Predicting Radon Testing Among University Employees

Journal of the Air & Waste Management Association

ISSN: 1047-3289 (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/uawm20

Predicting Radon Testing Among University Employees Elizabeth Walker Peterson & Jonathan Howland To cite this article: Elizabeth Walker Peterson & Jonathan Howland (1996) Predicting Radon Testing Among University Employees, Journal of the Air & Waste Management Association, 46:1, 2-11, DOI: 10.1080/10473289.1996.10467435 To link to this article: http://dx.doi.org/10.1080/10473289.1996.10467435

Published online: 09 Jan 2012.

Submit your article to this journal

Article views: 258

View related articles

Citing articles: 3 View citing articles

Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=uawm20 Download by: [192.30.84.98]

Date: 10 October 2016, At: 06:20

ISSN 1047-3289 /. Air & Waste Manage. Assoc. 4 6 : 2-11

TECHNICAL PAPER

Copyright 1996 Air & Waste Management Association

Predicting Radon Testing Among University Employees Elizabeth Walker Peterson University of Illinois at Chicago, Chicago, Illinois

Jonathan Howland Boston University School of Public Health, Boston, Massachusetts ABSTRACT To determine covariates of radon testing behavior, we surveyed by mail a random sample of all Boston University employees (N = 915) six to nine months after they had been informed of the availability of radon testing services through the University's medical center. The response rate was 58%. Analysis suggests blue collar workers were underrepresented within the response rate. Slightly more than half of the respondents (51%) were men. The majority (69%) were under the age of 45. Twenty-seven percent of the respondents (N = 143) had tested their homes for radon. Bivariate analysis revealed important differences between radon testers and nontesters. Testers were 12 times more likely to be home owners than renters (p = 0.00), and were more knowledgeable about radon's characteristics and testing procedures (p = 0.00). Testers were more likely to view radon as a serious problem (p = 0.00), to consider radon testing efficacious (p = 0.00), and to consider themselves susceptible to exposure (p = 0.00). Testers were also less likely to perceive barriers to radon testing. We used logistic regression to compare the usefulness of the Health Belief Model and the Diffusion of Innovations Model in predicting radon testing. We concluded that the knowledge deficits and barriers to radon testing identified in this study should be targeted in radon educational interventions. INTRODUCTION In the United States, 5,000-20,000 deaths from radon exposure may be occurring yearly.1 For persons who are exposed at the EPA action level of 4 pCi/2 over a lifetime, overall risk for lung cancer is approximately l%-3%. 2 It has been IMPLICATIONS Radon poses a serious health problem to a substantial portion of the population. Without regulations requiring mandatory testing and remediation, radon testing remains a voluntary act undertaken by landlords and private homeowners. Understanding the population's knowledge, attitudes, and behaviors toward radon testing can provide insights for policy makers and public health practitioners in developing testing promotion campaigns. This study compared within a defined population characteristics of those who had initiated testing and those who had not. The results of this study come at a time when radon testing promotion strategies are still in their formative stages.

2 Journal of the Air & Waste Management Association

estimated that 12% of all homes have concentrations exceeding the EPA/CDC action level.3 Radon is a naturally occurring gas which is not perceptible to the senses. Indoor levels of radon depend both upon a building's construction and the concentration of radon in the underlying soil.1 Consequently, radon levels vary greatly from house to house. Reduction of indoor radon involves a series of decisions.4 The first is the decision to test. Despite public education efforts to promote radon testing and the relative ease of testing, to date, few homeowners have tested. In a Maryland study evaluating a community radon testing promotion program, baseline testing levels were about 5%; the program increased this by about 10 percentage points to 15%.s While these changes were quite large from a marketing perspective, from a public health viewpoint, the increase in testing was not commensurate with the risk.5 Similarly, findings from a survey of New Jersey residents suggest that without vigorous attempts to encourage public action, few people will take action to reduce their risk from radon.6 The purpose of this study was to explore covariates of radon testing behavior among a defined population offered radon testing through their workplaces. Specifically, we surveyed by mail a random sample (N = 915) of all Boston University employees six to nine months after they had been informed about the availability of radon testing through the Radiation Protection Office of University Hospital, an institution affiliated with Boston University. We queried respondents about a) demographic characteristics, including housing circumstances; (b) knowledge and sources of knowledge about radon; and (c) testing and mitigation behaviors. In addition, we questioned subjects about factors which behavioral theory predicts would be associated with the propensity to test for radon. We compared two theoretical models—the Health Belief Model (HBM)7 and the Diffusion of Innovations Model (DIM)8—with regard to their usefulness in predicting radon testing. METHODS Sampling The study population consisted of the employees of Boston University. A random sample (N = 915), approximately 15% of the Boston University employee pool, was selected with the assistance of the University's Personnel Department. Volume 46 January 1996

Peterson and Howland In May of 1990, all subjects were sent via interdepartmental mail a radon questionnaire with a cover memo explaining the purpose of the project. Return of the completed questionnaire implied consent. Sampling and consent procedures were approved by the Boston University Medical Center Institutional Review Board.

Survey Instrument The survey instrument consisted of an 82-item, self-administered questionnaire. Respondents were asked to report on demographics, current living situations, the physical characteristics of their current residences, and their knowledge of radon and radon testing procedures. Respondents who reported that they had tested their homes for radon answered questions about their testing experience concerning the date of testing, the results of their test(s), and the initiation of mitigation activities. The Diffusion of Innovations Model (DIM) hypothesizes that important differences between "early" and "late" adopters of innovations include socioeconomic status, personality variables, and communication behavior. Accordingly, subjects were asked about their demographic characteristics (e.g., income, education, age, and sex); about their personal characteristics (e.g., travel, information sources, reading behaviors); and about their exposure to information about radon through mass media and interpersonal communication channels. Pursuant to the Health Belief Model (HBM), we questioned subjects about the following factors: perceived susceptibility to radon in the home, perceived seriousness of exposure to radon, perceived barriers to radon testing, and perceived benefits of radon testing and radon mitigation. Each major dimension of the HBM was operationalized by developing belief indices comprising Likert scales. Finally, respondents were queried regarding a variety of health behaviors (e.g., using a seat belt or smoking) and their health locus of control (perceived control over factors that could improve their "prospects for a long and healthy life").

Inclusion/Exclusion Criteria Participants were required to meet the following criteria: • At least 18 years of age • Employee of Boston University or University Hospital • Live/work within 150 miles of Boston

Analysis Univariate analysis and bivariate analysis were performed to identify differences between testers and non-testers. In further analyses, we collapsed responses to various questions to create six indexes. Five indexes were developed in order to operationalize the HBM. These included the "Knowledge Index" [KNOWRADON]; "Barrier Index" [BARRIERS]; "Efficacy Index" [EFFICACY]; and "Seriousness Index" [SERIOUS]. "Perceived Susceptibility to Radon" [SUSCEPTIBLE] involved one item only. A "Cosmopolitan Index" [COSMO] was Volume 46 January 1996

developed pursuant to the DIM which suggests that being "cosmopolitan" is associated with the tendency to adopt innovations before they are adopted by other members of a given community. Finally, a Health Index [HEALTH] was created in order to explore the relationship between health safety consciousness and testing for radon. Each index was constructed by summarizing respondents' rankings to questions within the category of interest. The items comprising the indices are listed in the Appendix. Multivariate analyses were performed to compare the contributions of the HBM and the DIM in explaining testing behavior. For each, we used stepwise logistic regression, with reported testing for radon as the dependent variable. A cutoff point of p-value of. 15 was used for including independent variables in the model, with the exception of the variable which reflected having discussed, read, or heard information about radon (p = .56). This variable was forced because of its relevance to the DIM. RESULTS Response Rate Of the 1,074 individuals we sampled from the list provided by the Boston University Personnel Department, 159 were no longer employed at Boston University at the time of the first mailing. Of the remaining 915 surveyed, 533 (58%) completed questionnaires. Boston University employees who were sent the questionnaire were divided into three groups: 1) Facilities/Mail Room/Security Personnel; 2) Administration/Library Personnel; and 3) Academic/Health Care Personnel. The response rate from each of these groups was 27%, 63%, and 61%, respectively. Thus Facilities/Mail Room/Security personnel were underrepresented.

Respondent Demographics Respondent demographic characteristics are shown in Table 1. Fifty-one percent of respondents were men. The majority (69%) were under the age of 45. Sixty-one percent had postgraduate degrees, and another 23 percent had undergraduate degrees. Fifty-nine percent of respondents were married; 68% reported no children living at home at the time of the survey. Fifty-two percent of respondents made > $50,000/year. Forty-eight percent of respondents lived in single family homes. Fifty-six percent owned their own homes. Two percent reported that their bedroom was located partially below or below grade, and 28% reported that their bedroom was located on the first floor. Twelve percent of respondents said that they planned to move within the next year. When we asked if any members of the respondent's family spent more than five hours in the basement or in a room below grade, 21% reported "yes."

Knowledge about Radon/Sources of Information Results of radon knowledge questions are presented in Table 2. Seventy-five percent of respondents correctly identified Journal of the Air & Waste Management Association

3

Peterson and Howland Table 1 . Characteristics of survey respondents (N = 533).

Table 2. Respondent knowledge of radon.

1. Sex Men Women

51% 49%

2. Age < 35 years of age 36 - 45 years 46 - 50 years > 51 years

38% 31% 10% 21%

Item 1. Most radon in homes comes from: Industrial pollution Uranium in soil Home appliances Don't know

3. Marital status Married Divorced/Separated Widowed Single

59% 9% 2% 30%

4. Education Some high school or grade school High school graduate Some college College graduate Post graduate

1% 5% 10% 23% 61%

5. Household income Under $15,000 $15,000 to just under $25,000 $25,000 to just under $35,000 $35,000 to just under $50,000 $50,00 to just under $65,000 $65,000 & over 6. Housing status Own Rent

12% 14% 22% 17% 35%

56% 44%

7. House type Single Family Duplex Townhouse Condominium Do not know

48% 13% 2% 36% 1%

8. Amount of time family spends in basement > 5 hours < 5 hours Do not know

21% 78% 1%

9. Plan to move next year Yes Maybe No Do not know

12% 16% 70% 2%

natural uranium in the soil as the source of radon. Eightyfour percent knew that radon had no odor. Sixty-six percent knew that radon caused lung cancer; 37% knew that people's risk from radon exposure increases if they smoke. Thirty-three percent knew that the level of radon measured 4


Percent Responding 3% 75% 1% 21%

2. Which best describes radon? No odor Slight odor Do not know

84% 1% 15%

3. First aware radon could cause health problems: Today Less than a month ago Between one and six months ago More than six months ago

4% 4% 7% 89%

4. Can exposure to high levels of radon cause lung cancer? Yes No Do not know

66% 1% 33%

5. When radon is measured in a home, the level will: Depend on time of year it's measured Not depend on time of year it's measured Don't know

33% 20% 47%

6. People's risk from radon exposure: Increases if they smoke Stays about the same if they smoke Don't know

37% 8% 55%

7. Radon levels are usually higher in the: Basement or lowest floor Don't know

90% 10%

8. To determine whether there is a high level of radon in your home requires: An inexpensive screen test administered by homeowners Expensive radiation equipment administered by trained professionals Don't know

76%

7% 17%

in the home depends upon the time of year it is measured, and 76% knew that the screening test used to determine radon levels can be inexpensively performed by building residents. Results of other knowledge questions are also presented in Table 2. Fifty-five percent of respondents had had a discussion about radon, or read or heard information on radon, in the months prior to the survey. Tables 3(A) and 3(B) describe the sources through which respondents recalled obtaining information about radon, and the relationship to the Volume 46 January 1996

Peterson and Howland Table 3(A)."Through which of the following sources have you received information about radon?"

Table 3(B). "With whom have you discussed radon or radon testing?" Relationship

Source

% "Yes"

% "Yes"

Relative

35%

Newspaper Magazine

81% 46%

Friend

42%

Co-worker

34%

Radio

42%

Physician

4%

Television Poster Presentation

58% 13% 8%

Neighbor

12%

Friend/Co-worker/Relative Boston University Radon Testing Service

35% 35%

Table 4. Perceived barriers. Item

person with whom they discussed radon and radon testing. Twenty-six percent of respondents knew someone who had tested their homes for radon.

Percent "Agree"

I have so many other things on my mind that I can't worry about radon right now

28%

If I had a radon problem it would be costly to fix

30%

Even if a radon problem was fixed, my home would still be worth a lot less

12%

I do not know how to test my home for radon

38%

I do not know where to buy a radon testing kit

33%

If I did buy a radon testing kit, I might make a mistake when testing my home for radon

20%

The results of radon tests are not reliable

55%

Perceived Susceptibility Fifty-two percent of respondents agreed with the statement, "I have not been exposed to radon in my home because I live above the first floor." Forty-three percent of respondents agreed with the statement, "No one in my neighborhood has a radon problem that I know of." Thirty-five percent agreed with the statement, "I have not been exposed to radon in my home because my home/apartment was built recently." Only two percent of respondents agreed that their non-smoking status protected them from "health problems related to radon."

Perceived Seriousness Twenty-three percent of respondents agreed that more people in the U.S. have health problems caused by exposure to radon than by exposure to asbestos. Sixty-six percent of respondents agreed that "high levels" of radon in their homes could cause lung cancer. Only 9% of respondents agreed that the media "overreacted" to the radon issue. Forty-three percent of respondents agreed with the following statement: "If the state and federal governments were concerned about radon, they would regulate radon testing and mitigation companies." Perceived Barriers

Table 4 shows responses to items assessing perceived barriers to radon testings. Thirty-eight percent of respondents reported that they did not know how to test their homes for radon. Fifty-five percent reported that they felt the results of radon tests were not reliable, and 36% reported that they would not be able to find an experienced radon contractor if needed.

Likelihood of Taking Action Six survey items were used to assess likelihood of non-testers taking an action related to radon testing. The proportion of respondents who said they were very or somewhat likely to Volume 46 January 1996

I don't want to get my home tested for radon because I think the results are available to the public (or the state)

2%

I don't have time to test my home for radon

11 %

If I did test my home for radon and the test revealed unacceptable levels of radon I would not know how to find an experienced radon contractor to fix the problem

36%

I don't trust testing companies that go to homes to test for radon 27%

take action in connection with radon testing and mitigation is reported in Table 5.

Testing Behaviors Twenty-seven percent of the respondents had tested their homes for radon. Among testers, 94% reported that they tested their home for radon because of concern about the health effects of radon. Fifteen percent responded that the purchase or selling of their home was a reason for testing, and 8% said that a close friend or relative suggested the test. Sixty-four percent of testers purchased their testing kit through the University. Sixteen percent purchased the test Journal of the Air & Waste Management Association

5

Peterson and Howland kit at a hardware store and 9% purchased the kit through a mail order company. Ten percent of those respondents testing their homes had results showing radon levels over 4 picocuries per liter. The following actions were taken by those respondents with results > 4 pCi/1: initiated repairs (14%); performed long term tests (20%); contacted the State of Massachusetts (5%); contacted the EPA (5%).

Covariate Analysis Testers and non-testers did not differ with respect to exposure to information about radon (55% vs 53%); nevertheless, testers were more likely to recall radon messages via magazine (58% vs 41%, p = .01). Some significant factors were related to testing for radon. The likelihood of testing increased with each five-year age group, up to the age of 50, and declined somewhat thereafter (p = 0.00). Men were more likely than women to report testing for radon (35% vs 18%, p = 0.00). The likelihood of testing varied significantly with marital status. Respondents who were married were five times as likely to test as people who were single (38% vs 7%, p = 0.00); the proportions of separated, divorced, and widowed persons who had tested were between these extremes. The likelihood of testing also increased as household income increased. Respondents with incomes above $65,000 were twice as likely to test as respondents with incomes between $35,000 and $65,000, and twelve times as likely to test as respondents with household income less than $35,000 per year. Similarly, when respondents were categorized into four groups according to number of children or adolescents who lived in their households (0,1, 2, 3+), the proportion who tested

liable 5. Likelihood of non-testers taking an action related to radon testing. Question

Percent "Very" or "Somewhat Likely"

How likely is it that you will take the following actions? Call or write the U.S. EPA to get information on radon

29%

Call or write the Boston University Radon Testing Service to get more information on Radon

47%

Use a radon testing kit bought from a department store to test your home for radon

15%

Use a radon testing kit bought from the Boston University Radon Testing Service

37%

Seal cracks in the basement or below grade foundation if you have a high level of radon

45%

Hire an experienced radon contractor to fix the problem if you have high levels of radon in your home

39%

6


increased with the number of children/adolescents living in the home (21%, 33%, 39%, 59% respectively, p = 0.00). Testers were 12 times more likely to be home owners than to be renters (p = 0.00). Thirty-seven percent of testers and 15% of non-testers reported that someone in their family spent more than five hours in their basement or in a space below grade level (p = 0.00). Testers were more likely than non-testers to have bedrooms on or below the first floor (34% vs 29%, p = 0.02), and to live in single family homes (83% vs 38%, p = 0.00). Testers were less likely than nontesters to report plans to move during the year subsequent to the interview (4% vs 15%, p = .001). Forty-eight percent of testers and 17% of non-testers knew someone who had tested their homes for radon (p = 0.00). Because the majority of respondents had at least college degrees, our analysis of testing behaviors with respect to educational background was limited to comparing those with college degrees only to those with graduate degrees. Testers were three times more likely to have graduate degrees (p = 0.00), and were more likely to be cosmopolitan than non-testers (p = 0.001); they were also more healthconscious (p = 0.009). Testers were more knowledgeable about radon's characteristics (including ill-health effects) and testing procedures (p = 0.00). In addition, testers were more likely to view radon as a serious problem (p = 0.00) and to consider radon mitigation activities efficacious (p = 0.00). Testers were more likely than non-testers to consider themselves susceptible to radon exposure (p = 0.00) and they were less likely to perceive barriers to radon testing.

Multivariate Analysis Table 6 shows results for the model assessing the predictive power of the HBM variables. The following variables were significant: age; number of children in the household; owning, as opposed to renting, one's residence; average number of hours per week spent in a basement or below-grade area of one's residence; knowledge index; efficacy index; and barrier index (see Appendix). Variables not significantly associated with testing in the model were: sex; education; marital status, location of bedroom; and the scale measuring belief in the severity of radon's threat to health. The chi square for the final model was significant (p = 0.00) at 180.65 with 13 df. The predictive power of the model as assessed by C was high: C = .91. Table 7 shows results for the model assessing the predictive power of the DIM variables. The following variables were significant: age; education; number of children in the household; location of bedroom; owning, as opposed to renting one's residence; average number of hours per week spent in a basement or below grade area of one's residence; having discussed, read or heard information about radon; and knowing another person who had tested. Volume 46 January 1996

Peterson and Howland Variables not significantly associated with testing in the model were sex, marital status, and the cosmopolitan index. The chi square for this model was significant (p = 0.00) at 161.85 with 11 df. The predictive power of this model was also high (C=.87), but not as high as the HBM. Results of the regression model, combining variables from the HBM and DIM models, are shown in Table 8. The following variables were significant predictors of testing: owning as opposed to renting one's residence; knowledge index; barrier index; average number of hours per week spent in a basement or below-grade area of one's residence; knowing another person who has tested; age; having discussed, read or heard information about radon; number of children in the household; education; and belief in personal susceptibility to health risks of radon. The only variable in the model not significantly associated with testing was belief in the efficacy of mitigation as measured by the efficacy index. Variables not selected for inclusion in the stepwise model were: sex; marital status; income; floor of bedroom; the cosmopolitan index; the index measuring belief in the severity of radon's threat to health; and the index measuring adoption of other health related behaviors. The chi square for the final model was significant (p = 0.00) at 244.80 with 11 df. The predictive power of the model exceeded that of the other two models: C = .92. DISCUSSION The results of this study suggest that a number of factors significantly influence the decision of whether to test for radon. Home ownership was significantly associated with having tested; persons who owned their homes were 12 times more likely to have tested than persons who rented. This was true even when Volume 46 January 1996

Table 6. Logistic regression: radon testing on Health Belief Model.

Variable INTERCEPT AGE SEX EDUCATION MARITAL CHILDREN BEDROOM OWN HOURS KNOWRADON EFFICACY SERIOUS SUSCEPT BARRIERS

Beta -4.81460374 0.27711094 0.08837472 0.42479677 0.06163780 0.28017205 -0.29679300 -1.72738474 -0.76396234 0.38060222 0.34930237 0.26867558 0.72153978 -0.39511057

Std Error 1.99296113 0.09469616 0.31935949 0.20152751 0.12229431 0.15733516 0.21661485 0.44904232 0.34862782 0.10665603 0.20646229 0.22766632 0.30978825 0.09303678

Chi Square 5.84 8.56 0.08 4.44 0.25 3.17 1.88 14.80 4.80 12.73 2.86 1.39 5.42 18.04

p-value

R

0.0157 0.0034 0.7820 0.0350 0.6143 0.0750 0.1706 0.0001 0.0284 0.0004 0.0907 0.2379 0.0199 0.0000

0.110 0.000 0.067 0.000 0.046 0.000 -0.153 -0.072 0.141 0.040 0.000 0.079 -0.172

Model Chi Square 180.65, p = 0.000,13DF,C = .91

Table 7. Logistic regression: radon testing on Diffusion of Innovations Model.

Variable INTERCEPT AGE SEX EDUCATION MARITAL CHILDREN BEDROOM OWN HOURS DISC/READ/HEARD KNOWTESTER COSMO

Beta 2.90489411 0.21788355 -0.40716046 0.39042717 -0.00620330 0.27841354 -0.46298412 -2.03269883 -0.52395523 0.046965556 i -1.61859988 0.05146855

Std Error 1.50074302 0.08282475 0.27633116 0.16869426 0.10528905 0.13488645 0.18767568 0.40258751 0.29576278 0.26398118 0.28400430 0.06982623

Chi Square 3.75 6.92 2.17 5.36 0.00 4.26 6.09 25.49 3.14 3.17 32.48 0.54

p-value 0.0529 0.0085 0.1406 0.0206 0.9530 0.0390 0.0136 0.000 0.6762 0.0752 0.0000 0.4611

R

0.092 -0.017 0.076 0.000 0.063 -0.084 -0.202 0.044 0.045 -0.230 0.000

Model Chi Square 161.85, p = 0.00,