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Occupational injuries and their long term consequences among mechanics and construction metal workers
Safety Science Vol. 28, No. 1, pp. 49–58, 1998 q 1998 Elsevier Science Ltd. All rights reserved Printed in The Netherlands 0925-7535r98 $19.00 q 0.00
Pergamon
PII: S0925-7535(97)00070-2
OCCUPATIONAL INJURIES AND THEIR LONG TERM CONSEQUENCES AMONG MECHANICS AND CONSTRUCTION METAL WORKERS P.-O. Bylund ) , Ulf Bjornstig ¨ The Umea˚ Accident Analysis Group, Department of Surgery, Umea˚ University, 901 85 Umea, ˚ Sweden
Abstract–A one year comprehensive material of 398 occupational injuries among mechanics and construction metal workers was analysed. Shop mechanics experienced the highest incidence of injuries. Upper extremity lacerations and eye injuries were the most common injuries; the latter were most often caused by flying fragments or welding flashes. Handheld tools were involved in just over a quarter of the injuries, and other metal working machines in one fifth. Almost every third injured worker had some form of persistent medical problems 2 years after the event, and almost every fifth still had problems after 5 years. One third of those with persistent medical problems were forced to significantly change their leisure time habits. Two percent of the injured were granted economic compensation for permanent medical impairment. Four percent of the injured were granted pension and early retirement Žcaused by back and knee injuries. or were forced to change jobs, due to the injury. q 1998 Elsevier Science Ltd. All rights reserved. Keywords: Occupational injuries; Mechanics; Construction metal workers
1. Introduction Occupational injuries in Sweden are described by the Information System on Occupational Accidents ŽISA. at the National Board of Occupational Safety and Health. Statistics are also collected on more serious injuries, even at the Swedish Work Related No-Fault Liability Insurance ŽTFA.. However, both of these registration systems are afflicted with drop-out problems, resulting in less accurate recognition of the overall picture for acute occupational injuries ŽLarsson and Bjornstig, 1990.. Also Fingar et al. Ž1992. concluded in a study from ¨ USA a substantial underreporting of occupational injuries to the Workers’ Compensation and to The National Injury Surveillance System. In a previous study, data from ISA and TFA were compiled with data from the University Hospital in Umea˚ ŽNUS., for the equivalent time period and area ŽLarsson and Bjornstig, 1990.. It was thereby possible to get a complete ¨
)
Corresponding author. Tel.: q46-90-785-2401; fax: q46-90-785-2401; e-mail: [email protected].
49
P.-O. Bylund, U. Bjornstig ¨
50
picture of the injury problem complex within a specified geographical region. ‘Mechanics and construction metal workers’ 1 was the occupational group with the highest injury rate Ž398 of a total of 1785.. Few studies have analysed nonfatal work-related injuries ŽHunting et al., 1994. and the scientific literature relating to this occupational group is rather poor. This study aims to fill part of this gap. The aim of the present study was to use the combination of three data sources to analyse the accident and injury panorama, the injury incidence, and especially the long term effects from this comprehensive 1 year data of injuries which afflicted mechanics and construction metal workers, employed in the township of Umea. ˚
2. Material and methods According to the Nordic Classification of Occupations Ž1984. and the 1990 population census ŽOfficial Statistics of Sweden, 1992., 2156 ‘mechanics and construction metal workers’ worked in Umea˚ during 1985. A total of 398 nonfatal injury cases to this occupational group were identified in our three registration systems with a distribution on the three different systems as in Fig. 1. All acute injuries Ž n s 9000. treated at University Hospital in Umea˚ ŽNUS. were registered continuously during 1 year ŽApril 1, 1985–March 31, 1986. under the auspices of the Umea˚ Accident Analysis Group. A total of 292 Ž73%. of the 398 injury cases were treated at the hospital, either as out-patients or as inpatients ŽFig. 1.. ŽThe remaining cases were treated by general practitioners or by company physicians.. The injured person answered at the hospital visit a questionnaire regarding the event, the products and the tools involved in the incident. Injuries resulting in at least one day of sick leave, andror dental injuries, should be reported to the Information System on Occupational Accidents ŽISA. at the National Board of Occupational Safety and Health. Reports are made by the employees to the Social Insurance Office who pass them on to ISA. A total of 208 Ž52%. of the 398 injury cases ŽFig. 1. were found in ISA records, which also included medical data. If the injury results in sick leave for more than one week, or result in persistent medical problems, the injured worker himself submits a report to the Work Related No-Fault Liability Insurance ŽTFA.. The worker then receives compensation in compliance with the agreement between the labour market parties to compensate any loss of income and any permanent medical impairment. In the TFA data base 57 cases ŽFig. 1. were identified and the medical data was studied. In Sweden, permanent medical impairment is defined in a Classification Manual used by the Insurance Industry ŽPersonskadekommitten Serviceaktiebo´ inom Forsakringsbranschens ` ` lag, 1989.. Medical impairment is a measure of loss of body function due to injury and is expressed as a percentage. Body part loss, mobility impairment, strength reduction, pain, reduced sensation and deficient function of different body parts are taken into consideration. However, no consideration is given to the extra difficulties experienced in the professional or personal life of the injured. The exact medical impairment is determined by medical specialists
1
Workers in this occupational group manufacture products in metal and similar material, fit and repair machines and engines. Welders and plumbers are also included as well as sheet-metal workers who sometimes work in the construction industry.
Occupational injuries and their long term consequences among mechanics and construction metal workers
51
Fig. 1. Distribution of the number of injured in the various materials.
once the injury has reached a stable condition, usually 2 years or more after the injury event, and when no further improvement can be expected. A follow up of medical records regarding the injuries and the length of treatment has been performed. Social insurance office documents have also been studied with regard to length of sick leave within 1 year following the event. Costs of sick leave were converted to US$ ŽUS$1s 7.55 SEK January 1, 1986.. Through compilation of statistics from the three registration systems a complete data set was available for 369 Ž93%. of the 398 injury cases. To acquire data concerning any persistent medical problems and changed leisure time habits following the injury event, as well as to collect any missing data, a second interview was performed by mail both 2 and 5 years following the event. Following one reminder notice, answers were received from 258 Ž65%. of the 398 people. A study of the drop-out group Ž n s 140., 5 years after the injury event, was performed by random selection of every fifth case to find out if the proportion of persons with persistent medical problems was equal in both populations. The drop-out group did not differ significantly Ž p - 0.05. when compared to the study group. Injury events which occurred commuting to and from work and occupational diseases are not included in this study.
3. Results 3.1. Gender and age distribution A large majority Ž n s 387; 97%. of the injured were men. A total of 147 Ž37%. were in the age group 20–29 years and 338 Ž85%. were between 20–49 years of age. 3.2. Injury incidence and type of accident The injury incidence was 18 per 100 gainfully employed workers, and was highest in the age group under 20 years ŽTable 1.. Shop mechanics had the highest injury incidence
P.-O. Bylund, U. Bjornstig ¨
52 Table 1 Number of injured, gainfully employed, and injury incidence per 100 workers and year Age Žyears.
Number of injured
Number of workers
Injury incidence
y19 20–49 50q Total
24 Ž6%. 338 Ž85%. 36 Ž9%. 398 Ž100%.
88 1720 348 2156
27 20 10 18
ŽTable 2.. Included in the group machinery fittersrmachine assemblers and engine mechanics Ž n s 111. were 41 auto mechanics, 38 machine fitters, 27 machine repairmenrmachine mechanics and 5 other repairmen. 3.3. Injury mechanism The mechanism which caused the actual injury is presented in Table 3. The injuries occurred most frequently when working with handheld tools Ž107; 27%., fixed metal-working machines Ž78; 20%., building partsrequipment Ž45; 11%. or with vehicles Ž36; 9%.. 3.4. Type of injuries Most injuries affected the upper extremities Ž154; 39%.. Welders and plumbers had a higher proportion of head injuries including eye injuries Ž38; 40% and 17; 35%, respectively., compared with other occupational groups ŽFig. 2.. The lower extremities were seldom injured, except for plumbers, where this was the second most injured body part. 3.5. Care and sick leaÕe Most of the injured workers required only outpatient care Ž387; 97%.. Eleven Ž3%. patients were admitted to the hospital for a total of 66 days; that is, an average of 6 in-patient days per person ŽTable 4.. The patient cared for the longest time Ž24 days. was a sheet-metal worker who suffered a fractured pelvis when he fell 2 m from a ladder onto a concrete floor. An auto mechanic suffered burn injuries and was admitted for 10 days, a plumber fell from a trestle and sustained multiple rib fractures, and was admitted for 7 days, and a milling-machine worker with a finger injury was admitted to the hospital for 6 days. Table 2 Number of injured and injury incidence per 100 workers and year within different occupational groups Occupational group
Number of injured
Injury incidence
Machinery fittersrmachine assemblers and engine mechanics Welders Shop mechanics Plumbers Sheet-metal workers Others Total
111 Ž28%.
14
94 Ž24%. 69 Ž17%. 49 Ž12%. 46 Ž12%. 29 Ž7%. 398 Ž100%.
20 38 23 19 12 18
Occupational injuries and their long term consequences among mechanics and construction metal workers
53
Table 3 Number of injured and various injury mechanisms Injury mechanism
Number of injured
Hit against object, cut Hit by flying object in eyerwelding flashes Muscle overloadrstrain Jammed Žcrush injury. Fell onror against something Contact with hot object or fire Other injury mechanisms Total
137 Ž34%. 114 Ž29%. 47 Ž12%. 34 Ž9%. 26 Ž6%. 8 Ž2%. 32 Ž8%. 398 Ž100%.
A total of 241 Ž61%. persons were on sick leave for 5818 days; that is, an average of 24 daysrperson on sick leave. Sheet-metal workers had the highest average number of sick leave days of all those on sick leave ŽTable 4.. A total of 37 Ž9%. persons were on sick leave for one month or more. Three persons were on sick leave for more than 1 year: A sheet-metal worker, who got his glove in a rotating rolling mill at a sheet-metal shop, got his right thumb amputated. A construction sheet-metal worker slipped on a roof and suffered a severe knee ligament injury.
Fig. 2. Type of injuries in different occupational groups.
P.-O. Bylund, U. Bjornstig ¨
54
Table 4 Number of injured and on sick leave, length of sick leave, and inpatient care days for different occupational groups Occupational group
Machinery fittersrmachine assemblers and engine mechanics Welders Shop mechanics Plumbers Sheet-metal workers Others Total
Number of injured
Sick leave Number on sick leave
Number of days
Average Ždays.
Number of care days
111
65
1699 Ž29%.
26
23
94 69 49 46 29 398
54 43 35 28 16 241
586 Ž10%. 990 Ž17%. 811 Ž14%. 1385 Ž24%. 347 Ž6%. 5818 Ž100%.
11 23 23 49 22 24
y 8 7 27 1 66
A machine-repairman got his hand in a machine at a dairy and crushed two fingers so badly that he lost sensibility in them. 3.6. Cost of care and sickness benefit An outpatient visit in 1985 did cost about SEK 650 ŽUS$86. and one day of inpatient care about SEK 2000 ŽUS$265.. With an estimated sickness benefit of SEK 250rday ŽUS$33., the total cost of care and sickness benefits amounted to about SEK 1.8 million ŽUS$238,500.; that is, an average of SEK 4500rinjured ŽUS$600.. Of this, the sickness benefit accounted for the majority, SEK 1.5 million ŽUS$199,000.. This shall be considered to be a minimum cost, since sick leave lasting over 1 year is not included in the calculations, nor are the costs for medical impairment, early retirement or other costs such as retraining. Recalculated in terms of 1996 values, care and sickness benefits would be about SEK 3 million ŽUS$400,000., or an average of SEK 7500 ŽUS$1000. per injury case. 3.7. Persistent medical problems Of the total of 258 people who responded to the questions about any persistent medical problems, 78 Ž30%. reported some form of persistent problem 2 years after the event, while 49 Ž19%. stated that they still had problems after 5 years. The most common persistent medical
Table 5 Number of people with different persistent medical problems after 2 and 5 years, respectively Symptom
2 Years
5 Years
Pain in extremityrback Reduced sense of touch in extremityrsense of coldness Reduced mobility Irritation in eye reduced vision Headacherfatigue Other, unknown Total
36 Ž46%. 13 Ž17%. 10 Ž13%. 7 Ž9%. 2 Ž2%. 10 Ž13%. 78 Ž100%.
28 Ž57%. 11 Ž23%. 4 Ž8%. 1 Ž2%. 1 Ž2%. 4 Ž8%. 49 Ž100%.
Occupational injuries and their long term consequences among mechanics and construction metal workers
55
Table 6 Occupation, degree of medical impairment and injury mechanism among the seven who got a medical impairment settled Occupation
Degree of impairment
Sheet-metal worker
15%
Machinery fitter Sheet-metal worker Other engineering worker Machine repairman Sheet-metal worker Machine repairman
12% 10% 10% 3% 2% 1%
Injury and injury mechanism Amputated thumb; glove was caught in a rotating rolling mill at sheet-metal shop. Nerve and tendon injury in hand; adjusted machine. Pelvic fracture; fell 2 m from ladder. Concussion; worker fell on the floor due to epileptic seizure. Crush injury hand; raised clutch for car. Crush injury finger; raised engine. Crush injury finger; tool caught in bicycle wheel.
problems were pain Žin extremity or back., and reduced sensation of touch and sense of coldness in a extremity ŽTable 5.. 3.8. Early retirement, job changes, and medical impairment Two of the injured workers suffered injuries Žstrained lumbar spine and strained knee. with so severe long term consequences that they were placed on full medical disability pension, while 3 persons were placed on 50% disability pension due to the injury Žtwo injured with strained lumbar spine and one person with strained knee.. One person at the 5 year follow up was still on sick leave full time. This was judged to be partially due to the knee injury which the patient suffered. Thirteen of the injured had changed jobs due to their injuries. In one other case the injury was partially responsible for the worker’s job change. Seven Ž2%. of the 398 injured had a medical impairment settled and received compensation for this impairment. The most severe impairment was suffered by a 18 year old sheet-metal worker who had part of his thumb amputated. Three of the seven impairment cases was among sheet-metal workers ŽTable 6.. 3.9. Changed leisure time actiÕities Of the 49 patients who still had some form of persistent medical problems 5 years after the injury, 16 Ž33%. had significantly changed their leisure time habits due to the injury.
4. Discussion The health care based registration system provided the best degree of coverage Ž73%., while the Information System on Occupational Accidents ŽISA. only registered just over half of known cases. To describe the comprehensive picture and consequences of these injuries, it is necessary that several injury registration systems are coordinated. Even long term consequences must be considered because the relatively few injuries, causing long term medical problems, will cost the social insurance system and the employee’s a great sum of money. For this reason data collected by the Swedish Work Related No-Fault Liability Insurance ŽTFA. are of great value to incorporate in the analysis to get the total picture of the consequences from these injuries.
56
P.-O. Bylund, U. Bjornstig ¨
On average, every fifth mechanic and construction-metal worker required medical treatment for an acute occupational injury annually. The injury incidence was nearly three times higher among the youngest Ž- 20 years. compared with those who were 50 or older. Comparable figures have not been found in the available scientific literature, but in a local Ž1991. in Sweden it was demonstrated that 20–25 year report from AMF-Trygghetsforsakring ¨ ¨ olds in industrial jobs were at high risk for severe injury caused by machine-related accidents. In manufacturing industry in the USA adolescent worker’s had the highest rate of injuries ŽBelville et al., 1993.. Further, Olson and Gerberich Ž1986. demonstrated that half of all amputations caused by occupational injuries in the USA were suffered by young people Ž- 26 years.. Youth Ž- 20 years. are also significantly over-represented with regard to injuries resulting in disability in other branches such as the timber industry ŽWestman, 1986.. The risk of injury during the first day on the job Žwithin the timber industry. was up to 50 times higher, than the risk for those with more than 1 year of experience ŽLarsson, 1988.. Adequate introductory training and restrictions in assigning high risk tasks to the youngest workers are probably of great value. All new workers need to be informed about the use of obligatory safety equipment, and the employee ought to sign a statement agreeing to comply with these rules. Most were injured when using handheld tools, while injuries caused by falling were relatively rare occurrences, which has also been found by Courau Ž1983. and Persson Ž1992.. Injuries resulting in medical impairment were in the present study associated with ‘manual handling’, ‘falls’ and work with rolling machines. Similar results concerning severe injuries have been presented by Jedeskog and Larsson Ž1988.. The most common injuries afflicted the upper extremities Ž39%. and were comprised primarily of cuts and lacerations. Use of work gloves is an important measure for preventing lacerations on the hands. However, Persson Ž1992. noted that work gloves also posed a risk, since half of those who suffered disabling injuries were injured when the work glove got caught in the machine while using drills, reamers, and tapers. This indicates that there is still room for better adaptation of work gloves, aids and technical improvements. In the present study, the most serious injury causing disability Žthumb amputation. happened when the glove of a 18 year old sheet-metal worker was caught in a rotating rolling mill. Noteworthy in our study was that almost one third of the injuries were located to the eye, despite the fact that all industrial workers should be equipped with safety glasses. Welders were the occupational group with the highest proportion of eye injuries Ž40%.. However, the eye injuries did not result in any medical impairment. A study from the USA ŽReesal et al., 1989., reported an impairment rate for this type of injuries of 0.3%. We did not have reliable data concerning the use of safety glasses, but Reesal et al. Ž1989. and Fong and Taouk Ž1995. reported that three quarters of injured welders did not use appropriate eye protection. Bakholdt and Illum Ž1990. also found that two thirds of those who suffered eye injuries at work, had not used safety glasses. However, the same authors reported that one third of those who used safety glasses still suffered eye injuries, which could have been caused by incorrect use of the safety glasses or because the glasses had not been optimally designed. Consistent use of safety glasses and development of more effective glasses would reduce the risk of eye injuries. Almost every third injured worker had persistent medical problems 2 years after the event, and almost every fifth after 5 years, of which one third were forced to change their leisure time activities due to sequele of the injury. Despite the fact that this indicates significant long-term effects for this group of injured, this is lower than the average for all gainfully employed workers ŽLarsson and Bjornstig, 1995.. In the present study, the proportion of ¨
Occupational injuries and their long term consequences among mechanics and construction metal workers
57
injured mechanics and construction metal workers, who suffered a medical impairment Ž2%., were half of the mean value for all occupational groups Ž4%. within the same geographic area ŽLarsson and Bjornstig, 1995.. Interesting was that back and knee injuries caused all cases ¨ who got disability pension and early retirement. The incidence of impairing injuries among mechanics and construction metal workers was 3.2r1000 employed and year, which is the same as the average in the entire country for the occupational group in question ŽAMF-Trygghetsforsakring, 1991.. People employed in the ¨ ¨ timber and steelrmetal industry and foundry workers had the highest risk of disability Ž6 per 1000 employed. ŽAMF-Trygghetsforsakring, 1991.. ¨ ¨ The results of this study illustrate the importance of not just focusing on the number of injured within a certain occupational category, but also considering the long-term effects. In addition to lengthy functional problems, the economic effects are significant for patients with prolonged medical problems or impairment. However, there does not appear to be any obvious visible link between settled medical impairment and early retirement.
Acknowledgements Tore J. Larsson, together with Anna-Maria Backlund and Jerzy Pilch are acknowledged for their valuable support during the collection and analyse of the comprehensive total overview material of all 1785 occupational injuries from the actual geographic area.
References AMF-Trygghetsforsakring, 1991. Svara ¨ ¨ ˚ olycksfall, 1988, 1991. ŽSevere accidents.. Stockholm ŽIn Swedish.. Bakholdt, V.T., Illum, D., 1990. Arbejdsbetingede Øjenskader. Ugeskr. Laeger. 13, 917–919. Belville, R., Pollack, S.H., Godbold, J.H., Landrigan, P.J., 1993. Occupational injuries among working adolescents in New York State. JAMA 269, 2754–2759. Courau, P., 1983. ‘Metalworking Industry’. Encyclopaedia of Occupational Health and Safety., 2: 1352–1355. Fingar, A.R., Hopkins, R.S., Nelson, M., 1992. Work-related injuries in Athens County 1982 to 1986. A comparison of emergency department and workers’ compensation data. J. Occup. Med. 34, 779–787. Fong, L.P., Taouk, Y., 1995. The role of eye protection in work-related eye injuries. Aust. N.Z.J. Ophthalmol. 23, 101–106. Hunting, K.L., Nessel-Stephens, L., Sanford, S.M., Shesser, R., Welch, L.S., 1994. Surveillance of construction worker injuries through an urban emergency department. J. Occup. Med. 36, 356–364. Jedeskog, B., Larsson, T.J., 1988. Allvarliga olycksfallsskador i verkstadsindustrin 1986. IPSO FACTUM 14. ŽInstitute for Human Safety and Accident Research.. Stockholm. ŽIn Swedish.. Institutet for ¨ personsakerhet ¨ Larsson, T.J., Bjornstig, U., 1990. The epidemiology of occupational accidents: three ways to measure the problem in ¨ a Swedish municipality. J. Occup. Health Safety—Aust. N.Z. 6, 39–52. Larsson, T.J., 1988. Risk and the inexperienced worker: attitudes of a social anthropologist. J. Occup. Health Safety —Aust. N.Z. 4, 35–40. Larsson, T.J., Bjornstig, U., 1995. Persistent medical problems and permanent impairment five years after occupa¨ tional injury. Scand. J. Soc. Med. 23, 121–128. Nordic Classification of Occupations, 1984. Nordisk Yrkesklassificering. Svensk Grundstandard. Arbetsmarknadsstyrelsen 1983. Liber Tryck. Stockholm. ŽIn Swedish.. Official Statistics of Sweden, 1992. Folk och bostadsrakningen 1990, 1992. Arbetsmarknad ŽLabour Market., ¨ Statistiska Centralbyran. ˚ Stockholm, Sweden. Olson, D.K., Gerberich, S.G., 1986. Traumatic amputations in the workplace. J. Occup. Med. 7, 480–485.
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Personskadekommitten Serviceaktiebolag, 1989. Grunder for ´ inom Forsakringsbranschens ¨ ¨ ¨ gradering av kvarstaende ˚ men efter skador Žmedicinsk invaliditet.. ŽPrinciples for the assessment of permanent impairment after traumatic injury Žmedical impairment.. Stockholm ŽIn Swedish.. Persson, I., 1992. Allvarliga olycksfallsskador i verkstadsindustrin 1987–1989. IPSO FACTUM 35. Institutet for ¨ ŽIPSO.. ŽInstitute for Human Safety and Accident Research.. Stockholm ŽIn Swedish.. personsakerhet ¨ Reesal, M.R., Dufresne, R.M., Suggett, R.N., Alleyne, B.C., 1989. Welder eye injuries. J. Occup. Med. 31, 1003–1006. Westman, E., 1986. Severe Hand Injuries among Woodworkers. Occupational injuries as reflected in claims for compensation under labour market insurance ŽAMF.. IPSO FACTUM 7. The Institute for Safety and Accident Research ŽIPSO.. Stockholm.
Pergamon
PII: S0925-7535(97)00070-2
OCCUPATIONAL INJURIES AND THEIR LONG TERM CONSEQUENCES AMONG MECHANICS AND CONSTRUCTION METAL WORKERS P.-O. Bylund ) , Ulf Bjornstig ¨ The Umea˚ Accident Analysis Group, Department of Surgery, Umea˚ University, 901 85 Umea, ˚ Sweden
Abstract–A one year comprehensive material of 398 occupational injuries among mechanics and construction metal workers was analysed. Shop mechanics experienced the highest incidence of injuries. Upper extremity lacerations and eye injuries were the most common injuries; the latter were most often caused by flying fragments or welding flashes. Handheld tools were involved in just over a quarter of the injuries, and other metal working machines in one fifth. Almost every third injured worker had some form of persistent medical problems 2 years after the event, and almost every fifth still had problems after 5 years. One third of those with persistent medical problems were forced to significantly change their leisure time habits. Two percent of the injured were granted economic compensation for permanent medical impairment. Four percent of the injured were granted pension and early retirement Žcaused by back and knee injuries. or were forced to change jobs, due to the injury. q 1998 Elsevier Science Ltd. All rights reserved. Keywords: Occupational injuries; Mechanics; Construction metal workers
1. Introduction Occupational injuries in Sweden are described by the Information System on Occupational Accidents ŽISA. at the National Board of Occupational Safety and Health. Statistics are also collected on more serious injuries, even at the Swedish Work Related No-Fault Liability Insurance ŽTFA.. However, both of these registration systems are afflicted with drop-out problems, resulting in less accurate recognition of the overall picture for acute occupational injuries ŽLarsson and Bjornstig, 1990.. Also Fingar et al. Ž1992. concluded in a study from ¨ USA a substantial underreporting of occupational injuries to the Workers’ Compensation and to The National Injury Surveillance System. In a previous study, data from ISA and TFA were compiled with data from the University Hospital in Umea˚ ŽNUS., for the equivalent time period and area ŽLarsson and Bjornstig, 1990.. It was thereby possible to get a complete ¨
)
Corresponding author. Tel.: q46-90-785-2401; fax: q46-90-785-2401; e-mail: [email protected].
49
P.-O. Bylund, U. Bjornstig ¨
50
picture of the injury problem complex within a specified geographical region. ‘Mechanics and construction metal workers’ 1 was the occupational group with the highest injury rate Ž398 of a total of 1785.. Few studies have analysed nonfatal work-related injuries ŽHunting et al., 1994. and the scientific literature relating to this occupational group is rather poor. This study aims to fill part of this gap. The aim of the present study was to use the combination of three data sources to analyse the accident and injury panorama, the injury incidence, and especially the long term effects from this comprehensive 1 year data of injuries which afflicted mechanics and construction metal workers, employed in the township of Umea. ˚
2. Material and methods According to the Nordic Classification of Occupations Ž1984. and the 1990 population census ŽOfficial Statistics of Sweden, 1992., 2156 ‘mechanics and construction metal workers’ worked in Umea˚ during 1985. A total of 398 nonfatal injury cases to this occupational group were identified in our three registration systems with a distribution on the three different systems as in Fig. 1. All acute injuries Ž n s 9000. treated at University Hospital in Umea˚ ŽNUS. were registered continuously during 1 year ŽApril 1, 1985–March 31, 1986. under the auspices of the Umea˚ Accident Analysis Group. A total of 292 Ž73%. of the 398 injury cases were treated at the hospital, either as out-patients or as inpatients ŽFig. 1.. ŽThe remaining cases were treated by general practitioners or by company physicians.. The injured person answered at the hospital visit a questionnaire regarding the event, the products and the tools involved in the incident. Injuries resulting in at least one day of sick leave, andror dental injuries, should be reported to the Information System on Occupational Accidents ŽISA. at the National Board of Occupational Safety and Health. Reports are made by the employees to the Social Insurance Office who pass them on to ISA. A total of 208 Ž52%. of the 398 injury cases ŽFig. 1. were found in ISA records, which also included medical data. If the injury results in sick leave for more than one week, or result in persistent medical problems, the injured worker himself submits a report to the Work Related No-Fault Liability Insurance ŽTFA.. The worker then receives compensation in compliance with the agreement between the labour market parties to compensate any loss of income and any permanent medical impairment. In the TFA data base 57 cases ŽFig. 1. were identified and the medical data was studied. In Sweden, permanent medical impairment is defined in a Classification Manual used by the Insurance Industry ŽPersonskadekommitten Serviceaktiebo´ inom Forsakringsbranschens ` ` lag, 1989.. Medical impairment is a measure of loss of body function due to injury and is expressed as a percentage. Body part loss, mobility impairment, strength reduction, pain, reduced sensation and deficient function of different body parts are taken into consideration. However, no consideration is given to the extra difficulties experienced in the professional or personal life of the injured. The exact medical impairment is determined by medical specialists
1
Workers in this occupational group manufacture products in metal and similar material, fit and repair machines and engines. Welders and plumbers are also included as well as sheet-metal workers who sometimes work in the construction industry.
Occupational injuries and their long term consequences among mechanics and construction metal workers
51
Fig. 1. Distribution of the number of injured in the various materials.
once the injury has reached a stable condition, usually 2 years or more after the injury event, and when no further improvement can be expected. A follow up of medical records regarding the injuries and the length of treatment has been performed. Social insurance office documents have also been studied with regard to length of sick leave within 1 year following the event. Costs of sick leave were converted to US$ ŽUS$1s 7.55 SEK January 1, 1986.. Through compilation of statistics from the three registration systems a complete data set was available for 369 Ž93%. of the 398 injury cases. To acquire data concerning any persistent medical problems and changed leisure time habits following the injury event, as well as to collect any missing data, a second interview was performed by mail both 2 and 5 years following the event. Following one reminder notice, answers were received from 258 Ž65%. of the 398 people. A study of the drop-out group Ž n s 140., 5 years after the injury event, was performed by random selection of every fifth case to find out if the proportion of persons with persistent medical problems was equal in both populations. The drop-out group did not differ significantly Ž p - 0.05. when compared to the study group. Injury events which occurred commuting to and from work and occupational diseases are not included in this study.
3. Results 3.1. Gender and age distribution A large majority Ž n s 387; 97%. of the injured were men. A total of 147 Ž37%. were in the age group 20–29 years and 338 Ž85%. were between 20–49 years of age. 3.2. Injury incidence and type of accident The injury incidence was 18 per 100 gainfully employed workers, and was highest in the age group under 20 years ŽTable 1.. Shop mechanics had the highest injury incidence
P.-O. Bylund, U. Bjornstig ¨
52 Table 1 Number of injured, gainfully employed, and injury incidence per 100 workers and year Age Žyears.
Number of injured
Number of workers
Injury incidence
y19 20–49 50q Total
24 Ž6%. 338 Ž85%. 36 Ž9%. 398 Ž100%.
88 1720 348 2156
27 20 10 18
ŽTable 2.. Included in the group machinery fittersrmachine assemblers and engine mechanics Ž n s 111. were 41 auto mechanics, 38 machine fitters, 27 machine repairmenrmachine mechanics and 5 other repairmen. 3.3. Injury mechanism The mechanism which caused the actual injury is presented in Table 3. The injuries occurred most frequently when working with handheld tools Ž107; 27%., fixed metal-working machines Ž78; 20%., building partsrequipment Ž45; 11%. or with vehicles Ž36; 9%.. 3.4. Type of injuries Most injuries affected the upper extremities Ž154; 39%.. Welders and plumbers had a higher proportion of head injuries including eye injuries Ž38; 40% and 17; 35%, respectively., compared with other occupational groups ŽFig. 2.. The lower extremities were seldom injured, except for plumbers, where this was the second most injured body part. 3.5. Care and sick leaÕe Most of the injured workers required only outpatient care Ž387; 97%.. Eleven Ž3%. patients were admitted to the hospital for a total of 66 days; that is, an average of 6 in-patient days per person ŽTable 4.. The patient cared for the longest time Ž24 days. was a sheet-metal worker who suffered a fractured pelvis when he fell 2 m from a ladder onto a concrete floor. An auto mechanic suffered burn injuries and was admitted for 10 days, a plumber fell from a trestle and sustained multiple rib fractures, and was admitted for 7 days, and a milling-machine worker with a finger injury was admitted to the hospital for 6 days. Table 2 Number of injured and injury incidence per 100 workers and year within different occupational groups Occupational group
Number of injured
Injury incidence
Machinery fittersrmachine assemblers and engine mechanics Welders Shop mechanics Plumbers Sheet-metal workers Others Total
111 Ž28%.
14
94 Ž24%. 69 Ž17%. 49 Ž12%. 46 Ž12%. 29 Ž7%. 398 Ž100%.
20 38 23 19 12 18
Occupational injuries and their long term consequences among mechanics and construction metal workers
53
Table 3 Number of injured and various injury mechanisms Injury mechanism
Number of injured
Hit against object, cut Hit by flying object in eyerwelding flashes Muscle overloadrstrain Jammed Žcrush injury. Fell onror against something Contact with hot object or fire Other injury mechanisms Total
137 Ž34%. 114 Ž29%. 47 Ž12%. 34 Ž9%. 26 Ž6%. 8 Ž2%. 32 Ž8%. 398 Ž100%.
A total of 241 Ž61%. persons were on sick leave for 5818 days; that is, an average of 24 daysrperson on sick leave. Sheet-metal workers had the highest average number of sick leave days of all those on sick leave ŽTable 4.. A total of 37 Ž9%. persons were on sick leave for one month or more. Three persons were on sick leave for more than 1 year: A sheet-metal worker, who got his glove in a rotating rolling mill at a sheet-metal shop, got his right thumb amputated. A construction sheet-metal worker slipped on a roof and suffered a severe knee ligament injury.
Fig. 2. Type of injuries in different occupational groups.
P.-O. Bylund, U. Bjornstig ¨
54
Table 4 Number of injured and on sick leave, length of sick leave, and inpatient care days for different occupational groups Occupational group
Machinery fittersrmachine assemblers and engine mechanics Welders Shop mechanics Plumbers Sheet-metal workers Others Total
Number of injured
Sick leave Number on sick leave
Number of days
Average Ždays.
Number of care days
111
65
1699 Ž29%.
26
23
94 69 49 46 29 398
54 43 35 28 16 241
586 Ž10%. 990 Ž17%. 811 Ž14%. 1385 Ž24%. 347 Ž6%. 5818 Ž100%.
11 23 23 49 22 24
y 8 7 27 1 66
A machine-repairman got his hand in a machine at a dairy and crushed two fingers so badly that he lost sensibility in them. 3.6. Cost of care and sickness benefit An outpatient visit in 1985 did cost about SEK 650 ŽUS$86. and one day of inpatient care about SEK 2000 ŽUS$265.. With an estimated sickness benefit of SEK 250rday ŽUS$33., the total cost of care and sickness benefits amounted to about SEK 1.8 million ŽUS$238,500.; that is, an average of SEK 4500rinjured ŽUS$600.. Of this, the sickness benefit accounted for the majority, SEK 1.5 million ŽUS$199,000.. This shall be considered to be a minimum cost, since sick leave lasting over 1 year is not included in the calculations, nor are the costs for medical impairment, early retirement or other costs such as retraining. Recalculated in terms of 1996 values, care and sickness benefits would be about SEK 3 million ŽUS$400,000., or an average of SEK 7500 ŽUS$1000. per injury case. 3.7. Persistent medical problems Of the total of 258 people who responded to the questions about any persistent medical problems, 78 Ž30%. reported some form of persistent problem 2 years after the event, while 49 Ž19%. stated that they still had problems after 5 years. The most common persistent medical
Table 5 Number of people with different persistent medical problems after 2 and 5 years, respectively Symptom
2 Years
5 Years
Pain in extremityrback Reduced sense of touch in extremityrsense of coldness Reduced mobility Irritation in eye reduced vision Headacherfatigue Other, unknown Total
36 Ž46%. 13 Ž17%. 10 Ž13%. 7 Ž9%. 2 Ž2%. 10 Ž13%. 78 Ž100%.
28 Ž57%. 11 Ž23%. 4 Ž8%. 1 Ž2%. 1 Ž2%. 4 Ž8%. 49 Ž100%.
Occupational injuries and their long term consequences among mechanics and construction metal workers
55
Table 6 Occupation, degree of medical impairment and injury mechanism among the seven who got a medical impairment settled Occupation
Degree of impairment
Sheet-metal worker
15%
Machinery fitter Sheet-metal worker Other engineering worker Machine repairman Sheet-metal worker Machine repairman
12% 10% 10% 3% 2% 1%
Injury and injury mechanism Amputated thumb; glove was caught in a rotating rolling mill at sheet-metal shop. Nerve and tendon injury in hand; adjusted machine. Pelvic fracture; fell 2 m from ladder. Concussion; worker fell on the floor due to epileptic seizure. Crush injury hand; raised clutch for car. Crush injury finger; raised engine. Crush injury finger; tool caught in bicycle wheel.
problems were pain Žin extremity or back., and reduced sensation of touch and sense of coldness in a extremity ŽTable 5.. 3.8. Early retirement, job changes, and medical impairment Two of the injured workers suffered injuries Žstrained lumbar spine and strained knee. with so severe long term consequences that they were placed on full medical disability pension, while 3 persons were placed on 50% disability pension due to the injury Žtwo injured with strained lumbar spine and one person with strained knee.. One person at the 5 year follow up was still on sick leave full time. This was judged to be partially due to the knee injury which the patient suffered. Thirteen of the injured had changed jobs due to their injuries. In one other case the injury was partially responsible for the worker’s job change. Seven Ž2%. of the 398 injured had a medical impairment settled and received compensation for this impairment. The most severe impairment was suffered by a 18 year old sheet-metal worker who had part of his thumb amputated. Three of the seven impairment cases was among sheet-metal workers ŽTable 6.. 3.9. Changed leisure time actiÕities Of the 49 patients who still had some form of persistent medical problems 5 years after the injury, 16 Ž33%. had significantly changed their leisure time habits due to the injury.
4. Discussion The health care based registration system provided the best degree of coverage Ž73%., while the Information System on Occupational Accidents ŽISA. only registered just over half of known cases. To describe the comprehensive picture and consequences of these injuries, it is necessary that several injury registration systems are coordinated. Even long term consequences must be considered because the relatively few injuries, causing long term medical problems, will cost the social insurance system and the employee’s a great sum of money. For this reason data collected by the Swedish Work Related No-Fault Liability Insurance ŽTFA. are of great value to incorporate in the analysis to get the total picture of the consequences from these injuries.
56
P.-O. Bylund, U. Bjornstig ¨
On average, every fifth mechanic and construction-metal worker required medical treatment for an acute occupational injury annually. The injury incidence was nearly three times higher among the youngest Ž- 20 years. compared with those who were 50 or older. Comparable figures have not been found in the available scientific literature, but in a local Ž1991. in Sweden it was demonstrated that 20–25 year report from AMF-Trygghetsforsakring ¨ ¨ olds in industrial jobs were at high risk for severe injury caused by machine-related accidents. In manufacturing industry in the USA adolescent worker’s had the highest rate of injuries ŽBelville et al., 1993.. Further, Olson and Gerberich Ž1986. demonstrated that half of all amputations caused by occupational injuries in the USA were suffered by young people Ž- 26 years.. Youth Ž- 20 years. are also significantly over-represented with regard to injuries resulting in disability in other branches such as the timber industry ŽWestman, 1986.. The risk of injury during the first day on the job Žwithin the timber industry. was up to 50 times higher, than the risk for those with more than 1 year of experience ŽLarsson, 1988.. Adequate introductory training and restrictions in assigning high risk tasks to the youngest workers are probably of great value. All new workers need to be informed about the use of obligatory safety equipment, and the employee ought to sign a statement agreeing to comply with these rules. Most were injured when using handheld tools, while injuries caused by falling were relatively rare occurrences, which has also been found by Courau Ž1983. and Persson Ž1992.. Injuries resulting in medical impairment were in the present study associated with ‘manual handling’, ‘falls’ and work with rolling machines. Similar results concerning severe injuries have been presented by Jedeskog and Larsson Ž1988.. The most common injuries afflicted the upper extremities Ž39%. and were comprised primarily of cuts and lacerations. Use of work gloves is an important measure for preventing lacerations on the hands. However, Persson Ž1992. noted that work gloves also posed a risk, since half of those who suffered disabling injuries were injured when the work glove got caught in the machine while using drills, reamers, and tapers. This indicates that there is still room for better adaptation of work gloves, aids and technical improvements. In the present study, the most serious injury causing disability Žthumb amputation. happened when the glove of a 18 year old sheet-metal worker was caught in a rotating rolling mill. Noteworthy in our study was that almost one third of the injuries were located to the eye, despite the fact that all industrial workers should be equipped with safety glasses. Welders were the occupational group with the highest proportion of eye injuries Ž40%.. However, the eye injuries did not result in any medical impairment. A study from the USA ŽReesal et al., 1989., reported an impairment rate for this type of injuries of 0.3%. We did not have reliable data concerning the use of safety glasses, but Reesal et al. Ž1989. and Fong and Taouk Ž1995. reported that three quarters of injured welders did not use appropriate eye protection. Bakholdt and Illum Ž1990. also found that two thirds of those who suffered eye injuries at work, had not used safety glasses. However, the same authors reported that one third of those who used safety glasses still suffered eye injuries, which could have been caused by incorrect use of the safety glasses or because the glasses had not been optimally designed. Consistent use of safety glasses and development of more effective glasses would reduce the risk of eye injuries. Almost every third injured worker had persistent medical problems 2 years after the event, and almost every fifth after 5 years, of which one third were forced to change their leisure time activities due to sequele of the injury. Despite the fact that this indicates significant long-term effects for this group of injured, this is lower than the average for all gainfully employed workers ŽLarsson and Bjornstig, 1995.. In the present study, the proportion of ¨
Occupational injuries and their long term consequences among mechanics and construction metal workers
57
injured mechanics and construction metal workers, who suffered a medical impairment Ž2%., were half of the mean value for all occupational groups Ž4%. within the same geographic area ŽLarsson and Bjornstig, 1995.. Interesting was that back and knee injuries caused all cases ¨ who got disability pension and early retirement. The incidence of impairing injuries among mechanics and construction metal workers was 3.2r1000 employed and year, which is the same as the average in the entire country for the occupational group in question ŽAMF-Trygghetsforsakring, 1991.. People employed in the ¨ ¨ timber and steelrmetal industry and foundry workers had the highest risk of disability Ž6 per 1000 employed. ŽAMF-Trygghetsforsakring, 1991.. ¨ ¨ The results of this study illustrate the importance of not just focusing on the number of injured within a certain occupational category, but also considering the long-term effects. In addition to lengthy functional problems, the economic effects are significant for patients with prolonged medical problems or impairment. However, there does not appear to be any obvious visible link between settled medical impairment and early retirement.
Acknowledgements Tore J. Larsson, together with Anna-Maria Backlund and Jerzy Pilch are acknowledged for their valuable support during the collection and analyse of the comprehensive total overview material of all 1785 occupational injuries from the actual geographic area.
References AMF-Trygghetsforsakring, 1991. Svara ¨ ¨ ˚ olycksfall, 1988, 1991. ŽSevere accidents.. Stockholm ŽIn Swedish.. Bakholdt, V.T., Illum, D., 1990. Arbejdsbetingede Øjenskader. Ugeskr. Laeger. 13, 917–919. Belville, R., Pollack, S.H., Godbold, J.H., Landrigan, P.J., 1993. Occupational injuries among working adolescents in New York State. JAMA 269, 2754–2759. Courau, P., 1983. ‘Metalworking Industry’. Encyclopaedia of Occupational Health and Safety., 2: 1352–1355. Fingar, A.R., Hopkins, R.S., Nelson, M., 1992. Work-related injuries in Athens County 1982 to 1986. A comparison of emergency department and workers’ compensation data. J. Occup. Med. 34, 779–787. Fong, L.P., Taouk, Y., 1995. The role of eye protection in work-related eye injuries. Aust. N.Z.J. Ophthalmol. 23, 101–106. Hunting, K.L., Nessel-Stephens, L., Sanford, S.M., Shesser, R., Welch, L.S., 1994. Surveillance of construction worker injuries through an urban emergency department. J. Occup. Med. 36, 356–364. Jedeskog, B., Larsson, T.J., 1988. Allvarliga olycksfallsskador i verkstadsindustrin 1986. IPSO FACTUM 14. ŽInstitute for Human Safety and Accident Research.. Stockholm. ŽIn Swedish.. Institutet for ¨ personsakerhet ¨ Larsson, T.J., Bjornstig, U., 1990. The epidemiology of occupational accidents: three ways to measure the problem in ¨ a Swedish municipality. J. Occup. Health Safety—Aust. N.Z. 6, 39–52. Larsson, T.J., 1988. Risk and the inexperienced worker: attitudes of a social anthropologist. J. Occup. Health Safety —Aust. N.Z. 4, 35–40. Larsson, T.J., Bjornstig, U., 1995. Persistent medical problems and permanent impairment five years after occupa¨ tional injury. Scand. J. Soc. Med. 23, 121–128. Nordic Classification of Occupations, 1984. Nordisk Yrkesklassificering. Svensk Grundstandard. Arbetsmarknadsstyrelsen 1983. Liber Tryck. Stockholm. ŽIn Swedish.. Official Statistics of Sweden, 1992. Folk och bostadsrakningen 1990, 1992. Arbetsmarknad ŽLabour Market., ¨ Statistiska Centralbyran. ˚ Stockholm, Sweden. Olson, D.K., Gerberich, S.G., 1986. Traumatic amputations in the workplace. J. Occup. Med. 7, 480–485.
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Personskadekommitten Serviceaktiebolag, 1989. Grunder for ´ inom Forsakringsbranschens ¨ ¨ ¨ gradering av kvarstaende ˚ men efter skador Žmedicinsk invaliditet.. ŽPrinciples for the assessment of permanent impairment after traumatic injury Žmedical impairment.. Stockholm ŽIn Swedish.. Persson, I., 1992. Allvarliga olycksfallsskador i verkstadsindustrin 1987–1989. IPSO FACTUM 35. Institutet for ¨ ŽIPSO.. ŽInstitute for Human Safety and Accident Research.. Stockholm ŽIn Swedish.. personsakerhet ¨ Reesal, M.R., Dufresne, R.M., Suggett, R.N., Alleyne, B.C., 1989. Welder eye injuries. J. Occup. Med. 31, 1003–1006. Westman, E., 1986. Severe Hand Injuries among Woodworkers. Occupational injuries as reflected in claims for compensation under labour market insurance ŽAMF.. IPSO FACTUM 7. The Institute for Safety and Accident Research ŽIPSO.. Stockholm.