30 times as high as those of the groups that report no problem. The pattern among workers with less than 7 years at work is similar except for hypertension that has a threshold value of ‘regular problem’.
611
Participatory research on workers’ health Table 7. Comparison between psychological loads and related health damage in the individual and collective questionnaires by years of work Time worked Less than 7 years
7 or more years
++++ Tension Ncrvousncss: Irritability Anxiety Depression
Fatigue Hypertension Ischemic heart disease Gastritis Diabetes Sleeping disorders
+++
++
Magnitude of the problem ++++ + (rate per 100 workers)
+++
++
+
-
75.0 83.3 75.0 91.7 8.3
55.0 43.0 37.0 76.0 7.0
39.5 23.4 16.9 70.2 7.3
19.8 7.8 6.3 42.2 6.8
9s 2.4 3.6 21.4 4.8
80.0 80.0 60.0 80.0 20.0
48.8 36.6 29.3 70.7 7.3
14.8 10.8 9.5 52.7 1.4
20.8 6.7 4.0 32.9 1.3
2.1 4.2 22.9 2.1
16.7 75.0 25.0 50.0
5.0 63.0 17.0 50.0
3.2 46.8 9.7 40.3
1.6 31.3 3.4 24.0
17.9 6.0 6.0
40.0 40.0
56.1 4.9 46.3
2.7 39.2 2.7 27.0
31.6 2.0 22.8
27.1 12.5
Source: Elaboration from individual and collective questionnaire. ‘Measured by the score of psychological load elaborated on the basis of the items included as psychological loads in the individual questionnaire.
The validation of the relationship ‘hazards/loadshealth damage’ shows that, generally speaking, the results of the two types of questionnaire coincide. Thus the identification, by groups of workers using the collective questionnaire, of the disorders or diseases provoked by the risks present at their workplace allows to get a precise idea concerning work-related health problems. The discrepancies in the results coincide with those encountered with respect to the profiles of health damage and can be explained by the same elements. Thus when a disease has a low prevalence the results of the individual questionnaire are not conclusive. A second aspect, discussed above, concerns workers’ perception of health damage since it involves the degree of suffering that they experience and the extent to which it interferes with their working capacity. This means that disorders that are not perceived as particularly disturbing are underreported in the collective questionnaire and, on the contrary, those experienced as very disturbing are overestimated. A third difficulty is that many of the reported disorders are associated to various hazards which introduces a confounding effect in the analysis. Finally it is necessary to consider the magnitude of the differences of the rates for the disorders/diseases that were found between the groups in the individual questionnaire. Although these differences in most cases are quite important-from 2 to 40 times more frequent-in others they are only 20-60% higher. One could legitimately ask if differences of that magnitude could be perceived by ihe workers. A tentative response would be that the group experience accumulated over a -period of time actually allows for discrimination even between those differences that are not very great but it would be convenient to continue the study of this problem. SSM 34,‘t-x
4. CONCLUSIONS
The results of the validation of the collective questionnaire lead to specific conclusions concerning its usefulness as a participatory methodology for the study of health at the workplace oriented to problem solving. The importance of the discrepancies that were detected between the results of the collective and individual questionnaire differs depending on the objectives pursued with the research. These could be to obtain data as a necessary first step in changing working conditions; to analyze the importance of work in relation to the pathological profile of a group of workers or a particular disease; or to achieve recognition, treatment and compensation of workrelated health damage. The collective questionnaire has some important advantages over most other methodologies if the main objective of the research is the first. Thus it provides qualitative information on the labour process that serves as a global frame work for the interpretation of the risks and health damage referring them to a group of workers. The other possibility to obtain this type of information would be with the direct observation by an expert with access to the work place, which is very difficult to achieve in Latin America. Furthermore, the collective questionnaire methodology provides a precise picture of the main hazards and loads that affect a group of workers; how they are produced and where they reach the highest concentration. The two main limitations would be certain imprecision concerning the exact number of workers exposed and the loss of some ‘invisible’ risks (for instance radiation or certain chemicals). An in-depth group discussion would solve the first problem and a systematization of what could be the invisible risks the latter. On the other hand, this methodology provides precise semiquantitative data on those diseases/ disorders that produce the most important problems to workers or that affect their working capacity. As
612
ASA CRISTISA LAURELL ef al.
was pointed out, the limitations of the collective questionnaire are that it overestimates diseases/ disorders with an important subjective component or that hinder work and underestimates some clinically well-defined problems and report irregularly those with a low prevalence. Nevertheless, from the point of view of action oriented to improve work and health conditions, the first does not represent, strictly speaking, a limitation since improving health conditions is strongly related to the diminishing of the degree of dis-ease, i.e. with disease as a subjective-objective-phenomenon, and not only to the elimination of a clinical entity. What remains to be solved are the serious diseases with a low prevalence or a long latency. It should be stressed that the collective questionnaire is more sensitive in this respect than the individual one, given that it provides indicative information. Nevertheless, it should be complemented with other studies such as specific laboratory tests or environmental measurements. The collective questionnaire establishes with precision simple and complex ‘risk-health damage’ relationships, which is crucial for guiding action and setting priorities. Further, another results of the collective questionnaire are proposals for action given that the methodology includes the discussion of what measures should be taken to improve working and health conditions. The other main advantage of this methodology when research is action oriented, is that it is based on worker participation and collective consciousness raising. Taken together these characteristics turn the collective questionnaire into the methodology of choice when the purpose of research is to change working and health conditions and establish preventive measures. When the purpose of a study is to analyze the importance of work in relation to the pathological profiles of a group of workers, the limitations of the collective questionnaire are more important. Its major advantage is that it highlights that work plays an important role in producing a large part of what are usually considered common diseases and nonspecific disorders. The knowledge obtained concerning the labour process and its risks also leads to an explanation of how they are produced. In this context it should be recalled that the risk-health damages relationships reported by the collective questionnaire in their great majority were confirmed by the data of the individual questionnaire and special studies. On the other hand, the individual questionnaire showed that the workers studied suffered from a rather high frequency of diseases that were not reported in the collective questionnaire because they were not considered to be work-related. This means -that the homogeneous groups are capable of discriminating between pathology that is work-related and that which is not. Even if the collective questionnaire identifies what part of pathology is work-related and contributes with important explanatory elements, it has the dis-
advantage that it does not permit the utilization of quantitative epidemiological procedures. Thus it is not posible to calculate risk measures, to measure exposure and to apply statistical techniques. This limitation is particularly restrictive when dealing with diseases with a low prevalence. In order to solve this problem, it is necessary to complement it with quantitative research techniques and special research design. Nevertheless, it should be stressed that the collective questionnaire allows us to generate innovative hypothesis since it emphasizes the analysis of the complex relationships between work and health. The limitations of the collective questionnaire become important when the purpose of the research is to achieve recognition, treatment and compensation for work-related health damage. This is so because of a problem inherent to this methodology and because of a formal-legal reason. The first stems from the fact that, by nature, the collective questionnaire produces information referred to the group of workers, its environment and work relations while the recognition-treatment-compensation of work-related diseases almost always refers to the individual worker. Thus this methodology is only useful to argue the recognition of a specific work-related disease for a specific type of workers in the collective bargaining agreement or law. Even so, the formal-legal limitation tends to be imposed, since the legal proof that is demanded is expected to be produced on the basis of a monocausal relationship between a risk and a disease or a quantitative epidemiological study. The results of the validation of the collective questionnaire allow us to argue that it has the same probatory value as a classic epidemiological study but it is probable that such an argument would not be legally accepted. Acknowledgemenr-This research was from the International Development (IDRC), Ottawa, Canada.
supported by a grant Research
Center
REFERENCES
Laurel1 A. C. Trabajo y salud. El estado del conocimiento. In Debares en Medicina Social en AmPrica Lafina (Edited bv Franc0 S. and Nunes A.). Panamerican‘ Health brganization, Washington Dd, 1991. This ‘state of the art’ article, written in mid-1989, reviews 108 Latin American books and articles on work and health. Of these references 10 were published between 1974 and 1979, 48 between 1980 and 1984 and 50 between 1985 and 1989. It includes authors from Argentina, Bolivia, Brazil, Central America, Colombia, Chile, Ecuador, Mexico, Peru and Venezuela. Twenty of the articles discuss and/or use participatory research methods. be it the LEST method. Workers Model or work place check lists. Oddone 1. et al. Ambienre di Lavoro: la Fabbrica nel Terriforio. Editrice Sindicale Italiana, Rome, 1977. See for instance: Alvear G., Rios V. and Villegas J. Condiciones de trabajo y salud de las costureras. Saiud Probtema 14,25, 1988; Facchini L. A. Proceso de Trabajo, Cambio Tecnologico y Desgaste Obrero: El Caso de1 Ingenio A. Lopez Mateos. Theses, Universidad
Participatory research on workers’ health Autonoma Metropolitana-X, Mexico, 1986; Marquer M. and Romero J. El desgaste de las obreras en la maquila electro-electr6nica. Salud Problema 14, 9, 1988. 4. See for instance: Biocca M. and Schirripa P. Esperienzo di Lotta Contra la Nocivitci. CENSAPI, Rome, 1981; Bagnara S., Biocca M. and Mazxonis D. Trends in occupational health and safety policy in Italy. ht. J. Hlth Serv. 11, 431, 1981. 5. Laurel1 A. C. Ciencia y experiencia obrera. Cuadernos Politicos 41, 63, 1983.
6. Laurel1 A. C. Noriega M. L.a Salud en la Fkbrica. ERA, Mexico, 1989.
613
7. For a detailed description of the collective questionnaire see: Laurel1 A. C., Noriega M., Lopez 0.. Martinez S., Rios V. and Villegas J. Conocer paru cumbiar. UAM-X, Mexico, 1989. 8. Guelaud F. et al. Para el Anrilisis de las Condiciones del Trobajo Obrero en la Empresa. INET-INDA, Mexico. 1981. 9. Frankenheauser M. and Garde11 B. Underload and overload in working life. J. Human Stress 2, 35, 1976. 10. Hallowell D. Guide for the classification of hearing handicap in relation to the international audiometric zero. Otolaryngology 1, 60, 1965. II. Cazamian P. Le Trov~il de Nuit. ILO, Geneve, 1977.
PARTICIPATORY
Copyright
RESEARCH
ON WORKERS’
0277-9536192 S5.00 + 0.00 r% 1992 Pergamon Press plc
HEALTH
ASA CRISTINALAURELL,MARIANONORIEGA,SUSANAMARTINEZand JORGEVILLEGAS Master Program of Social Medicine, Department of Health Care, Autonomous Metropolitan University Xochimilco, Mexico City, Mexico Abstract-The concern for workers’ health has increased in Latin America during the last decade both on the part of research institutions and trade unions. A special emphasis has been given to active participation of workers not just in the transformation of working conditions to improve health but also in generation of knowledge. This paper presents an action oriented participatory research methodology based on a collective questionnaire that permits the recollection of data on characteristics of the labour process, risks and health damage. A comparison between the information on risks, health damage and the relationship risksdamage obtained with this methodology and those of an individual questionnaire applied at the same steel factory shows that the results produced are very similar. In view of these findings it is concluded that the participatory methodology has some important advantages over traditional methodologies since it provides qualitative information on the labour process, a precise picture of the main risks and how they are produced and semi-quantitative data on health damage, and at the same time, generates a process of consciousness and organization among workers that enables them to promote health oriented action. Key words-occupational
health, participatory research, Latin America, steel workers
with a collective and preventive orientation. However, despite the fact that this methodology was used in a large number of studies in Italy during the seventies [4] its results were never compared with those of studies using traditional scientific research techniques. The objective of this paper is to make such a confrontation, or validation, between the results of two phases of a study carried out at the same workplace; the first using a collective questionnaire methodology based on the Workers’ Model and the second based on traditional methodology. The study was made at a steel factory in Mexico during the period 1985 to 1988 in collaboration with the local union (Local 271 of the National Miners’ Union).
1. INTRODUmION
During the last 15 years studies on workers’ health and efforts to improve it have increased considerably in a relevant number of Latin American countries [ 11. Furthermore, part of the research in this field has been greatly influenced by the school of Latin American social medicine [l] that emphasizes on the social nature of the process of health-disease and assigns a central role to workers in the production of knowledge and not just in the transformation of working conditions to promote health. This has led some researchers to the search for participatory research methodologies that facilitate the construction of studies leading to an integral comprehension of work related health problems and which, at the same time, promote consciousness raising and organization among workers taking into account existing conditions, i.e. the circumstances under which workers act and the type of intervention that is sought. Such a methodology should at least include the following characteristics: be accessible to groups of organized workers, produce reliable information on risks and health damage, be action oriented and based on epidemiological and preventive criteria. In this context the so-called Italian Workers’ Model [2] has attracted great interest [3] since it permits analysis of the labour process, risks and related health problems by means of a procedure that mobilizes workers’ collective experience and transforms it into systematized knowledge. In addition, part of its results are specific proposals for action Address reprint requests to: Dr Asa Cristina Laurel1 Apartado postal 70-212, 04510 Mexico DF, Mexico. SSM 34,&a
2. ON THE METHODOLOGY (a) The collective questionnaire
The methodology used in the first phase of the research project at the steel industry is a modified version of the Workers’ Model [2]. The modifications were based on a critical analysis of its content that included both its theoretical assumptions and the characteristics of the information recollected [S]. The main changes referred to the theoretical assumptions since the Workers’ Model presents workers’ ‘experience’ as the only source of knowledge concerning reality; a conception that excludes the need to validate it against knowledge generated with other procedures; i.e. the Workers’ Model maintains an implicitly phenomenological position with the assumption that only ‘what is lived is real’. Our collective questionnaire, on the contrary, is structured according to a previously elaborated conception of the nature of the relationship between work and
603
604
ASA CRISTINALAURELLel al.
health [6]. Based on this conception the elements relevant to study were established before starting the research. Thus, it guarantees the recollection of the necessary information in order to make a significant reconstruction of the relationship between work and health. Nevertheless, our collective questionnaire preserves various aspects of the Workers’ Model and is therefore based on the recognition of the possibility to mobilize and systematize workers’ experience of working conditions and their impact on health and to translate it into exact knowledge concerning the reality of the workplace. The condition, however, is that it is structured according to a theoretical conception that allows us to distinguish circumstantial from essential facts. In order to have access to this knowledge a ‘homogeneous group’ is formed, i.e. a group of workers that share the same working conditions and have a basic organization that allows it to act efficiently. The homogeneous group-with IO-12 members--collectively resolves the questionnaire with a procedure called ‘consentual validation’, which means that only the information recognized as correct by all group members is registered. The group discussions allow us to produce the necessary information and, at the same time, enable the workers to structure a common body of knowledge as a result of the confrontation between their individual experiences. The questionnaire covers five broad themes: the characteristics of the labour process, its risks or loads, the health damage they provoke, the existing health protective measures and those proposed by the workers to protect and promote health. Concerning each of these themes the collective questionnaire poses a series of ‘questions or discussion themes’ [7]. That is, it points out which problems to treat in order to orient the discussion while leaving sufficient margins so that the workers’ perception is not restrained by closed questions. The information gathered with the collective questionnaire has two main characteristics. On one hand, it is intentionally related to the group of workers and not to individuals, and, on the other, it is mainly qualitative. However, it allows for an estimation of the magnitude or intensity of the risks, the proportion of workers exposed, and also the proportion of workers that has experienced a specific health damage. The first part of the collective questionnaire is related to the labour process and gathers information on the place of the department in the global process-particularly with respect to its organizing segments-the flow scheme of the department, its spatial organization and its subsegments. These elements provide an initial approach to the transformations and transfer of the working object, to the instruments of work, to the type and number of workers and to the characteristics of their tasks and work relations. Subsequently the working object(s) and raw materials, the instruments of work and the division and
organization of work are analyzed in depth. With the discussion of these ‘themes’ the homogeneous group makes a reconstruction of the dynamic of the labour process. The reconstruction and analysis of the labour process is the starting point for the second part of the collective questionnaire with reference to the work risks or loads. In the questionnaire they are arranged in a manner similar to the ‘risk groups’ of the Workers’ Model given that it is convincingly argued that they synthesize workers’ representation of this aspect of the factory [2]. Thus, the first group-composed of elements that can be identified inside and outside the factory-includes physical hazards like temperature, humidity, ventilation, noise, vibration and illumination. The second grouyomposed of elements typical to the factory-include mainly chemical hazards such as dust, fibers, smoke, gas, solvents, vapors but also radiation. The third group-composed of elements related to the use of the body-include physiological work loads like heavy work and working positions. Each of these risks are analyzed to determine whether or not they constitute a problem; how they are generated, i.e. the relationship to the work object and instruments and the conditions of the installations; approximate intensity and duration; the most critical spots or the workers with the highest exposure and the manner in which the organization and division of labour affect its magnitude and time of exposure. The fourth risk group--composed of elements that cause tension or mental fatigue-includes the psychological load. In our collective questionnaire these are more developed than in the Workers’ Model and incorporate elements of the LEST Method [8] and the studies of Gardell-Frankenheauser [9] but seen in relationship to the group of workers and not to the individual worker. This group includes elements such as shift work, double shifts; work perceived as dangerous; emergencies; working speed; isolation, degree of control over working instruments and tasks; monotony and repetitiveness; characteristics of supervision, etc. Although the psychological loads are most directly related to organization and division of work, they also express imperatives of machinery and working objects. Once these risks have been detected it is necessary to estimate their intensity and distribution among workers according to their tasks. The fifth risk group, that is not included in the original Workers’ Model, includes the elements that might cause accidents. Once the labour process and its hazards and loads have been reconstructed the questionnaire proceeds to study health damage-understood as disorders and diseases-related to each of the risk groups. It is emphasized that both diseases and disorders are of interest since the two taken together give a more integral understanding of the process of worker wear and tear. For each type of health damage the approximate proportion of workers that experiences it is
Participatory research on workers’ health registered together with its seriousness. The reason for discussing damage in relation to each of the risk groups is that it allows clarification, on the one hand, the specific relationship between risks and damage and, on the other, the complexity of causal relations. The last part of the collective questionnaire is dedicated to mapping existing health protective measures and to the formulation of workers’ proposals for the elimination of risks and the improvement of health. Thus, this part is the principal support for action. (6) The methodology of the second phase The second phase of the study was carried out in order to produce the necessary information for validating the results of the collective questionnaire. An individual questionnaire and some special studies were applied to a probabilistic sample of 17% of the 5400 workers. Fifteen percent of the sample did not respond which is considered acceptable given the practical difficulties of the study. The individual questionnaire contained the following items: personal data; working history; present work situation; level of exposure to physical, chemical, physiological, psychological and mechanical risks; interrogation of symptoms of chronic and repetitive acute disorders and two scales of self-response (Cornell Medical Index and the Yoshitake scale). The study was restricted to chronic and repetitive acute disorders/diseases since it was considered that these could be related to work. The integration of the diagnosis was done on the basis of the interrogation of symptoms and the scales with pre-established criteria. The special studies practiced on all the workers of the sample were spirometry; audiometry (if the results suggested auditive fatigue the test was repeated after 12-24 hr of rest from work); blood sample; two measures of blood pressure; height and weight. Complementary studies were made to a part of the sample with the following criteria: chest X-ray on workers with symptoms suggestive of respiratory disease in the questionnaire and/or pathological changes in spirometry and/or 7 years or more of exposure to dust; eye examination performed by a ophthalmologist to those with symptoms suggestive of eye diseases in the questionnaire. The data processing was done with a microcomputer. Contrary to the information produced in the first phase of the study with the collective questionnaire, the data of the second phase refers to individuals and is in this sense quantitative. A limitation of the methodology of the second phase is that it only captures the characteristics of the labour processin terms of its risks thus excluding the possibility to reconstruct its complex dynamics. (c) The validation of the collective questionnaire methodology In order to validate the participatory methodology, the data of the second phase of the study was used as
605
the parameter against which the results of the collective questionnaire are compared. Nevertheless, it is convenient to comment on the procedure because it oversimplifies the methodological problem involved. In fact it would be more adequate to compare the two sets of data analyzing: on the one hand, in which aspects the results of the different methodologies coincide and, on the other, in which aspects the results differ. Consequently it would be possible to determine which of the two gives a better understanding of the significative phenomena. Furthermore, it is necessary to point out two problems that interfere with the validation as it was done. The first relates to the nature of the object of study-health-as an objective-subjective phenomenon and involves conceptual and methodological questions. It could thus be questioned legitimately if the health-disease process could be understood dissociating its objective components from the subjective ones and if the method of choice is the objective test. A second point of interest is more technical since it concerns what, how and when a phenomenon is best measured. Neither of these problems is solved in this study however it is worth taking them into account in the interpretation of results since they allow for a richer analysis. The validation is done in the first place with information from the individual and collective questionnaires but the results of the special examinations are also included. With this information it is possible to analyze health damage (diseases/disorders), hazards or loads (risks) and the relationship risks-health. The information of the collective questionnaire on the labour process and protective measures is excluded since these items were not studied in the second phase of the study. Given the qualitative and semi-quantitative nature of the information gathered with the collective questionnaire, it was not possible to apply the standard methods used for validation. Therefore, the procedure employed is to make a qualitative and semi-quantitative comparison between the two sets of data (profiles) which allowed, on the one hand, to check the correspondence between the different profiles and, on the other, obtain an estimate of the order of magnitude of each of its components.
3. RESULTS OF THE VALIDATION
(a) Profiles of health damage
Table 1 shows the profiles of health damage constructed with information from the collective and individual questionnaires. The profile resulting from the collective questionnaire is qualitative and rank ordered by the approximate proportion of workers for whom the diseases/disorders is reported. Given that it is based on the accumulated health experience
ASA CRISTINALAURELL er al.
606
Table I. Comparison between the profiles of health damage by collective and individual auestionnaires Questionnaire Disorders/diseases Shift work syndrome: gastritis, fatigue and sleeping disorders Irritative eye disease Acute and chronic upper respiratory diseases Nervousness, irritability Back disorders Joint diseases Skin diseases Hearing loss C.N.S. symptoms: (dizziness, nausea, vomiting, blurred vision, somnolence) Varicose veins, hernia Diabetes Kidney stone Tuberculosis of lung Skin cancer Brain cancer Myocardial infarction Stomach infections Other infections Anemia All other causes
Collective’
lndividu#
Majority Majority
66.7 60. I
Majority More than half More than half More than half Close to half Close to half
55.8 34.7 19.0 10.8 56.2 34.5
Close to half Less than half Few Few Few one case one case one case
31.2 15.4 6. I I.9 0.7
21.9 6.4 2.5 6.4
‘Proportion of workers that suffer from the disease/disorder. “Rate per 100 workers. Source: Elaboration from collective and individual questionnaires.
of the group, it refers not just to active workers but also to those who might have left work. The profile based on the data of the individual questionnaire expresses the diseases/disorders of active workers in rates per 100. As can be observed in Table 1 the two different methodologies reach the same results in terms of the qualitative profile of health damage and also show similarities in the frequency of the disorders/diseases. Thus in the coilective questionnaire profile the most frequent disorders are shift work syndrome, irritative eye diseases and acute repetitive and chronic upper respiratory diseases. This pattern is the same in the individual questionnaire profile with rates of 66.7, 60.6 and 55.8 per 100 workers. The pathology identified by the collective questionnaire with an intermediate frequency presents in the results of the individual questionnaire rates between 15 and 30 per 100, with exception of skin diseases with a rate of 56.3 and joint diseases with a rate of 10.8 per 100. The diseases identified as infrequent by the collective questionnaire also show the lowest rates in the individual questionnaire. These findings suggest that workers conceive health damage as a subjective-objective phenomenon and thus do not use exclusively medical criteria in its identification but also the degree of ‘suffering’ they experience or the extent to which the disorders interfere with their working capacity. The disorders that present those characteristics, then, are perceived more strongly by the workers even if they are medically ill defined. This would explain why this type of disorders are more frequently reported in the collective ques-
tionnaire. This would be the case, for instance, of joint diseases that in the individual questionnaire were diagnosed with a strict medical criteria while simple joint ache was reported in the collective questionnaire as a disorder. Conversely certain types of pathology are underestimated in the collective questionnaire since they are not perceived as relevant by the workers as, for instance, would be the case of skin diseases. It was also found that very serious diseases and those with a low prevalence are not satisfactorily registered by neither of the questionnaires which shows the necessity to work with special research designs to study them. Nevertheless, the collective questionnaire has some advantage over the individual one because it gives clues to what are the serious diseases given that the accumulated experience of the group tends to retain those cases and report them even if the sick workers have already left work. Examples of this are the cases of myocardial infarction and cancer that were reported. The individual questionnaire was designed to detect chronic and acute repetitive diseases/disorders related or not to work and registers certain pathologies such as infections and anemia that do not appear in the results of the collective questionnaire which was designed to register only work-related diseases/disorders. This shows that the workers discriminate well between work-related problems and those that are not related to work even if they are frequent such as infections. In order to deepen the analysis of the profile of health damage resulting from the two types of questionnaires the same procedure of validation was repeated for seven departments of the plant typical of its different labour processes. The comparison between the two profiles for each of the different departments confirmed the findings of the general profiles of health damage. The special examinations performed in the second phase of the study show results similar to those of the individual and collective questionnaires. In the eye examination chronic irritative eye diseases were found at a rate of 68.4 per 100; i.e. higher than the rate detected in the individual questionnaire and similar to the estimation of the collective one that a majority of workers suffer from this problem. The audiometries showed a rate of crippling hearing loss, using the strictest medical criteria [IO], of 4.5 per 100 workers; a figure that increases to 15.8 including severe but not crippling hearing loss according to the same criteria. Summing all audiometries, that show changes typical of exposure to industrial noise, a rate of 41.8 per 100 was found: the rate found in the individual questionnaire, 34.5, ranks between the rates of those with severe hearing loss and those showing the changes typical of industrial noise. The estimation of the collective questionnaire that close to half of the workers suffer from hearing
Participatory
research
loss coincides with the data on audiometries with industrial noise changes. The X-rays showed a rate of 5.3 per 100 with pneumoconiosis that increases to 10.6 including all radiological lung pathologies. This figure is not comparable to the one of the collective questionnaire given that the method does not distinguish particular diagnosis. However, is wellknown that there is not an exact coincidence between the radiological and clinical diagnosis. (b) Risk profiles The second item validated between the two questionnaires was the risk profiles (combinations of risks-hazards and loads-haracteristic of a working area). This validation, however, involves some difficulties due to the fact that the two methodologies are based on different conceptions. Thus, in the collective questionnaire risks are analyzed in direct relation to the labour process, its space and the group of workers. This implies that its analytical logic is qualitative and centered on how hazards are produced and their place in the labour process. This contrasts with the individual questionnaire that is necessarily centered on individual workers and their jobs. The importance of a particular hazard or load, then, is derived from the number of workers exposed and its intensity. It is not possible to compare immediately the two forms of measuring the importance of a hazard or load which affects the procedure of validation. This limitation should be borne in mind when comparing the two profiles. The comparison between the results of the two questionnaires shows that the general risk profiles are qualitatively similar but that there are some differences with respect to the importance of each of the hazards or loads. As can be observed in Table 2 those hazards considered to affect ‘all’ workers in the collective questionnaire (heat, noise and dust) also present very high percentages in the individual questionnaire. However, the coincidence is not that clear with respect to the hazards or loads that the homogeneous groups considered to affect the ‘majority’ or ‘few’ or ‘very few’ workers. Thus among the physical hazards humidity and illumination seem to be overestimated in the collective questionnaire. Nevertheless the major discrepancies are observed concerning the psychological loads related to emergencies, sustained attention, monotony, confusing orders and punishments are underestimated collecive questionnaire. It is interesting to note that the greatest discrepancies between the two methodologies are related to the risks that have the highest subjective content since it indicates that the individual perception in these cases is different than the one that results from a collective discussion. Finally the hazards of risk groups V tend to be underestimated which probably is due to the fact that the group discussion was oriented to detect principally the problems of group I-IV.
on
workers’ health
607
Table 2. Comparison between risks profiles reported in the collective and individual questionnaires Questionnaire Collective’ IndividuaP Risk group Physical hazards: Noise Health Lack of ventilation Humidity Poor illumination Chemical hazards: Dust Welding fumes Coke gas Solvents Oven gas Quartz Tar Physiological loads: Forced working positions Heavy physical work Psychological loads: Shift work Dangerous work Double shifts Tight supervision Emergencies Sustained attention Monotony Confusing orders Too much work High speed Isolation Punishments Mechanical hazards: Unsafe electrical installations Unsafe machinery Unsafe floors __ _ . Unsate
tools
Exposed workers
88.8
Intensity’ d or e
All All Majority Majority Majority
82.3 51.0 36.1 33.5
19.6 73.2 45.6 27.0 21.7
All Majority Majority Majority Few Few Few
82.0 49.8 44.8 42.5 30.5 26. I 21.1
75.1 35.0 31.9 29.9 19.4 21.3 12.9
Majority Majority
60.5 59.6
49.7 48.8
Majority Majority Majority Majority Few FCW Few FCW Few Few Few Very few
75.4 12.2 52.9 50.8 69.3 64.9 56.9 42.1 38.4 33.1 20.6 53.7
49.5 46.2 44.1 50.0 31.3 31.4 33.7 52.7 37.5 38.3 24.6 52. I
Majority Majority Few
89.8 89.5 94.1 75.1
42.1 14.2 60.4 54. I
tew
‘Proportion of workers exposed. “Percentage of exposedworkers with respect to all workers. ‘Percentage of workers that consider the problem very seriou& or seriouZ with respect to all exposed workers. Data from the individual questionnaire. Source: Elaboration from collective and individual questionnaires.
The analysis of the general risk profiles was complemented repeating the same procedure with the profiles for seven departments of the plant typical of its different labour processes. These comparisons essentially confirmed the findings of the general risk profiles. Thus the hazards and loads identified are almost always the same in the collective and individual questionnaires and the discrepancies found concern the number of workers exposed. Moreover the coincidence tends to be greater with respect to the more ‘objective’ hazards than with respect to those that are more ‘subjective’, i.e. the psychological loads. As in the case of health damage these discrepancies seem to be related to the different nature of the two questionnaires given that the collective one rests more heavily on the subjective experience of workers than the individual one. (c) The relationship ‘risks-health damages’
The third aspect of the collective questionnaire that was validated is the relationship between risks and
608
ASA CRISTINA LAURELL Ed al. Table 3. Comparison
between physical hazards and related health damage in the collective and individual questionnaire by years of work Time worked 7 or more years
+++ Notie : Hearing loss Nervousness: Irritability Anxiety Depression Headache Hear : Dehydration Headache Chronic irritation eye disease Upper resp. diseases’ Nervousness: Irritability
Anxiety Depression Skin diseases Joint ache Varicose veins Kidney stone
Less than 7 years
Magnitude of the problem + +++ ++ (rate per 100 workers)
++
+
_
45.3
30.4
25.0
28.6
25. I
Il.4
6.3
8.3
36.3 24.3 21.0 40.7
23.2 13.4 9.8 33.9
II.4 Il.4 2.3 25.0
32. I 8.9 12.5 25.0
23.5 14.5 I I.2 29.6
18.6 8.6 7.1 24.5
25.0 3.1 3.1 21.9
I I.1 II.1 II.1 22.2
59.2 32.4 72.8 61.0
19.0 30.4 63.3 49.4
15.2 28.3 60.9 45.7
4.2 24.2 65.3 41.1
50.7 26. I 56.0 50.0
14.4 30.8 47. I 50.0
10.7 21.4 42.9 50.0
2.0 12.3 42.9 29.6
36.2
31.6
26. I
20.0
23.9
21.2
18.4 15.2
21.7 19.6
10.5 9.5
12.7 14.2
14.4 7.7
17.9 3.6
14.3
23.0 19.2 65.3 16.4 2.8 3.3
55.1 10.8 1.9 2.5
58.7 17.4 4.3 -
60.0 12.4 6.3 4.2
47.8 5.2 -
55.8 I.9 0.9 1.9
7.1 28.6 7.1 -
6.1 2.0 53.1 6.1 -
Source: Elaboration from collective and individual questionnaires. ‘Chronic and acute repetitive (more than three times in I2 months).
diseases/disorders. In an action oriented research methodology, this aspect is particularly important since it is the basis for setting priorities for health protective action. When this relationship is discussed with the homogeneous group, it is stressed that a single risk could produce different disorders/diseases and also that a specific disorder/disease could be associated to more that one risk. In order to validate this part of the collective questionnaire we used the data of the individual questionnaire resulting from crossing the information on risks with the corresponding diagnosis. Thus Tables 3-7 are based on the relationship of ‘riskshealth damage’ identified by the homogeneous groups and the data on the same relationships found in the individual questionnaire expressed in rates per 100. In the analysis, the years worked at the factory are taken into account as an indicator of the time of exposure.* As can be seen in Table 3 the homogeneous groups related noise with hearing loss, nervousness and headache. In the data of the individual questionnaire this relationship is only verified totally with respect to anxiety and headache in workers who have worked 7 or more years at the plant with rates that increase when the level of exposure goes up. *One could object to the use of years worked at the factory as an indicator of ‘time of exposure’ with the argument that the information on risks refers to-the moment when the questionnaire was applied. Nevertheless the system of promotion employed at the steel plant implies that workers do not move from one department to another and therefore the risks typical of a specific department are the same over time for each worker.
With respect to hearing loss there is a gradient in relation to the seriousness of exposure to noise that is however inconsistent with regard to the groups with little or no exposure. Similar behavior is found for headache among workers with less than 7 years at the plant. This pattern does not invalidate the riskhealth damage relationships identified by the workers-that are well-known-given that it is compatible with the fact that low levels of noise are not pathogenic. The audiometry data show a similar pattern since workers with long working experience and severe or regular exposure to noise have a significantly higher frequency of the audiometric changes typical of exposure to industrial noise than those with little or no exposure. The data of the individual questionnaire with regard to the types of ‘nervousness’ [except anxiety among workers with more than 7 years of work) show a consistent pattern among workers that report noise as a problem but inconsistent among those who do not report it. i.e. As can be observed in Table 3 the groups with severe exposure to noise present much higher rates for these disorders than the groups with little exposure but those who report no exposure also have high rates. However, if the workers with no exposure to noise but with a high psychological load are excluded the expected gradient is re-established. In the collective questionnaire workers associated dehydration, headache, chronic irritative eye diseases, upper respiratory diseases, nervousness, skin diseases, joint ache, varicose veins and kidney stone with exposure to heat (see Table 3). The results of the individual questionnaire confirm these relationships with regard to dehydration for all workers and to headache, chronic irritative eye diseases, upper
Participatory
research
on workers’
609
health
Table 4. Comparison between chemical hazards and related health damage in the collective and individual questionnaire by years of work Time worked 7 or more years +++ Solvents and vapors: C.N.S. symptoms Headache Skin diseases Dusts: Upper resp. diseases Lower resp. diseases Skin diseases Chronic irritative Eye diseases Welding fumes: Upper resp. diseases Bronchitis Chronic irritative Eye diseases C.N.S. symptoms Headache Source: Elaboration
Less than 7 years
+ +++ ++ (Rate per 100 workers)
+
-
46.3 46.3 70.5
28.9 42. I 63.1
23.1 35.4 69.2
29.2 29.2 51.7
47.8 41.3 67.4
22.6 16.1 58.1
30.0 27.5 37.5
23.3 30.2 47.7
60.8 12.2 65.8
50.0 a.9 54.5
48.6 4.8 64.9
44.8 I.9 56.2
51.8 5.4 51.8
53.8 2.6 40.4
40.9 63.6
36.3 2.6 49.1
71.4
65.2
70.3
62.1
57.3
51.9
31.8
46.0
62.8 6.6
53.4 II.0
41.0 2.7
49.1 4.4
49.2 4.6
48.9 2.2
44.1 -
41.8 I.8
73.5 50.4 48.8
78.1 28.8 38.4
71.8 28.2 35.9
61.4 26.0 29.7
56.9 43.1 41.5
66.7 26.1 24.4
52.9 14.7 29.4
41.2 23.6 26.7
from collective and individual questionnaires.
diseases for workers with 7 or more years of work. The eye examinations, also, confirm the association between high exposure to heat and chronic irritative eye diseases. In the group of ‘nervousness’ irritability is the only mental disorder that shows a consistent pattern in relation to the magnitude of heat exposure. The associations, identified by the homogeneous groups, between heat and skin diseases, varicose veins, joint ache, and kidney stone are not verified by the data from the individual questionnaire (see Table 3). For skin diseases this inconsistency could be explained by the fact that there are many other work environment hazards that provoke these diseases. In the case of joint ache, as was mentioned above, the criteria used in the individual and collective questionnaires were quite different. Finally it seems that the inconsistency between the two methodologies regarding kidney stones and varicose veins could be explained by their low prevalence. The diseases/disorders identified as related to exposure to solvents and vapors by the homogeneous groups were C.N.S. symptoms (dizziness, nausea, vomiting, blurred vision, somnolence), headache and skin diseases (see Table 4). These relationships are verified by the results of the individual questionnaire for the groups with high exposure. It is interesting to note that headache as a single symptom shows a clear gradient with levels of exposure among workers with 7 or more years at the plant but not among those with less than 7 years since it coincides with the obcervation in the groups discussion that prolonged exposure to solvents tend to make the problem chronic. As a supporting fact concerning the magnitude of the problems caused by exposure to solvents and their vapors, it was found that 4.6% of blood samples show toxic granulation in the differential count even if specific diseases were not found. respiratory
++
According to the collective questionnaire, exposure to dust is associated with upper and lower respiratory diseases, chronic irritative eye diseases and skin diseases (see Table 4). The results of the individual questionnaire confirm this association with respect to upper respiratory diseases among all workers and lower respiratory diseases among workers with 7 years or more at the factory. This finding is consistent with the fact that the latter have a longer latency than the upper respiratory diseases. The chest X-rays confirm this interpretation since there is almost no pathology in the group with less than 7 years while among workers with long work experience there is a marked difference between those exposed to dust and those who are not. As can be observed in Table 4 the irritative eye diseases show a relatively consistent pattern in relation to the intensity of exposure to dust. Nevertheless, it should be considered that there are other work environmental hazards related to these disorders. In addition the eye examination showed a significantly higher frequency of these diseases among workers who reported dust as a severe problem. The skin diseases do not show a clear relationship to the exposure to dust. This is probably due to the fact that it needs to be associated with other hazards as, for example, heat. This assumption was confirmed by the analysis of those that are exposed to dust and heat that show high rates of skin diseases. The collective questionnaire reported as related to exposure to welding fumes upper respiratory diseases and bronchitis, chronic irritative eye diseases and C.N.S. symptoms including headache. The results of the individual questionnaire confirm the association with upper respiratory diseases. Concerning the rest of the disorders, rather than a gradient there is a threshold response among workers with high or high to regular exposure to welding fumes. In the special
610
ASA CRISTINALAIJRELLet al. Table
5. Comparison
between
physiological individual
loads
and
questionnaire
related
health
Time 7 or more
++
+
and
7 years
of the problem +++
per
100 workers)
++
+
-
work:
Backache
29.8
27.5
20.0
14.6
25.9
12.1
3.5
5.1
7.3
3.9
7.4
I.1
31.0
20.7
22.0
16.7
14.1
3.2
3.6
8.0
2.0
I
Hernia
Forced or uncomfortable
working position
Backache Varicose
the collective
Less than
(rate
Heavy physical
m
worked
Years Magnitude
+++
damage
by years of work
veins
5.7
14.7
-
-
: Il.3
-
-
12.5 -
15.3 0.8
Nervousness: Irritability
34.
33.6
34.0
26.4
37.0
21.7
17.5
Anxiety
23.0
23.6
24.0
12.7
16.7
19.6
7.5
5.3
Depression
23.0
17.1
12.0
12.2
II.1
18.5
7.5
3.1
39.7
33.6
20.0
23.4
25.9
23.9
30.0
23.7
Headache Source:
Elaboration
from
collective
and individual
studies this pattern was confirmed for eye diseases but not in the chest X-rays. In relation to the problems associated to heavy physical work the results of the collective and individual questionnaires coincide concerning back disorders as can be observed in Table 5. The relationship is not confirmed for hernia in the individual questionnaire despite the fact that it is well-known. This question might be explained by the low prevalence of the disorder. The homogeneous groups identified forced or uncomfortable (including immobility) working positions as associated to backache, varicose veins, nervousness and headache. The results of the individual questionnaire verify this association with regards to backache and, partially, nervousness and headache but not to varicose veins. Again, the low prevalence of varicose veins might explain this finding. In the collective questionnaire shift work was identified as one of the working conditions that provokes more health problems. It was related to gastritis, nervousness, sleeping disorders, headache, irritative eyes diseases and also weight loss and family problems. In this respect the individual questionnaire shows a similar pattern among workers with 7 years Table
6. Comparison
in the collective
between
shift work
and individual
and related
questionnaires Time
7 or more Shift
Gastritis
Less than Shift
worker No (rate
damage of work
worked
years
Yes
health
by years
worker
Yes
per
7 years
No
100 workers)
37.5
23. I
37.2
40.8
34.2 22.4
26.2 16.2
21.3 9.3 -.
21.6 14.4
Nervousness: Irritability Anxiety Depression
19.5
12.2
7.7
12.0
Sleep disorders
37.5
23.1
26.2
24.0
Headache
32.7
25.8
26.8
22.4
Eye irritation
67.3
67.6
53.6
44.0
Weight
loss*
Familv
oroblems’
Source:
Elaboration
‘Information
from
not recollected
collective
and
-I
individual
in the individual
questionnaires.
questionnaire.
15.3
questionnaires.
or more at the factory except in relation to eye disorders, that was not confirmed in the ophthalmological study either. However, there is no clear pattern among workers with less than 7 years of exposure. These results do not invalidate the observation of the workers on the health effects of shift work since it was verified for an important group. In an epidemiological perspective the finding is interesting since some studies on shift work [l I] show, on the one hand, that the related disorders become chronic and irreversible only after many years of exposure and, on the other, that the most vulnerable workers-some 20%-leave work because of these disorders, a finding that was verified in the present study. The homogeneous groups pointed out a series of elements of the labour process that provoke prolonged tension among which the most important are dangerous working situations, tight supervision, double shifts (16 hr), emergencies, monotony, sustained attention, confused orders and punishments. The disorders and diseases they related to this tension were nervousness, chronic fatigue, sleeping disorders, gastritis, hypertension, ischemic heart disease and diabetes. In order to validate these observations a score of tension was elaborated based on the sum of the qualifications (o-4) of each of the psychological loads. As can be observed in Table 7 the results of the individual questionnaire verify the relationships identified by the homogeneous groups. Among workers with 7 or more years at the factory all the disorders associated to prolonged tension show a clear gradient in relation to the level of exposure to tension. The differences between the rates of the groups are even more significant than with respect to the other risks since those of the groups with severe problems can be 30 times as high as those of the groups that report no problem. The pattern among workers with less than 7 years at work is similar except for hypertension that has a threshold value of ‘regular problem’.
611
Participatory research on workers’ health Table 7. Comparison between psychological loads and related health damage in the individual and collective questionnaires by years of work Time worked Less than 7 years
7 or more years
++++ Tension Ncrvousncss: Irritability Anxiety Depression
Fatigue Hypertension Ischemic heart disease Gastritis Diabetes Sleeping disorders
+++
++
Magnitude of the problem ++++ + (rate per 100 workers)
+++
++
+
-
75.0 83.3 75.0 91.7 8.3
55.0 43.0 37.0 76.0 7.0
39.5 23.4 16.9 70.2 7.3
19.8 7.8 6.3 42.2 6.8
9s 2.4 3.6 21.4 4.8
80.0 80.0 60.0 80.0 20.0
48.8 36.6 29.3 70.7 7.3
14.8 10.8 9.5 52.7 1.4
20.8 6.7 4.0 32.9 1.3
2.1 4.2 22.9 2.1
16.7 75.0 25.0 50.0
5.0 63.0 17.0 50.0
3.2 46.8 9.7 40.3
1.6 31.3 3.4 24.0
17.9 6.0 6.0
40.0 40.0
56.1 4.9 46.3
2.7 39.2 2.7 27.0
31.6 2.0 22.8
27.1 12.5
Source: Elaboration from individual and collective questionnaire. ‘Measured by the score of psychological load elaborated on the basis of the items included as psychological loads in the individual questionnaire.
The validation of the relationship ‘hazards/loadshealth damage’ shows that, generally speaking, the results of the two types of questionnaire coincide. Thus the identification, by groups of workers using the collective questionnaire, of the disorders or diseases provoked by the risks present at their workplace allows to get a precise idea concerning work-related health problems. The discrepancies in the results coincide with those encountered with respect to the profiles of health damage and can be explained by the same elements. Thus when a disease has a low prevalence the results of the individual questionnaire are not conclusive. A second aspect, discussed above, concerns workers’ perception of health damage since it involves the degree of suffering that they experience and the extent to which it interferes with their working capacity. This means that disorders that are not perceived as particularly disturbing are underreported in the collective questionnaire and, on the contrary, those experienced as very disturbing are overestimated. A third difficulty is that many of the reported disorders are associated to various hazards which introduces a confounding effect in the analysis. Finally it is necessary to consider the magnitude of the differences of the rates for the disorders/diseases that were found between the groups in the individual questionnaire. Although these differences in most cases are quite important-from 2 to 40 times more frequent-in others they are only 20-60% higher. One could legitimately ask if differences of that magnitude could be perceived by ihe workers. A tentative response would be that the group experience accumulated over a -period of time actually allows for discrimination even between those differences that are not very great but it would be convenient to continue the study of this problem. SSM 34,‘t-x
4. CONCLUSIONS
The results of the validation of the collective questionnaire lead to specific conclusions concerning its usefulness as a participatory methodology for the study of health at the workplace oriented to problem solving. The importance of the discrepancies that were detected between the results of the collective and individual questionnaire differs depending on the objectives pursued with the research. These could be to obtain data as a necessary first step in changing working conditions; to analyze the importance of work in relation to the pathological profile of a group of workers or a particular disease; or to achieve recognition, treatment and compensation of workrelated health damage. The collective questionnaire has some important advantages over most other methodologies if the main objective of the research is the first. Thus it provides qualitative information on the labour process that serves as a global frame work for the interpretation of the risks and health damage referring them to a group of workers. The other possibility to obtain this type of information would be with the direct observation by an expert with access to the work place, which is very difficult to achieve in Latin America. Furthermore, the collective questionnaire methodology provides a precise picture of the main hazards and loads that affect a group of workers; how they are produced and where they reach the highest concentration. The two main limitations would be certain imprecision concerning the exact number of workers exposed and the loss of some ‘invisible’ risks (for instance radiation or certain chemicals). An in-depth group discussion would solve the first problem and a systematization of what could be the invisible risks the latter. On the other hand, this methodology provides precise semiquantitative data on those diseases/ disorders that produce the most important problems to workers or that affect their working capacity. As
612
ASA CRISTISA LAURELL ef al.
was pointed out, the limitations of the collective questionnaire are that it overestimates diseases/ disorders with an important subjective component or that hinder work and underestimates some clinically well-defined problems and report irregularly those with a low prevalence. Nevertheless, from the point of view of action oriented to improve work and health conditions, the first does not represent, strictly speaking, a limitation since improving health conditions is strongly related to the diminishing of the degree of dis-ease, i.e. with disease as a subjective-objective-phenomenon, and not only to the elimination of a clinical entity. What remains to be solved are the serious diseases with a low prevalence or a long latency. It should be stressed that the collective questionnaire is more sensitive in this respect than the individual one, given that it provides indicative information. Nevertheless, it should be complemented with other studies such as specific laboratory tests or environmental measurements. The collective questionnaire establishes with precision simple and complex ‘risk-health damage’ relationships, which is crucial for guiding action and setting priorities. Further, another results of the collective questionnaire are proposals for action given that the methodology includes the discussion of what measures should be taken to improve working and health conditions. The other main advantage of this methodology when research is action oriented, is that it is based on worker participation and collective consciousness raising. Taken together these characteristics turn the collective questionnaire into the methodology of choice when the purpose of research is to change working and health conditions and establish preventive measures. When the purpose of a study is to analyze the importance of work in relation to the pathological profiles of a group of workers, the limitations of the collective questionnaire are more important. Its major advantage is that it highlights that work plays an important role in producing a large part of what are usually considered common diseases and nonspecific disorders. The knowledge obtained concerning the labour process and its risks also leads to an explanation of how they are produced. In this context it should be recalled that the risk-health damages relationships reported by the collective questionnaire in their great majority were confirmed by the data of the individual questionnaire and special studies. On the other hand, the individual questionnaire showed that the workers studied suffered from a rather high frequency of diseases that were not reported in the collective questionnaire because they were not considered to be work-related. This means -that the homogeneous groups are capable of discriminating between pathology that is work-related and that which is not. Even if the collective questionnaire identifies what part of pathology is work-related and contributes with important explanatory elements, it has the dis-
advantage that it does not permit the utilization of quantitative epidemiological procedures. Thus it is not posible to calculate risk measures, to measure exposure and to apply statistical techniques. This limitation is particularly restrictive when dealing with diseases with a low prevalence. In order to solve this problem, it is necessary to complement it with quantitative research techniques and special research design. Nevertheless, it should be stressed that the collective questionnaire allows us to generate innovative hypothesis since it emphasizes the analysis of the complex relationships between work and health. The limitations of the collective questionnaire become important when the purpose of the research is to achieve recognition, treatment and compensation for work-related health damage. This is so because of a problem inherent to this methodology and because of a formal-legal reason. The first stems from the fact that, by nature, the collective questionnaire produces information referred to the group of workers, its environment and work relations while the recognition-treatment-compensation of work-related diseases almost always refers to the individual worker. Thus this methodology is only useful to argue the recognition of a specific work-related disease for a specific type of workers in the collective bargaining agreement or law. Even so, the formal-legal limitation tends to be imposed, since the legal proof that is demanded is expected to be produced on the basis of a monocausal relationship between a risk and a disease or a quantitative epidemiological study. The results of the validation of the collective questionnaire allow us to argue that it has the same probatory value as a classic epidemiological study but it is probable that such an argument would not be legally accepted. Acknowledgemenr-This research was from the International Development (IDRC), Ottawa, Canada.
supported by a grant Research
Center
REFERENCES
Laurel1 A. C. Trabajo y salud. El estado del conocimiento. In Debares en Medicina Social en AmPrica Lafina (Edited bv Franc0 S. and Nunes A.). Panamerican‘ Health brganization, Washington Dd, 1991. This ‘state of the art’ article, written in mid-1989, reviews 108 Latin American books and articles on work and health. Of these references 10 were published between 1974 and 1979, 48 between 1980 and 1984 and 50 between 1985 and 1989. It includes authors from Argentina, Bolivia, Brazil, Central America, Colombia, Chile, Ecuador, Mexico, Peru and Venezuela. Twenty of the articles discuss and/or use participatory research methods. be it the LEST method. Workers Model or work place check lists. Oddone 1. et al. Ambienre di Lavoro: la Fabbrica nel Terriforio. Editrice Sindicale Italiana, Rome, 1977. See for instance: Alvear G., Rios V. and Villegas J. Condiciones de trabajo y salud de las costureras. Saiud Probtema 14,25, 1988; Facchini L. A. Proceso de Trabajo, Cambio Tecnologico y Desgaste Obrero: El Caso de1 Ingenio A. Lopez Mateos. Theses, Universidad
Participatory research on workers’ health Autonoma Metropolitana-X, Mexico, 1986; Marquer M. and Romero J. El desgaste de las obreras en la maquila electro-electr6nica. Salud Problema 14, 9, 1988. 4. See for instance: Biocca M. and Schirripa P. Esperienzo di Lotta Contra la Nocivitci. CENSAPI, Rome, 1981; Bagnara S., Biocca M. and Mazxonis D. Trends in occupational health and safety policy in Italy. ht. J. Hlth Serv. 11, 431, 1981. 5. Laurel1 A. C. Ciencia y experiencia obrera. Cuadernos Politicos 41, 63, 1983.
6. Laurel1 A. C. Noriega M. L.a Salud en la Fkbrica. ERA, Mexico, 1989.
613
7. For a detailed description of the collective questionnaire see: Laurel1 A. C., Noriega M., Lopez 0.. Martinez S., Rios V. and Villegas J. Conocer paru cumbiar. UAM-X, Mexico, 1989. 8. Guelaud F. et al. Para el Anrilisis de las Condiciones del Trobajo Obrero en la Empresa. INET-INDA, Mexico. 1981. 9. Frankenheauser M. and Garde11 B. Underload and overload in working life. J. Human Stress 2, 35, 1976. 10. Hallowell D. Guide for the classification of hearing handicap in relation to the international audiometric zero. Otolaryngology 1, 60, 1965. II. Cazamian P. Le Trov~il de Nuit. ILO, Geneve, 1977.