Public attitudes towards chemical hazards

The Science of the Total Environment, 51 (1986) 125--147 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands

PUBLIC ATTITUDES

TOWARDS

125

CHEMICAL HAZARDS

TERENCE R. LEE

University of Surrey, Guildford GU2 5XH, Surrey (United Kingdom)

ABSTRACT Public concern over chemical hazards is increasing in a context where overall life expectancy has rapidly improved. However, people's expectations of safety continue to exceed the presently attained levels and a mistrust of technological expertise is pervasive. Paradoxically this may arise because the ordinary person has assimilated scientific notions of causality that partially replace religious or magical explanations for accidents and catastrophes. The public's perceptions of risk frequently diverge considerably (in either direction) from the probabilistic risk assessments made by engineers and scientists. Both assessments are usually wrong: reconciliation rather than confrontations should be sought. The public is not 'irrational', it has different reasons and values. A brief view is given of the methodology and main findings of research on perceived risk, both comparative approaches and those where perceptions of a single hazard are explored in detail. Illustrative studies of community attitudes to pesticides, chemical food additives and of people's beliefs about nuclear power are outlined.

INTRODUCTION T h e b u r g e o n i n g p u b l i c c o n c e r n o v e r h a z a r d s a n d t h e i r m a n a g e m e n t is a phenomenon that needs to be explained. It can hardly be attributed to a n o v e r a l l i n c r e a s e in t h e r i s k i n e s s o f o u r e n v i r o n m e n t , f o r d e a t h a n d h e a l t h r i s k s a r e a c t u a l l y l o w e r in m o d e r n , i n d u s t r i a l i s e d c o u n t r i e s t h a n a t a n y p r e v i o u s t i m e in h i s t o r y ( L o w r a n c e , 1 9 7 6 ; R a v e t z , 1 9 7 9 ) ; n e i t h e r is i t a response to legislation or regulation, for these are primarily the effects and not the causes of public concern. T h e s h i f t in n u m b e r a n d m a g n i t u d e t o w a r d s m a n - m a d e d i s a s t e r s is o b v i o u s l y i m p o r t a n t . A l t h o u g h m a n y natural h a z a r d s h a v e b e e n b r o u g h t under control, we now have extensive use of pesticides and artificial f e r t i l i s e r s , l i q u i d n a t u r a l gas c o n t a i n e r s , r o a d a n d s e a c o n v e y o r s o f t o x i c chemicals and man-made pharmaceutical compounds that can have malignant side effects. B u t e v e n m o r e i m p o r t a n t , in m y v i e w , is t h a t t h i s i m m e n s e t e c h n o l o g i c a l

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126 expansion has been accompanied by a change in the public's attribution of responsibility and blame. The ordinary man is forsaking the explanations based on magic and religion that have been used since the beginning of time for coping with disaster and adversity. This is not to say that he may not preserve private or public religion for other purposes (including perhaps for 'Acts of God' or 'natural' hazards) but so far as man-made hazards are concerned he seems to be saying " . . . y o u made it, y o u control it". He is substituting, partially (for he wisely hedges his bets), the explanatory notion of determinism, the professional though usually implicit tenet of scientists; the working creed of the majority of participants at the WHO seminar. Scientific determinism is the notion that all natural events have antecedents, all effects have causes. Also, that although the causes may be interactive, regressive and infinitely complex, their identification and understanding is the most powerful form of explanation available to us. Everyone has their favourite example of our previous forms of explanation. Among the Cree Indians mothers explained the death of their children by saying that they were taken away by a spirit (the expression 'spirited away' is a c o m m o n metaphor in our own language) and that some protection could be afforded by providing the child with a moccasin with a hole in it! If approached by a spirit to embark on a long journey, the child could then ask leave first to return to its mother in order to have the hole repaired~ the better to travel. Belief in magic has not wholly disappeared from our own civilisation. Many people observe superstitious rites as one line of defence among others, bearing in mind that the cost is very low. Gamblers touchingly believe in some kind of magical force, and this is confirmed by their reluctance to lay bets after the dice have been thrown but before the outcome is known. However, although these magical forms of explanation and intervention cannot be wholly discounted, they have been much diminished in importance over recent decades. It is a mistake (as well as being offensive to many people) to equate religion with magic. In particular, the widespread observance of Christianity does not necessarily include the belief that God intervenes directly into h u m a n affairs to cause or withhold disastrous events. However, what is beyond doubt is that this particular aspect of religious belief, whatever its validity, was previously almost universally held, while it is now professed in practice by only a minority. What has replaced it is the belief that ultimately almost all adverse events can be prevented by removing their causes, or diminished in seriousness by controlling their consequences. Moreover, the necessary a c t i o n s are within the control of man himself~ or more specifically of the Government, the new deity. This new attribution of responsibility has been tacitly accepted; governments now look to their scientists, technologists and industrialists to extend our knowledge of hazards and risks, and to develop effective procedures for their control.

127 APPROACHES TO RISK There are two clearly distinguishable approaches to the study of risk. The first may be properly called objective or 'probabilistic risk assessment' and the second, subjective, or 'perceived risk assessment'. The first attempts to measure the f r e que nc y and sometimes the consequences of adverse events arising f r om hazards; these data are then used to extrapolate future probabilities. The second approach is concerned with the estimates of probability and loss t hat are made by ordinary people, individuals or groups (see Conrad, 1980; Royal Society, 1983). It is easy to fall into the trap o f describing the first m e t h o d as 'real' and the second as 'irrational'. Both are equally real and I hope to show t hat perceived risk has greater influence u p o n o u r affairs than statistical risk, at the present time.

PROBABILISTIC RISK ASSESSMENT Engineers and ot he r scientists measure risks in terms of the probability o f the event occurring against a unit of time or n u m b e r of exposures. The consequence is specified, but it is usually mortality. The event may be a well known natural hazard such as a fire, earthquake or tempest. Many of the relevant statistics already exist and this partly governs the procedure. It should be m e n t i o n e d t hat in cases where the adverse events have not occurred, such as in new technologies, attempts are made to aggregate the probabilities f r om the failure of const i t uent elements, which are known. Examples are collisions occurring between liquid natural gas containers and also, of course the m or e familiar area of radiation leak or core meltdown in nuclear installations. The c o n c e p t of 'acceptable' risk is very important. This assumes a threshold level, a kind of plimsoll line below which risks are unacceptable. It assumes t hat all risks can be placed somewhere on a dimension of magnitude and t hat a certain level of riskiness is an inevitable part of life and the environment. The not i on is also used for making particular 'paired comparisons', e.g. a particular new form of sport may be assessed for its riskiness by comparing it with the familiar activities of m ot orcycl i ng or train journeys. This approach seems sensible enough, but it has a n u m b e r of obvious shortcomings; (1) Risk must be regarded as a c o m p o u n d of the probability of an event occurring and its consequences if it should occur. The latter are m uch harder to quantify than the f o r m e r The event of death is clearly important, but longterm m o r b i d i t y and the kind of affront to moral values which may be involved in certain pollution or nuclear risks, is much harder to quantify. (2) We must obviously feel u n h a p p y about those hazards for which there is no dependable past experience of adversity but whose consequences may be p r o f o u n d .

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Fig. 1. Perceived versus actual number of deaths for a range of hazards (U.S. sample) (source: Slovic et al., 1979). (3) Experts and scientists are plainly human. Without being wilful they are inevitably biased in some cases by personal interests deriving particularly from occupational affiliations and what may sometimes be lifetime loyalties to particular technological enterprises. (4) The extrapolation of past experience into the future must depend on m a n y other synergistic variables, which may not remain the same. (5) In assessing consequences, a great deal depends on who is affected; different sections of the public are not interchangeable; it has to be conceded that potential death or injury to one's family or neighbours is likely to be perceived as more serious than the same consequences for distant and u n k n o w n persons. (6) It is self-evidently almost meaningless to c o m p a r e certain risks at all. For example, those arising from such complex and diverse hazards as smoking versus acid rain.

PERCEIVED RISK A number of researchers have shown that the public has an approximate idea of the objective probability of quite a wide range of risks, when measured in terms of mortality. The classic work by Lichtenstein et al.

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(1978) has shown that there is a tendency for people to overestimate the frequency of low probability risks and to underestimate high probability risks. (Fig. 1). A replication of this study, carried out by Renn (1983) in Germany, shows instead a fairly consistent overestimation throughout the range (Fig. 2). However, the main lesson we can draw is that people have a rough idea of the different mortality rates attaching to a wide range of hazards. Unfortunately, as some would say, this knowledge does not appear to inform their perceptions of the severity or magnitude of the risks. The public frequently displays attitudes and emits behaviour that appear to be completely incompatible with the evidence arising from statistical risk assessment. Because of public indignation or remorseless pressure, mediated through the press or through their elected representatives, policies are implemented that often seem 'irrational' or just plain crazy to the scientist or administrator. For example, immense sums of money have been spent on placing collision barriers down the central reservations of motorways in the U.K., although careful cost benefit analysis by the Transport and Road Research Laboratory demonstrated that this was an extremely expensive, and therefore profligate, way of saving lives on the roads. Even more dramatically, the estimated cost of saving a single life through the safety measures implemented after the Ronan Point disaster (when a few floors of a tower block collapsed) was £20 million, whereas WHO have reported that a life can be saved for $15 by means of a smallpox injection. In the

130

U.K., the slightest indication of possible side-effect arising from a drug that relieves the pain and suffering of thousands will lead to its banishment. Because of public feelings in the matter, somewhere between 37 and 50% of the costs of all pharmaceuticals is allocated to safety measures and we currently spend 2500 times as much on safety in this area than in agriculture. Per contra, the public has a touching faith in civil engineering, despite the distinctly trial and error way in which it has developed its skills. Over 100 dams have collapsed since 1930, many domes have fallen in and 16% of bridges fail in the course of construction. There has not been a single death directly attributable to the use of nuclear power to generate electricity in the U.K. and there were no deaths in the much publicised Three Mile Island incident in the U.S.; but, there were no fewer than 12 fatalities between 1971 and 1979 in the U.K. due to a recreational activity for young people called Outward Bound which aims to inspire self-confidence and skills by stressful physical challenge. There have been about the same number of deaths from hang-gliding. However, having pointed to the limitations of statistical risk assessment, we shall see that there is an even more compelling case for listing similar shortcomings on the part of the public. (1) They do not study the issues about which they are concerned with any measure of care, let alone quantitative sophistication. (2) They appear to be easily influenced by media campaigns. (3) The public uses short cuts or 'heuristics' in attempting to arrive at estimates of risk and these have been shown to be particularly subject to bias. (4) Although we are not infrequently informed by economists and others that risks are a balance of costs and benefits, there is only dubious evidence that the public actually effects a synthesis leading to a consistent and considered judgement; the tendency seems to be to oscillate, sometimes stressing the risks and at other times the benefits of a hazard.

R E C O N C I L I A T I O N IS C A L L E D F O R

Given the contrasting perspectives on risk adopted by scientists and by the public, there has been a tendency to keep them apart. Policy making proceeds by attempting to make probabilistic risk assessments and having them implemented without disruption by the disturbing irrationalities of public opinion. As I have indicated, such efforts not infrequently come unstuck. The opposite strategy is that the public, excited by the media who only want to please their consumers, decides that something is a horrendous hazard and any responsible government should do something about it. I shall argue in this paper that the only sensible alternative is one of negotiation leading to reconciliation. The public must become informed by

131

statistical risk assessment and use its findings as primary data. However, risk assessors must learn that people's perceptions of a hazard are multidimensional, often taking into account factors which are not recognised, let alone measured, by scientists. There is also an affective dimension composed of anxieties that are real and which need to be assuaged. To revert to one of my earlier examples, I would guess that the public insisted on m o t o r w a y barriers because of the pervasive anxiety of driving continuously in a situation of potential head-on collision and not because they f o u n d the relevant statistical probability of mortality unacceptable. My next point, which is the link to the remainder of my paper, is that perceived risk is just as amenable to scientific study as statistical risk. We need to understand the complex variables that determine it.

COMPARATIVE RISK PERCEPTION

The basic approach of the early work on risk perception was to present a list of familiar hazards to a sample of subjects, asking them to scale them along a single dimension of magnitude or severity. A variety of psychometric scaling methods have been used with varying degrees of sophistication. This is a highly flexible technique which subsequently lends itself to a comparison between different groups of respondents, between particular types of hazard and different forms of evaluation. A good example is the work of Slovic and his colleagues (1979) from Decision Research, Oregon, who have probably been the most productive researchers in the field. It will be seen from Table 1 that there are substantial differences between the rank orderings of the hazards as judged by a group of students, a set of 'League of Women Voters' subjects, a group of young executives and a sample of experts. There is no way of saying who is 'right'; they are informed by different knowledge bases, have assimilated different value systems, work on different timescales and are perhaps perceiving the implications of each hazard for different sub-groups of the population. Another example of the application of this scaling approach is its use by Green (1979) in comparing two clear criteria for risk perception. Using a 15-item scale of risks going from snakebite to the accidental release of radiation from nuclear power plants, he asked his subjects to assess them for severity under two different criterion conditions, i.e. as a 'threat to self' (i.e. a personal safety criterion) or a 'threat to society' (i.e. a long-term, 'future generation' risk). One of the principal approaches used by the Oregon group to explain public perceptions is the use of various heuristics. For example, a greater weight is given by the public to hazards about which there is much information readily available -- the more information provided through the press, the more salient and 'imaginable' and hence more serious the risk appears to be. A correlation between press column inches and perceived seriousness has been demonstrated, although it must be pointed out that the direction of causality may be opposite to that suggested by the authors, Combs and Slovic (1979).

132 TABLE 1 ORDERING OF PERCEIVED RISK FOR 30 ACTIVITIES AND TECHNOLOGIES (The ordering is based on the geometric mean risk ratings within each group. Rank 1 represents the most risky activity or technology)

Nuclear power Motor vehicles Handguns Smoking Motorcycles Alcoholic beverages General (private) aviation Police work Pesticides Surgery Fire fighting Large construction Hunting Spray cans Mountain climbing Bicycles Commercial aviation Electric power (non-nuclear) Swimming Contraceptives Skiing X-rays High school and college football Railroads Food preservatives Food colouring Power mowers Prescription antibiotics Home appliances Vaccinations

League of Women voters

College students

Active club members

Experts

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

1 5 2 3 6 7 15 8 4 11 10 14 18 13 22 24 16 19 30 9 25 17 26 23 12 20 28 21 27 29

8 3 1 4 2 5 11 7 15 9 6 13 10 23 12 14 18 19 17 22 16 24 21 20 28 30 25 26 27 29

20 1 4 2 6 3 12 17 8 5 18 13 23 26 29 15 16 9 10 11 30 7 27 19 14 21 ~8 24 22 25

(Reproduced from Slovic et al., 1979) O t h e r h e u r i s t i c s are ' a n c h o r i n g ' - - a r e v i s i o n f r o m a n i n i t i a l r e f e r e n c e point but with insufficient adjustment to take account of new information. ' R e p r e s e n t a t i v e n e s s ' , w h i c h is t o o m u c h r e l i a n c e o n a d e c e p t i v e s i m i l a r i t y b e t w e e n u n c e r t a i n events a n d other, past r e l e v a n t events. ' O u t of sight o u t o f m i n d ' is a n e x c e s s i v e r e l i a n c e o n t h e l i m i t e d d a t a t h a t are a c t u a l l y p r e s e n t e d w i t h i n a s i t u a t i o n w h i l e n e g l e c t i n g t o give d u e w e i g h t t o i n f o r m a t i o n t h a t is n o t c u r r e n t l y o n t h e t a b l e . T h e s e r e s e a r c h e r s h a v e also s h o w n a d i s t u r b i n g ( b e c a u s e u n j u s t i f i e d ) over-confidence in r i s k a s s e s s m e n t s b y p r o f e s s i o n a l p e o p l e , w h o h a v e p r e s u m a b l y l e a r n e d t h a t a n air o f decisiveness, a s s u r a n c e a n d r a p i d p r o c e s s i n g m a k e s a g o o d i m p r e s s i o n i n c a r e e r t e r m s .

133 Such a tendency, like m a n y others, is often reinforced by a boost to self esteem and only rarely exposed to the critical conditions that give negative reinforcement by way of an accident. These are the characteristics of 'risk takers' that need to be taken into account in any management strategy, at whatever level of organisation. Each heuristic implies an error proneness of a distinctive kind which would, of course, be further compounded by the more familiar factors of fatigue or ineptitude. Another approach is based on the general notion that the public is influenced by a number of important attributes of hazards or hazardous activities. If we could identify these and quantify their effects, it would be possible to use them as mediating variables in predicting the public's response. Examples are voluntary/non-voluntary; catastrophic potential, i.e. the number of people who could be killed at any one time; immediate or delayed effect, threat to self, threat to society; and familiarity.

THE PERCEIVED ATTRIBUTES OF SINGLE HAZARDS The development which goes further than the measurement of perceived magnitude is the attempt to describe the full range of qualities attaching to different hazards. It can be assumed that the 'meaning' of a hazard is the sum of its perceived attributes and that people develop and apply a multidimensional framework of such attributes (what some psychologists call a 'construct system') in order to make sense of their environment or to 'construe' their perceived world. Various techniques have been used for eliciting these frameworks, but the basis of them all is to request people to assess a varied set of hazards on a wide range of attributes. A prime example is Slovic et al.'s (1979) study of 30 hazards, each of which were rated by subjects on nine characteristics. These were 'voluntary', 'controllable', 'known to those exposed', 'familiar', 'known to science', 'dreaded', 'certain to be fatal', 'catastrophic' and 'immediate in effect'. The analysis is based on the assumption that there is an underlying congruence between some of the nine dimensions and that by factor analysis of the intercorrelations it is possible to reduce them to a small number of underlying 'principal components'. For example, there is a component of 'dread' which is independent of the other main component of 'familiarity'. Pesticides, food colouring and food preservatives are perceived as completely 'unfamiliar' and moderately 'dreaded' while alcoholic beverages are (perceived as) relatively benign and thoroughly familiar. In terms of mortality per hours of exposure, the latter is probably, of course, many times more dangerous! Slovic and his colleagues have repeated this study on a sample of college students with a much larger number of hazards, 90 in all, and no less than 18 risk characteristics (Slovic et al., 1980).

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Fig. 3. Factor analysis of 18 'Risk Characteristics' of 90 hazards. Hazard locations on factors 1 and 2 of the three-dimensional structure derived from the interrelations among 18 risk characteristics. Factor 3 (not shown) reflects the number of people exposed to the hazard and the degree of one's personal exposure (source: Slovic et al., 1980). T h e u n d e r l y i n g pattern that e m e r g e s is m u c h t h e same, e x c e p t that an a d d i t i o n a l c o m p o n e n t has b e e n extracted. This e x t e n d s f r o m single, personal e x p o s u r e t o an increasing n u m b e r o f p e o p l e likely t o be affected. This c o m p o n e n t appears to be a s y n t h e s i s o f t w o variables that have p r e v i o u s l y b e e n judged i m p o r t a n t , i.e. 'catastrophic p o t e n t i a l ' and 'threat to self versus threat t o s o c i e t y ' . T h e results are s h o w n in Fig. 3. T h e i m p o r t a n c e o f these variables, o f course, is that t h e y c o n f i r m t h e u n d e r l y i n g c o n s i s t e n c y or l a w f u l n e s s o f public p e r c e p t i o n s , h o w e v e r bizarre these m a y appear to experts, and t h e y o f f e r t h e p o t e n t i a l o f predicting h o w t h e public's r e s p o n s e t o n e w hazards is likely to deviate f r o m t h e e x p e c t a t i o n s based o n statistical risk assessment. In this study, it will be seen ( f r o m Fig. 3) that a group o f c h e m i c a l or

135 similar risks associated with food (sodium nitrate, saccharin, food preservatives, food colourings and food irradiation) are perceived as moderately 'dreaded' and very much 'unknown'. Herbicides, DDT and pesticides are perceived as moderately ' k n o w n / u n k n o w n ' but highly 'dreaded'. An alternative way of exploring data of these kind is through multidimensional scaling. Instead o f seeking to identify the principal components in the perceptions, it retains the distinctiveness of each of a larger number of dimensions, while showing broadly how each one relates to the other. A study of m y own will illustrate this (Lee, 1981). Eight characteristics of 38 different sports were analysed and the results are shown in Fig. 4. The computer makes a single, optimal resolution of the points (sports) in a two-dimensional space in such a way that similarity (correlation) between the sports is represented by spatial proximity. The programme (Guttman-Lingoes MDS, see Lingoes, 1973) does this in such a way that the clearest possible separation of each of the dimensions is retained. In the plots illustrated, the space partitioned with the numbers 1--3 represents increasing strengths of the dimension concerned. This study also makes a conceptual point that is critical to our discussion. Many activities involve potentially unpleasant or adverse outcomes and their perception will therefore include a risk dimension that is likely to be correlated with other qualities, some of them similarly negative but others positive. We are now converging on the concept of synthesised risk/benefit. It will be seen that the riskier sports in our example tend also to be those that give a sense of achievement, that involve skill and are highly organised; but they are unrelated to the competitive dimension and inversely related to the potential for relaxation. A carefully detailed study of the public's perceptions of various industrial risks, using multidimensional scaling, was carried out by Vlek and Stallen (1980, 1981) in the harbour area of Rotterdam in the Netherlands. They also found nuclear power to lie at the extreme of a severity dimension, but for reasons that were obviously contextual to some extent, the perceived risks of this were exceeded by those of chlorine trains and, even more so, by m a m m o t h tankers. Pesticides and the landing of liquified natural gas into harbours were also seen by the public as very severe risks. Other criteria that appeared to be employed by the public were 'degree of organised safety' and 'perceived degree of control'.

THE DETAILED STUDY OF SINGLE HAZARDS The comparative studies of risk perception have been invaluable in mapping the 'meaning space' of environmental hazards and in identifying the main underlying factors which explain the large disparity of magnitude between risks as perceived by the public and by 'experts'. However, if a single hazard or class of hazards is sufficiently important to require control or regulation, then it may invite study in its own right. Nuclear power is the

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Fig. 4. M u l t i d i m e n s i o n a l analysis o f risk w i t h seven other characteristics o f sport.

obvious example and many studies of the public perception of this energy source have been made. Unfortunately, there are not many single-hazard studies in other areas, and this is a pity, since nuclear power is strictly outside our present brief. Nonetheless, I shall refer later to one such study for its theoretical and methodological implications. First, however, two examples from chemical hazards; one from the perception of the risks of pesticides and the other from public attitudes towards additives and other chemicals in food.

137

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Community attitudes to pesticides Hawkes et al. (1984) have explored the responses of a number of communities in California towards various State administered eradication or control programmes for pest invasions. Insect pests have the potential to devastate millions of dollars in crops or, in underdeveloped countries, to take thousands of lives. In consequence, some 300 millions pounds weight of pesticides are utilised in Californian agriculture each year. Furthermore, the stakes are so high that spraying

138 TABLE 2 CONTROL OVER PESTICIDES POLICY: PERCEIVED VERSUS P R E F E R R E D Agents/influence

Stockton

Concord

Milpitas

Orangevale

Government Perceived Preferred aDifference

92 81 -11

85 92 + 7

92 81 --11

90 81 -- 9

Industry Perceived Preferred aDifference

71 27 -- 44

70 30 - 40

67 29 - 38

65 12 -- 53

Politics Perceived Preferred aDifference

89 13 -- 76

88 11 -- 77

91 17 -- 74

88 8 - 80

Citizens Perceived Preferred aDifference

48 93 + 45

50 97 + 47

42 94 + 52

48 91 ÷ 45

University Perceived Preferred aDifference

78 95 + 17

79 97 + 18

72 97 + 25

82 96 + 14

72 40

85 46

71 54

79 40

-- 32

-- 39

-- 17

-- 39

62

69

60

46

78 + 16

82 + 13

82 + 22

80 + 34

Media Perceived Preferred aDifference Public i n t e r e s t g r o u p s Perceived

Preferred aDifference

aperceived and preferred influence was calculated by summing 'great' and 'somewhat' responses. The difference was derived by subtracting one from the other. (Reproduced from Hawkes et al., 1984.) t a k e s p l a c e in d e n s e l y p o p u l a t e d u r b a n ar eas as w e l l as o v e r a g r i c u l t u r a l land. In 1980, helicopters and ground crews sprayed Malathion or Diazimon over 1300 square miles, including parts of Los Angeles, to eradicate the M e d i t e r r a n e a n fruit fly. Later, Carbaryle was used against a g y p s y m o t h i n v a s i o n in S a n t a B a r b a r a a n d t h e J a p a n e s e b e e t l e in S a c r a m e n t o C o u n t y , w h e r e t h e c o n t r o v e r s i a l c h e m i c a l O f t a n o l was also introduced. When surveyed, about 60% of respondents, while saying that pesticides w e r e safe f o r h o m e u s e , c l a i m e d t h a t t h e y w e r e h a r m f u l t o t h e a g r i c u l t u r a l w o r k e r s w h o had to h a n d l e t h e m . This was p r e s u m a b l y because o f the

139 closer contact with larger quantities and the less effective controls over use. F o r t y o n e percent were 'not comfortable' with home use of pesticides. Around 50%, depending on the agricultural orientation of their c o m m u n i t y , expressed concern over spraying from the air over farms, but the proportion rose to 75% over spraying from the air over city neighbourhoods. Two-thirds of the sample were nonetheless willing to trade off the advantages of 'bug-free' food against the disadvantages of chemical contamination, but that leaves a substantial minority who, despite regulatory levels and monitoring, expressed serious anxiety. Even those willing to make the trade-off said that they were "very concerned" about residual traces of chemicals in foods. It was generally claimed that exposure was " w i t h o u t consent" and between 95 and 100% of people in the different communities said they had a right to much more detailed information on potential toxicity. This is the 'involuntary' aspect of risks which figures so prominently in the public's assessments of severity. It is typical of public responses to hazards, as with nuclear energy, that alternative, supposedly safer measures (in this case biological control) are proposed by those at risk. Opponents of nuclear energy, of course, propose wave power, windmills, etc. Those responsible for the hazard are accused by the public of using the cheapest, short-term methods for their own advantage. It is clear that, in this as in many other cases, there is a lack of trust in the decision makers and a strong conviction that the citizens themselves should have a greater voice. When asked to estimate the actual influence of various agencies and the degree of influence they would prefer, there were large disparities. These are shown in Table 2. The apparently contradictory advice given by experts does little to reassure the public. For example, nuclear power stations are said to present virtually zero risk but are sited in low density areas to "facilitate evacuation". During the urban spraying in California, agricultural and government officials explained the benign nature of Malathion, but advised residents to stay indoors, close windows and shut off air conditioners to reduce exposure. Those with respiratory diseases and pregnant women were warned to leave! Understandably in such circumstances, public controversy erupts and there is a demand for reliable information which is sometimes met with the response that no one can be absolutely certain about the safety of chemicals under all conditions, especially those for which experience has not yet been gained.

Risks from chemicals in food Much of the public anxiety about chemical risks focuses on the cumulative effects of small quantities of chemical substances entering the

140

food chain. This can occur either through the contamination of ground water, primarily from artificial fertilisers, but also from hazardous waste disposal; or more directly through the ingestion of pesticides used for the spraying of crops or through chemical additives for colouring, flavouring or preserving manufactured foodstuffs. There is also concern about possible airborne pollutants from chemical or other industrial plants or from products such as asbestos which damage health through inhalation. The particular insidiousness of chemical risks, so far as the public is concerned, is that the technology that underlies them is so poorly understood. I can illustrate this from a recent study of attitudes towards foodstuffs that we have undertaken for the Technical Change Centre (Lee et al., to be published). Using the results of a sample of 40 intensive open-ended interviews in the home, we devised a multidimensional scaling approach suitable for application to a larger sample (N = 203). Modern, technological aspects of food processing were divided into three groups: preservatives, substitutes and additives. Our subjects were asked to evaluate sets of these on 10 attributes and the results were analysed using Multidimensional Scalogram Analysis (Guttman and Lingoes). It will be seen (see Fig. 5) that, although they were capable of making a number of clear distinctions between the preservatives and substitutes, the evaluations of additives were almost uniform. They could give a general order of preference, but it was much the same on almost every attribute. They have anxiety over 'Safety' and a concern that many additives are not 'Good for Health', but they have no knowledge or set of beliefs about the nature, mode of operation or particular consequences of ingesting these chemicals. They are just 'worrying'. About a quarter of the home interview sample considered that additives are used unnecessarily or to excess and, in the MDS study, half of them are placed in the lowest category on the 'Necessary' attribute. Artificial colouring is rated b o t t o m on all attributes and four out of the six additives are assessed low on the 'Health' attribute. Turning specifically to the preservatives, our subjects were told that irradiation "is a process in which fresh food can be preserved by radiation w i t h o u t altering the appearance or taste in any way; for example, strawberries treated in this way will keep for several days". Notwithstanding, irradiation was rated in the lowest category on every attribute including taste, presumably because of its unfamiliarity and its association with military and civil nuclear power. In the home interviews, the same picture emerged, and it was noticeable that the housewives had no knowledgeable beliefs about the process, no implications or consequences of its use, only a blanket negative evaluation, a general distaste. THE C O N T E X T OF B E L I E F S

Before leaving the case of the single hazard it is worth reminding y o u that attitudes of this kind do not exist in isolation. They form part of a complex

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144

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Fig. 6. A t t i t u d e t o n u c l e a r p o w e r in t h e c o n t e x t of o t h e r c o n t r o v e r s i a l issues ( F r a n c e ) . S o m e o f t h e 76 issues ( a n d t h e i r p o s i t i o n s in t h e factorial space) f r o m t h e 1981 survey are s h o w n (source, B r e n o t et al., 1983).

hierarchical structure of beliefs and attitudes a b o u t the world and it is the fact that they are firmly nested in this way that makes them particularly resistant to easy manipulation. Some interesting research that illustrates this point has been done by Brenot et al. (1983) in France. They have sought the opinion of their subjects on 50 controversial topics, in a survey-type format. The great strength of their findings is that they have a longitudinal dimension, having carried out basically similar surveys on five occasions between 1977 and 1982 (see also Pages et al., 1982). Some of what they call 'conflictual topics' are as follows: Liberalisation of the Abortion Law is a good thing Price rises can be avoided Construction of nuclear power plants must be continued God exists One may have confidence in the judicial system There are t o o many immigrant workers Pollution is extremely worrying Death penalty must be abolished.

145

They were able to establish a factorial space showing the position of each of these topics, and it will be seen from Fig. 6 that their factors or principal components were, firstly, from 'harmony/serenity' up to 'violence/ anxiety' and, secondly (roughly orthogonal to this) from 'sacred/status quo' to 'profane'. Their findings suggest that in the 'phoenix from the ashes' atmosphere of technological white heat in the 50s, the pros saw nuclear power as a serene, technological challenge. The antis, on the other hand, were worried about the risks and expressed this anxiety in the form of direct, violent action. In the 60s, the position of the critical attitude to nuclear plants moves in an anti-clockwise direction round the factor space. Concensus is no longer a challenge and the issues are becoming rather dull to the pros. The antis continue to denunciate but they also move anticlockwise in the space, reducing direct action, becoming more 'moralistic'. The next stage, in the 70s, is that the pros see nuclear power as essential, prestigious, sacred to France and closely identified with patriotism. They are now towards the sacred/status-quo end of the dimension and, conversely, the antis have moved to the opposite end, identifying with the profane movement and their attitudes being associated with 'no abortion', 'no marriage', 'no work', 'no death penalty', etc., i.e. with a rejection of traditional values and a denouncement of the technico-economic system. These investigators even claim to show a hiccup in the changing attitudes of the French as a result of the Mitterand Socialist Government's policy. The technique is similar in principle to those described earlier. If two 'conflictual topics' are located close together they are correlated, i.e. responded to in the same way. What the study demonstrates so clearly is that attitudes do not develop in isolation but in systems.

SOME BROAD CONCLUSIONS (1) It is doubtful if the earlier approach to scale the comparative magnitude of different risks has much more mileage, although it served an extremely useful purpose in clarifying and developing psychometric techniques for this field and 'mirroring' the statistical risk assessors' tables. Its major shortcoming is the old familiar one of comparing oranges and apples. Each hazard has a complex set of meanings, implications or consequences and we need to concentrate on 'unpacking' the perceived qualities of each hazard and the ways in which they combine. An obvious case that is ripe for treatment is the area of pharmaceuticals where very little work has been done on public perceptions. (2) We also need to move on to consider not the public as a whole but meaningful subgroups. There is no equitable way of distributing costs and benefits from hazardous technologies and the allocation can only be made by sagacious decisions of elected representatives. However, the quality of their decisions is likely to be much improved if they can be better informed on the perceptions of the subgroups concerned, as well as on 'objective' measures of potential harm.

146

(3) More work is needed on the way in which the perceived risks of technology fit within the context of other, broader, attitudes to technology. Sociologists and others have begun to study these broad orientations, for example 'post materialism' and the 'new environmental paradigm' which broadly concentrate on the quality of human life and the preservation of the most valued aspects of the natural environment -- by contrast with support for entrepreneurial, galloping technology. Another group comprises those who 'prefer not to know'. (4) It is evident t h a t people use 'coping strategies' at the cognitive level to deal with sources of anxiety. One can suppress evidence about the threat, trust the authorities, actively redefine the evidence or totally withdraw. The adoption of one or other of these strategies may be determined by personality factors laid down constitutionally or resulting from particular family and wider social environmental experiences. They are also a consequence of particular memberships in cultural groups or settings, and some recent work by anthropologists (Douglas and Wildavsky, 1982) has indicated the importance of trying to understand people's risk-coping strategies in terms of their cultural imperatives. More research is needed. (5) We know from a great deal of recent evidence on stress that the belief that one has some control over the source of the threat is an important means towards relief. The work on risk perception confirms t h i s - strongly; the voluntary/involuntary dimension is very important and the feeling of virtual impotence in relation to such risks as nuclear power probably exacerbates their perceived magnitude. Without being cynical, there is much that could be done to increase the public's feeling of involvement and we, as a result of our own research, have strongly urged that government and industry should take a much more positive stance towards informing, educating and generally involving the public in the decision making process. We are convinced that the same principles apply at every organisational level when risks are at issue. If they are pushed under the carpet, someone will trip over them and the damage will be that much greater.

REFERENCES Brenot, J., J. Fabre, G. Morlat, J.P. Pages and E. Stemmelen, 1983. Structure of public opinion and nuclear debate in France. Unpublished paper presented to NATO Conference on Risk Perception, Les Arcs, September 1983. Combs, B. and P. Slovic, 1979. Causes of death: biased newspaper coverage and biased judgements. Journ. Q., 56: 8 3 7 - 8 4 3 . Conrad, J. (Ed.), 1980. Society, Technology and Risk Assessment. Academic Press, London. Douglas, M. and A. Wildavsky, 1982. Risk and Culture , University of California Press, Berkeley. Green, C.H., 1979. Someone out there is trying to kill me: Acceptable risk as a problem definition. Unpublished paper presented to International Conference on Environmental Psychology, University of Surrey, Guildford.'

147 Hawkes, G.R., M.C. Stiles and R.V. Dowell, 1984. Pesticides, politics, and the public: A study of citizens' attitudes in California. Mimeo: University of California, Davis, Dept. of Applied Behavioural Sciences. Lee, T.R., 1981. The public's perception of risk and the question of irrationality. Proc. R. Soc. London 276: 5--16. Lichtenstein, S., P. Slovic, B. Fischhoff, M. Layman and B. Combs, 1978. Judged frequency of lethal events. J. Exp. Psychol. (Human Learning and Memory), 4: 551-578. Lingoes, J.C., 1973. The Guttman--Lingoes Non-metric Program Series. Ann Arbor, MI. Lowrance, W.W., 1976. Of Acceptable Risk: Science and the Determination of Safety. W. Kaufmann, Los Altos, CA. Pages, J.P., G. Morlat and E. Stemmelen, 1982. Structures de l'opinion publique et debat nucleaire dans la societe francaise contempraine. Rev. Gen. Nucl., 2: 140-149. Ravetz, J. (Ed.), 1977. The Acceptability of Risks. Barry Rose, London. Renn, O., 1983. Technology, risk and public perception. Appl. Syst. Anal., 4: 50--65. Royal Society, 1983. The Perception of Risks. In: Royal Society Study Group Report on Risk Assessment. Royal Society, London. Slovic, P., B. Fischhoff and S. Lichtenstein, 1979. Rating the risks. Environment 21: 14--20; 36--39. Slovic, P., B. Fischhoff and S. Lichtenstein, 1980. Perceived risk. In: R.C. Schwing and W.A. Albers (Eds), Societal Risk Assessment: HOw Safe is Safe Enough. Plenum Press, New York. Vlek, C. and P-J. Stallen, 1980. Rational and personal aspects of risk. Acta Psychol. 45: 273--300. Vlek, C. and P-J. Stallen, 1981. Judging risks and benefits in the Small and in the Large. Ration. Behav. Human Perf., 28: 235--271.