ZPA-230-04-39-049
RADON RISKS: ATTITUDES, PERCEPTIONS AND ACTIONS
Lennart Sjoberg
Center for Risk Research
Stockholm School of Economics
August 1989
Prepared for
Dr. Ann Fisher
Economics Analysis Division
Office of Policy, Planning and Evaluation
U.S. Environmental Protection Agency
Washington, DC 20460
The information in this document has been funded in part by the
United States Environmental Protection Agency (EPA) under
Cooperative Agreement CR-811075. It has been subjected to the
Agency's peer and administrative review, and approved for
publication as an EPA document. Mention of trade names or
commercial products does not constitute endorsement or
recommendation for use.
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Preface
Indoor radon constitutes a major health risk. As many as 8 million
homes in the USA may have elevated radon levels with accompanying
lung cancer risks several orders of magnitude above many other
environmental hazards. Still, less than 5 percent of all homes have
been tested for radon and interest in the topic seems to be
tapering off, after a rise following the widely publicized
discovery of extreme radon levels in some homes in early 1985.
The U.S. Environmental Protection Agency has sponsored a
program of research on radon risk communication aimed at finding
effective methods for informing people about radon risks and
encouraging them to monitor their homes and mitigate if high radon
levels are found. State level agencies also have sponsored research
on this topic. Several studies have now been completed. Others,
while still not'finished, have produced some; significant interim
results. This report summarizes this research, discusses it
critically and suggests conclusions relevant to radon policy as
well as topics for further research. Some studies performed in
Sweden also have been treated.
I have written this report mostly from the perspective of a
psychologist, and I have attempted to relate some of the radon risk
communication research to general discussions of attitude change
and attitude measurement. Some practical implications are
summarized in the appendix.
Ann Fisher and Reed Johnson have given very valuable and
detailed comments on the manuscript. Amos Tversky made several
stimulating remarks.
Stockholm, Sweden
August, 1989
Lennart Sjoberg
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Table of contents
Page
Preface i
List of Figures v
List of Tables vi
1. Executive summary 1
1.1. Introduction 1
1.2. The media and radon risk 1
1.3. Properties of radon risk l
1.4. Radon risk compared to life style risks 2
1.5. Studies of risk attitudes and risk perception ... 2
1.6. Mitigation of radon risk ..... 5
1.7. Message format and contents 5
1.8. Methodology 6
1.9. Social diffusion 8
1.10. House values and house sales 3
1.11. Missing information: groups not studied 9
1.12. Conclusions 9
2. Introduction 11
m. Information, the media and radon 15
4. Characteristics of radon risks 17
5. Empirical studies of radon risk perception and attitudes . 20
5.1. Introduction 20
5.2. Maine study 20
5.2.1. Design and selected results . 20
5.2.2. Evaluation 21
5.3. Focus groups ... .21
5.3.1. Design and selected results 21
5.3.2. Evaluation 23
5.4. NYSERDA Study 23
5.4.1. Design and selected results 23
5.4.2. Evaluation 27
5.5. New Jersey study 28
5.5.1. Design and selected results 28
5.5.2. Evaluation 30
5.6. New Jersey experiment on radon information .... 31
5.6.1. Design and selected results 31
5.6.2. Evaluation 32
5.7. Study of effectiveness of communication formats . . 32
5.7.1. Design and selected results 32
5.7.2. Evaluation 34
5.8. Maryland study 35
5.8.1. Design and selected results 35
5.8.2. Evaluation 36
ii
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1
5.9. Florida risk attitudes study 37
5.9.1. Design and selected results 37
5.9.2. Evaluation 33
5.10. Florida personality study 33
5.10.1. Design and selected results 38
5.10.2. Evaluation 40
5.11. Onondaga study 40
5.11.1. Design and selected results 40
5.11.2. Evaluation 40
6. Empirical studies of mitigation 41
6.1. Introduction to mitigation research 41
6.2. Maine study 41
6.3. New Jersey study 41
6.4. Washington study 43
6.5. Colorado study of testing and mitigation at time of
home sale 45
6.6. Some Swedish experience: the Sollentuna study ... 46
6.7. Evaluation and conclusions of mitigation studies . 49
7. Comments on empirical studies of radon risk perception and
mitigation 51
8. Predicting monitoring for radon
9. Factors affecting risk perception 54
9.1. Risk denial 54
9.2. Diffusion processes 56
9.3. Assimilation-contrast model of risk perception . . 57
9.4. Risk posterior to action 57
9.5. Objective vs subjective risk 58
9.6. Demographic characteristics . ; 59
9.7. Cognitive processing limitations . 59
9.8. A note on terminology: Hazard and outrage 59
10. Risk perception and protective action .....-.:.... 60
11. Message format and contents 62
12. Personality, risk taking, and attitude change 63
12.1. Personality and behavior: general 63
12.2. Vigilant vs. defensive response to threats .... 64
12.3. Need for cognition and uncertainty orientation . . 64
12.4. Health concern 66
12.5. Emotions and risk perception . . . 66
13. Methodological issues 67
13.1. The definition of risk
13.2. Response rates
13.3. Response scales . . . 69
iii
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n
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Page
13.4. Time perspective 70
13.5. Attitude measurement . 70
13.6. More detailed information about crucial
decisions 71
14. Discussion and conclusions 71
14.1. Summary and discussion 71
14.2. Conclusions 80
15. References . 32
APPENDIX 93
IV
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List of Ficrures
Page
Figure 1. Number of published articles about radon in the New
York Times. 1980-87 17
Figure 2. Frequency of mitigation as a function of radon
concentration 49
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List of Tables
Page"
Table I. Distribution of radon exposure in various
countries. 12
Table'II. Reasons for not testing for radon (from Weinstein
et al) 29
Table III. Percentage of persons who had mitigated as a
function of their first floor radon reading. Data from
Weinstein, Sandman and Roberts (1988) 41
Table IV. Percentage of persons who had mitigated as a
function of their radon reading. Data from Doyle et al.
(1989) 44
Table V. Percentage of persons who had mitigated as a function
of the initial radon reading. Data from Akerman
(1988) 48
Table VI. Response rates in cited radon studies, measured as
the percent of the studied sample that (a) accepted to
participate, and (b) gave usable responses
vi
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1. Executive summary
1.1. Introduction
Indoor radon constitutes a major health risk. As many as 8 million
homes in the USA may have elevated radon levels with accompanying
cancer risks several orders of magnitude above most other
environmental hazards. Nevertheless, less than 5 percent of all
homes have been tested for radon. Radon in private homes remains
the responsibility of the home owners and there is no legislation
that compels people to reduce this particular risk.
The U.S. Environmental Protection Agency has sponsored a
program of research aimed at finding effective methods for
informing people about radon risks and encouraging them to monitor
their homes and mitigate if high radon levels are found. State
agencies also have sponsored research on this topic. This report
summarizes the research, discusses it critically and suggests
conclusions as well as topics for further research.
Some studies performed in Sweden are included because of
interesting differences between that country and the USA in
reactions to radon risk. Also, radon has been an issue longer in
Sweden than in the USA, especially radon emitted from building
material.
1.2. The media and radon risk
Radon was not widely discussed as a health risk in the USA before
1985. That year national attention was given to a very dramatic
case in the home of a Pennsylvania resident. The radon level was
much beyond what had previously been believed to be possible from
geological radon in a home. Subsequent screening has shown that
there is definitely a radon problem in many homes, although very
few have had levels as high as the initial Pennsylvania case. Radon
was highly salient in the media in 1985 but according to some
authors interest is now tapering off (see Figure 1, page 17).
1.3. Properties of radon risk
Radon is a risk with certain unique properties. It shares some of
the characteristics of all risks from ionizing radiation (slow
effects in the form of cancer, a risk from a physical agent that
cannot be sensed). At the same time it is a risk that people are
exposed to in their homes. Homes are usually perceived as safe
places under one's own control and responsibility. It is not
obvious that some person or organization is to be blamed for radon
risks, in contrast to such risks as nuclear power plants.
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1.4. Radon risk compared to life style risks
Radon risk has been compared to such life-style risks as smoking
or drinking alcohol. The similarity is that people take these risks
as private individuals. Society is reluctant to legislate the risk
level to which they can expose themselves. They must act
voluntarily to mitigate or eliminate these risks.
There are also differences between radon and life-style risks.
First, radon exposure does not confer any benefit as smoking and
alcohol do. Second, it is not clear who/ if anyone, is responsible
for radon risk. Radon risks were largely unknown to the us public
before 1985 and most home owners bought their current houses before
then.
Reducing a life-style risk involves making a commitment to
action in spite of temptations to delay action. In this sense,
there is a similarity between radon and life-style risks. Many
people in one of the studies reviewed here became
"procrastinators", i.e. they changed from indifference towards the
risk to acknowledging the necessity of action "in principle". It
is well known that people find it very difficult to quit a risky
habit and that rationalized delays are very common. It is too early
to tell if the same phenomenon will occur for radon risk but it
possible. On the other hand, testing for radon and mitigati
require only two discrete actions while the ex-smoker has to resi
cigarettes several times a day. People do not have to quit a habit
(or develop a new one) in order to test and mitigate for radon.
I
1.5. Studies of risk attitudes and risk perception
There have been several studies of how people perceive and respond
to radon risk. Initially it was believed that information about
radon risk might give rise to panic reactions, but experience has
not confirmed this concern. On the contrary, people are often quite
indifferent to the issue, at least in regard to their own homes.
This indifference can be interpreted as a manifestation of a rather
general tendency to deny health risks. It has been suggested that
denial of radon risk is moderately strong compared to other kinds
of denial*
Many people are outright negative to radon testing.
Pennsylvania authorities at one point went from door to door and
offered free radon testing. Still, about 50 percent refused to have
their homes monitored. Some of them may have been concerned that
rumors of a radon problem would affect property values in an area.
It is worth stressing that people tend to be indifferent
radon risk in spite of the fact that the EPA action level is
high compared to other risks. The actual risk level seems to be a
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poor predictor of public response to risk. The action level in
Sweden is presently 2.5 times higher than the US level
corresponding to the lung cancer risk of smoking a pack of
cigarettes per day. Still, Swedes are as indifferent to radon risk
as Americans.
As might be expected on the basis of these facts, there is
usually only a weak correlation between the scientifically
estimated risk level, as physically measured, and the level of
perceived risk. Some people with low levels of radon in their homes
are quite concerned while others, with quite high levels, are
indifferent. This low correlation may partly arise from the fact
that the physical measurements are not perfect indicators of the
actual risk level. The risk also depends on how much time people
spend in the house, their age and other factors. Still it is
reasonable to conclude that there is a weak correlation between
perceived and actual radon risk. There is little evidence
suggesting that people do not believe that the radon readings are
accurate or that the risk assessments are incorrect. They probably
believe that the risk is there, in principle and for people in
general, but that they themselves are for various reasons less
vulnerable, more lucky or they just do not care about getting
involved in protecting themselves against another risk, they just
take it.
However, the effects of information about radon risk provide
a partly different picture. Two studies have shown that people
revise their risk estimates in the "right" direction, i.e. in the
direction suggested by the readings of radon levels in their homes.
Still, other data suggest that even for risk revisions there may
be irrational denial factors at work. There is some support for the
thesis that people are more inclined to accept that other people's
homes in their community may be at risk than that their own homes
may be at risk.
If actual risk is not strongly correlated with perceived risk,
then what accounts for perceived risk? There are some correlations
with background data. Older people are less worried about radon,
and parents.of small children more so. In some studies women have
been shown to be more worried than men, but the gender difference
is much smaller for radon risk than for many other types of risk.
People with a family member with cancer were more concerned about
radon in one study. Some personality variables have been suggested
as predictors of perceived radon risk but so far little research
has been carried out on this issue.
These factors are only weakly related to perceived radon risk.
There is simply not enough research available to support more
definite statements about what factors influence perceived radon
risk.
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I suggest that radon risk perception is a special case of e
related risk, i.e. it is a risk that is closely related to s
conceptions. This hypothesis is derived from evidence that peop
tend to perceive their homes as extended parts of their selves,
especially if they have lived in them for a long time. And there
is a tendency to deny that something as closely related to oneself
as one's home (or body) could be threatening.
Data indicate that people with a longer history of living in
a house are more likely to deny radon risk. Other supporting data
show that people react strongly to radon risk when it is imposed
on their neighborhood - not on their homes. Part of this reaction
is probably a result of moral indignation over being exposed to a
risk by someone. People strongly resent a loss of control, and they
tend to perceive that which they can control and are responsible
for as benign.
Communication about radon risk with the general public has
been studied in two major investigations, one of which was
especially concerned with mitigation. These studies also
investigated the effects of a major attempt by a television channel
in the Washington, D.C., area to encourage people to buy test kits,
available at reduced price in grocery stores. Over 100,000 kits
were quickly sold and demand was by no means exhausted. About 6
percent of the home owners in the area bought test kits. Howevej
only about half of those who bought the kits turned them in
analysis and few people who had elevated radon levels in the!
homes reported any effective mitigation beyond such behavioral
measures as keeping windows open more often.
The EPA-sponsored outreach activities in a Maryland community
were probably more effective than the simultaneous television
campaign in stimulating people to test for radon. The proportion
that tested their homes rose from about 5 to 15 percent. There is
some evidence that the television campaign was effective in making
people aware of radon risk, but less effective in stimulating them
to act. A similar finding was reported in a New Jersey study of
smaller scope where it was found that there is a link between risk
perception and action but that the link was quite weak. The weak
effects of the television campaign are in line with extensive
experience from other studies of health-related public service
message*. The effects are usually quite marginal. In addition,
people tend to distrust television.
A few studies have investigated knowledge about radon and
found that people are fairly well aware of its general properties,
although they lack specific knowledge. Some misunderstandings are
probably rather common. People may also lack knowledge about how
to test for radon and whom to ask about testing and mitigation.
They are especially uncertain about mitigation and its costs.
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It is relatively easy to inform people about radon facts.
However, there is little relation between knowledge and tendency
to test and mitigate. This finding is in line with a generally
noted lack of relationship between attitudes or beliefs and
knowledge.
1.6. Mitigation of radon risk
There is a rather low correlation between scientifically estimated
risk and mitigation, but a strong correlation between perceived
risk and mitigation. This is an example of a quite general truth:
people react to what they perceive reality to be rather than what
it really is.
It is not yet clear how much mitigation one can expect in
different circumstances. Some data (see Figure 2, page 50)
certainly suggest that home-buyers are likely to be among the most
responsive to the radon risk message. On the other hand, not all
data on mitigation are as negative as the ones reported in the
study of the Washington, 0. C., television campaign. A follow-up
of highly motivated New Jersey homeowners found a high rate of
mitigation. Swedish data were in between the two American data
sets. (Cultural comparisons are risky, however, since many crucial
aspects, such as the economics of housing and mitigation, differ
dramatically between Sweden and the USA).
1.7. Message format and contents
A few studies have investigated the format and contents of radon
risk messages. A major study compared "command" and "cajole" styles
of communication. That study also investigated and compared
qualitative vs quantitative types of information. The results were
somewhat complex and differences were not large but there was a
tendency for a command style of communication to be most effective.
That study also compared the use of a Jorief fact sheet as a
replacement for more extensive brochures. It was found that those
who had been given the fact sheet tended to be more concerned about
their risJc level than others. This was true in spite of the fact
that the fact sheet was only given to those who had very low levels
of radon in their homes.
The investigators concluded against the use of the fact sheet.
That may be a reasonable conclusion for that particular group of
homes and their owners. It may still be the case that a short fact
sheet would be useful for people who have higher levels of radon
measured in their homes. It has been found that people, if given
the chance by rich information material, tend to construct
defensive denial conceptions. In other words, more information
makes it easier for them to come up with rationalizations for lack
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of action. Of course, a short fact sheet need not be very
to the one used in the NYSERDA study.
An experimental study of risk communication formats found that
a brief statement about the action level was best for eliciting
continued concern. On the other hand, full information about the
risfc, including numerical, comparison and graphical information,
was best for creating a balanced view. A major difficulty was
communicating absolute risk levels. A graphical display seemed
sufficient to make people disregard a difference in absolute risk
level in the range 1-25 (between radon and asbestos risks).
Another reason for favoring very brief messages is that people
have difficulty in handling information and that they are not very
motivated to obtain it. Studies of public service information in
the form of printed brochures usually have shown that most people
do not bother to read them and that those who do read them quickly
forget most of their contents. Other investigators have studied the
effects of level of risk communicated and found that a more
threatening message tended to invite more risk denial. The
conclusion is that the most effective message format and contents
should be brief and not too threatening.
The conclusion should be regarded as preliminary. It is based
on a rather complex set of findings from -radon risk communicatio
studies and from communications research in general, as well
basic principles of cognitive psychology.
1.8. Methodology
The empirical studies reviewed in the report vary considerably by
methodology. Virtually all- were quantitative and employed either
mail or telephone survey methods but they differed in many other
respects.
There is evidence that people are not very eager to
participate in surveys of this kind. Response rates around 60
percent or lower are common in spite of several reminders. Some of
the problems of low response rates have been attributed to data
collection during holidays, but there is no evidence that these
particular studies yielded especially low response rates. Indeed,
the US public is saturated with opinion polls and survey
investigations and it is becoming more and more difficult to
recruit respondents for new waves of data collection.
Women seem to be more likely to accept invitations to
participate in radon risk studies than men, and the result is that
females are over-represented in some of the studies. Also, the
samples tend to consist of highly educated and financially securd
people, possibly because the studies have focused on home owner^
rather than renters.
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Attitude change has been studied for decades. It is usually
quite hard to change people's attitudes, especially to change them
permanently and to affect behavior. Changes tend to be short lived.
The empirical work on radon so far has not followed attitudes for
a more than a few months, with the exception of the NYSERDA study.
Longer follow-up times are called for in order to get a realistic
idea about how persistent attitude changes are.
It would probably be fruitful to investigate in more detail
how people reason with regard to radon and testing. One piece of
information that is lacking in these studies is why people test
(there is data on why people do not test). Testing can be motivated
in many ways, for example health, economic factors or conformity
to expectations by friends. The reasons people have for testing
could stimulate the formation of hypotheses about effective methods
of risk communication.
Qualitative information about the conceptions and
misconceptions that people have about radon would also be of
interest. Among other things, such conceptions could be of crucial
importance for mitigation. Some people may believe that radon is
most likely to be found in the attic rather than the basement of
a house (since many gases are lighter than air). Ionizing radiation
is also something that people know little about and have several
misconceptions. A study of this type is under way at Carnegie-
Mellon University.
There have been few attempts to analyze the contents of radon
risk attitudes. So far, most data suggest that health concerns are
most important. Many studies could have profited from a more
extensive mapping of the components of risk attitudes, using one
of the well known models of attitude measurement, such as that
devised by Fishbein (Fishbein & Ajzen, 1975).
Another possibility involves switching to the common
international measureBq/Hr rather than pCi/1. Since 1 pCi/1 = 40
Bq/m3 such a switch would involve larger numbers that could by
itself have an effect (whether positive or not).
Many of the studies reviewed here used a risk concept that was
not further explained to respondents, who were asked to judge such
perceptions as size of radon risk. However, other research has
shown that people interpret the word risk in various ways. There
may be differences among genders and educational strata in whether
respondents interpret risk as probability, as the size of the
consequences or as a combination of these two concepts.
Interpretations of results may be misleading if this factor is
neglected.
Another interesting methodological aspect is the response
scale. It is difficult to translate the judgment of seriousness of
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a risk into subjective probability. On the other hand, it
notoriously difficult to obtain valid judgments of small percei^
risk. As an alternative, comparative risks often are used to assi
people in judging small risks. The radon risk has been compared to
the risks of smoking, for example. This approach is well worth
trying but one should bear in mind that comparative risk judgments
are more complex than absolute ones because they involve two risk
levels rather than one. Risks are probably perceived in a context
of several threatening events and conditions and the judgment of
any given risk may well be affected by how certain other salient
risks are perceived. For example, people with a very risky job may
perceive their radon home risk as minor just because it is
implicitly or explicitly compared to a job risk.
1.9. Social diffusion
In many circumstances people are most strongly affected by social
diffusion of information and attitudes, i.e. what their friends,
neighbors and locally prominent people tell them. For this process
to spread quickly there must be many willing "informers". However,
in the case of radon there are still very few people who have shown
any active interest in the issue of home testing, and those who
have informed their friends and neighbors have sometimes met with
hostile reactions.
1.10. House values and house sales
There has been little work on property values and house sales as
related to radon. A Swedish study recently found that radon did not
seem to affect house prices. Informal information from realtors in
the USA confirms this finding. However, a Colorado study showed
that many people are quite concerned about getting a house tested
for radon before they buy. Some 50 percent of the home-buyers
participating in the study reported that they had done so. These
people also tended to mitigate much more oftenr than those who
bought test kits and monitored their own homes. Indeed, the
prevalence of testing at or above the action level of 4 pCi/1 was
100-200 times as great for home-buyers as for homeowners. People
whose employer was especially concerned about the radon risk and
those who were in contact with a knowledgeable-realtor or building
contractor were especially prone to test and mitigate. These
results were obtained in a state where radon risks have not been
extensively discussed in the media (Colorado).
The fact that real estate prices are not affected by radon may
be related to the prevalent information that a radon problem
usually can be fixed quickly and fairly cheaply. There has bee
little awareness so far about how often continued monitoring f,
radon will be required and additional mitigation will have to
8
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a
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undertaken. When this issue is given wider publicity there could
be an effect on real estate prices.
1.11. Missing information: groups not studied
Virtually all research so far has been conducted with homeowners
so the social strata that have been represented have not been
representative of the whole population. We do not know how people
who rent their homes respond to radon risk, or how involved their
landlords are in monitoring and mitigating such houses. There is
also very little work reported about attitudes to radon in schools,
public buildings and workplaces.
1.12. Conclusions
Research on radon risk perception and risk mitigation has not
proceeded very far, simply because the problem is so recent.
However, it is possible to draw some conclusions on the basis of
existing research results.
(1) . The major problem is indifference to high-level risk,
especially among people who already live in a home that may have
an elevated radon level.
(2). Home buyers are probably much easier to alert to the issue,
with ensuing radon testing and mitigation if called for.
(3). Studies of variations in risk communication material suggest
that brief, to-the-point recommendations about what to do are
better than longer messages that allow the reader to form his
personal opinion. It is just too likely that these personal
opinions will be defensive risk denials.
(4). Even the most effective mass media campaigns and outreach
community programs investigated so far have succeeded in
stimulating only a small fraction of the population of homeowners
to monitor and mitigate. Whether these campaigns have still
justified their costs has not been determined. A community outreach
program appeared to be more promising than a major television
campaign, although they probably reinforced one another.
(5) . Further research should be conducted on the components of
radon risk attitudes and conceptions, in particular why some people
test and mitigate. Interpretation of findings would probably be
helped by more information on how people interpret such key terms
as "risk".
(6). There are important ethical aspects of radon risk that have
been neglected in research. Some people see nobody as responsible
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for a radon problem, others may blame themselves, contractors
the government. The owner of a house may or may not fee
responsible for the health of others who live in it. At the tin!
of a house sale there is a special ethical problem if the seller
knows there is a radon problem. These are important matters for
further research.
(7). There is a total lack of data on how renters, as opposed to
homeowners, perceive risk and how their landlords view the radon
issue. There is very little data on the perception of radon risk
in public buildings and workplaces. Perhaps some homeowners can be
alerted about their home risks if they get involved in school
building risks.
(8). Although the sparse data that exist on the issue suggest that
radon risk does not reduce property values, the issue certainly
needs much more investigation, will the lack of effect persist when
more experience with mitigation and its costs and effects
accumulate? People may at this time be overly optimistic about how
easy it is to "fix" a radon problem permanently. Do people see
monitoring as a potential economic threat? Or will lack of
monitoring and disclosure of results at the time of a house sale
be the real economic threat in the sense that homes that have not
been tested will sell for a lower price?
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"Don't expect too much. People can understand risk tradeoffs,
risk comparisons, and risk probabilities when they are
carefully explained. But usually people don't really want to
understand....Over the long haul, risk communication has more
to do with fear, anger, powerlessness, optimism and
overconfidence than with finding ways to simplify complex
information." (Sandman, 1986, p. 23).
2. Introduction
Radon is a colorless and odorless gas that is emitted from uranium
in rock and soil. It can enter houses through cracks and openings
in foundation walls and floors, drains or ventilation systems, or
by being released from water from underground sources. It is
radioactive2. In addition to naturally occurring radon, there is
some radon emitted from building materials. About 10 percent of the
indoor radon in the USA is estimated to emanate from building
materials (Krimsky & Plough, 1988).
There is consensus among experts that prolonged exposure to
high levels of radon can cause lung cancer. This consensus is based
on data on the prevalence of lung cancer among uranium miners
(National Research Council, 1988) and general knowledge about the
health effects of ionizing radiation.
Radon has been named as the most serious environmental health
hazard threatening the -American people (Lafore, 1987; us
Environmental Protection Agency, 1987 b; Kerr, 1988), and most
experts agree that radon is the most serious indoor pollutant. The
average indoor radon level in the USA is estimated to be 1.5
picocuries per liter of air3 (pCi/1), the outdoor level to be 0.2
pci/l.
Data on indoor radon levels are available also from other
countries in North America and Europe. The following data (see
1. Sea the special issue of American Water Works Association
Journalf 1987, 80. No. 7.
2 When radon releases its ionizing radiation it is transformed
to so-called radon daughters, the radioactive isotopes P0213 and
P0214 which constitute a more dangerous threat than radon itself.
When they are inhaled and deposited on the bronchial tree they can
be carcinogenic.
3. 1 pCi/1 means that about two radon atoms per liter of air
decay per minute.
11
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Table I) were compiled by Akesson, Bergman and Johnson (undated^
based on data from the Swedish National Institute for RadiatiB
Protection (1987) and Nero (1989).
Table I. Distribution
countries .
Country Mean pCi/1
Sweden
. Norway
Finland
USA
Canada
West Germany
Great Britain
1.3
1.5
0.7
0.7
0.3
of radon exposure in various
Percent of
2.5 pCi/1
10
12
3
0.7
na
homes that exceed
5 pCi/1 10 pCi/1
3 1
4 1
1 0.2
. -<0.1
0.2 <0.1
It is worth noting that, according to these figures, the radon
problem seems to be somewhat worse in the USA than in other
countries where measurements are available.
EPA has estimated that 12 percent of the homes in the USA may
have radon levels exceeding 4 pCi/1, which is the lowest level for
EPA's official action guidelines . Later estimates of 20 percent
have been mentioned (Krimsky & Plough, 1988)..
Cohen & Gromicko (no date) compiled a large number of radon
measurements (about 35 000 homes) and presented results which
probably give a good picture of the situation in the USA as a
whole. They found that the distribution of radon concentration was
skew% with an excess of houses with very high levels. One house in
\ EPA's action guidelines are not health-based standards.
They are recommendations based both on health considerations and
what was judged to be achievable in terms of reducing indoor radon
levels at reasonable cost.
2. Averages were typically twice the median and only 24% o™
the houses were above average.
12
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1000 was estimated to have a radon level 100 times or more above
the mean. They also found that there was a seasonal variation
(about 60% higher values in the winter), and a low correlation with
the age of the house. Basements had 2-3 times higher concentration
than livingrooms. Weatherization activities since 1974 were
estimated to have increased radon levels by about 15%.
Lifetime exposure to EPA's action level of 4 pCi/1 has been
estimated to carry a 1-5 percent increased risk of lung cancer. It
is estimated that the lung cancer risk of 20 pci/l corresponds to
smoking more than a pack of cigarettes per day. Of all lung cancers
not related to smoking, 10-50 percent are due to radon exposure.
Smokers are more seriously affected by radon than nonsmokers
(National Research Council, 1988).
Risk estimates are seldom final, of course. Estimates of the
risks of low-dose ionizing radiation are based on data from
survivors of the Hiroshima and Nagasaki bombs and there is
considerable controversy about those data. Recent revisions of
interpretations of Hiroshima and Nagasaki data imply that the risks
are probably between 5 and 15 times as large as previously believed
(Rotblat, 1988). The extrapolation of radon risks from data on
uranium miners is uncertain because home radiation generally is
much lower and because working in a mine is a very different
activity from being at rest at home. However, it should be noted
that some homes do have levels as high as those observed in the
epidemiological studies of miners. Also, not all the time spent at
home is spent resting. Some of it can involve physical exertion
similar to that in mines. It has also been pointed out that there
is no sizable positive correlation between the prevalence of lung
cancer and radon statistics across regions.
Since controlled experiments on humans are ethically and
legally unacceptable there is bound to be continued controversy.
This can be compared with the risks of fluoride in drinking water,
for, which there is still considerable uncertainty about the issues
despite 40 years of investigation (Hileman, 1988).
Until 19851, there was little attention in the United States
to high radon levels in residential buildings, resulting from
geological radon. The problem had been discussed earlier in other
countries (Sweden and Canada), and it had been mentioned in a UN
1. In December of 1984, Stanley Watras, a resident of
Boyertown, Pennsylvania, set off radiation detectors as he entered
his place of work, Philadelphia Electric Company's Limerick
generating station, a nuclear power plant. A subsequent test of his
home showed that it measured 2700 pCi/1. The lung cancer risk of
this level of radon exposure has been estimated to be equal to that
of smoking 280 packs of cigarettes per day.
13
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report in 1977 (United Nations Scientific Committee on Effects
Atomic Radiation, 1977). This is in spite of the fact that the
was considerable concern in the 1970's about radon emanating from
man-made sources, such as uranium mill tailings and phosphate slag
in building materials. The EPA was criticized in the early 1980's
for its concern over radon risks from mill tailing piles, which
were seen by some as minor in relation to the risks from geological
radon.
EPA had published a risk estimate (5000 - 20 000 lung cancer
deaths per year in the USA due to indoor radon) in 1979 (Guimond
et al., 1979). The current official estimate is about the same.
Since December of 1984, the problem has been intensely
analyzed and it is now known that many homes in the USA are likely
to have radon problems, perhaps as many as 8 million of the
nation's 70 million homes. It is the federal policy that every home
in the USA should be tested for radon. There is, however, no
legislation that forces any private citizen or any government
agency to do so. It is up to the individual to monitor his or her
own risk level, and to take appropriate action.
It is relatively easy and inexpensive to test for radon. It
is also usually rather straightforward to mitigate against any
radon problems that might be discovered in testing, by means
improved ventilation, sealing of holes and cracks, etc1. Stil
very few people have tested their home for radon (less than
percent of the US homes as of November, 1988).
ny
1
The population's indifference to home radon risks starkly
contrasts with the strong reactions observed in the New Jersey
community of Vernon to the proposed deposit of soil somewhat
contaminated by industrial radioactive wastes (Chess & Hance,
1988) . The enraged people of Vernon who threatened civil dis-
obedience (and were successful in avoiding having the contaminated
soil deposited in their community) were some of the same people who
did not bother to test for radon risks in their homes - risks that
were, according to experts, much larger. Outrage over risks from
toxic waste has, of course, been noted many times, e.g., in the
case of Love Canal (Mazur, 1984).
Because the radon problem was discovered only recently it is
only natural that rather little research has been carried out on
the perception of and attitudes toward radon risks. Still, the
acute nature of the problem has motivated some rather extensive
attempts at mapping people's reactions to radon risks and to
1. The question of how often such repairs need to checked an
improved in the future has been rather little discussed. A rad
problem is, of course, seldom solved for as long a time as tt
lifetime of the house.
nd|
i
14
-------
investigate the effectiveness of risk communication methods in this
area. This report reviews these studies, draws conclusions from
them, and suggests topics for further research. The reader is also
referred to Fisher and Sjoberg (in press).
I will concentrate on the reactions of homeowners to radon in
their own homes. A few researchers have collected additional
information about people's reactions to radon risks in public
buildings and to taxation aspects. While these problems certainly
are important, I feel that there is as yet too little information
to warrant detailed coverage. The importance of radon risks for
property values is another aspect that so far has not been treated
thoroughly in empirical research.
Before discussing current research I will sketch the
development of public radon awareness and attitudes in the USA.
3. Information, the media and radon
Mazur (1987) has described in some detail how radon came to be an
issue on the public's risk agenda. Radon risks did not receive
national attention in the USA until 1985. Risk estimates had been
published in professional journals and by the EPA several years
earlier but with little impact.
There was (and perhaps still is) a wide spread belief in the
positive effects of radon. On November 25, 1984, just before the
Watras incidents, the New York Times had the following to report:
"People suffering from arthritis, headaches and other ailments
come from all over the world to seek cure in former gold,
silver and uranium mines in southwestern Montana, whose rock-
walled tunnels emit radon, a radioactive element produced by
natural decay of uranium; among physicians reactions range
from charges of quackery to tacit blessings for patients who
have no other relief". (New York Times. November 25, 1984).
The New York Times Index offers some further information on
the issue. There was a rather alarmist article- published already
in 1980, citing among other things some Canadian data, but it seems
not to have had much impact on the public. Then, the newspaper was
almost silent on radon issues until 1984. The New England Journal
of Medicine published an editorial in the spring of 1984, mentioned
by the New York Times on June 7, 1984. The editorial stated that
there may be up to 100 000 cancer deaths among non-smokers every
year in the USA. The statements made by physicians can be assumed
to be of special importance for public opinion.
The Watras incident (see page 13, note 1) was of critical
importance for alerting the public to radon risk. In addition, a
few weeks before the Watras incident (in December, 1984) the home
15
-------
* • *•
i
of Joel Nobel, which measured 55 pCi/1, had received sofl
publicity, even on national television. ^
The Watrajj family evacuated their house, "in some panic"
(Mazur, 1987, p. 39). The Pennsylvania DER then conducted a survey
of some neighboring houses, found some elevated radon levels,
although nothing close to the level in the Watras house, and
informed a township commissioners' meeting on January 7, 1985.
After that, local news media were quick to report the Watras event
and it was given wide spread local attention. However, according
to Mazur it was ignored by national media until May, 1985, when a
first page article appeared in the New York Times1, other national
media then picked up the story and concern about radon rose
significantly, leading to renewed activities by the EPA.
Mazur points out that the current risk estimates agree well
with those published in the 1970's. Strictly speaking, radon is
not a "new" risk, and the fact that it was ignored for almost a
decade needs an explanation. The risk itself is larger than many
of the other risks that people have cared about and that EPA has
regulated, so its size cannot explain the lack of concern.
According to Mazur, the limited publicity that had occurred in the
Nobel case, just before the Watras incident, was an important
factor in sensitizing the public (and decision makers). Th
vigilant response by the Pennsylvania OER did much to add moment '
to the issue. It can be added that the sheer magnitude of radiati
measured in the Watras house was quite surprising. It established
a possibility of disastrous radiation in a home, which had not been
expected before. Finally, perhaps the connection to nuclear power
(Watras worked in a nuclear power plant) may have added some
attention value.
Following the Watras incident there was considerable mass
media attention to radon in the USA, especially in the East. The
fact that the Watras family had evacuated their home made a strong
impression. It has been suggested that apathy might be lessened if
it were made known-that a nearby family had evacuated their home
(Chess & Hance, 1988). The contents of local Pennsylvania
newspapers during the first nine months of 1985 were compared to
national media by Friedman et al. (cited by Lehrer, 1988). They
found that local newspapers gave much more attention to the radon
issue than national media but that headlines tended not to be
alarmist, avoiding such words as cancer and threat. Local editors
said they wanted to avoid panic and adverse effects on the housing
market.
1. However, the New York Times had carried an article aboijH
elevated radon levels in New Jersey homes already on February \l,
1985.
16
-------
According to Sandman (1986), the strong initial response in
Pennsylvania and New Jersey soon tapered off. in the New York Tiises
there was a tremendous increase in the number of radon related
articles in 1985-86, but in 1987 the number dropped, see Figure 1.
Sales of test kits went down in the winter of 1987 compared to one
year earlier (Sandman, Weinstein & Klotz, 1987) . Sandman explained
this by the facts that radon risks are chronic, not acute, events,
and that there is no obvious "villain" or social and political
conflict involved.
so
40
30
•8 20
10
8081828394888687
Figure 1. Number of published articles about radon in the New
York Times. 1980-87.
It is clear that few people actively seek information about
radon. When it comes to media and other sources of information they
tend to trust local scientists, the EPA, and possibly newspapers.
The attitude toward local government agencies varies.
-j
4. Characteristics of radon risks
It is difficult to predict how people will respond to new hazards.
When indoor radon in homes was first widely discussed in the USA
there were some expectations among administrators that people might
panic (Sandman, Weinstein & Klotz, 1987). The opposite occurred.
The reasons for this indifference constitute a crucial problem in
communicating about radon risks.
A number of factors that have been mentioned as explanations
for the lack of urgent responses to radon risks.
A.There is no "bad guy" responsible for the risks from geological
radon. The existence of a villain to blame for a risk has been
singled out as an important factor in accounting for public outrage
(Baum, Fleming & Davidson, 1983). An often quoted comment by a
17
-------
participant in a focus group is "What are we going to do, sue God?B
(Desvousges & Kollander, 1986). This factor may be related to the'
lack of a discrete source - be it an object or a person -
responsible for the risk1.
B. The hazard is a natural one, not man-made. People tend to
underestimate the risk of natural hazards (e.g. Kunreuther et al.,
1978; Lehman & Taylor, 1987). The reason for this underestimation
may be that nature is seen as benevolent, or it is believed that
ve are biologically adapted to it. In Sweden, the initial strong
reaction against radon was probably due to the belief that it was
caused solely by building materials. When it was later found that
most of the problem was caused by naturally emitted soil gas,
protests dwindled.
C. The hazard cannot be sensed, so it tends to be underestimated.
It has been suggested that if radon was not odorless there would
not be a radon problem.
D. The illness, lung cancer, does not give early warning signals
and takes a very long time to develop.
E. It is not possible to identify, in concrete cases, that radon
has caused a person's lung cancer. Lung cancer deaths are^
undramatic and occur singly.
F. Persons typically have a long history of benign experience with
their homes.
G. The choice of a home is under one's own control, so the risk
may appear to be "voluntary". This point can be disputed. Lehrer
(1988) compared it to such life style risks as smoking which also
calls for protective action by the individuals exposed to the risk.
He judged radon risk to be clearly involuntary.
H. The risk is higtoly variable from house to house and depends on
a number of factors that are hard to understand completely.
I. Testing and mitigation are complex and new activities that
people know little about.
Against these factors that are believed to reduce risk
perceptions there are a few that might work in the opposite
direction:
J. The risk is relatively unfamiliar and new.
1. This idea was suggested by Amos Tversky.
18
-------
K. Testing is simple and cheap, and mitigation relatively so, in
most cases. These facts are likely to moderate the tendency for
risk denial.
L. The risk is, after all, a cancer risk and cancer is a much
feared illness.
And, finally, some factors are ambiguous:
M. Extensive mass media attention, such as that recently given to
radon, should increase risk awareness and increase the perceived
level of risk. On the other hand, mass media attention is never
constant. In the case of radon it is probably tapering off from an
early peak in 1985-86.
N. Radon threatens people in a very personal and serious manner.
This makes it subject to the phenomenon of risk denial, which is
very common when it comes to health risks.
0. There are no benefits from radon exposure. This factor
distinguishes it clearly from life style risks, where there is
usually a temptation due to the pleasure that follows upon
consumption.
Some comments are in order. It is illustrative to compare
radon with a well known highly threatening risk, such as the risk
of nuclear power (cf. Sjoberg & Drottz, 1987).
The lack of a "bad guy" is a factor that may be more true of
radon than of nuclear power. It has some anecdotal support as
reducing perceived risk, but no theoretical underpinnings.
Many risks that people fear strongly cannot be sensed. Both
radon and nuclear power cannot be sensed but there is widespread
fear of nuclear power. Thus this factor can hardly explain
indifference to radon risks.
Cancer with a long latency between exposure and illness is a
characteristic of both radon and nuclear power risks. The long
latency factor cannot explain why people ignore radon risks.
The more unique factors in the case of radon appear to be
mainly that is a natural hazard and that it is related to one's
home and under one's personal responsibility and control, as
compared to nuclear power risks or smoking. Furthermore, it is easy
to delay action about radon, because there are no obvious adverse
consequences from postponing testing (or mitigation) for some time.
Radon risk communication also needs to be viewed in the
perspective of risk communication and health promotion in general.
It has been found repeatedly that it is very hard to induce health
19
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promoting behavior (Adler & Pittle, 1934). Some more optimist
results were reported by Viscusi, Magat and Huber (1986) and Pus
et al. (1979). The former was concerned with a laboratory
simulation, however, and the latter with a very extensive mass
media campaign, much more extensive than would be realistic to
consider in the USA.
Thus, risk communication is difficult and rather little is
known about how it should be carried out most efficiently in any
given field. In addition, rirk advisory programs at EPA have seldom
been evaluated (U.S. Environmental Protection Agency, 1987).
Current EPA sponsored activities constitute a response to this
need for research. Several attempts (by EPA and others) have been
made, and others are underway, to study empirically the properties
of radon risk perceptions and attitudes and how risk communication
can be improved. This work is reviewed in next section.
5. Empirical studies of radon risk "perception and attitudes
5.1. Introduction
In this section, brief descriptions will be given of each of ti
studies carried out so far. The general strategy in reporting thej
studies has been to begin with a seminal investigation of somewhl
limited scope, to continue with preparatory work for more extensive
studies, then to deal with the three major studies of risk
perception and radon monitoring that have been carried out, and
finally to treat a number of smaller and more specialized
investigations. A special section, see page 41, is devoted to work
on mitigation, which is more recent and not yet as fully developed.
5.2. Maine study
5.2.1. Design and selected results
Johnson and Luken (1987) analyzed data from 230 Maine households,
who were interviewed in the fall of 1985. The respondents had
participated in a lung cancer epidemiology study. They had received
radon measurements of their homes and a University of Maine radon
information pamphlet.
Data were collected on risk perceptions, mitigating activities
and socioeconomic characteristics. The risk judgments were both of
current risk perception and what the respondents remembered that
their risk perception had been before they obtained the radon
readings.
I
Johnson and Luken found that information about radon chang
risk perceptions, and that mitigation activities tended to lowe
their personal risk estimates. However, they also found that
20
-------
mitigation was equally likely for those who had obtained low radon
readings as for those who had obtained high readings. The
respondents greatly understated their radon risks, with few
exceptions. In spite of this, about half of them reported some kind
of mitigation.
A subset of these data were also analyzed by Smith and Johnson
(1988). They could use data from only 117 of the 230 respondents,
due to missing data. It was found that people adjusted their risk
estimates according to the information they obtained, in line with
a simple Bayesian model. They also confirmed the Johnson & Luken
finding that individuals who took some mitigating actions reported
lower risk perceptions after that action.
Smith and Johnson stated that these results suggest that
people may be more rational than previously believed and that they
may be open to new information about risks and adjust their risk
estimates accordingly.
5.2.2. Evaluation
This study is obviously of limited scope. The sample was small and
consisted of a very special group of patients and the data
collected were not very extensive. The study was important mainly
because it initiated an interest at EPA in conducting further work
on radon risk communication.
The claim to rationality in people's risk perception made by
Smith and Johnson is similar to a claim made in the NYSEROA1 study,
next section, and it will be discussed more extensively in that
context. However, it must be noted here that the use of
retrospective risk estimates is not very satisfactory. Clearly,
there is no support for the implicit assumption that people can
remember and correctly report what risk perception they used to
have. On the contrary, Fischhoff's well known studies of hindsight
bias (Fischhoff & Beyth, 1975) have demonstrated that people
consistently distort -their memories of earlier judgments, to be
more in line with information current at the time of judgment.
Smith and Johnson were well aware of these limitations, of course.
5.3. Focus groups
5.3.1. Peaion and selected results
EPA sponsored several focus groups on radon. Desvousges and
Kollander (1986) reported initial trials with 6 focus groups. They
were conducted with homeowners having different degrees of
awareness of the radon problem. The purpose was to evaluate
'. New York State Energy Research and Development Authority.
21
-------
information materials to be used in the NYSERDA study and to
some preliminary insights into radon attitudes. In the second
group study (Desvousges and Cox, 1986) two groups of homeowners who
had tested their homes for radon participated. Preliminary versions
of two of the NYSERDA booklets were evaluated. A further activity,
preliminary testing of materials to be used in the Maryland study,
involved four groups - two in Pennsylvania and two in Maryland
(U.S. Environmental Protection Agency, 1987 a). Both testers and
non-testers of different educational backgrounds participated. The
purpose of these four groups was to probe why some paople had
tested for radon while others had not. Results from all of the
focus groups were used to plan further, more precise and extensive
work.
Focus groups are useful for getting qualitative information
about the important factors in any attitude study. They cannot give
information about how common the opinions are, or about strength
of relationships, in a population (Desvouges & Smith, 1988).
Some of the findings were:
- Quantitative information was often called for, as well as risk
comparisons.
- Nonsmokers were more satisfied with comparisons to smoking ri
than smokers who found such comparisons "confusing".
- Color coding of risk charts was rated favorably.
- People were unhappy and confused when informed about uncertainty
in risk estimates.
- Some people preferred numerical risk estimates, others verbal
labels and still others graphical information.
- People wanted answers to concrete questions such as "What is my
risk" and "Where can I get information about mitigation".
- Some found the risks charts too scary, others liked them to be
scary.
- Testers had (with one exception) spoken to friends or family
members before deciding to test.
- Non-testers showed the familiar denial dynamics, i.e. they did
not believe that they themselves were at risk, and they found
special reasons for "proving" that view. (Radon risk is not well
understood by experts, the risk is only one among many, "everyth-
ing gives you cancer", "Three Mile Island is much more of a dang^
to me").
22
-------
- Concern about property values could both motivate testing and
cause people to abstain from testing.
- Many non-testers believed that mitigation would be difficult,
expensive and risky.
- Information about radon was mainly obtained from newspapers and
television. EPA and state environmental agencies were rated highest
in credibility.
5.3.2. Evaluation
These were relatively minor studies performed as part of designing
the NYSERDA and Maryland studies to be described in following
sections. Work of this kind cannot provide quantitative estimates
of the frequency of various opinions or the importance of factors
determining attitudes and behavior but it can give a rough idea
about what factors are important.
Some interesting information from these groups has not been tested
in subsequent research. For example, there may be individual styles
of information processing since some ' people prefer verbal
information, others graphical. Perhaps information could be
tailored to fit these styles. Another idea is the use of
appropriate comparative risk. There was some indication that
smokers did not like smoking as a comparative risk. Perhaps smokers
tend to deny risks of smoking and therefore are confused when
smoking risks are brought in as a reference norm. At any rate, if
comparative risks are used it seems important to get independent
measures of how the reference risks are evaluated.
5.4. NYSERDA atudv
5.4.1. Design and selected results
This study (Smith, Oesvousges, Fisher & Johnson, 1987, 1988), was
an attempt to test different approaches to risk communication. The
participants in the study were homeowners in the State of New York
who had agreed to participate in a state-wide sample organized by
New York State's Energy and Research Development Authority
(NYSERDA). NYSERDA's objective was to test a sample of homes in the
state for radon in order to map the prevalence of radon problems
in the state.
Baseline data concerning risk perception and knowledge about
radon were collected while the radon monitors were in place. The
same data were collected for a comparable non-testing control
23
-------
group'. Brochures were then sent to the homeowners in the
monitoring group together with information about their radg^
levels .
The NYSERDA sample was divided into several groups, with each
group receiving a different information treatment. Four brochures
contained information about risk levels and mitigation. They
differed with respect to two dimensions: (a) Whether information
about the risk level was given in quantitative or qualitative
format and (b) the tone of the. text which was either directive
("command") or evaluative ("cajole").
The command tone emphasized what an expert (in this case the
EPA) recommended as the appropriate response to the risk level
while the cajole tone encouraged the recipient to form his or her
own opinion on the basis of the information presented.
The four brochures contained the same information except that
only the cajole brochures contained information about how to adjust
the test result to reflect different lengths of exposure.
Households with a radon level of at least 1 pCi/1 also received
EPA's mitigation brochure , but mitigation was discouraged on the
basis of a 2-3 month reading alone.
Other groups received EPA's Citizen's Guide or a radon fact
sheet developed by the State of New York (and similar to fac
sheets used in other states). All treatments involved giving t
homeowners the same information except that the fact sheet had le
information. It was, however, sent only to a subset of those who
had test results of less than 1 pCi/1.
wu
i
Baseline data were obtained in the summer of 1986 and the
first follow-up interviews were carried out six months later
(telephone interviews). A second set of follow-up data was obtained
in the period September, 1987, to January, 1988 (mail
questionnaires), after the annual radon readings had been sent to
the homeowners.
2300 homeowners participated in the NYSERDA study, and there
were 252 nontesting homeowners in the comparison group. The
response rates for those participating in the NYSERDA study were
high: 97 percent in the baseline interview, 91 percent in the first
Th«r« is some doubt about the status of this control group.
It should perhaps more appropriately be called a comparison group.
It was selected later than other groups, it had a low response rate
and there may have a been a self-selection bias in the monitoring
study. The comparison group was selected using the same protocol
as the original monitoring sample, though.
2 Two sets of measurements had been carried out: a short-term
measure (2-3 months) and two annual measures (12 months).
3 Radon Reduction Methods; A homeowner's guide.
24
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follow-up and 74 percent in the second follow-up. 50 percent of
those approached for the comparison group agreed to participate.
Three major questions were analyzed:
(1) Which information treatment led to the most learning?
(2) Which was best in helping people form realistic perceptions
of their radon risk?
(3) Which was most effective in making them feel that they had
enough information to make a decision about whether to take action?
Knowledge about radon increased in all treatment groups, but
the increase was smaller for those who only received the fact
sheet. There was also an increase in the comparison group's
knowledge. The respondents turned out to be fairly knowledgeable
when it came to radon measurement, less so with regard to risks and
mitigation. The four brochures seemed to work about equally well
in this respect, with a possible advantage for the cajole
qualitative brochure, which facilitated learning about radon more
than other brochures. The quantitative brochures were best for
communicating risk levels. A higher radon reading also seemed to
go together with a higher level of knowledge. Older people (over
40) knew less. Education was a positive predictor, and so was early
awareness of radon (measured at the time of the baseline
measurement).
Why did the particular NYSERDA brief fact sheet work so
poorly? The major reason is probably the very special circumstances
of testing it. It was used with people who had very low radon
levels in their homes. Hence, the normative response was to
decrease concern about the risk. The fact sheet probably did poorly
because of this peculiar circumstance. People who have not yet
tested or who have tested and obtained a high radon reading should
be encouraged to test or to mitigate, and such groups were not
given the brief fact sheet in the study.
Personal radon risks were perceived as lower than general
population risks of radon. Personal ratings were also more
influenced by information, and far fewer people answered "Don't
know" to the personal risk question in the first follow-up compared
with the baseline. Memory of readings of lifetime risks from risk
charts was better for homeowners who had received the experimental
brochures than for those who had received the EPA Citizen's Guide.
Those who had obtained higher readings were more likely to
remember incorrectly.
It was found that people updated their risk estimate somewhat
in accordance with the radon reading that they had received. Young
and well-educated people were most likely to do so. The updating
25
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results were different for 'the first and second follow-up
however.
For the first follow-up, the radon readings (living area) were
generally low (average = 1.39 pCi/1, range = 0-39.8 pCi/1). The
average risk perceptions dropped by some 20 percent (Johnson &
Fisher, 1989) . Johnson and Fisher suggested that there still may
be an overall tendency to overstate the posterior risk, i.e. to
adjust the risk ratings too little downward1.
This finding is important, and goes against the general
finding in other studies that there is only a weak relationship
between perceived radon risk and actual risk. However, this is the
only study as far as I know that has investigated changes in radon
risk ratings before and after a reading of the actual radon level
has been obtained.
The NYSERDA brochures led to a lower rating of radon risk than
the factsheet, especially the quantitative versions. Those who
received the factsheet tended to remain concerned (in spite of the
low readings, always <1 pCi/1), and were interested in paying for
more information and guidance. The estimated willingness to pay was
the second highest for this group, and 80 percent (the highest
figure of all groups) said they wanted more radon risk information.
Smith et al. (1988) concluded that giving very little information
about a risk may increase worries about it rather than the othcfl
way round2. Those who made more effective use of the brochures werv
less likely to demand more information, as were, in particular,
older respondents.
For the second follow-up, the radon readings were somewhat
higher than for the first follow-up. The average living area
measure was comparable, but the basement reading was twice as high
(average * 3.37 pCi/1, range » 0-114.9 pCi/1). The result was that
respondents adjusted their risk estimates- upwards, especially if
they had received the command/qualitative NYSERDA brochure. This
brochure encourages thinking about the radon risk as related to a
1 This may be an example of the often observed tendency of
intuitive judgments to be too conservative as compared to the
normative Bayesian model.
2 However, the contents of the information may be just as
important. The fact sheet contained some basic information about
radon and its measurement, and about EPA's recommended action
levels. The fact sheet did not specifically state that a level
below 1 pCi/1 is nothing to worry about. It did state that the two-
month reading "should not be directly compared" to the EPj
guidelines, because it was not an annual concentration and becaus
it was for a specific location only, not for a whole house.
26
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threshold (of 4 pCi/1). Those obtaining basement values exceeding
the threshold consequently had a rather strong increase in
perceived risk1.
The conclusion of this report is that the cajole/qualitative
brochure was best at stimulating learning about radon while the
two quantitative brochures did best at providing a more realistic
risk estimate. All booklets did about equally well in reducing the
demand for more risk information.
The findings indicate that none of the four employed varia-
tions is best in all respects but the over-all performance seems
to be best for a command/quantitative approach, which combines
clear directions for action with precise information. The NY fact
sheet is judged to be too brief and also misleading, since those
homeowners who had less than 1 pCi/1 still were worried if they had
received the fact sheet.
The latter conclusion may have other implications. If people
on the whole underestimate radon risk it may be that the fact sheet
format is useful in promoting a more vigilant attitude.
5.4.2. Evaluation
At the time of writing, this project is not yet finished. Only
preliminary mitigation data have been collected but they are not
yet analyzed. The full set of mitigation data were collected early
in the spring of 1989, but no analysis is available at the time of
writing this report (August, 1989).
•
The study is, however, one of the most important and ambitious
attempts at studying radon risk communication. The design was very
carefully planned, response rates were excellent and the data
analysis is quite exhaustive.
Some limitations should be noted. There are no data on testing
decisions because NYSERDA had already contacted homeowners and
gotten them to agree to participate. It is not known how
representative these homeowenrs were or how many were approached
and declined to participate. Furthermore, there is some information
suggesting the NYSERDA sample homeowners were not representative
when it comes to radon awareness.
The choice of the two independent variables (cajole/command
and qualitative/quantitative) for designing the four brochures
seems a bit arbitrary, and the report does not explain in full how
1 It would be interesting to analyze the data'separately for
those who received readings crossing the threshold, or to
investigate any lack of linearity in the relationship between
perceived risk and basement radon reading.
27
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the group of experts reasoned when they recommended th
particular variables. The researchers state that these factors we'
considered to be the most interesting ones because the expert:
thought they might make a big difference and because they tended
to disagree about how the factors might differ in their effects.
4
rtT
There is, of course, a vast number of possible variations on
risk information messages and the empirical research is, so far,
not very extensive. Maybe it would have been better to start by
performing rather extensive pilot work to be ible to zero in on
the most efficient designs for risk communication. As it now
stands, the study gives merely a single piece of information about
a few selected designs, which, as it happened, did not differ much.
The study also takes an unusual approach in expressing concern
that some people may exaggerate radon risk, rather than neglect it,
which is by far the most important problem in the area. The brief
fact sheet could well have been distributed also to people with
high radon levels. It would have been interesting to see if it
works well in those cases. The present data, obtained only from
homeowners with very low radon levels, suggest that the fact sheet
or something similar may defend its place as an efficient means of
risk communication when people tend to neglect a risk.
I
The finding that people tend to revise their risk estimat
in the right direction is not inconsistent with a lack
correlation between technical and subjective risk levels, ofte
noted by psychologists. The reason why there is no positive
correlation between technical and subjective risk may simply be
that people quite rarely receive explicit risk estimates. In this
situation, their risk perception is prey to all sorts of subjective
bias factors and personal tendencies.
5.5. New Jersey study
5.5.1. Design and selected results
This is one of the earliest and most ambitious studies of the
public's response to the radon threat (Weinstein, Sandman & Klotz,
1987). Th« authors investigated two samples:
1. Random sample: Owners of single-family homes in New Jersey in
the Reading Prong area or near it. Data were collected in April of
1986. People who said they never heard of radon were excluded. 61.7
percent of eligible households participated. They tended to have
higher education and higher income than the overall population of
this region. Mean age was 47.4 years.
2. Confirmatory sample: All households who had contacted
Jersey's Department of Environmental Protection after
28
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obtained a reading of at least 4 pCi/1 through June, 1986. The net
completion rate for this sample was 43.3 percent. Data were
obtained in May-July, 1986. This sample had very high levels of
education and income, and more males than in the random sample.
The respondents had high trust in authorities. Many basic
facts about radon were well known, a bit less when it came to
health-related effects. The subjects underestimated the seriousness
of radon health threats. It was apparently much easier to find
reasons to expect that one's own home had less radon than the
average (247 reasons given) than why it could have more radon than
the average (45 reasons given). The subjects of the random sample
did not seek information actively.
Emotional reactions were discussed as related to decisions to
test for radon, unrealistic optimism, explicit emotional reactions,
community interactions and views on blame and responsibility.
Few respondents had monitored, and there were signs of apathy
rather than panic. There was clear evidence of unrealistic optimism
when it came to personal radon risks. Direct ratings of emotional
responses indicated moderate to high concern and moderate worry/
but levels in other aversive emotions (anger, fear, etc) were low.
The confirmatory sample did not show any different emotional
reactions than the random sample, in spite of having found elevated
radon levels in their homes. Those who had monitored felt high in
concern and low in helplessness, while those who had not even
thought about monitoring felt low in concern and high in
helplessness.
Blaming nobody for the radon risk correlated with monitoring,
as did willingness to pay for remediation.
Weinstein et al. asked about reasons for not testing, and
obtained the following results (see Table II).
The data suggest that people have not tested because they have
too little information or that th«y have given a test low priority.
This is a "rationalistic" pictur§cof their (lack of) action. It is
to be expected that people wish to describe themselves as rational.
For that reason, it may be that the reasons given in the table to
a larga extent are due to a strategy to exhibit a rational way of
behaving.
Klotz, Weinstein and Sandman (undated) found that the actual
radon level had little to do with emotional distress. It correlated
only weakly with perceived risk and perceived difficulty of
remediation. Respondents were also concerned about potential
economical losses.
Intention to remediate was not correlated with income and
education, nor with the cost, feasibility and efficacy of radon
29
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Table II. Reasons for not testing for radon (from
Weinstein et al).
Reason for not testing Percentage
Don't know what method is best 45.3
Don't think I have a problem in my home 42.4
Just haven't gotten around to it 35.9
Don't know how to get the test carried out 32.2
Will wait: to see what others in community find 26.3
Wouldn't know what level is safe anyway 14.9
Costs too much 3.5
Don't think tests are reliable 7.1
Think results wouldn't be kept confidential 6.4
Reducing radon levels is too expensive 5.8
Didn't know it was possible 5.4
Neighbor's readings were low 3.4
Not interested . 2.4
I'd rather not know if there is a problem 2.4
Too much trouble 1.4
Nothing can be done about radon anyway 1.4
Note. People were asked this question if they planned to
test. were undecided, or thought a test wag not needed.
reduction. Radon levels correlated weakly with intentions
mitigate.
j/2
5.5.2. Evaluation
This study is especially interesting because of its attempt to map
psychological factors of importance for understanding how people
react to-radon risks.
The traditional psychometric approach employed here differs
somewhat from the more econometric approach taken in the NYSERDA
study. However, the methods of the NYSERDA investigators are based
on multivariate linear models, just as the ones used by Weinstein
and collaborators. There is no reason to believe that the choice
of statistical method is very important for the conclusions drawn
here, and, in particular, that it can explain the somewhat
different pictures of risk perception that have emerged.
It is interesting to compare the NYSERDA and New Jersey
studies with reference to their general orientations to
rationality. The NYSERDA investigators looked for rationality and
found it in risk revisions, while the New Jersey investigators
looked for lack of rationality, and found it in risk denial
lack of relationship between subjective and technical risk.
30
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Reasons for neglecting to act given by the respondents in the
New Jersey study may not have been the real ones. People tend to
rationalize and to hide reasons which they believe are socially
unacceptable. This suspicion is supported by a general lack of
rationality in other aspects of the behavior observed here. There
was little correlation between technical and subjective risk
levels, and between mitigation and intentions to mitigate and
technical risk. Also, there was clear evidence of risk denial in
these data.
5.6. New Jersey experiment on radon information
5.6.1. Design and selected results
Weinstein, Sandman and Roberts (undated) mailed radon information
brochures and questionnaires to 400 homeowners in New Jersey. A
form for ordering a radon test kit at a reduced price ($ 20) was
included. The brochures differed as to their descriptions of risk
likelihood and severity and the efficacy of radon mitigation
techniques.
It was found that the 19 percent of the sample who ordered the
test kit did not differ across the various brochure treatments.
Subjective risk estimates and self-reported concerns correlated
with ordering test kits and intentions to test. (All respondents
were asked about their intentions to test, and all were given the
chance to order a test kit). Perceived mitigation difficulty was
unrelated to test intentions.
Weinstein, Sandman, and Roberts had predicted that providing
homeowners with information about radon risk factors would decrease
their concerns and risk estimates2. This was found to be true only
under the high threat condition, for one of the risk measures
(absolute ratings of own risk). The high threat condition involved
depicting the radon risk as quite likely and severe. The prediction
did not hold for comparative ratings where own risk was compared
to community riste* -
There was a moderate amount of optimistic bias (i.e., people
underestimated the risk) in the radon risk perceptions, as compared
1. The response rate was 68 per cent (271 responded) in this
group. The authors do not state how many refused to participate of
those who were approached.
2. The rationale behind this prediction was that risk
information provides material for constructing explanations why
they are not at risk. People use it in order to defend themselves
against anxiety by means of denial and rationalization.
31
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to ratings of other health hazards on the same scale (WeinsteiM
1988). This may be a sign of risk denial. Implications of ris^P
denial for risk communication are discussed in section 9.1, page
54.
Although the treatments in which respondents were exposed to
high risk messages were partly successful in boosting their beliefs
in a high risk level (with the exception noted above), the effects
were not strong enough to stimulate an increased level of testing
behavior. Tt is interesting to note that this occurred in spite of
a good fit of a model assuming that risk information gives rise to
the perception of increased risk which in turn causes protective
behavior. The model fitted well, but the effect was weak.
5.6.2. Evaluation
This study is mainly of theoretical interest. For ethical reasons,
the risk level communicated cannot vary greatly in practical
campaigns, even if it can be depicted in different ways.
As for methodology, the group of subjects was small. No
information is given on how many people refused to participate in
the study. The reduced price of $20 for a radon test kit seems
still to be high, as compared to the price charged in other
studies, such as the Maryland study (see Section 5.8, page 35).
lower price may have given a quite different result in terms of t
number of people who ordered a test kit. It is not stated why ttf
particular price level was chosen. It is possible, but not
documented, that $20 was a reasonably low price for a test kit in
New Jersey at the time of the study.
<=i.
I
The prediction of a paradoxical decrease of perceived risk
with an increase in information was only partly supported. As an
after-thought, this may be a type of effect that is secondary to
the main effect of risk information, which should be to increase
perceived risk and risk awareness, at least up to a point of
moderate threat. It is conceivable that a very strong threat may
give rise to denial, but such threats are probably uncommon with
radon risk.
5.7. Study of effectiveness of communication formats
5.7.1. Design and selected results
The systematic study of effects of varying communication formats
in communicating radon risk was begun by the NYSERDA study. That
study was concerned with the tone of the verbal contents of the
messages and with qualitative versus quantitative risk information.
32
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A study by Weinstein, Sandman and Roberts (1989) deals with
the format issue in a very ambitious manner. They investigated two
risks: radon and asbestos. Recommended action levels correspond,
in these two cases to quite different scientifically estimated
risks. The asbestos risk from the action level recommended for
schools1 (3 f/1) is only 1/25 of the risk of 4 pCi/1. The authors
chose to present both risks in comparable numbers, i.e. asbestos
risk in f/1 and radon risk in pCi/1.
Seven different designs of information brochures were tested:
- Probability only (numercial probability of harm)
- Probability plus comparison to smoking risks
- Graphic probability display
- Information about action guideline level only
- Action level, numerical probability and risk comparison
- Action level and detailed action advice
- Action level, probability, risk comparison and advice
All brochures contained an initial 3 pages of detailed
descriptions of the risk (radon or asbestos). These formats were
evaluated in several measures of communication effectiveness. An
experimental design was used. A total of 1948 subjects
participated. Of those who were intitally contacted, 34.2% agreed
to participate. Of these 67% did respond to the questionnaires,
yielding an over-all response rate of 23 percent.
The subjects were given hypothetical risk information about
their homes.
There were several interesting findings. Two will be mentioned
here. First, information about the action level induced more
differentiation among risks as a whole, not only in the
neighborhood of the action level (some discontinuity could be
discerned around that level). Information about the action
guideline only was the condition giving rise to the highest level
of perceived risk and most concern. The authors point out that this
condition waa the only one lacking a risk ladder or a graphical
probability display. The subjects had no way of knowing if a value
below or above the action guideline was little or much different
from it. A ladder gives strong cues as to the difference between
an obtained radon or asbestos reading and the action guideline.
Second, the condition giving most information came out as the
most effective format. There was no evidence of information
\ There is no official action level for asbestos in homes.
Perhaps that is part of the reason why radon risk seems to be more
socially acceptable than asbestos risk. Radon risk for schools
might be more comparable to asbestos risk action level as here
defined.
33
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overload. This condition contained numerical risk probabilitie:
risk comparisons (smoking), action guideline and advice.
The action level only condition thus appears to be especially
effective in alerting people to a risk, while the most informative
formats are good at eliciting realistic risk estimates, i.e.
alerting some people and reassuring others, depending on their risk
readings.
Third, radon and asbestos risks were rated as approximately
equivalent in all conditions, despite the true 1-25 range, which
was of course communicated both in risk probabilities and in
comparison risk estimates. The authors suggest that the reason is
the strong cues provided by the exposure ladder. The ladder covered
a whole page for both radon and asbestos risks. A smaller ladder
for asbestos, appropriate for the lower level of risk, might give
a different result. On the other hand, the condition that gave only
the action level also did not differentiate between asbestos and
radon, perhaps because there was no information about the varying
risk levels in that case.
The problem seems to one of using graphics for conveying
absolute risk levels, not only relative ones (Cleveland & McGill,
1984; Tufte, 1983).
5.7.2. Evaluation (
The study, together with the NYSERDA study, is a good start towards
systematic investigation of the effectiveness of risk presentation
formats. As the authors point out, there is almost no previous
research on the topic - in spite of the existence of several
manuals on risk communication.
The response rate of this study was low. This means that the
results cannot be safely generalized. On- the other hand, the
authors state that the response rate did not vary systematically
across conditions so the differences between conditions cannot be
due to differential response rate.
People who had actually tested their homes for asbestos or
radon were systematically assigned to the condition of the risk
they had not tested for. It is not stated how many these people
were, but presumably they were few. otherwise, the policy might
have created some systematic biases.
The hypothetical nature of the risks presented here
constitutes a problem. It is possible that the paradoxical lack of
a difference between radon and asbestos risks may be due to a low
level of motivation for the subjects who knew that they were not
actually exposed to those risks.
34
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Work on risk presentation formats might profit from a contact
with psychological scaling research where it has long been known
that "absolute" judgments always are affected by context (Parducci
& Perrett, 1971).
5.3. Maryland study
5.8.1. Design and selected results
The study evaluates an attempt to inform people about radon risks
(Desvousges, Smith & Rink, 1988, see also U.S. Environmental
Protection Agency, 1988 a). Three communities in Maryland were
involved: Frederick, Hagerstown and Randallstown. These communities
were chosen because they had elevated radon levels, a high
percentage of owner-occupied, single-family homes and separate
media markets. Residents of Frederick received the most extensive
treatment: media (radio and local newspapers) information plus a
community program. The media program was organized around the theme
"Test now and be sure"1. This theme consisted of the following
parts:
- Radon is a serious health risk: You may be at risk
- Radon testing is easy/inexpensive
- Radon problems can be fixed
- The State of Maryland has a toll-free number to provide testing
and mitigation information
The community program involved presentations to community
organizations, the placement of posters and brochures in public
places and a radon awareness week.
Residents of Hagerstown received the media program only while
residents of Randallstown constituted a comparison group used to
approximate a control group. In addition, residents of Hagerstown
and Frederick received-a utility bill insert that reinforced the
media theme.
A local television channel, WJLA, carried out a radon campaign
which coincided in time with the efforts of the study, leading to
a rather difficult methodological problem of separating effects of
the television campaign from those of the intervention.
In all three communities there were two samples of par-
ticipants: a panel sample and a random sample interviewed only
after the intervention. The subjects were approached in telephone
interviews. The first wave of data was collected in December 1987.
Followup data were collected in April 1988.
'. On the basis of the NYSERDA study, messages were phrased
more in a command than in a cajole tone.
35
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The findings were that
- There was a high awareness of radon, possibly increased by ttiP
WJLA campaign.
- Testing for radon increased only under the most heavy interven-
tion (Frederick), roughly from 5 to 15 percent, mainly due to the
intervention.
- Mass media intervention tended mainly to make people "procras-
tinators", i.e. they now acknowledged the problem but had not
gotten around to doing something about it.
- Knowledge of radon increased (and was the only variable showing
sensitization effects in the panel samples), especially when it
came to general, non-specific questions.
5.8.2. Evaluation
This is a sequel to the NYSERDA study in the sense that the
information material was designed on the basis of the results in
the previous project. It is a major attempt at risk communication.
The economic constraints precluded extensive use of tele-
vision, but it is likely, on the basis of much previous research
on public service broadcasts, that the results would have bee
meager anyway (McGuire, 1985). It is well known that public servi^
campaigns on television, aiming at inducing healthy habits, usuall^
have only marginal success.
The researchers concluded that the WJLA campaign had probably
only marginal effects on testing for radon. That statement was
based on data analysis which attempted to single out the WJLA
effects and measure them separately from any effects of their own
interventions. It is a bit strange that the official EPA report of
the same study (United States Environmental Protection Agency, 1988
a) states that "WJLA's campaign was particularly effective in
increasing knowledge, awareness and testing" (p. 31). It is unclear
what on what the grounds for this statement are. The researchers
reported (Desvousges, Smith & Rink, 1989) that WJLA effects were
most clear for awareness, doubtful for knowledge and that "there
was no measured effect of the WJLA campaign on testing decisions"
(p. 8-14). Since the official EPA document and its assertion about
large effects of the WJLA campaign fails to report any supporting
evidence the researchers seem to be arguing more strongly for their
standing on this issue. The WJLA effects were small. This
conclusion is also in line with a large amount of previous work on
TV campaigns, see above.
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5.9. Florida risk attitudes study
5.9.1. Design and selected results
This is a study of people living in Florida's three "hot spot"
counties: Polk, Hillsborough and Alachua1 (Valenti & Ferguson,
1987) . Phosphate mining is extensive in Polk, there is some in
Hillsborough and virtually none in Alachua. Phosphate mining is
associated with elevated radon levels.
A sample of 837 homeowners were interviewed by telephone.
Homeowners with no telephone or with unlisted numbers were not
sampled, which excluded about 30 percent of the residents.
Interviews were completed with about 40 percent of the remaining
sample. About 60 percent of the respondents were female. The data
were collected in the fall of 1987.
76 percent of the sample were aware of radon, males having
heard of radon more often than females. Even though many people
had heard of radon, most of them did not feel they knew much about
it. They said they wanted more information, but did little to
obtain such information. What they wanted to know was how to test,
how to mitigate, what level is safe and where levels are highest.
Valenti and Ferguson point out that while people relied on
mass media for information, these media did not have a very high
credibility. The media create awareness, but not. necessarily
concern, and concern is necessary for testing.
It was found that higher concern leads to more blame
attributed to the government and puts less responsibility on the
individual. Higher awareness, on the other hand, was correlated
with greater perceived responsibility on the part of the homeowner.
The question is whether it is possible to increase awareness
without, at the same time, generating increased concern.
Polk homeowners were most likely to say there might be
elevated levels of radon in their county. At the same time they
were most likely to deny that there might be elevated levels in
their own-homesI Males and older respondents were most likely to
deny personal risks.
About 48 percent said they were very or somewhat concerned
about the effects of radon. Less educated respondents were more
concerned, females more than males, younger more than older. This
matches the pattern of risk denial rather well. Those who were very
concerned were more likely to say they would test for radon, even
if a test would lead to a drop in market value of their house.
1. In each of these counties at least one home had measured
8 pCi/1 or more.
37
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However, only 3 percent had tested their homes for radon.
percent of those who had tested said they had taken action
reduce radon levels in their homes.
The subjects were also asked about responsibility for radon.
Those living in Polk were, as could have been expected, most likely
to blame the phosphate industry, but the most common answer was
"nature" or "nobody". Those who were less concerned were more
likely to blame nature or nobody. In Alachua, the most common
answer about mitigation was that the homeowner should pay, while
it was more common in Polk and Hillsborough to state that the
government should pay. Few seemed to require that the phosphate
mining industry should pay.
The respondents were asked about their confidence in various
potential sources of information about radon. High ratings were
given to the University of Florida scientists, the EPA, the
National Centers for Disease Control, and the American Cancer
Society. Low ratings were given to the Florida Phosphate Council
and "a company selling radon test kits". Compared with male
respondents, females had more trust in medical sources and media.
More concerned people had more trust in .medical sources, in the
media and in experts. More concerned people also said more often
they wanted more information about radon.
5.9.2. Evaluation
This study is relatively ambitious but has some flaws, especially^
in the low response rate. The variable of concern is given a
somewhat confusing treatment. It is seen as necessary for testing,
on the one hand, and as detrimental because high concern leads to
blaming others, on the other.
There may be a nonlinear relationship between concern and
testing, with very high levels of concern being associated with a
decreasing tendency to test. Perhaps a high level of concern is
associated with a high probability of testing and a tendency to
blame others for the radon risks. At any rate, the concern
variable needs to be further analyzed, both theoretically and
empirically. The statistical analysis in this study was not carried
very far and it is likely that more credible results could have
been achieved with more ambitious analysis.
5.10. Florida personality study
5.10.1. Design and selected results
Ferguson, Valenti and Melwani (1988), building on Zuckerman's work
on sensation seeking, constructed a personality questionnaire for
measuring three dimensions: adventurousness, impulsiveness and
rebelliousness. These dimensions resemble Zuckerman's (1988)
38
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factors of sensation seeking: thrill and adventure seeking,
experience seeking, disinhibition and boredom susceptibility.
Ferguson, Valenti and Melwani found some correlations between
their personality dimensions and media preferences for getting
information about health hazards. Reliance on television correlated
positively with impulsiveness, while rejection of newspapers
correlated with the other two dimensions. Their scales were
correlated with health attitude, a measure of concern for one's own
health, and with a low level of concern over food irradiation and
air pollution risks.
The survey also measured the Health Locus of Control
(Wallston, Wallston, Kaplan & Maides, 1976). Persons scoring high
on this index would be expected to exhibit more concern and more
responsibility for their own health. There were some rather weak
correlations between this scale and the Ferguson & Valenti scales.
Ferguson and Valenti (1988) used the three dimensions of
adventurousness, impulsiveness and rebelliousness to measure risk
aversion. They hypothesized that more risk averse people would rate
risks as larger and that they would be especially likely to show
concern if risks were said to be threatening their children, and
if they were not presented with specific steps to take in order to
mitigate or avoid the risk, and if the risk is presented together
with a simple fear arousing schema rather than in the context of
other risks.
They recruited persons who participated in their telephone
survey (see Section 5.9, page 37) and 706 out of a total 837 agreed
to participate in a panel. They were mailed booklets including
radon messages. These messages varied as to alleged source
(newspaper vs government brochure), whether children were
specifically singled out as being at risk, whether the radon risk
was associated with nuclear power (simple, fear-arousing) or with
smoking and X-rays" (more elaborated cognitive structure), and
finally how specific and available were the steps to test for
radon. About 320 persons"responded (38 percent). The researchers
found high risk ratings when the more complex comparison schema was
activated (i.e. smoking and X-rays) in a newspaper context. They
found high fear ratings when children were targeted, with a complex
comparison schema, regardless of context. More information about
radon wa» requested when the target was an adult rather than a
child, especially if the source was depicted as a government
brochure. People who were risk averse requested more information
when the source was a newspaper message with low specificity. There
were some further interactions between personality and the message
variables, partly different for men and women, but these findings
only partly confirmed the hypotheses. They were complex and seem
to need replication.
39
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5.10.2. Evaluation
This work is of interest mostly because it is one of the very few
attempts to relate personality variables to attitudes to radon
risks. The response rate was rather low and the variables seem of
doubtful value since they are based on very few items. The findings
were suggestive at best, and need replication. There were many
complex results, some of which may be due to sampling and
measurement errors.
5.11. Onondaaa study
5.11.1. Design and selected result^
Mazur and Hall (no date) conducted a study of 204 single family
dwellings in Onondaga county, New York. Radon data were obtained
during the 1986-87 heating season. The homes had been selected
because there were suspicions of high radon levels. These suspi-
cions were confirmed, median readings being 5.1 pCi/1 and 4.6
pCi/1, for basement and living areas, respectively. 52 percent of
the living area readings were above the .EPA action level of 4
pci/l.
They found that specific concern about radon, related to t
respondent himself, was correlated with information search
mitigation, while general concern (concern without speci __
reference to the respondent himself or his home) did not correlate
with mitigation. Specific concern was correlated with radon
readings (about 0.5) but not with family or media influence, which
however correlated with general concern.
5.11.2. Evaluation
This study was of limited scope but it did introduce an interest-
ing distinction between personal and general concern. It is
possible that personal concern can be expected to be stronger for
radon risks than for many other risks since, according to
weinstein, denial of such risks is relatively weak. That may be
the reason why Mazur and Hall found that specific concern was
strongly related to technical risk. On the other hand, the finding
is puzzling since other researchers have failed to find any
relationship.
1 Some of these correlations were remarkably high, such a
0.76 correlation between specific concern and the intention
mitigate.
40
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6. Empirical studies of mitigation
6.1. Introduction to mitigation research
Even if people test for radon and find that their house has a high
level of the gas, there is no guarantee that they actually do
something about that condition. Therefore, special studies of
mitigation are needed. Very few such studies have been published
so far.
The problem of mitigation and risk perception is a special
case of the problem of the relationship between attitudes and
behavior. People have been found in many studies to behave quite
differently from what they say they will do or what they prefer
(Wicker, 1969). Indeed, Wicker reviewed data showing very weak
relationships between general attitudes and specific behavioral
measures. On the other hand, Fishbein and Ajzen showed quite
convincingly that there is a strong relationship between attitudes
and behavior whenever attitudes are measured at the same level of
specificity as the behavior. In other words, if a specific
protective behavior is to be predicted from an attitude measure,
that measure should be equally specific.
6.2. Maine study
The first reports on the relationship between mitigation and radon
readings have been disappointing (Johnson & Luken, 1987; Weinstein,
Sandman & Klotz, 1987). People with a higher objective risk level
were not more likely to mitigate.
According to Weinstein, Klotz and Sandman (1988) "People are
seldom willing to take preventive measures unless convinced that
their own risk is significant and that^isks would be serious" (p.
796). - ~_,
6.3. New Jersey study
One of the first major attempts to study mitigation of radon
problems was reported by Weinstein, Sandman, and Roberts (1988).
They followed 123 New Jersey homeowners who had discovered at least
two years previously (in 1986) that they had a radon problem, i.
e., a level exceeding 4pCi/l. The percentages of people in each
exposure category who did at least some mitigation is shown in
Table III.
. Some physical changes were required in order to qualify
for the mitigation category. Behavioral changes, such as more
frequent opening of windows, did not count.
41
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Table III. Percentage of persons who had mitigated as a
function of their first floor radon reading. Data from
Weinstein, Sandman and Roberts (1988).
First floor reading (pCi/1) Percentage who mitigated.
> 20 93
3-20 71
4-8 62
< 4 45
Note that nearly half in the group below the official action
level actually did carry out some mitigation.
Few people retested after mitigation. (A retest is important
because there is no guarantee that the actions taken actually will
reduce the radon level) . A third of those who had done some
modifications did not retest, and none of those who relied on
behavioral methods (such as opening windows frequently) had
retested.
Of those who had retested their homes following mitigation 9j
percent said modifications were successful. There was an averac
drop from 15.2 to 2.0 pCi/1. (First-floor level). Basement readingl
dropped from an average of 37.3 to 3.9.
Weinstein, Sandman, and Roberts estimated that radon remedia-
tion saved between 8 and 13 lives for every 100 households in the
confirmatory monitoring program with ratings of experience and
frequency) and personal experience.1 About 30 percent of the lives
saved were estimated in homes with initial radon levels below 20
pCi/1. These estimates should be taken with a grain of salt, of
course, since they are based on a small sample and since these
people were atypical in being among the first to test and mitigate.
The best predictor of mitigation was not the actual radon
level measured but how serious people felt it to be. Other
significant predictors of action were perceived likelihood of
health problems, of effects of radon on home property value,
distress du« to worry over the radon risk, and perceived personal
susceptibility. The dominant reason for not acting was that the
homeowner did not believe that the risk was very serious. The most
1. Several assumptions were behind these figures, of course.
Perhaps the most crucial assumptions were (a) that people would be
exposed to the measured radon level for a lifetime, and (b) that
mortality is a linear function of the radon level, starting witlf
2 lung cancer cases per 100 persons for a level of 4 pCi/1.
42
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frequently mentioned difficulty of mitigation was getting
information about how radon levels could be reduced.
The authors point out that the group may be atypical since
they had shown their concern by confirmatory retesting and also by
agreeing to take part in the follow up study.
6.4. Washington study
The most extensive study of mitigation so far was performed by
Doyle et al. (1989). They mailed a questionnaire to 920 homeowners
in the Washington, D. C., area who had tested their homes for
radon. The tests had been performed in the beginning of 1938 in
response to an extensive television campaign on the WJLA channel.
Test kits had been made available at a reduced price1 at local
Safeway stores and through a newspaper advertisement. A total of
116,000 kits were sold, by no means exhausting the demand. A
testing firm named Air Check had analyzed the kits that were
submitted to them and had reported back to the homeowners about
their radon levels .
The test results from Air Check were sent together with some
additional information. Homeowners were told that no mitigation
should be undertaken unless a second test also showed an elevated
radon level. Those with radon levels exceeding 4 pCi/1 were advised
to perform a second test. Those with radon levels between 4 and 20
pCi/1 were sent a somewhat revised version of EPA's booklet "A
Citizen's Guide to Radon11, while those with levels higher than 50
pCi/1 received EPA's booklet "Radon Reduction Methods'1 and a free
test kit for a re-test.
Stratified sampling was employed, i.e. an equal number of
homeowners was sampled for the four radon levels <4 pCi/1, 4-20
pCi/1, 20-50-pCi/1 and >50 pCi/1. The .77 percent response rate
was quite good. The data were collected in December 1988.
In spite of the strong recommendation to perform a second
follow-up test, over 85 percent of the respondents had not done
so. (Due to the design of the study, about 75 percent of the total
sample had obtained radon levels exceeding 4 pCi/1).
The results on mitigation are given in Table IV. In this
table, mitigation refers to any kind of action taken by the
respondents, i.e. including simple behavior changes such as leaving
windows open more frequently. Opening doors and windows more
1. The price was reduced to about half the regular level.
2. About 56,000 of the 116,000 that were sold.
43
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frequently was, in fact, by far the most common mitigat;
activity.
Table IV. Percentage of persons who had mitigated as a
function of their radon reading. Data from Doyle et al,
(1989).
Radon level (pci/l) Percentage tfho mitigated
> 50 49
20-50 . 42
4-20 14
< 4 3
These figures are considerably lower than those reported by
Weinstein, Sandman and Roberts (1988), see Table III. However, the
latter data refer mitigation likelihood to first floor readings,
while Doyle et al. did not analyze their data for differe
responses contingent on where in the house the test kit had be
placed. The data obtained by Doyle et al. suggest that most te
results refer to basement readings. It is natural to expect more
concern about a first floor reading than about the same reading
from the basement.
= *
i
Still, the differences between the two data sets are so
extensive that it appears likely that other factors also have
affected the samples differently. Most important, the Weinstein et
al. sample, consisted of highly motivated people who were among the
first to test their homes, and they were followed for a longer
time1 than the Washington group, which was probably more typical in
their level of involvement in the issue of radon risk.
Doyle et al. also reported that the reasons homeowners gave
for mitigating their homes were predominantly health related, very
few referred to economic value and homesale consequences. Of
course, few may have been considering selling their homes at this
particular point in time (homes are sold after 10 years of
residence, as a national US average).
'. The time factor may have been unimportant. Less than 1 pei
cent of the respondents in the Washington study said they planned
mitigation in the future.
44
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Doyle at al. estimated the effects of the WJLA campaign in
terms of how large a share of the population of homes in need of
mitigation was actually mitigated in a "credible" manner. The
results were about 0.1 percent for houses with a level between 4
and 20 pCi/1, 0.5 percent for those above. About half of the test
kits were returned for analysis, and some kind of mitigation was
performed in slightly less than 50 percent of the cases where the
level exceeded 20 pCi/1. However, only about 30 percent of
mitigation went beyond habit changes such as leaving windows open
more frequently. In addition, those with radon levels between 4 and
20 pCi/1 were much less likely to mitigate, and that group is, of
course, the major "problem" group since there are so many more
homes in this group, even if those with higher readings constitute
a larger risk for the individuals concerned.
Summing up, the net result in terms of credible mitigation
was meager. There were two major reasons for this finding:
(1) Few people bought test kits, only about 6.5 percent.
(2) Only a minority mitigated. The percentage of homes mitigated
was especially low for radon levels between 4 and 20 pCi/1.
Doyle et al. conclude that "the likely credible mitigation
resulting from the program has been so small as to suggest that
such programs may be a very expensive way for society to achieve
mitigation" (1989, pp. 164-165).
6.5. Colorado study of testing and mitigation at time of home sale
This is a study by Doyle et al. (1989) of recent home buyers. The
purpose was to determine how common testing is at the time of
buying and whether such testing leads to mitigation. The authors
also report some information about common practices among realtors
in several States. Their own data were obtained in Boulder,
Colorado. There had been no prior extensive attempts to inform the
public about radon in that state.
L -.' ;
Doyle et al. reported the results of a telephone survey of
100 home buyers in Boulder. They had to approach 210 buyers in
order to get 100 interviews, so the response rate'was slightly less
than 50 percent. The houses had been bought in the fall of 1988 and
the interviews were made in December of that year.
The number who had tested for radon in connection with the
sale was 43, most before the sale closed. Of those who had tested
for radon, 8 reported some kind of mitigation and 5 of those had
retested to check the outcome. Of the 8 mitigators, 7 had had close
contact either with an employer (IBM) who strongly supported radon
testing and mitigation, or with a realtor or a contractor who
provided expertise in the area.
45
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Doyle et al. pointed out that the overall mitigation rate
this group was about 15 percent, to be compared with the o.l
percent obtained in the Washington study. (Data refer in both cases
to those homes that had radon levels > 4 pCi/1). Thus, the
effectiveness for stimulating radon testing and mitigation of
buying a house was about 150 times as great as that of a major
media campaign.
6.6. Some Swedish experience; the Sollentuna study
Concern about radon started earlier in Sweden than in the USA. Alum
shale was frequently employed as a building material before 1975,
and the initial concern was with radon emitted by building
material. Subsequently, geological radon has come into focus. The
National Institute of Radiation Protection has estimated that radon
causes about 1100 lung cancer cases in Sweden yearly (in a
population of 8.5 million). The figure is much higher per capita
than the corresponding American estimate of a maximum of 20 000
cases per year. This is somewhat puzzling, since data indicate that
the home radon levels are probably somewhat higher in the USA than
in Sweden, see page 12, Table I.
The action level recommended by the Institute is 10 pCi/11,
in other words 2.5 times that of the EPA. It is unclear why Swedis
authorities are so much more prone to accept radon risks. T
Swedish action level corresponds to the lung cancer risk of smoki
a pack of cigarettes per day .
• ,
I
Local authorities inform home owners that this level involves
an elevated risk of lung cancer. The local authorities are
responsible for dealing with radon risks, but their policies vary
greatly. Swedes are just as indifferent to mitigating their homes
for radon as are Americans (Johnson, 1987).
^ •
Akerman (1988) reported a study of mitigation and willingness
to pay for mitigation in Sollentuna, a suburb north of Stockholm.
Radon had received considerable attention in this town. Home owners
could have the local health department conduct a test and the cost
was 400 SEK, about $65. If the result was above 10 pCi/1 the health
department offered a free retest and provided mitigation advice.
Akerman obtained extensive data from a sample of 317 homes
that had been tested with results above 10 pCi/1. The estimated WTP
. In Sweden the scale used is that of Bq/m . The conversion
formula is 1 pCi/1 =40 Bq/m3.
2. However, a recent decision states that the maximum allowe^
concentration in new construction is 2 pCi/1. ™
46
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in 1986 prices (yearly cost) was 3120 SEK ($510) , or 918 SEX ($150)
per person since there were on the average 3.4 persons per
household.
The data in this study were obtained from archives'. There was
no information about actual mitigation costs, but experts estimated
the generic costs on the basis of detailed information about radon
readings and technical characteristics of houses.
The implied WTP of these data was $0.35 for reducing exposure
by 1 Bq/m per person, or $13 for a reduction of 1 pCi/1. The
general policy of the National Institute of Radiation Protection
is that one should be willing to pay 43.50 SEK per annum for a
reduction of 1 Bq/m ($88.50 for 1 pCi/1), roughly 6 times as much.
It is possible that this difference reflects the often noticed
difference between individual and collective risk taking.
Collectively taken risks are accepted only at a level an order of
magnitude less than that accepted for individually taken risks
(e.g. Sjoberg & Winroth, 1986). Akerman, Bergman & Johnson (no
date) argue that the estimates are understatements of the true WTP
values since (a) all costs could not be taken into account, and (b)
it is unknown what risk perceptions the homeowners actually had,
but likely that they perceived smaller risks than the expert risk
judgments on which the calculations were based. As the authors
stressed, further work on WTP should make use of individuals' risk
judgments rather than expert estimates. The problem that will then
arise is, of course, that unbiased risk judgments are very
difficult to get.
WTP methods can be discussed. Do people really give realistic
estimates of their willingness to pay? Oicke, Fisher and Gerking
(1987) compared actual purchases (of strawberries) with stated
willingness to buy. They found rather good correspondence between
the two sets of data. However, we still—do not know how realistic
such estimates are in different settings and with more important
choices, such as those involving health risks. It may be that
people are less^likaly to give such ratings in an unbiased manner.
Strategic considerations may easily enter.
-re
Akerman initially found: only a weak correlation between
mitigation cost and initial radon reading. This result is in line
with some American data, perhaps most clearly the Maine study.
However, after controlling for several independent variables, most
notably Jcind of ventilation1, she found a clear relationship
between WTP and probability of mitigation and initial radon
reading, see Table V for the latter relationship.
'. Three types were distinguished: passive ventilation,
forced-air exhaust ventilation and forced-air intake and exhaust
ventilation.
47
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Tibia V. Percentage of persons who had mitigated asa I
function of the initial radon reading. Data from Akerman
(1988) .
Radon level (pCi/1) Percentage who mitigated
12.5 38
25.0 50
37.5 57
50.0 62
62.5 65
75.0 63
87.5 70
Bergman, Soderqvist and Akerman (1988) also reported a study
of sales prices as a function of radon. They did not find any
significant influence of radon on price level, confirming the
impressions by American realtors reported by Doyle et al. (1989).
However, Bergman et al. also pointed out .that the tax assessment
of houses had been lowered whenever there was an elevated radon
reading, leading to a somewhat smaller tax. The tax "discount"
could have been enough to compensate for the presence of radojfl
risk.
Some of the Swedish results are different from American data.
The overall picture in Akerman's study was one of a certain degree
of rationality.- The reason could be, of course, that her WTP data
were based not on homeowners' actual investment in protective
behavior, but in experts' estimates of generic costs. Presumably,
experts are more rational than p'eople in general. The reason could
also be that Swedes, especially those in places where radon has
been intensely discussed, such as Sollentuna, are more
knowledgeable than Americans about radon, or that they have access
to better advice. Finally, the reason could be the smaller income
variation in Sweden, which decreases the confounding effects of how
much money people can afford to spend on mitigation. Also, state
subsidized loans are available to homeowners in Sweden for radon
mitigation, and even ordinary bank loans may be cheaper than in the
U.S. because interest is deductible up to 50 percent.
It should be added that rationality is not overwhelming in
AJcerman's data. 30 percent are estimated to ignore mitigation with
an exposure level of 87.5 pCi/1. At this level, the estimated added
risk of lung cancer approaches 1/2, corresponding to about 10 packs
of cigarettes per day for every family member, including children.
Willingness to pay data imply an implicit life value of some $6000
per family member at this level of exposure, a small fraction of
official figures both in Sweden and the USA.
48
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The estimated over-all implied life value, according to
Akennan, Bergman & Johnson (no date), was only about $100 000. This
compares unfavorably with the range $2 million to $7 million per
statistical life save reported for American data (Fisher, Chestnut
& Violette, 1988).
The reason could be the above mentioned risk denial that was
probably present, or it could be that people do not believe that
a reduction of radon below the action level (10 pCi/1) has any
positive health effects. The Swedish information material does not
mention that a further reduction is of any value.
A further possibility, not mentioned by the authors, is that
human life simply is less valued, at least in monetary terms, in
Sweden than in the USA. Damage compensation awarded by Swedish
courts for loss of life or various types of smaller damages tend
to be 1-3 orders of magnitude smaller than the American
corresponding figures. It seems, however, that comparisons of
countries are quite complicated because Swedish authorities are
likely to react to prevent damage, even if they do not feel that
individuals should be compensated financially to any great extent
once damage has occurred.
6.7. Evaluation and conclusions of mitigation studies
A major factor in mitigation is, of course, the measured radon
concentration level of a home. The three studies of mitigation
discussed above all produced some quantitative information about
mitigation frequency as a function of radon concentration. They are
plotted in the same graph1 in Figure 2 .
It can be seen that the data from the study by Weinstein et
al. deviate from the two other data sets in yielding much higher
levels of mitigation. As pointed out above (see page 44) the values
obtained in the New Jersey study refer to living room readings and
may therefore be misleadingly high. In addition, that study
involved a group of people who were probably unusually strongly
motivated.
Research on mitigation has so far not been very extensive and most
of the experience is very recent. However, some observations can
1. *-data from Weinstein et al., *-data from Doyle et al.,
••data from Akerman et al.
2. In the plot of Figure 2 the minimum and maximum levels of
radon concentration for the two sets of American data were
estimated by adding or subtracting 20% from the stated lower or
upper limit, respectively.
49
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1.0
oa
00
04
02
00
ao
oo
RM£J> ocrantralon In OQA
Figure 2. Frequency of mitigation as a function of radon
concentration.
be made.
(1). Given that people have tested and found an excess level of
radon it is reasonably likely that if they they are going to
mitigate, they do it within one year. Ho data support the
assumption that they may delay mitigation longer than that.
(2) The probability of mitigation has in almost all studies been
found to be an increasing function of initial radon reading.
•
(3) In a few studies there has been an obscure raw data
relationship between initial radon reading and mitigation behavior.
The reasons could be (a) technical characteristics of houses,
perhaps in particular type of ventilation system, (b) the income
variation in the sample, (c) availability of expert advice and (d)
variability of risk preferences.
(4) People seemed less likely to re-test to find out if their
mitigation had been effective, with the possible exception of those
who had just bought a house, or were in the process of buying one.
(5) The net effect of media campaigns on the number of people who
mitigate is probably quite small. The effect of encouraging
realtors or employers at the time of buying a house seemed in one
small-scale study to be 100-200 times larger.
50
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7. Comments on empirical studies of radon risk perception
mitigation
Early concern that people would panic over radon has clearly been
found to be unsupported. The opposite is true: people are too
little concerned about radon risk.
There have been three major attempts to investigate risk
perception and testing decisions: the NYSERDA, Maryland and Nev
Jersey studies. Studies of mitigation have so far been few, and
more such studies are needed; some are under way.
The most successful variables in predicting testing found so
far are those that measure (a) personal risk perception and (b)
social influence. Personality variables have not been found to be
very important when it comes to the perception of radon risk or
testing decisions.
The most common problem in these studies has been that of
representativeness of the sample studied. Probably because the
problem is so new and research resources have been limited there
have been few attempts to test variations of messages in
communication studies. It seems, however, that simple and
straightforward messages are to be preferred. Messages that are
too simple can be detrimental if the purpose is to reassure people
that the risk is negligible. On the other hand, the most common
problem is the opposite one: how to motivate people to test and
mitigate if appropriate. Therefore, it is possible that one should
consider quite brief and simple messages.
•
Are people at all rational when it comes to the perception of
radon risks? Psychologists have tended to emphasize that, in
general, people perceive risks incorrectly. Depending on
circumstances, they may exaggerate or understate risks. However,
in the Maine and, in particular, the NYSERDA studies it was found
that people revised their risk estimates in accordance with the
information that they received.
This finding is not inconsistent with a general skepticism
about people's subjective risk perceptions. In the cited studies,
there was still virtually zero correlation between subjective risk
and measured home pCi/1 level. Maybe people have such a distorted
view of risks partly because they seldom get clear information and
feedbacfc about risk levels. The finding that they would revise
their risk estimates in a correct direction suggests that they sao
treat risk information in a correct manner. The problem may simply
be that they seldom receive such information.
51
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8. Predicting monitoring for radon
Some of the studies treated above investigated the tendency of
people to monitor for radon. It is a potentially important issue
to determine whether it is possible to predict who is most likely
to test. However, the problem is difficult to investigate because
so few people have tested, less than 4 percent in the population.
A statistical analysis is not meaningful if the number of testers
is so few as, e.g., in the Florida study (Section 5.9, page 37).
Weinstein finds the following predictors of the intention to test:
- believing that radon is a personal risk
- believing that others are concerned about radon
- a feeling of distress caused by worry over the radon risk
• having more children
- being better educated
- having lived fewer years in home
• being a nonsmoker
Weinstein also found that several factors were not predictive
of testing intentions:
• knowledge about radon
- perceived effect of radon on home values
• perceived cost of remediation
- perceived severity of risk
- perceived efficacy of mitigation
Note especially the last two factors which should have been
efficient according to models of protective behavior, such as the
Health Belief Model (Becker, 1974).
Those who had never thought about testing knew less about
radon. They were quite different from the ones who had thought
about the issue and found it unnecessary to test.
Further analyses of testing behavior were reported in the EPA
Interim Report on the Radon Risk Communication Project (U.S.
Environmental Protection Agency, 1987 b). These results were
derived from the New Jersey data collected by Weinstein and co-
workers and from a University of Pittsburgh study of people who
had purchased test kits (N»70,000) or been provided with such kits
at no cost (N-3,500).
Major findings from New Jersey data, in addition to those
already stated, were that
- Testers were affluent and middle-aged.
- People who planned to move within the next two years were more
likely to test for radon.
52
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- Households in which someone usually sleeps in the basement were
more likely to test.
- Households with children under 10 were slightly more likely to
test.
Findings based on the University of Pittsburgh study were that
- States that contained radon "hot spots" had more testers, as
compared with states that had no such hot spots.
- People who suspected elevated levels before testing tended to be
right.
The Maryland study (Section 5.8, page 35) reported only three
significant predictors of spontaneous monitoring:
- Level of knowledge about radon1.
- Whether people asked their physician a lot of questions about
their health.
- Educational level.
In conclusion, the following factors have been documented as
being of some importance for the testing decision:
- Demographic characteristics: young or middle-aged people, and
parents, tend to be more inclined to test.
- Nonsmokers are slightly more inclined to test than smokers.
- The perception of a risk as personal rather than general is
associated with testingv
- The perception that others are concerned about testing is
associated with testing.
- A fealing of distress over the radon risks is associated with
testing.
- General health concern
'. The causal direction here is debatable. Other data show
that people do not become more likely to monitor if they get more
information. Possibly, the process of monitoring by itself involves
learning about radon.
53
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These findings suggest that risk communication should
personal risks and that social diffusion processes should
employed, whenever possible.
9. Factors affecting risk perception
Few people seem to be concerned enough about radon risks to test
their homes and to mitigate. One of the most important variables
responsible for this indifference is the perceived risk, which is
low. Therefore, an analysis of risk perception is called for in
order to give a background for improved risk communication.
9.1. Risk denial
Risk perception has often been studied within the perspective of
cognitive psychology and heuristics (Sjoberg, 1979). This
literature is probably less relevant for understanding of radon
risk where other factors seem more important.
People tend to be indifferent toward abstract threats to
society (Snarlin, 1987), but concerned if threats are oriented
towards themselves or significant others. At the same time, there
is often denial of risks to oneself, a phenomenon well documented
in health psychology (Weinstein, 1980, 1984, 1987).
People deny many health risks, among them the risk from
This is an example of a general trend toward exaggerated optimi
when it comes to one's own person (Perloff, 1983). Why is there
such a tendency? Kunda (1987) suggested that people construct self-
serving theories, or evaluate evidence in a self-serving manner,
and that this process is motivationally guided. It is relatively
easy for most people to come up with ad hoc causal "explanations"
for anything, after the fact has occurred (Anderson & Sechler,
1986). At the same time it is increasingly difficult to predict
anything on the basis of such construals because people generate
such theories even on the basis of a single instance (Anderson,
1983).
Weinstein (1987) investigated several factors that had been
suggested as causes of optimistic bias in risk estimation:
defensive denial, self-esteem (as reflected in ratings of risk
preventability and embarrassment if exposed to risk), cognitive
errors (revealed through the correlations of bias with ratings of
experience and frequency) and personal experience. The latter
concept was measured by responses to the statement: "If you haven't
had this problem by the time you're my age, it's not likely to
happen to you".
Weinstein obtained data from a random sample of 296 New Jersey
residents (survey response rate 68 percent). They rated 32
54
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different health hazards, making comparative risk judgments1. They
also rated the hazards in several other respects.
There was no evidence of defensive denial. The strongest
determinant of optimistic bias seemed to be personal experience.
Variables .related to self-esteem were important and cognitive
errors seemed to enter as well. Optimistic bias was largely
unrelated to background factors such as age, gender, race and
education.
Weinstein stressed that if people believed that there was the
slightest chance that their characteristics (lack of certain risk
factors) might enhance their chances of avoiding disaster, they
took full advantage of the opportunity to create optimistic
beliefs. In doing so, they utilized specific factors that were
characteristic: of their situation. To counteract optimistic bias
it will therefore be necessary to individualize the general
knowledge that people have about a, risk, and at the same time avoid
the influence of individualized wishful thinking.
Weinstein, Sandman & Klotz (1988) argued that radon risk
differs from many other health risks because it (a) .does not
threaten self esteem, and (b) is hard to deny on the ground that
the risk is low because no symptoms have yet been observed. (Lung
cancer does not occur until late in life anyway, so the argument
would be inconsistent with medical science). However, these
arguments have not been tested empirically. Even if an owner who
bought his or her house before 1984 cannot, logically speaking, be
blamed for having a house with an elevated level of radon, it is
•still quite possible that the owner blames him- or herself.
Moreover, despite medical science, people may argue that "I have
lived in this house for 30 years and I have not developed lung
cancer so I don't believe there is a risk" as a reason to justify
lack of action. Weinstein found that such reasoning was the
strongest determinant of optimistic bias.
Weinstein also found clear evidence of risk denial. This was
apparent in several of his variables. For example, only 6 percent
of those who had an opinion said their radon level was likely to
be more or much more than the average in their community.
Optimistic bias was evident in the overall reasoning of the
subjects, who used their knowledge about radon to construct
. The format of the rating scale was: "Compared to other
men/women my age, my chances of getting the problem in the future
are: much below average, below average, ...etc... to much above
average". Seven rating categories were used. The responses were
scored on a scale from -3 to +3, 0 indicating a rating of average
risk. Evidence of optimistic bias was available at the level of
group data whenever average ratings were <0. Such was the case for
31 of the 32 health hazards.
55
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optimistic scenarios. Among those who had tested for radon, th<
was only a very slight correlation between the judged seriousnel
of the risk and the radon level obtained. A similar finding was
reported by Johnson and Luken (1987).
Weinstein et al. proposed that the reason why radon risks are
underestimated, while many other environmental hazards (waste
disposal, nuclear power, etc) are commonly overestimated by the
public, is that nobody can be blamed for radon risks. This is an
interesting hypothesis, but so far little has been presented to
support it. In addition, it is not clear why nobody should be
blamed for the radon risk. One could argue, for example, that
planners and realtors should have foreseen the risk and avoided
building on sites where radon is likely to be high, or that a
homeowner should have taken action to reduce the risk. Maybe that
type of blame is unlikely because the risk is so new.
9.2. Diffusion processes
>*> 0
i
Risk perception has been found to be quite sensitive to social
influence such as messages from friends and neighbors. Part of the
spread of risk attitudes in a population is therefore dependent
upon social diffusion. For social diffusion to work, homeowners
must perceive their neighbors to be concerned about radon and the;
must interact with them about the issue (Unger & Wandersman, 1985)
In the New Jersey study, people reported a lack of knowledge abo
how their neighbors viewed radon risk and a need for such
knowledge. Furthermore, if they reported an opinion, they tended
to say that they saw their neighbors as little concerned. People
who had tested wanted to tell others about it, however, and more
often so if they had obtained high radon level test results. But
they said their neighbors did not want to listen.
Desvousges,. Smith and Rink (1989) found that one of the best
predictors of testing for radon was whether a person had talked to
someone else about radon. This finding is open to various
interpretations. It is plausible that testing itself is the cause
of some verbal interaction. On the other hand, other research
strongly supports the interpretation that personal interaction
among people is conducive to behavior change.
According to Rogers (1987) new precautions are by themselves
much less likely to spread through a population than other new
ideas, because they entail immediate costs and no immediate
benefits. This is in addition to the negative experiences of those
people who actually h£y£ tried to talk to their neighbors about
radon testing; they feel stigmatized.
Diffusion seemed to work in the HJ study, but there was too
little "input" for it to spread widely. There were too few people
56
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who had tested for radon, and those who had tested were sometimes
discouraged from talking about it with their neighbors.
Mazur and Hall {no date) and Mazur (1981) argued that risk
perceptions are especially amenable to social influence when they
concern risks that are abstract and not immediately present, while
imminent hazards are perceived in a fairly realistic and rational
manner. People are influenced, if risks are distant and diffuse,
by the opinions their friends have, and by mass media.
9.3. Assimilation-contrast model of risk perception
Sjoberg and Drottz (1988) studied various groups of nuclear power
plant personnel and found an inverse U-shaped relationship, across
groups, between perceived everyday life risks, e.g. traffic risks,
and job risks!. The maximum rated general (everyday life) risk level
was found for those who had rated their job risk as being of a
medium size job risk. For low to medium size risks, the correlation
between perceived everyday life risks and job risk was positive,
and for medium to high job risks it was negative.
Sjoberg and Drottz suggested that a threat of low to medium
strength increases all risk estimates by assimilation (enhanced
similarity) while a medium to very strong threat will so dominate
a person's perception of risks that other risks appear as small,
a contrast effect.
The assimilation part of the model has been supported in other
work. Johnson and Fisher (1989) found that when people were
informed about radon risks (which happened to be quite low in their
sample) their perception of these risks dropped, but so did their
ratings of other risks. (The opposite would occur, according to the
model, if people were to be re-assured about a risk they had
greatly exaggerated).
9.4. Risk posterior to action
There is considerable evidence that risk perceptions correlate with
action. It is usually assumed that risk perceptions are prior to
and partially cause action. Mazur and Hall (no date) suggested the
opposite relationship, i.e. that risk perception is a function of
action, or lack of action, and that highly discrepant risk
perceptions may serve as justification for lack of appropriate
action.
Although this interpretation may at times have some validity
it seems unlikely that it would be generally true.
57
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9.5. Objective vs subjective risk
Most risk researchers seem to agree that people's responses to
threats and hazards are more determined by their subjective
perception of risk than by the objective, or true, level of risk1.
Mazur and Hall (no date) suggested that this psychological
explanation may sometimes be incorrect and that objective risk may
directly drive behavior when the risk is imminent and the response
specific. With more distant or diffuse hazards and more generalized
responses the psychological model would still be expected to hold,
according to these authors.
These notions can be debated. First, it is unclear how an
objective risk could have an effect on behavior except as a
subjective experience. If the objective risk is found to "drive"
behavior, this is consonant with a subjective risk that is an
accurate reflection of the objective risk. Second, a high degree
of correspondence between subjective and objective risk requires
freedom from emotional interference with risk perception. Such
interference is especially likely whenever the risk is imminent and
large. Denial of risk has been found to prevail quite generally,
especially for very threatening risks.
Hence, it does not seem likely that objective risks are of
direct relevance except possibly when the risks are moderate or
small. Information about objective risks have rarely been found toj
affect people's behavior in published research on the issue.
There is a possibility that the lack of effect of risk
information is due to an illusion. First, researchers may be most
concerned with problematic cases where people have failed to
respond. Second, social concerns about lack of response may arise
because a minority of people neglect warnings, while most people
do respond in an adequate manner. Lack of response to warnings and
even to legislation in even a small minority of people may be a
social problem, partly because they may constitute a danger to
others (e.g., drunk drivers). Hence, concern about lack of response
to risk information may be confused with its prevalence.
It should be added that even if these arguments have some
validity in general they do not seem to pertain to radon. Radon is
certainly a case where most people have, so far, failed to respond
to warnings. Objective risk does not appear to be important in
affecting behavior in this area.
1 I bypass the often tricky problem of how to define true risk
see Freudenberg's (1988) stimulating discussion.
58
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9.6. Demographic characteristics
Sex differences are commonly found in risk studies. There is no
clear evidence that men and women experience different levels of
concern when it comes to radon, but some findings suggest that
women are more worried over health risks while men are concerned
over the economic aspects, such as potential loss of property
value. Women seemed to be better informed about radon risks than
men (U.S. Environmental Protection Agency, 1987 a). Couples with
small children, or expecting a child, seem to be more concerned
about radon than others.
Long torm residents in an area are usually found to be more
skeptical about the necessity of radon testing than those who_hav«
lived a shorter time in an area. Of course, those who have lived
longer in an area would tend to be older. They might also'be more
personally involved with their homes and have a longer story of
benign exposure to their environment.
There are some weak effects on testing of education and non-
smoking, and from having small children;
9.7. Cognitive processing limitations
It has been shown in many studies that people have limited ability
to process information (e.g. Anderson, 1985) and that their
attitudes tend to be determined by a few salient attributes rather
than a complex net of many aspects (Krosnick, 1988)•
These findings are somewhat difficult to reconcile with the
well-known list of risk dimensions of Slovic, Fischhoff and
Lichtenstein (1981). These authors suggested a fairly large number
of risk dimensions. On the other hand, Sjoberg and Winroth (1986)
investigated the moral dimension of risky actions and found that
it accounted^ for .a very sizable proportion of judgments of
acceptability of risk* The predominance, of morality seems to be in
line with general principles of cognitive psychology in the sense
that one single factor accounts for a large share of the variance
of rated risk acceptability.
9.8. A note on terminology; Hazard and outrage
Sandman, Weinstein and Klotz (1987) introduced a distinction
between hazard and outrage. Hazard refers to "risk estimates based
on mortality and other 'objective1 data" (p. 106), while outrage
is based on "subjective" factors. Sandman et al. mentioned
especially the factors "fairness, naturalness, familiarity and
controllability" (p. 106).
59
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These terms seem to denote much the same as the more
terms subjective and objective rislc. The authors stated that the
wanted to replace the traditional terminology in order to avoid
encouraging the experts "to see the public as mistaken, misguided,
wrong in its subjective risk assessments" (p.106). Although their
objective was worthwhile, their choice of new terminology seems
less than perfect. According to Webster's Ninth New Collegiate Dic-
tionary (1987) outrage means
(1) An act of violence or brutality.
(2 a) Injury or insult.
(2 b) An act that violates accepted standards of behavior or
taste.
(3) The anger and resentment aroused by injury or insult.
The intention to convey less irrationality by switching from
the term subjective risk to outrage hence seems not to be well
served by the word outrage. In addition, outrage connotes a rather
strong, emotionally flavored response. Neither of these components
is necessarily true of subjective risk.
10. Risk perception and protective action
One persistent problem is the lack of correspondence betwe*
knowledge and attitudes on the one hand and action on the othei
People frequently agree that many types of behavior should
avoided, yet find it very unattractive and difficult to do so."
Examples are provided by all sorts of addiction. People agree that
they should test their homes for radon or change their food habits
but delay such rational and health-promoting actions indefinitely.
The question is why people act this way.
Sjoberg ^studied addictive behaviors (smoking, drug addiction,
alcohol abuse .jand excessive eating), in particular relapses in
addiction [see^Sjoberg (1980, 1985) for reviews of this work]. Re
found that people.who try to live up to a long term commitment,
such as sobriety1;-frequently fail when they are emotionally
agitated. Emotional agitation seemed to be equally disruptive when
it was negative as when it was positive. The most-crucial factor
in the regulation of action was the ability to counter-act
emotionally induced short-sighted behavior.
This kind of behavior was mediated by cognitive deterioration.
People were very good_ at producing excuses for lapses and virtually
never told themselves in a cold and rational manner that they no
longer needed to adhere to their commitments.
Although this work is only indirectly relevant to health
protective behavior when it comes to radon there may some simila-
rities that make generalizations plausible, at least for some type*
of behavior that neglect health. The difference is, of course, thfl
60
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existence of strong positive attraction in the case of addiction.
Procrastination seemed to be a dominant behavior pattern in the
Maryland stxidy (see Section 5.8, page 35), and procrastination is
a typical form of irrationality (Silver & Sabini, 1981).
Weinst«in (1988) suggested a model of stages of health-
protective behavior. He contrasted this stage-oriented, dynamic
approach with traditional decision-oriented models. Models such as
the health belief model (Becker, 1974) and variants, such as
Fishbein's theory of reasoned action (Fishbein & Ajzen, 1975),
assume that people integrate beliefs and values according to some
simple decision rule* usually a multiplicative one. They then
choose the option with the largest, criterion value, e.g. the
largest expected utility, and act accordingly.
These nodeIs seem plausible; perhaps they indeed are little
more than common sense. They imply that once people are credibly
informed about the importance of a given type of health protective
action, they should behave rationally. But people often do not act
rationally, at least not in this sense of the word. Decision model
approaches are virtually useless for understanding health
protective behavior.
Weinstein's stage model is an attempt to account for decision
making as a process involving several stages. It is broader in its
conception of: the important factors in action, as compared to
traditional decision models. It includes the following stages:
(1). "Has heard of hazard"
(2). "Believes in significant likelihood for others"
(3). "Acknowledges personal susceptibility"
(4). "Decides to take precaution"
(5). "Takes precaution"
Although it. still largely untested, Weinstein's model seems
rather promising and it is certainly an interesting alternative to
the traditional health belief model. It is, however, mainly a
cognitive model* Weinstein argues for a cognitive model by stating
that "new preventive actions usually involve high-level cognitive
functioning and advance planning" (p. 358). In the case of radon,
it is doubtful if one can classify the needed actions in testing
one's home as "high-level cognitive functioning", although
Weinstein illustrates his model with the radon case. The fact that
a number of steps are postulated does not mean that there is high-
level cognitive functioning. In addition, even if high-level
cognitive functioning is called for, one can still question a model
that generally ignores emotional influences. Such influences seem
to be especially likely to occur in steps 3 and 4. There is reason
to believe that emotional influences are more important when more
sophisticated cognitive functioning is involved.
61
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In spite of this criticism, Weinstein's paper is recommend
for several insights and suggestions, including the importance „„
prompts and reminders in eliciting action and the choice of time
horizon.
Sjoberg used the concept of mental energy to explain relapse
in addictive behavior. According to him, mental energy is needed
for the orderly regulation of action. Under emotional agitation,
competing action tendencies arise, often in the fora of tempting
imagery. These action tendencies require additional mental energy
resources for processing, and since these resources for processing
are finite, the cognitive system will work at a lower level,
accepting low quality "excuses* and rationalizations. Hence, the
crucial problea in- pursuing longtent goals is that supply of mental
energy.
Similarly, Weinstein suggested a "messy desk" analogy to
health protective actions. Such actions must compete with many
other duties and demanding activities. Clearly, the difficulties
of the messy desk can be explained in terms of limiting cognitive
capacity or in terms of limited, energy resources. The latter
approach has the advantage of phenomenological plausibility. In
addition, most health protective behaviors are not cognitively
demanding. Testing one's home for radon or quitting smoking is not
cognitively difficult to do, the difficulty is doing it. This is
why a cognitive model is likely to be insufficient in accounting*
for lack of rationality in health protective.behavior. "I
11. Message format and contents
Message format has been found to be quite important in determining
how people react to a message (Magat, Payne £ Brucato, 1986).
A traditional issue in work on attitude change, is that of one-
sided vs two-iilded messages. A one--sided»rmessage gives only
arguments pro op con an issue, while a two-sided gives both types
of arguments. It has been found that one-sided messages are more
efficient when the issue is unfamiliar (Chu, 1967).
It is commonly"believed that messages that are "personalized"
are more- effective when it comes to behavior change. But what is
"personalized"? The concept is rather unclear and quite different
aspect* of communication are believed to lead to "personalization".
Thus, personalization of risks has been suggested to occur when (a)
communication is face-to-face rather than via mass media, (b)
communication contents directed to parents refer to children at
risk, and (c) whenever the respondent is made to believe that he
or she is personally at risk. These three specifications of
personalized risk are very different.
62
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Rogers (1983) and Leventhal (1970) studied the vividness of
the information and the personal relevance of the outcomes. While
expected effects were found in terns of fear and perceived
vulnerability, it was. not clear that actual protective behaviors
were more likely under fear arousal (Leventhal, 1986).
Petty and Cacioppo (1981, 1986) suggested a distinction
between central and peripheral routes to persuasion. The central
route involves thinking and elaboration and leads, according to
the authors, to more permanent attitude change. The peripheral
route is typically evoked in topics of small concern to a person.
Much less and more superficial processing is involved in this case.
In the peripheral route, ..efficient cues may be "irrational" or
superficial.
Communication technology now makes it possible to make complex
information accessible in a dialogue mode. A computer program for
communicating radon risk has been developed by Florig and Morgan
(no date). The program simulates a house and shows how various
factors affect the radon level. It has not yet been evaluated but
it seems like a promising development. There may be a risk,
however, in excess credibility in such a computerized mode of
communication. Real houses have many characteristics that cannot
be simulated and generalization from the computer house to a real
house is therefore unjustified however tempting it may be.
A final matter of importance is to what extent risk
communication needs to be tailormade to fit each risk. Can general
principles be designed or does each communication effort need its
own research agenda?
n.
12. Personality, risk taking, and attitude^change
12.1. Personality and behavior: general ..
People vary greatly in how they respond to threats, risks and
attempts at communication. The field of personality psychology
might be expected to explain this variability, but results so far
have been meager. .This is a reflection of general difficulties in
finding trait measures with sufficient generalizability. Mischel
(1973) summarized the field and came up with the disconcerting
conclusion that personality dimensions seldom explain more than 10
percent of the behavior variance. Many have since attempted to
disprove this conclusion but so far with little success.
Notwithstanding, personality measures might give some
additional understanding of risk attitudes, even if it is marginal.
For example, Sjoberg and Orottz (1988) found in a study of nuclear
power plant personnel that generalized anxiety scores correlated
about 0.15 with job risk perception. (This correlation is
statistically significant).
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12. 2. _. vigilant vs. defensive response to threats
Recent work on attitude change has found personality correlates
for reactions to communicated messages (Eagly, 1981). Janis (1962,
1982) studied the contrast between those who react with vigilance
and those who ignore risks .
These notions were applied by Stallen and Thomas (1988) to
how people respond to industrial hazards. They suggested a typology
of reactions to risk: secure, accepting, vigilant and defensive.
The first two consist of people who really do not see a problem.
The vigilant and the defensive acknowledge the existence of a
problem, but they differ in hope. The defensive lack hope and see
no way they can personally control the risk, while the vigilant
have hope. The study was of a preliminary character but the
concepts may be fruitful in further work.
12.3. Need for cognition and uncertainty orientation
Cacioppo and Petty (1982) suggested a dimension that they
called need for cognition, based on previous work by Cohen (Cohen,
Stotland & Wolfe, 1957). Need for cognition is a need to- structure
and understand the world. People who are high in need for cognition
enjoy complex rather than simple tasks, and may be more responsive
to focused arguments than to peripheral cues.
Cacioppo^ and Petty devised a scale for measuring need
cognition and successfully predicted that those high 'on" the scale
would prefer a complex to a simple task, while the opposite would
hold for those low on the scale. •- ...
Another somewhat related dimension of potential interest is ]
uncertainty; orientation (Sorrentino, Short £ Raynor, 1984) . j
According to Sorreiitino, Short and Raynor, uncertainty orientation j
determines' whether a problem situation' fa situation characterized ,;
by uncertainty about the" self or the environment) triggers approach j
or avoidance motivation. People who are uncertainty oriented would j
be more^ attracted to such a situation, especially if it is ego ;*
related (relevant to self esteem) , and would be more influenced by 1
cognitively demanding arguments. Certainty oriented people would
be more influenced by 'cognitively simple messages and they would
rely on heuristics rather than elaborate cognitive processing. On
the other hand, if the situation does not pose an important ego
related problem, these trends would be reversed, i.e., certainty
oriented people would1 use more elaborate processing than
uncertainty oriented people.
3(3
Sorrentino and coworkers proposed to measure uncertainty
orientation by combining a sentence completion test scored for
uncertainty imagery with a • questionnaire measuring
authoritarianism.
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The concept of uncertainty orientation is related to the
cognitive psychological notion of levels of processing (Schneider
& Sniffrin, 1977). Cognitive processing can be carried out either
in an elaborated, conscious manner or in a more automatic,
simplistic and undemanding way. Petty and Cacioppo (1986) suggested
that high-level processing is more likely with personally highly
relevant and involving thought contents. This notion enjoys a high
level of credibility in current attitude research, but recent work
casts some doubt on its generality.
Sorrentino et al. (1988) found convincing evidence for this
prediction in an experimental study. Personal relevance increased
systematic processing of message contents only for uncertainty
oriented subjects, the opposite was true for certainty oriented
subjects. For the latter type of subjects personal relevance
decreased systematic processing. This is an interesting finding
because it suggests that the currently popular notions of Petty
and Cacioppo (1986) only if people are uncertainty oriented. In a
practical application to risk communication, we might expect most
people to be certainty oriented and hence most responsive to little
elaborated messages, provided that the risk is conceived as a
personal throat.
It would be interesting to test the hypothesis that a risk
message is most effective if it is cognitively undemanding and if
the threat is personalized. The hypothesis also implies that the
message is most effective if the risk is abstract and the message
cognitively elaborated. The hypothesis follows from Sorrentino et
al., provided that most people are certainty oriented. For
uncertainty oriented persons the trends would be opposite. A three-
way interaction between certainty orientation* elaboration of risk
message and personalized vs. abstract risk is thus predicted.
It may- be the case that different cultures- differ in uncer-
tainty, orientation. Sorrentino et al. suggested that their data
indicated a lower level of uncertainty orientation in Canadian than
in US students. This would explain why Petty and Cacioppo, working
with US student groups, obtained results showing that people
process information in a more sophisticated manner if they are
personally involved. Sorrentino et al. also suggested that
certainty orientation may be the dominant trend in the population
and that the hope that people are more rational when they face a
personally important problem therefore is futile (Sorrentino &
Hancock, 1987).
. That is, that personal relevance of an issue increases the
level of processing and makes people more likely to be influenced
by more elaborate argumentation.
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12.4. Health concern
Smith at al (1987) used a potentially important variable that might
be termed "health concern": a 4-category rating of the statement
"You always ask your physician a lot of questions or regularly read
articles about your health". The idea of measuring health related
attitudes in order to account for some of the individual variation
in response to risk is promising. It measures individual behavior
at a level close to risk perception in meaning. Research on
behavior and attitudes has repeatedly found that the most behavior
relevant attitudes are those that are semantically close to the
behavior under study.
Miller (1980) suggested a variable for measuring monitoring
with regard to illness symptoms. People high in monitoring would
be more prone to see a doctor whenever they would be worried about
their health. Miller, Brody and Summerton (1988) reported some
evidence for this hypothesis, and also found that those high in
monitoring were low in desire to control. They left that to the
doctors. The people who tested very early for radon, in the New
Jersey study confirmatory sample, appear to resemble the
"monitoring syndrome" described by. Miller et al. They were quite
concerned and kept extensive files about radon, in stark contrast
with the rest of the population. The Miller scale has not as far ,
as I know been applied to the perception of hazards and technology :
risks of but it would be interesting to do so, in order tj| •
understand a part of the variance in risk response that might bm 4
attributable to personality. ^ *
12.5. Emotions and risk perception : }
1
Emotional states may also influence risk judgments and risk taking. J
Johnson & Tversky (1983) found that an experimentally induced mood ]
had a global effect on risk judgments: a depressed mood appeared {
to create higher^.risk judgments. In contrast, Sjoberg and Winroth j
(1986) found tKat,t|«pressed subjects tended to rate risks as more ]
acceptable than other, subjects did. These findings may be !
reconciled if a depressed mood is associated with a more tolerant i
attitude toward oj^ej;,people's risk taking at the same time as it >
is associated with aversion for personal risk. Isen et al. (1982) >
found that positive emotional states were associated with risk ;
taking in low risk situations but with risk aversion in high risk -
situations.
The perception of an acute threat and consequent high risk
judgment can be expected to lead to anxiety, at least in those
people who do not cope with the situation by means of denial.
Anxiety, in turn, is known to lead to a deteriorated level of
cognitive functioning (e. g. Deffenbacher, 1978), possibly because
of a loss of short-term memory capacity (Darke, 1988). The likely
result is procrastination since people under such circumstances
easily fall prey to rationalized excuses for inaction.
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13. Methodological issues
13.1. The definition of risk
Most research reviewed here has utilized risk ratings as dependent
variables without a clear specification of the meaning of the term.
However, risk is an unusually ambiguous word. It can denote the
probability of harm, the size of a loss or a combination of the two
(e.g. their product). Sjoberg and Orottz (1988) asked their
subjects whether they judged risk as a probability, the size of a
consequence or a combination- of the two. While most subjects chose
the first definition, many opted for the other two. There were
systematic differences in risk judgments depending on the choice
of risk definition. It may be important to pay attention to how the
subjects understand the term risk in interpreting their judgments.
13.2. Response rates .
Table VI indicates that response rates have been fairly low in
these studies. The table also gives the total number of respondents
which could be used for data analysis and as can be seen that
number varies by an order of magnitude across samples.
The last column gives the final response rate of all those
that were eligible for inclusion in the sample. It is the outcome
of several factors which give rise to drop-out. For example, in the
Florida risk attitude study (Section 5.9, page 37) 30 percent of
eligible homeowners could not be reached on the telephone* and of
those that could be reached, 40 percent agreed to participate.
Hence, the total response rate is given as 28 percent.
Sometimes the researchers have given conditional rather than
absolute final response rates. In the NYSERDA study, comparison
sample, followup;, survey^.the response rate is given as 72.2
percent. However, this is in percent of those who completed the
baseline survey, not of all those who were eligible for inclusion.
The latter percentage is more informative as to the information
value of the data obtained-, and it is considerably smaller (36
percent). (Strangely enough, the results for the monitored group
are given according to the principle suggested here).
I have tried to distinguish, whenever relevant, between
acceptance to participate and actual response. In some cases the
reports do not give any information about how many people were
approached to give a certain number of people who agreed to
participate. This is a piece of information that should have been
included. Even if data do not aspire to strict statistical
representativeness it is useful to know if 10 or 90 percent of
those approached accepted to participate.
The overall picture is not too bad. Several studies reached
respectable response rates. Some comments about the lower values
are in order, however.
67
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— ^c.shw.,u^ rates in ci-su radon studies, measured as
percent of the studied sample that (a) accepted to participate, and
gave usable responses.
Type of data Number
Maine study.
Section 5.2*
NYSERDA study
Section 5.4
Monitored group
Baseline
1st followup
2nd: followup* -
Comparison group-
Baseline
1st followup
New Jersey study
Section 5.5
Random sample
Confirmatory sample
New Jersey study
of radon information
Section 5.6
of Prop. Prop.
collection usable accept, resp
method respondents
Telephone
221
Telephone 2231
Telephone 2087
Mail ca.1700
New Jersey study
of communication format
Section 5.7*
Maryland study
Section 5.8 •.•:.;::...:;... '. . 'M:;. •:
Baseline.;:;:: '••••-' •'•' ' ''^':,^':
FollOWUp .. >W^-;:
Florida study i xi1^""';i'
Section 5.9;.;.-; .. ;--: ;,••::<;•••>
Florida personality ^ v
study, Section 5.
Onondaga study • ~
Section 53Hfe&* *
Washington^ D. C,, study
of mitigation
Section 6.4
Telephone
Telephone
Mail
Mail
Mail
Mail
252
657
141
271
1948
Telephone 1547
Telephone? 1528
Telephone 837
Mail
Mail
Mail
320-
204
709
No info,
No info.
50
78
47
No info.
34
28
84
No info
77
.97:^:1111^
9*C:::«ixI:i
50
36-
79
75
67
38?
81,
77
Notes. 1. A few of the minorr exploratory studies are excluded,
2. All data have not been collected at the time of
writing. ,. 'lr
68
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Desvousges et al. were concerned about their response rate
(which is by no means dramatically low) and suggested that it may
have been related to the fact that they had to carry out their data
collection during the Christmas holidays. However, since their
response rate is no worse than that obtained by others, it seems
that the explanation may be less credible. Perhaps there is a
general decline in response rates to telephone interviews because
of their increasing use and new computer technologies.
What are the possible effects of these low response rates?
Weinstein et al. argued that the people who respond probably are
more concerned and know more and that, therefore, risk denial may
be underestimated by these data. On the other hand, the better
studies have examined some characteristics of respondents as
compared with the population being studied. They have often failed
to detect important differences, with the possible exception of
gender. Women tend to be over represented among the respondents.
Since women are known to be more-risk averse than men, this is
likely to create some bias.
13.3. Response scales
Weinstein et al. included "don't know" among their response
alternatives and many people chose that alternative, perhaps partly
because the radon issue was new and people in fact knew little
about it. These responses were then treated as missing data,
creating some- problems with correlation statistics and regression
models.
Krosnick and Schuman (1988) showed that more intense or
extreme attitudes are just as vulnerable to such response effects
as effect of the order of questions, with one exception: if a
middle, neutral, response is provided it is usually very attractive
to those who have-only weak convictions.
Smith et al. (1987) obtained explicit ratings of information
materials and found- that homeowners discriminated little between
them. This was so in spite of other findings in their study which
clearly showed that one condition (the fact sheet) was inferior
because it led to less knowledge and clearly exaggerated risk
rating**
It is an open question if responses to a question about
willingness to pay for additional information give a valid
indication of true demand.
Some work has indicted consistency between actual purchase and
CV questions, however. Dickie, Fisher and Gerking (1987) found that
there was no difference between the amount of strawberries actually
bought and the amount that people just said that they would buy.
This result has some interest but, as the authors point out, it
cannot readily be generalized to WTP measures used for evaluating
environmental protection measures. The latter usually concern much
69
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more important issues and people can be suspected of letting t
judgments be influenced by strategic considerations.
Methodology may account for the difference between the NYSERDA
and New Jersey studies. In the NYSERDA study it was found that
people exaggerated the radon risks while some aspects of data in
the New Jersey study suggested the opposite. The NYSERDA results
utilized the absolute level of the risk scale, transformed to a
probability scale. However, the absolute level may not be very
informative since scale levels are notoriously sensitive to
contextual factors. Another big difference may be that the NYSERDA
subjects all had agreed to have their homes tested. So they-may
have been more health-conscious, or risk averse, than the original
NJ samples. In addition, it is unclear that risk may be
straightforwardly translated to probability. The sheer lack of
concern over radon, as shown by the lack of radon testing,
indicates that people at least in that sense underestimate the
risk.
Risk estimates can be given either in an absolute or a
comparative manner. Absolute ratings utilize a scale from, say, 0
(no risk at all) to 7 (a very high, or severe, risk). Comparative
ratings are done with reference to a standard, such as the average
radon risk in the respondent's community or compared to smoking
risk.
These two types of ratings can be expected to have somewhat
different properties. Sjoberg and Drottz (1988) obtained compara-^
tive and absolute ratings of job risks from nuclear power plant
employees. They found that comparative risk ratings carried
information about both the reference level and the compared risk. ,
The finding of Weinstein, Sandman and Roberts (undated) that >
absolute risk ratings showed the expected negative relationship to i
risk information, while comparative risk ratings did not, may have '
been due to these different informational bases behind the two •
types of ratings. . . )
*.-..-,,-.._. , • •
13.4. Time perspectj-Vfl' _ ..... _ I
. _: •••-->• : • ' •
Almost all studies were concerned with short-term changes in :
knowledge, attitude*, and behavior. The persistence of attitude ;
change is, of course, no trivial matter (Cook & Flay, 1978). For
voluntary changes in behavior (e. g. testing and mitigation) it is
probably necessary to have lasting changes in attitude. In the
radon case, attitude changes need to last long enough to elicit
testing and mitigation.
13.5. Attitude measurement;
In some studies the coverage of attitude about radon risk has been
sketchy. It would be useful to obtain more detailed information on
the components of the risk attitude. This could be done with the
help of a well established attitude model such as the one devised
by Fishbein (Fishbein & Ajzen, 1975).
70
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Concern has been found to be an important variable in some
radon risk, studies. There have been doubts that people can give
valid estimates of concern or importance of attitude components
(Slovic & Lichtenstein, 1971). in the field of political attitudes,
for example, it has been hard to demonstrate that aspects of a
candidates' policy judged as more important also in fact are more
decisive when it comes to voters' choices. Krosnick (1988), showed
that these difficulties were largely methodological, that people
can make valid judgments of importance, and that more important
dimensions also have a larger weight in accounting for choice.
Attitude measurement tends to utilize rather simple responses
and does not usually involve attempts to get more detailed
information about the thought process behind risk, attitudes and
perceptions. Bostron (1989) attempted just that, however. She
collected extensive interview data about radon attitudes and
perceptions from 24 subjects, who were all reasonably knowledgeable
and involved. She devised an interesting scheme for scoring the
accuracy of people's notions about radon and came up with several
(preliminary) conclusions. People were found not to understand
concepts of radioactive decay, to have scanty knowledge about
mitigation, to be unclear about the effects of radon (many
mentioned cancer unspecifically, not lung cancer), and to know
little about the concept of a soil gas. Some of these findings
could perhaps have been obtained with, a more conventional and
simple approach, but the results still indicate that further work
along this line could be of value.
13.6. More detailed information about crucial decisions
•
The studies reviewed here have collected an impressive amount of
information about, how people perceive radon risks. Still, there
are some types o£>sinformat±on that are missing.
Several projects collected data on reasons for not testing
for radon, such as those shown in Table II above from the New
Jersey study. However, I lack comparable data from testers on why
they have tested. Such data may be even more informative than
reasons for not testing, which seem a bit like excuses rather than
real reasons. There may be several routes to testing that differ
in interesting and important ways, e.g. health concerns, social
pressure and property value concerns.
14. Discussion and conclusions
14.1. Summary and discussion
Radon is a risk with certain unique properties. It shares some of
the characteristics of all risks from ionizing radiation (slow
effects in the form of cancer, a risk from a physical agent that
cannot be sensed). At the same time it is a risk that threatens
people in their homes and homes are usually perceived as safe
places under one's own control and responsibility.
Radon risk has been compared to such life-style risks as
smoking or drinking alcohol. The similarity is that people take
71
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these risks as private individuals. Society is reluctant
legislate the risk level to which they can expose themselves. T
must act voluntarily to mitigate or eliminate these risks.
There are also differences between radon and life-style risks.
First, radon exposure does not confer any benefit as smoking and
alcohol do. Second, it is not clear who, if anyone, is responsible
for radon risk. Radon risks were largely unknown to the US public
before 1985 and most home owners bought their current houses before
then.
Reducing a life-style risk involves making a commitment to
action in spite of temptations to delay action. In this sense,
there is a further similarity between radon and life-style risks.
Many people in one of the studies reviewed here became
"procrastinators", i.e. they changed from indifference towards the
risk to acknowledging the necessity of action "in principle". It
is well known that people find it very difficult to- quit a risky
habit and that rationalized delays are very common. It is too early
to tell if the same phenomenon will occur for radon risk but it is
possible. On the other hand, testing for radon and mitigating
require only two discrete actions while the ex-smoker has to resist
cigarettes several times a day. People do not have to quit a habit
(or develop a new one) in order to test and mitigate for radon.
1
Most smokers know that their habit is unhealthy but th
procrastinate in spite of their own knowledge of what is in the
best long-term interest. Something similar seems to be going on
the case of radon. More information will therefore probably not be
sufficient. It has even been argued that more information will
provide people with material for twisted rationalizations for why
they have not tested and can go on postponing it indefinitely
(Weinstein, Klotz & Sandman, 1988). It is furthermore well known
from research on such hazard warnings as for floods and hurricanes
that people tend to ignore them if the warnings are not directed
to them personally- in a very concrete manner (Mileti & Sorensen,
1987) or supported by feedback from friends (Kunreuther et al.,
1978). — •"••• -v
In the present report I have reviewed several studies of-how*
people perceive antf respond to radon risk. Initially it was
believed that information about radon risk might give rise to panic
reaction*, but experience has not confirmed this concern. On the
contrary, people are often quite indifferent to the issue, at least
in regard to their own homes. This indifference can be interpreted
as a manifestation of a rather general tendency to deny health
risks and it has been suggested that denial of radon risk is
moderately strong compared to other kinds of denial.
Many people are outright negative to radon testing.
Pennsylvania authorities at one point went from door to door and
offered free radon testing. Still, about 50 percent refused to havej
their homes monitored. Some people are concerned that rumors of af
radon problem will affect property values in an area.
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It is worth stressing that people tend to be indifferent to
radon risk in spite of the fact that the EPA action level is quite
high compared to other risks. The actual risk level seems to be a
poor predictor of public response to risk. The action level in
Sweden is 2.5 times higher than the US level and it corresponds to
the lung cancer risk of smoking a pack of cigarettes per day.
Still, Swedes are just as indifferent to radon risk as Americans.
As might be expected on the basis of these facts, there is
usually only a weak correlation between the scientifically
estimated risk level, as physically measured, and the level of
perceived risk. Some people with low levels of radon in their homes
are quite concerned while others, with quite high levels, are
indifferent. This low correlation may partly arise from the fact
that the physical-measurements are not perfect indicators of the
actual risk level. The risk also depends on how much time people
spend in the house, their age and other factors. Still it is
reasonable to conclude that there is a weak correlation between
perceived and actual radon risk.
There is little evidence suggesting that people do not believe
that the radon readings are accurate or that the risk assessments
are incorrect. They probably believe that the risk is there, in
principle and for people in general, but that they themselves are
for various reasons less vulnerable or more lucky. It is also
possible that or they just do not care about getting involved in
protecting themselves against another risk, they simply go ahead
and take it.
The effects of information about radon risk provide a partly
different picture. Two studies have shown that people revise their
risk estimates in the "right" direction, i.e. in the direction
suggested by the readings of radon levels, in their homes, still,
other data suggest that even for risk revisions there may be
irrational denial factors at work. There is some support for the
thesis th^t people are more inclined to accept that fi£h££ people's
homes in theia?- community may be at risk than that their own homes
may be at risk. _;. ,; „
If actual risk is not strongly correlated with perceived risk,
then what accounts for perceived risk? There are some correlations
with background data. Older people are less worried about radon,
and parents of small children more so. In some studies women have
been shown to be more worried than men, but the gender difference
is much smaller for the perception of radon risk than for many
other types of risk. People with a family member with cancer were
more concerned about radon in one study. Some personality variables
have been suggested as predictors of perceived radon risk but so
far little research has been carried out on this issue.
Nevertheless, these factors are only weakly related to
perceived radon risk. There is simply not enough research available
to support more definite statements about what factors influence
perceived radon risk.
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People seem inclined to deny radon risk as they do a m
of other health related risks. This reaction is in contrast to
attention given to the risks from industrial pollution. Thus, there
is no tendency for people to deny risks in general. Only certain
risks are denied. It would be of interest, in future work, to
investigate why some risks are denied and others exaggerated. It
may be that risks that are denied are risks where the threatening
agent is associated with the self.
I suggest that radon risk perception is a special case of ego-
related risk, i.e. it is a risk that is closely related to self
conceptions. This hypothesis is derived from evidence that people
tend to perceive their homes as parts of their selves, especially
if they have lived in them for a long time. And there is a tendency
to deny that something as closely related to oneself as one's home
could be threatening. Reactions to radon risks may therefore be
related to perception of one's home. It is conceivable that risk
communication would be more efficient if the risk would be clearly
separated from the home.
The hypothesis is supported by data that indicate that people
with a longer history of living in a house are more likely to deny
radon risk. Other supporting data show that people react strongly
to radon risk when it is introduced in their neighborhood - not on
their homes*- Part of this reaction is probably a result of moraJ
indignation over being exposed to a risk by someone. Peop]'
strongly resent a loss of control, and they tend to perceive
which they can control and are responsible for as benign.
As an alternative explanation of perceived radon risk, risk
reactions could be seen as dependent on a number of risk
characteristics such as those suggested by Fischhoff et al. (1979).
The problem with that approach is that it assumes that risks
reactions are based on cognitive information integration. It misses
the motivational and emotional aspects jpj£ risk-, perception. Few
attitudes are morwel£kely to be dependent ...upon emotional reaction
than risk attitudeV. In addition* it i*. w»lL known that-attitude*
in general cannot" be veil explained by beliefs (McGuire, 1985).
This is not to say that there is not some correlation between risk
attitudes and risk characteristics. The question is what the
correlation means. Slovic et al. assumed that attitude* are caused
by belief*. It i* more likely that both attitudes and beliefs are
caused by an underlying common image (Sjoberg & Biel, 1983).
Concern about radon risk may be problematic by itself. It has
been reported in some work that higher concern about radon leads
to more blame attributed to the government and puts less
responsibility on the individual. Higher awareness, on the other
hand, was correlated with greater perceived responsibility on the
part of the homeowner. The question is whether it is possible to
increase awareness without, at the same time, generating increased
concern. More research on this topic could be fruitful.
Communication about radon risk with the general public has
been studied in two major investigations, one of which was
especially concerned with mitigation. These studies also
74
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investigated the effects of a major attempt by a television channel
in the Washington, D.C., area to encourage people to buy test kits,
available at reduced price in grocery stores. The television
campaign created an impressive interest in buying test kits. Over
100 000 kits were quickly sold and demand was by no means
exhausted. About 6 percent of the home owners in the area bought
test kits. However, only about half of those who bought the kits
turned them in for analysis and few people who had elevated radon
levels in their homes reported any effective mitigation beyond such
behavioral measures as keeping windows open more often.
The EPA-sponsored outreach activities in a Maryland community
were probably more effective than, the simultaneous television
campaign in stimulating people to test for radon. The proportion
that tested their homes rose from about 5 to 15 percent. There is
some evidence that the television campaign was effective in making
people aware of radon risk, but less effective in stimulating them
to act. A similar finding was reported in a New Jersey study of
smaller scope where it was found that there is a link between risk
perception and action but that the link was quite weak. The weak
effects of the television campaign are in line with extensive
experience from other studies of health-related public service
messages. The effects are usually quite marginal.
A few studies have investigated knowledge about radon and
found that people are fairly well aware of its general properties,
although they lack specific knowledge. They may also lack knowledge
about how to test for radon and whom to ask about testing and
mitigation. They are especially uncertain about mitigation and its
costs. . '
It is relatively easy to inform people, about radon facts.
However, there is little relation between.knowledge and tendency
to test and mitigate. This finding is in line with a generally
noted lack of relationship between attitudes or beliefs and
knowledge. . ......
Risk communication is a topic of much current concern. EPA
has published a brochure containing "Seven cardinal rules of risk
communication11 (O^ S. Environmental Protection Agencyr 1988 b). It
is reasonable to ask what relevance such advice has in a concrete
case such as radon risk.
The Cardinal Rules make a rather pallid impression, on closer
scrutiny. To be more specific, the communicator is advised to
- Accept and involve the public as a legitimate partner
- Plan carefully and evaluate your efforts
- Listen to the public's specific concerns
- Be honest, frank and open
- Coordinate and collaborate with other credible sources
- Meet the needs of the media
- Speak clearly and with compassion
It is hard to avoid the impression that these rules have been
designed for a case where the communicator wants to reassure the
75
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public that the risks are smaller than they fear. Such risfl
exist, but the problem with radon risk is the opposite. Still, the
brochure never states that its applications are only one type of
risk, it seems on the contrary to be aimed at very general
application.
Since radon has been stated as one of the major threats to
public health it would be valuable to have rules designed for the
case when people need to be alerted to a danger. The fact that this
has not been dona already may be due to the fact that radon in
homes constitutes no threat to the industry, while public concern
over mean* of energy production aad disposal of industrial waste
does constitute such a threat, at times.
There is-an increasing-interest in research on mitigation of
radon risk. It baa been found, that there is a rather weak
correlation between scientifically estimated risk and mitigation,
but a stronger correlation between perceived risk and mitigation.
This is an example of a quite general truth: people react to what
they perceive reality to be rather-than what it really is.
It is not yet clear how much mitigation one can expect in
different circumstances* Some data certainly suggest that home-
buyers are likely to be among the most responsive to the radon risk
message. On the other hand, not all data on mitigation are at
negative as the ones reported in the study of the Washington,
C., television campaign* A follow-up of highly motivated New Jersej
homeowners found a high rate of mitigation. Some Swedish data were
in between the two American data sets. (Cultural comparisons are
risky, however, since many crucial aspects, such as the economics
of housing and mitigation, differ dramatically between Sweden and
the USA). -•• -... .: -,.. - .= .*..•
-A few studies haver investigated the format and contents of
radon risk messages.. Av aw^oc study compared "command*" and* ""cajole/1'
styles of cpmmualcation*.That study also investigated and compared
qualitative vs quantitative types of information. The results were
somewhat complex-and differences were-not large but- there was a
tendency for a command; stylesof communication to be-mo»t effective.
That study also compared the use of a brief fact sheet as a
replacement for more extensive brochures* It was found that those
who had be*n given the fact sheet tended to be more concerned about
their risk-level than.others. This was true in spite of the fact
that the* fact sheet was only given to those who had very low levels
of radon in their homes.
The investigators concluded against the use of the fact sheet.
That may be a reasonable conclusion for that particular group of
homes and their owners. It may still be the case that a short fact
sheet would be useful for people who have higher levels of radon
measured in their homes. It has been found that people, if given
a basis in rich information material, tend to construct defensive
denial conceptions. In other words, more information makes it
easier for them to come up with rationalizations for lack of
action. Of course, a short fact sheet need not be very similar to
the one used in the NYSEROA study.
76
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Thera have been few attempts to analyze the contents of radon
risk attitudes. So far, most data suggest that health concerns are
most important. Many studies could have profited from a more
extensive mapping of the components of risk attitudes, using one
of the veil known models of attitude measurement, such as that
devised by Fishbein (Fishbein & Ajzen, 1975).
Many of the studies reviewed here used a risk concept that
was not further explained to respondents, who were asked to judge
such variables as size of perceived radon risk. However, other
research has shown that people interpret the word risk in various
ways. There may be differences among genders and educational strata
in whether respondents interpret risk as probability, as the size
of the consequences-or- as a combination of these two concepts.
Interpretations of results may be misleading if this factor is
neglected.
Another interesting methodological aspect is the response
scale. It is difficult to translate the judgment of seriousness of
a risk into subjective probability, and seriousness could refer to
either probabilities or consequences. On the other hand, it is
notoriously difficult to obtain valid judgments of small perceived
risk. As an alternative, comparative risks often are used to assist
people in judging small risks. Radon risk has been compared to the
risks of smoking, for example. This approach is well worth trying
but one should bear in mind that comparative risk judgments are
more complex than absolute ones because they involve two risk
levels rather than one. Risks are probably perceived in a context
of several threatening events and conditions and the judgment of
any given risk may well be affected by how certain other salient
risks are perceived. For example, people with a very risky job may
perceive their radbn home risk as minor just because it is
implicitly or explicitly compared to job risk.
In many circumstances people are most strongly affected by
social diffusion of information and attitudes, i.e. what their
friends and neighbors and locally prominent people tell them. For
this process to spread quickly there must be many willing
"informers", However, in the case of radon there are still very
few people who have shown any active interest in the issue of home
testing, and those who have informed their friends and neighbors
have sometimes met with hostile reactions. It would be of interest
to investigate such obstacles to social diffusion.
There has been little work on property values and house sales
as related to radon. There are indications that this aspect is very
important for some homeowners. An interim report on radon risk
communication states that "Some Regions indicated that many of
their radon-related telephone calls focus primarily on the real
estate implications of radon rather than on health concerns" (U.S.
Environmental Protection Agency, 1987 a, p. 4).
A Swedish study recently found that radon did not seem to
affect house prices. Informal information from realtors in the USA
confirms this finding. However, a Colorado study showed that many
-------
people are quite concerned about getting a house tested for
before they buy. Some 50 percent of the hone-buyers participa
in the study reported that they had done so. These people also
tended to mitigate much more often than those who bought test kits
and monitored their own homes. Indeed, the prevalence of mitigation
at or above the action level of 4 pCi/1 was 100-200 tines as great
for hone-buyers as for homeowners. People whose employer was
especially concerned about radon risk and those who were in contact
with a knowledgeable realtor or building contractor were especially
prone to test ard nitigate. These results were obtained in a state
where radon risks had not been extensively discussed in the nedia.
The fact that real estate prices are not affected by radon
nay be related to the prevalent information that a radon problem
usually can be fixed quickly and fairly cheaply. There has been
little awareness so far about how often continued monitoring for
radon will be required and additional mitigation will have to be
undertaken. When this issue is given wider publicity there could
be an effect on real estate prices.
Virtually all research so far has been conducted with
homeowners so the social strata that have been represented have
not been representative of the whole population* We do not know
how people who rent their homes respond, to radon risk, or how
involved their landlords are in monitoring and mitigating
houses. There is also very little work reported about attitudes
radon in schools, public buildings and workplace*.
J.4.2. Conclusions
Research on radon risk perception and risk mitigation has not
proceeded very far, simply because the problem is so recent-
However, it is possible to draw some conclusions on the basis of
existing research results.
: .-?••« •'•: • iSrtc <. ••= •- •
(1). The major problem is indifference to high-level risk,
especially among people who already live in a home that may have
an elevated radon level. _.,_-..
(2). Hose buyers are probably much easier to alert to the issue,
with ensuing radon testing and mitigation.
(3). Studies of variations in risk communication material suggest
that brief, to the point, recommendations about what to do are
better than longer messages that allow the reader to form his
personal opinion. It is just too likely that these personal
opinions will be defensive risk denials.
(4). Even the most effective mass media campaigns and outreach
community programs investigated so far have succeeded in,
stimulating only a small fraction of the population of homeowners
to monitor and mitigate. Whether these campaigns have justified
their costs has not been determined. A community outreach program
80
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An experimental study of risk communication formats
(Weinstein, Sandman & Roberts, 1989) found that a brief statement
about the action level was best for eliciting continued concern.
On the other hand, full information about the risk, including
numerical, risk comparison data and graphical information, was best
for creating a balanced view. A major difficulty in this study was
that of communicating absolute risk levels. A graphical display
seemed sufficient to make people disregard a difference in absolute
risk level in the range 1-25 (between radon and asbestos).
The NYSERDA fact sheet was somewhat similar to the condition
of stating the action level only in the study by Weinstein, Sandman
and Roberts (1989). In particular, the fact sheet did not specify
anything about the risk of radon levels lower than 4 pCi/1. one can
conclude that a brief message is most likely to elicit continued
concern among horn* owners.
Another reason for favoring very brief messages is that people
have difficulty in handling information and that they are not very
motivated to obtain it. Studies of.public service information in
the form of printed brochures usually have shown that most people
do not bother to read them and that those who do read them quickly
forget most of their contents. Other investigators have studied the
effects of level of risk communicated and found that a more
threatening message tended to invite more risk denial.
The conclusion is that the most effective message format and
contents should be brief and not too threatening. Messages should
furthermore emphasize that radon is a risk that must be taken
seriously. Comparing it to some other risks, such as smoking, can
help people understand its size, rt should be clear that it is
simple and cheap to test for radon and relatively simple and cheap,
in most cases, to mitigate. Quantitative information about the risk
level is to be preferred to qualitative, and a11 command" tone is
better than a "cajole" tone for eliciting radon testing.
Another possibility _ involves switching to the common
international measure Bq/m3 rather than pci/l. Sine* 1 pCi/1 -40
Bq/m3 such a switch would involve larger numbers that could by
itself have an effect (whether positive or not).
These conclusions should be regarded as preliminary. They are
based on a rather complex set of findings from radon risk
communication studies and from communications research in general,
as well as basic principles of cognitive psychology.
It is important to determine what the goals of radon risk
communication should be. Should it be aimed at inducing behavior
change, i.e. testing for radon and mitigation if the levels are
high? Or should it aim at informing the public so that they can
make well-informed decisions? If the latter path is chosen, some
problems arise. First, it is very hard to know if a person has made
a well-informed choice. Indeed, the concept itself needs
considerable clarification. Second, information is by itself
77
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insufficient to induce much behavior. The studies have found ve.
low correlations between acquired knowledge and testing for radon
Research methodology is an important issue in a discussion of
risk cosaunication. The empirical studies reviewed in the report
vary considerably in this respect. Virtually all were quantitative
and employed either nail or telephone survey methods but they
differed in many other respects.
There is evidence that people are net very eager to
participate in surveys of this kind. Response rates around 60
percent or lover are common in spite of several reminders. Some of
the problems of low response rates have been attributed to data
collection during holidays, but there is no evidence that these
particular studies yielded especially low response rates. Indeed,
the US public probably is saturated with opinion polls and survey
investigations and it is becoming more- and more difficult to
recruit respondents for new waves of data collection.
It should also be pointed out that several of the major
studies reviewed here reported quite good response rates and that
there is no evidence of any major bias in the samples of
respondents.
It can still be noted that women seem to be more likely tod
accept invitations to participate in radon risk studies than menfl
and the result is that they are overrepresented in some of the'
studies. Also, the samples tend to consist of highly educated and
financially secure people, possibly because the studies have
focused on home owners rather than renters.
Attitude change has been studied for decades. It is usually
quite hard to change people's attitudes, especially to change them
permanently and. to affect-behavior* Changes'tend to be-short lived.
The empirical work on radon so far has- not followed attitudes for
a more than a few months, with the exception of the NYSEROA study.
Longer follow-up tines- are called fo* in order-to get a realistic
idea about ban-persistent attitude change* are.
It would probably be fruitful to investigate in more deta-il-
how people reason with regard to radon and testing. One piece of
information that is~ lacking in these studies is whv people test
(there is data on why people do not test). Testing can be motivated
in many ways, for example health, econonic factors or conformity
to expectations, by friends. The reasons people have for testing
could stimulate the formation of hypotheses about effective methods
of risk communication.
Qualitative information about the conceptions and
misconceptions that people have about radon would also be of
interest. Among other things, such conceptions could be of crucial
importance for nitigation. Some people may believe that radon is!
most likely to be found in the attic rather than the basement of
a house (since many gases are lighter than air). Ionizing radiation
is also something that people know little about and they tend to
espouse several misconceptions.
78
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appeared to be more promising than a major television campaign,
although they probably reinforced one another.
(5) . Further research should be conducted on the components of
radon risk attitudes and conceptions, in particular why some people
test and mitigate. Interpretation of findings would probably be
helped by more information on how people interpret such key terms
as ."risk".
(6). There are important ethical aspects of radon risk that have
been neglected in research. Some people see nobody as responsible
for a radon problem, others may bias* themselves, contractors or
the government. The owner of a house may or may not feel
responsible) for the health of others who live in it. At the time
of a house sal*- there is a special ethical problem if the seller
knows thero is a radon problem. These are important matters for
further research. .
(7). There is a total lack of data on how renters, as opposed to
homeowners, perceive risk and how their landlords view the radon
issue. There is very little data on the perception of radon risk
in public buildings and workplaces. Perhaps some homeowners can be
alerted about, .thair home risks if they get involved in school
building risks.
(8). Although the sparse data that exist on the issue suggest that
radon risk does not reduce property values, the issue certainly
needs much more investigation. Will the lack of effect persist when
more experience with mitigation and its costs and effects
accumulate? People may at this time be overly optimistic about how
easy it is to "fix" a radon problem permanently. Do people see
monitoring as a potential economic threat? Or will las& of
monitoring and disclosure of results at the time of a house sale
be the real economic threat in the sense that homes that have not
been tested will sail for a lower price?
81
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APPENDIX
COMMUNICATING RADON RISK.
Practical implications of recent research findings
This appendix provides a summary of principles of effective risk
communication applied to radon risk, based on current research.
The basic principles of good communication are a first step
for successful communication of radon risk. Guidance on these
principles is readily available elsewhere (e.g EPA's "Seven
Cardinal Rules of Risk Communication").
Research on persuasion and attitude change has shown that it
is difficult to change attitudes and even more difficult to change
behavior. Knowledge is easier to communicate but knowledge is by
no means sufficient to cause a change in behavior or attitudes.
Fortunately, it has still been found that skillful and enthusiastic
attempts at communication of radon risks have had some success.
People often have biased perceptions of risks. They may
dismiss or exaggerate them, depending on many factors. Unlike such
risks as nuclear power or toxic wastes, the largest problem with
radon is that people tend to dismiss or deny the risk.
There are several reasons why people tend to deny and dismiss
radon risk:
- the risk is associated with one's home which is usually perceived
as a source of security and as part of one's identity.
- acknowledging the risk carries with it both, economic and
psychological costs: it requires testing and possibly costly
mitigation, and also worry about health effect*.
'•(•'•.. : • . - . T . ; .
- adverse effects will not show up for a long tin*, and: people are
more concerned about the short run.
• the risk is perceived as natural rather than man-made.
The objective of any radon risk communication program should
be to •rouso - but not alarm - people and motivate them to take
appropriate action. The following points can help in designing such
a program:
1. People are more likely to acknowledge and act on a risk if they
(a) see it as a serious threat, and (b) perceive that measures to
mitigate the risk exist and are within their reach. Both these
points must be formulated clearly. First;, people need to be aware
of the risk. Radon cannot be perceived with the senses, and its
effects, if any, are delayed. People need to be informed that even
if they have already been exposed to radon for a long time, it is
never too late to mitigate since the body can repair some damage
if exposure is decreased so any reduction in exposure reduces
risks. Make then aware that test kits are easy to get and
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inexpensive. Try to diminish fears that mitigation is
expensive and complicated.
This suggests the following strategy:
A. Raise awareness: "Say, have you heard about Radon? It is a
colorless and odorless radioactive gas that seeps into some homes
and can cause lung cancer".
B. "It is easy to find out whether your home has dangerous radon
levels - testing is inexpensive and you can get a do-it-yourself
test kit at your nearby hardware store, supermarket, or discount
store."
C. "You can stop worrying if your radon level is low. If it is
high, mitigation is affordable and effective."
D. "What if you have already been living for^a long time in a house
with high radon levels?" (Provide material-about lungs repairing
damage).
E. "But I only plan to live here for a few years, at the most, why
should I mitigate?" (Point out that mitigation apparently protects
resale value - however, there is little research yet on this
problem. Point out that mitigation is a way of protecting one's-
investment in a house, and a way of avoiding unpleasant surprisfl
when selling it).
2. People frequently dismiss potential hazards when it comes to
their own personal risk, yet accept that others, unrelated to them
but otherwise siail&r, are at risk. This tendency may be enhanced
when _the probability is small (say, less than 0.1) or uncertain.
Sometimes these difficulties may be avoided by accumulating risks
over a longer time period or by framing them in appropriate terms,
e. g., the number of people in the community likely to develop lung
cancer from a.given.level of radon, exposure.
3. People dislike uncertainty and may use it as an excuse for
disregarding a risk message that indicates a lack of complete
understanding of a risk or conflicts among experts. Of course,
honesty is essential. The best strategy is to formulate the message
that although experts do not have a complete understanding of all
issues involved, they do agree about important practical
conclusions.
4. Because it is hard to understand probabilities, people prefer
safety thresholds. They dislike being faced with a complex decision
involving trade-offs between various value dimensions that are
difficult to compare. Many people like to have someone they trust
make a difficult decision for them or to be advised according ta
a simple rule of the kind "act if value exceeds x". This means thaM
EPA1 s action guidelines will often be treated as safety standards!
5. Personalized risks, i. e. messages that are concrete and vivid
and that depict people with whom one can identify, are essential.
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6. Direct social influence from friends and neighbors is probably
the most powerful way of affecting behavior. However, it is not
easy to initiate such a process and, in the case of radon, people
may be unwilling to tell others about their experiences. One tactic
that has worked is for community leaders to support the testing
program by publicizing tests of their own homes and to encourage
others to test. Try to encourage people who have tested and
mitigated to tell their friends and neighbors about their
experience,, It should be seen as a smart and sensible thing to do.
It may help to associate testing with scientific and technological
advances.
7. There is some evidence that too little information may make some
people unnecessarily anxious about radon risk. Too much information
may, on th« other hand, be detrimental because it is too much to
absorb. People are exposed to an enormous amount of mass media
information. The obvious conclusion is that it is important to
formulate complete, but concise, messages.
8. Use as many media channels as possible. Design the message so
as to attract attention, make it concrete and repeat it often. A
utility bill flyer had encouraging results. Posters required
considerable'effort to place. Effectiveness of PSA's on radio has
been difficult to judge. EPA has produced a slide show, including
an audio tape and script. It is available through the Radon Office,
phone 202/475-9605.
9. Research has shown that people are especially averse to certain
losses. Here is a strategy that takes advantage of that tendency:
"Are you worried about what radon may do to you and your family?
Radon risk is one worry you can get rid of1 A radon test of your
home will either relieve you or all future worry over the issue -
a likely outcome - or it will be the first step in permanently
removing a threat to you and your family".
This gives a positive message rather than a negative one, while
doing nothing leaves one more thing to worry about.
10. SOB* data suggest that women are more likely to carry out
testing than men, and that they are particularly concerned about
their children's health so work especially with women and emphasize
that tasting for radon is very easy and requires no special
technical skill.
11. As pointed out earlier, information campaigns for motivating
voluntary changes in behavior are likely to have limited success.
Legislation has often turned out to be necessary in order to make
a difference, as in the case of seatbelt use in automobiles.
Effective reduction of radon risks may involve
(a) requiring construction techniques that reduce likely in-
filtration of radon; and
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ngl
(b) requiring testing at the time of a real estate sale, prob
after the buyer takes possession to avoid inaccurate low readin
Summing up, we conclude that risk communication is difficult
but by no means impossible. Important results have been achieved,
and the principles discussed here have shown promise in practical
applications. Further results are expected fron on-going research,
especially on mitigation behavior.
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