Home Page Virtual Tour Departments Personnel Projects Website Index

Survey of Factors Related to Radiation Exposure

and Perceptions of Environmental Risks

in Carlsbad, Loving, Malaga, and Hobbs, New Mexico


Issued: April 7, 1998


Table of Contents

  • Table 1. University of New Mexico Health Sciences Center Epidemiology & Cancer Control Program Project Staff (1996)
  • Table 2. Final Disposition of Calls to Randomly Selected Telephone Numbers in the Communities of Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 3. Numbers Living in Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 4. Characteristics of Heads of Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 5. Housing Characteristics of Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 6. Primary Sources of Drinking Water and Purification Systems Used by Households in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 7. Reported Frequency of Consumption of Home- and Locally-grown Produce, Meats, and Wild Fish and Game for Households in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table8. Reported Frequency of Indoor Radon Testing for Households in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 9. Proportion of Adult Interviews Completed by Total Number of Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 10. Characteristics of All Adults Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 11. Usual Occupations and Types of Industries in Which Adults are Employed Among Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 12. Smoking Histories of Adults Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 13. Height in Inches for Adult Males Residing in Carlsbad, New Mexico
  • Table 14. Height in Inches for Adult Females Residing in Carlsbad, New Mexico
  • Table 15. Weight in Pounds Adult Males Residing in Carlsbad, New Mexico
  • Table 16. Weight in Pounds for Adult Females Residing in Carlsbad, New Mexico
  • Table 17. Height in Inches for Adult Males Residing in Loving and Malaga, New Mexico
  • Table 18. Height in Inches for Adult Females Residing in Loving and Malaga, New Mexico
  • Table 19. Weight in Pounds for Adult Males Residing in Loving and Malaga, New Mexico
  • Table 20. Weight in Pounds for Adult Females Residing in Loving and Malaga, New Mexico
  • Table 21. Height in Inches for Adult Males Residing in Hobbs, New Mexico
  • Table 22. Height in Inches for Adult Females Residing in Hobbs, New Mexico
  • Table 23. Weight in Pounds for Adult Males Residing in Hobbs, New Mexico
  • Table 24. Weight in Pounds for Adult Females Residing in Hobbs, New Mexico
  • Table 25. Prevalence of Radiation Therapy Received in Past 3 Months by Adults Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 26. Prevalence of Adults in Carlsbad and Loving-Malaga, New Mexico Who Reported Ever Having Been Employed in Occupations With a Potential for Exposure to Radioactive or Chemically Hazardous Materials
  • Table 27. Prevalence of Adults in Hobbs, New Mexico Who Reported Ever Having Been Employed in Occupations With a Potential for Exposure to Radioactive or Chemically Hazardous Materials
  • Table 28. Perceptions of Quality of Life and Environment Among Adults Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 29. Levels of Concern on Issues of Environmental Quality and Health as Expressed by Adults Surveyed in Carlsbad, Loving- Malaga, and Hobbs, New Mexico
  • Table 30. Proportions of Adults Willing to Give Samples of Blood or Urine Among Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 31. Authenticity and Level of Agreement for Supervisor Call-backs to Households Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico
  • Table 32. Level of Acceptance of Survey Estimated from Supervisor Call-backs to 150 Households Surveyed in Carlsbad and Loving-Malaga, New Mexico
  • Table 33. Level of Acceptance of Survey Estimated from Supervisor Call-backs to 25 Households Surveyed in Hobbs, New Mexico
  • Table 34. Characteristics of Households and Adults Surveyed in Carlsbad, Loving-Malaga, and Hobbs, New Mexico, and 1990 Census Figures for Residents of Carlsbad, Hobbs, and Loving, New Mexico
  • Table 35. Reported Frequencies of Households with Published and Unpublished Telephone Numbers by Ethnicity Among Survey Participants in Hobbs, New Mexico

Survey of Factors Related to Radiation Exposure and Perceptions of Environmental Risks in Carlsbad, Loving, Malaga, and Hobbs, New Mexico

INTRODUCTION

This study was conducted by investigators with the Epidemiology & Cancer Control Program, University of New Mexico Health Sciences Center (Table 1), under a contract with New Mexico State University (NMSU), with funding by the Carlsbad Environmental Monitoring & Research Program (CEMRP), which was supported by a grant from the U.S. Department of Energy (DOE) to NMSU (DE-FG04-91AL74167). This research is part of a larger CEMRP project to implement independent health and environmental monitoring in the vicinity of the WIPP, and to make the monitoring results available to all interested parties.

The purpose of this study was to gather baseline data on selected parameters of the resident population in the vicinity of the U.S. Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP), in southeastern New Mexico. The study focused on (1) specific factors related to health and exposure to environmental contaminants (e.g. diet, smoking, occupation) and (2) public perceptions about quality of life and the environment.

Potentially Impacted Communities

The WIPP is located in the sparsely populated southeastern corner of New Mexico. The information in this report focuses on three population centers in the vicinity of the WIPP. Carlsbad (1990 population 26,119) is in Eddy County and is about 26 miles west of the WIPP. The communities of Loving and Malaga (combined 1990 population 1,243) are also in Eddy County, and are about 18 miles southwest of the WIPP (Census 1990b, Westinghouse 1995). Hobbs (1990 population 29,115) is about 40 miles northeast of the WIPP, and is located in Lea County.

Carlsbad is an urban community comprised mainly of whites who are not of Spanish or Mexican ancestry (non-Hispanic whites) (Census 1990b). According to 1990 US Bureau of the Census figures (1990a), 20.7% of Carlsbad residents had incomes below the poverty level, and the median household income was $22,605. The proportion of residents with a high school degree or higher education was 68.9% in Carlsbad.

Loving and Malaga are rural communities comprised primarily of Hispanic whites (Census 1990b). Throughout this report, data for these two communities are combined into a single community category (referred to as Loving-Malaga). The median household income was $15,893, 42.3% of the residents had a high school degree or higher education, and 29.7% of the residents had incomes below the poverty level (Census 1990a). Mining (especially potash mining) and oil and natural gas production are important industries in both communities.

Hobbs is an urban community comprised mainly of non-Hispanic whites (61.5%) (Census 1990b). According to 1990 U.S. Bureau of Census figures (1990a), 24.8% of Hobbs residents had incomes below the poverty level, the median household income was $22,807, and the proportion of residents with high school degree of higher education was 66.4% Important industries in Lea County include mining (BBER 1995), cattle ranching, and oil and gas production.

Throughout this report, numerous comparisons of Hobbs and Carlsbad are made because of their similar size and characteristics. However, because of Hobbs' greater distance from the WIPP site, residents of Hobbs are less likely than those in Carlsbad to benefit economically from, or to be exposed to releases from, the WIPP operations. Therefore, the population of Hobbs represents a potential reference population with which to measure any effect of waste disposal at the WIPP, as compared to the population of Carlsbad. The data presented herein are characterized with respect to the study participants only; no analyses are presented to apply the results to entire communities. Such analyses, which require weighting factors derived from census data and other adjustments, will be undertaken in future comparative studies.

MATERIALS AND METHODS

Pilot tests of the telephone survey were conducted in December, 1994, and February and March, 1995, to evaluate the questionnaire and its operation on a Computer-Assisted Telephone Interviewing (CATI) system. Interviews of Carlsbad and Loving-Malaga residents began on March 28, 1995, and ended on July 18, 1995. Hobbs residents were interviewed between March 28, 1995 and January 11, 1996.

Survey Design

The surveys of Carlsbad and Loving-Malaga used a random sample of published residential telephone numbers from directories. For Hobbs, the survey used a random sample of published and unpublished numbers from a survey marketing firm (Survey Sampling, Inc. Fairfield, Connecticut). According to US Census Bureau data (1990a), there are approximately 2.74 individuals per household in Eddy County. The original survey design included interviewing 500 households (250 in Carlsbad and 250 in Loving-Malaga), collecting information from approximately 1,400 individuals. After as many as seven attempts, the surveyors were only able to complete interviews with 172 households from the 391 published residential telephone numbers in Loving-Malaga. When further calls to households in Loving-Malaga were not successful, efforts were re-directed to Carlsbad. The result was a final sample of 778 households in Eddy County (606 in Carlsbad and 172 in Loving-Malaga).

For Hobbs, the survey design included 250 households (125 unpublished and 125 published telephone numbers) collecting information for approximately 700 individuals (at 2.81 persons per household in Hobbs) (Census 1990a). After as many as seven attempts, surveyors were able to complete interviews with 314 households. Approximately 25% (71) of households had unpublished telephone numbers and 75% (214) had published telephone numbers. Detailed information was collected from 347 adults in these households.

Telephone Interview

The questionnaire was administered in a standard manner to adult household members (18 years and older). Adults who considered themselves to be the head of their household were designated the first head of household and were asked 70 questions that included information about the household (e.g., number of persons living in home, house construction, diet, etc.). Subsequent adult household members were asked questions that only pertained to themselves (e.g., employment status, smoking, etc.). Information on household members who were less than 18 years of age was obtained from the first head of household. Several calls were usually needed to complete the interviews with all participating adult members of each household. The interview time required was 30 to 40 minutes per household. Two percent of the interviews for Carlsbad and Loving-Malaga were administered in Spanish, while 3.7% of the interviews for Hobbs were completed in Spanish. The survey questions asked of heads of households and adults, and about children, are presented in Appendix A.

At least three calls were placed to each selected telephone number in an attempt to conduct an interview. To ensure that the survey participants were representative of both the employed and unemployed population, calls were made between 4 and 9 PM on weeknights, 10 AM and 9 PM on Saturdays, and 12 noon to 8 PM on Sundays. Surveyors attempted to interview all adult members of each household. Because other adults were often not available at the time of the first interview, it was necessary to call most households again to obtain these interviews. At least three attempts were made to reach other adults in each household before ending the effort.

Quality Control

The questionnaire was administered using the CATI system, enabling interviewers to read questions from video display screens and record answers directly into terminals. This system allowed survey data to be stored directly on-line, which can improve data collection efficiency and accuracy by allowing interviewers to edit incorrectly entered responses and to advance to the next appropriate question in an interview script. The CATI system also allowed interviewers to schedule calls with respondents, and enabled supervisors to monitor productivity rates.

The interviewing was directed by a supervisor who conducted regular briefing and debriefing sessions, monitored quotas, and was available to assist the interviewers. A guide was developed for the survey that included instructions, protocols, and a Spanish-language script for interviews with respondents who indicated that they spoke only Spanish (Appendix B). In addition to the quality control measures in the design and implementation of the study, a verification survey was conducted (Appendix C). Random samples of the telephone survey participants were selected for calls by the study supervisor. The supervisor asked participants selected questions a second time to confirm the authenticity and accuracy of answers, and solicited comments about the quality of the interview, interest level in the survey, and reasons why respondents indicated that they would or would not be willing to provide samples of urine or blood.

RESULTS

Household Response Rates

Interviewers attempted to call 20.6% of the published residential telephone numbers in the Carlsbad community (1,960 out of a potential 9,518), 99% of those in the Loving-Malaga area (387 out of a potential 391), and 11.0% of available published and unpublished numbers in Hobbs (1,271 out of a potential 11,557). The final disposition of the 2,347 calls made to randomly selected telephone numbers in Carlsbad and Loving-Malaga, and the 1,271 calls in Hobbs are presented in Table 2. Selected telephone numbers were considered ineligible if they were no longer in service; were busy or never answered during repeated attempts; or belonged to a business, a hearing impaired individual/family, or a family whose primary language was not English or Spanish. In addition, when households whose primary language was Spanish were initially contacted, a Spanish-speaking interviewer was not available. Subsequent calls to these households by a Spanish-speaker were sometimes unsuccessful. Interviews were completed with 606 households in Carlsbad and 172 households in Loving-Malaga, representing response rates of 64.5% and 73.8%, respectively. The combined response rate for both of the communities was 66.3%. Interviews were completed for 314 households in Hobbs, representing a response rate of 69.8%. Response rates were calculated by dividing the number of completed household interviews by the sum of completed household interviews and refusals.

Household Interviews

Demographics

The total number of adults and children living in households surveyed in Carlsbad, Loving-Malaga, and Hobbs are presented in Table 3. The average number of people per household was approximately 2.5 (1.9 adults and 0.6 children) in Carlsbad, 2.9 (2.1 adults and 1.0 child) in Loving-Malaga, and 2.8 (1.9 adults and 0.8 children) in Hobbs. The number of households with children was 200 of 606 in Carlsbad (33%), 88 of 172 in Loving-Malaga (51%), and 140 of 326 in Hobbs (43%).

Head of Household Characteristics

Characteristics of heads of households surveyed in Carlsbad, Loving-Malaga, and Hobbs are presented in Table 4. Approximately two-thirds of the respondents were female (64.7% in Carlsbad, 66.9% in Loving-Malaga, and 62.5% in Hobbs) and two-thirds were married (68.1% in Carlsbad, 66.9% in Loving-Malaga, and 67% in Hobbs). The majority (81.7%) of the heads of households surveyed in Carlsbad were non-Hispanic white, and 10.5% were Hispanic white. Over half (56.8%) of the heads of households surveyed in Loving-Malaga were non-Hispanic white, and 36.1% were Hispanic white. The majority (77.4%) of the heads of households surveyed in Hobbs were non-Hispanic white and 13.5% were Hispanic white. Over two-thirds of the respondents from Carlsbad (70.7%) and Hobbs (77.4%) were born outside their respective counties, and about half (53.3%) of the respondents from Loving-Malaga were born outside of Eddy County.

In Carlsbad, 44.3% of heads of households surveyed reported being 60 years of age or older, and 37.7% reported being retired. In Loving-Malaga, 30.2% of heads of households surveyed reported being 60 years of age or older, and 24.3% reported being retired. In Hobbs, 34% of heads of households surveyed were 60 years of age or older, and 26.8% reported being retired.

Education levels and employment status of heads of households also differed among the communities. In Carlsbad, 53.1% of the respondents had education beyond the completion of high school, 43.1% were employed, and 16.6% were unemployed. In Loving-Malaga, 42.6% of the respondents had education beyond the completion of high school, 52.1% were employed, and 19.5% were unemployed. In Hobbs, 56.2% of respondents had education beyond the completion of high school, 55.7% were employed, and 13.9% were unemployed.

Housing

Housing characteristics of surveyed households are presented in Table 5. The majority of households interviewed reported living in free-standing, single-family homes (81.2% in Carlsbad, 72.5% in Loving-Malaga, and 79.5% in Hobbs). Most of the remaining households reported living in mobile homes. About half of the households in Carlsbad and Loving-Malaga reported living in homes of wood frame construction (56.7% in Carlsbad and 54.9% in Loving-Malaga), but this was less common among respondents in Hobbs (39.3%). Slab foundations were the most common type of foundation in all three communities, and over half of the surveyed households reported that their homes had three or more bedrooms.

Over two-thirds of the households interviewed reported that their homes were built in or after 1950. One-third or less of heads of households interviewed had lived in their current home for 20 years or more (35.3% in Carlsbad, 24.4% in Loving-Malaga, and 23.9% in Hobbs).

Sources of Water

The primary sources of drinking and cooking water and water purification systems used by households are presented in Table 6. The majority of households reported using municipal water for drinking (82.5% in Carlsbad, 75.8% in Loving-Malaga, and 62.2% in Hobbs). However, some households reported using private wells (5.0% in Carlsbad, 5.5% in Loving-Malaga, and 26.0% in Hobbs) or neighborhood systems (5.5% in Carlsbad, 9.9% in Loving-Malaga, and 2.4% in Hobbs).

Frequency of use of water purification systems was similar among respondents in the three communities (11.4% in Carlsbad, 9.9% in Loving-Malaga, and 16.0% in Hobbs.

Diet

The reported frequencies of consumption of game and home- and locally-grown produce, dairy products, and meats for participating households are presented in Table 7. Consumption of home-grown and local farmers’ produce was highest among residents surveyed in Loving-Malaga (55.2%-58.8% reporting consumption at least once per week) and lowest in Hobbs (36.6%-37.8% reporting consumption at least once per week). Households surveyed in Loving-Malaga also reported eating home-grown milk, eggs, and meats more frequently than households surveyed in Carlsbad or Hobbs. Deer and antelope were reported to be eaten once or more per year by 50.3% of households surveyed in Loving-Malaga, 35.6% in Carlsbad, and 27.4% in Hobbs.

Radon

The reported frequencies of indoor radon testing for households interviewed are presented in Table 8. About one-tenth of households reported ever having tested for radon. Less than 15% of households surveyed in the three communities reported every having tested for radon, and the vast majority (95%) were unable to recall the concentration measured. One respondent reported a radon measurement of 67.4 pCi/L; the accuracy of this report is not known.

Adult Interviews

Demographics

Total numbers of adults interviewed in the telephone survey were 719 in Carlsbad, 225 in Loving-Malaga, and 347 in Hobbs. The proportions of completed adult interviews (completed adult interviews divided by the total number of adults living in a household) are presented in Table 9. In homes where one adult completed the household interview, it was usually possible to also complete interviews with the other adults living in the household (91.8% in Carlsbad, 97.4% in Loving-Malaga, and 95.9% in Hobbs). Completion percentages fell off steadily as the number of adults in households increased, reflecting the difficulties of contacting all household members for interviews. In households with three adults, interviews were completed with all of the adults one-third to one-half of the time.

Adult Characteristics

Characteristics of all adults surveyed are presented in Table 10. The majority of adults surveyed were also the first heads of households (79.7% in Carlsbad, 75.1% in Loving-Malaga, and 82.7% in Hobbs). Other adult members of the households interviewed numbered 156 in Carlsbad, 56 in Loving-Malaga, and 60 in Hobbs.

Many of the characteristics for all adults were similar to those for heads of households. Roughly two-thirds of the respondents were female (62.7% in Carlsbad, 60.4% in Loving-Malaga, and 61.4% in Hobbs) and two-thirds were married (70.7% in Carlsbad, 66.7% in Loving-Malaga, and 70.9% in Hobbs). In Carlsbad, the large majority (83.2%) of the adults surveyed were non-Hispanic white, and only 9.7% were Hispanic white. In Loving-Malaga, about half (55.1%) of the adults surveyed were non-Hispanic white, and 35.6% were Hispanic white. In Hobbs, about three-fourths (77.5%) of the adults surveyed were non-Hispanic white, and 13.3% were Hispanic white. About half (52.0%) of the respondents from Loving-Malaga and over two-thirds of the respondents from Carlsbad (71.8%) and Hobbs (77.5%) were born outside of Eddy or Lea County, respectively.

The ages and education levels of all adult respondents were also similar to those of the heads of households. In Carlsbad, 53.2% of the respondents had education beyond the completion of high school, 45.1% were employed, and 16.4% were unemployed. In Loving-Malaga, 40.4% of the respondents had education beyond the completion of high school, 54.2% were employed, and 19.6% were unemployed. In Hobbs, 53.9% of the respondents had education beyond the completion of high school, 55.8% were employed, and 15.0% were unemployed. In Carlsbad, 42.1% of adults surveyed reported being 60 years of age or older and 35.7% reported being retired. In Loving-Malaga, 27.1% of adults surveyed reported being 60 years of age or older and 21.8% reported being retired. In Hobbs, 33.2% of adults surveyed reported being 60 years of age or older, and 25.4% reported being retired.

Usual occupations and types of industries in which surveyed adults were employed are presented in Table 11. Mining was an important industry in Carlsbad and Loving-Malaga at the time of study, employing 17.1% of surveyed adults in Carlsbad and 17.6% in Loving-Malaga. The proportions of adults surveyed in Carlsbad and Hobbs that were employed in white-collar occupations such as management/professional (29.1% and 36.7%, respectively) and technical/sales/administrative support (15.2% and 19.4%, respectively), were higher than in Loving-Malaga (18.7% and 8.0%, respectively). However, a larger proportion of adults surveyed in Loving-Malaga were employed in other occupations, such as farming (12.4%) and service (16.9%).

Smoking histories of adults surveyed are presented in Table 12. About half of the surveyed residents had never smoked. Of those who had smoked, approximately one-fourth continue to smoke. Slightly less than half of the smokers (47.6% in Carlsbad, 49.0% in Loving-Malaga, and 48.0% in Hobbs) began smoking before age 18. Of those respondents who smoked, 60%-76% smoked one pack of cigarettes a day or less.

Height and Weight Distribution

The height and weight distributions of adults surveyed are presented in Tables 13-24. These distributions are comparable in magnitude to US rates (NCHS 1987).

Exposure to Radiation

The prevalence of radiation therapy received in the past three months by adults surveyed is presented in Table 25. Only 4.0% of adults surveyed in Carlsbad, 2.2% in Loving-Malaga, and 2.0% in Hobbs, reported that they had received some type of radiation therapy or diagnostic test. Types of treatment included external ionizing radiation, and injection and ingestion of tracers.

Information about potential job-related exposures to ionizing radiation based on occupation, whether a dosimeter is or was worn, and whether exposure screening tests were performed is presented in Tables 26 and 27. Among adults interviewed in Carlsbad and Loving-Malaga combined, 1.4% reported working in underground uranium mines (2.8% of males and 0.5% of females) and 13.8% of adults reported working in underground potash mines (34.2% of males and 1.5% of females). Thirty-three percent of men and approximately 2% of women reported serving time in the armed services. Forty percent of men who served in the military reported some work with weapons, and 6.8% reported working with military nuclear power reactors. Twenty-two percent of adults reported work experience in the oil and gas industry, and approximately 12% in hazardous waste handling and disposal. Three adults reported work experience in nuclear fuel production, several had experience in nuclear weapons production and testing, and eight had worked in commercial nuclear power plants.

Among adults interviewed in Hobbs, 0.6% reported working in underground uranium mines (no males and 0.9% of females) and 3.0% of adults reported working in underground potash mines (6.5% of males and 0.9% of females). A reported 30.6% of men and 1.4% of women served time in the armed services, and of men who served in the military, 44.7% worked with weapons, and 2.6% worked with military nuclear power reactors. A reported 59.7% of men worked in the oil and gas industry, and 16.1% worked in hazardous waste handling and disposal. Three adults reported work experience in nuclear fuel production, two had experience in nuclear weapons production and testing, and one had worked in a commercial nuclear power plant.

Quality of Environment

Perceptions of the quality of life and the environment among adults surveyed are presented in Table 28. Over half of the survey participants in all three communities rated all the questions in this grouping as "very good" or "excellent." Participants in Carlsbad and Loving-Malaga answered the question about cleanliness of air most positively, with 81.1% in Carlsbad and 80.9% in Loving-Malaga answering either "very good" or "excellent." Participants from Hobbs answered the question about cleanliness of water most positively, with 60.8% answering either "very good" or "excellent".

Levels of Concern

Levels of concern about issues of health and environmental quality among adults surveyed are presented in Table 29. Answers to these questions were given on a scale of 1 to 5, where "1" meant "not at all concerned" and "5" meant "very concerned." In general, participants from both communities reported high levels of concern about these issues, giving answers of 4 and 5. A high proportion of participants gave a rating of 5 to questions about pollution in the environment (48.4% in Carlsbad, 56.9% in Loving-Malaga, and 49.4% in Hobbs), the possibility of getting cancer (40.6% in Carlsbad, 51.1% in Loving-Malaga, and 45.1% in Hobbs), and toxic waste (41.4% in Carlsbad, 49.3% in Loving-Malaga, and 47.7% in Hobbs). Participants seemed less concerned about, and gave a rating of 1 to, questions about the risk of birth defects (39.2% in Carlsbad, 34.7% in Loving-Malaga, and 32.4% in Hobbs) and about radioactive waste (22.3% in Carlsbad, 18.7% in Loving-Malaga, and 16.5% in Hobbs). In general, adults surveyed in Loving-Malaga and Hobbs answered that they were "very concerned" about issues of health and environmental quality more often than adults surveyed in Carlsbad.

Willingness to Give Bioassay Samples

Proportions of participating adults willing to give samples of blood or urine for bioassays are presented in Table 30. Over half (56%-64%) of the adults surveyed in all communities stated willingness to give samples.

Quality Control and Verification Study

Results of the verification study are presented in Tables 31-33. The accuracy of answers to selected questions ranged from 84.0% to 100% when the questions were asked a second time by the survey supervisor. In addition, 72%-76% of verification survey participants reported that they were either "very interested" or "somewhat interested" in the survey, and many stated that they were motivated to participate in the survey because they wanted to "help the community" and to "help with health." Reactions to the survey question about occupation were mostly positive; 76%-81.8% of the responses were neutral to positive, and no people said that the survey was too long.

Reasons given by respondents for agreeing to participate in bioassay surveillance included to help researchers, the community, themselves, and/or the environment. Reasons given for unwillingness to participate included health restrictions, bad experiences with previous medical tests, old age, busy lifestyle, or a concern about confidentiality of test results. Only five participants in the verification study indicated that they wanted to change their initial answer regarding their willingness to give a blood or urine sample.

DISCUSSION

Summary of Main Results

This effort demonstrates that it is feasible to use telephone interviews to complete a systematic survey of large numbers of people in an extensive area, and to characterize the prevalence of factors associated with risk of environmental exposure to radionuclides or other contaminants. Because of the random selection of households (within the constraints identified previously), and the large number of households surveyed, these data represent a range of opinions and perceptions of risks posed by environmental pollution in these communities.

The sampling strategy of interviewing all adult household members who are willing to participate in the survey is not common, and there is no source with which to compare the figures. However, the survey’s household response rates of 64.5% for Carlsbad, 73.8% for Loving-Malaga, and 69.8% for Hobbs are, in general, about what is expected (Frey 1989).

The average numbers of persons per home in the households participating in the survey were slightly lower than 1990 US Census data (1990b) indicated for the subject communities. Additional characteristics of participating households and adults surveyed in Carlsbad, Loving-Malaga, and Hobbs, along with corresponding 1990 US Census data, are presented in Table 34. In general, the group of people surveyed was comprised of more women, non-Hispanic whites, people over 60, people with higher education, and unemployed people than observed for the corresponding areas in 1990 US Census figures. For example, 9.7% of the survey respondents in Carlsbad, 35.6% in Loving-Malaga, and 13.3% in Hobbs characterized themselves as Hispanic white, while the 1990 US Census reported 33.4% of the population in Carlsbad, 77.8% of the population in Loving, and 30.1% of the population in Hobbs were Hispanic white.

Although 1990 US Census data indicated that virtually all homes in the three communities are connected to municipal water supplies, this survey suggests that a small proportion (<10%) of households used bottled water for drinking and cooking. Results of this survey also suggest relatively high frequencies of consumption of locally-grown foods, including vegetables, meat, fish and game.

The survey clearly showed that the public had a high level of concern about protecting health and the environment, although perceptions about community quality, air, water and soil "cleanliness" tended to be lower among participants in Hobbs than in Carlsbad or Loving-Malaga.. While the people interviewed generally regarded the air, water, and soil in the communities as clean, the majority were concerned about pollution from pesticides, and toxic and radioactive wastes. These results indicated that the public was concerned about threats to what they believe to be a generally clean local environment. Relative to the possibility of having a heart attack or the risk of birth defects, people were very concerned about the risk of cancer.

The analysis of blood and urine is a common method of determining the presence of radioactive materials within the human body. Such analyses could be used in future studies of the resident population in the region of the WIPP, should an increase of radioactive materials in other monitored parameters (e.g. air, water, soils) suggest that the population could be exposed to radioactive contaminants. The level of willingness among respondents in this study to participate in providing bioassay samples, indicates the level of effort that would likely be necessary to achieve adequate sample sizes for such bioassay studies.

Potential Sources of Bias

When compared with 1990 US Census figures, males and Hispanics were underrepresented in the telephone survey. One factor that may explain this discrepancy is the larger proportion of Hispanic white households than non-Hispanic white households in Eddy and Lea counties without a telephone; 1990 US Bureau of Census data (1990c) indicated that 20.2% of Hispanic white households in Eddy County and 37.6% in Lea County were without a telephone, compared to 6.2% and 8.1% of non-Hispanic white households in Eddy and Lea counties, respectively.

In the design of the study, primarily published numbers were used, as opposed to random-digit dialing, to reduce the costs of dialing many unproductive numbers (e.g., businesses and numbers no longer in service). Use of randomly varied telephone numbers might have increased the proportion of Hispanic whites in the study if it resulted in contacting more unpublished telephone numbers, but this is not an efficient method of sampling households with unpublished telephone numbers. For part of the study (Hobbs), a list of unpublished residential telephone numbers purchased from a marketing firm was used. The frequencies of ethnicities of heads of households with published and unpublished telephone numbers among the survey participants in Hobbs are presented in Table 35. Of the 71 surveyed households with unpublished telephone numbers, 29.6% had Hispanic heads of households. In comparison, 13.1% of heads of households surveyed with published telephone numbers characterized themselves as Hispanic. Thus, the use of unpublished telephone numbers may have contributed to a higher representation by Hispanic whites in the Hobbs sample than would have been obtained otherwise. The proportion of unpublished residential phone numbers in New Mexico is approximately 20% (Survey Sampling 1995); unfortunately, proportions are not known by ethnic groups.

There were no substantive differences in the rates of refusal to participate among households with Hispanic surnames than among households with non-Hispanic surnames. Approximately 2-3% of all interviews were conducted in Spanish.

A greater proportion of women than men were interviewed in this survey, while 1990 US Census figures (1990c) indicate approximately equal proportions of men and women in the subject communities. The initial contact with targeted telephone numbers resulted in a majority of women providing information for the household and for themselves. Attempted call-backs to interview all other adult household members, had limited success in increasing the overall representation by men.

Limitations

Despite the apparent under-representation of Hispanic whites and men, information about personal characteristics, lifestyle, and perceptions of environmental risks was successfully collected from 121 Hispanic white households and 354 men. Because of these relatively large sample sizes, it is likely that the study obtained information on the full range of behaviors and perceptions within these groups. However, in future studies, to draw generalizations at the level of entire communities will require adjustments by weighting data, to correct for the differences between the sample populations and the general populations.

Implications for Quantitative Risk Assessment

Before this survey, information on lifestyle and risk perceptions was not available for the communities surveyed. Quantitative assessments of risks of exposure to radioactive or hazardous chemical materials require information about location and type of residence, sources of water and food, and occupation. In regions where residents have known or suspected exposures to radioactive and/or hazardous contaminants, data on such parameters are generally unavailable or incomplete. While some data are available from the US Bureau of the Census, such data have not been collected for the specific purpose of risk assessment. The data presented in this report were obtained to provide a baseline for such quantitative assessments during future comparative studies after the WIPP begins waste disposal operations.

REFERENCES

Frey, J. H. (1989). Survey Research by Telephone. Second Edition. Sage Library of Social Research, Volume 150. California: Sage Publications, Inc.

Survey Sampling, Inc. of Fairfield, Connecticut. (1995). Personal communication with Renate Mahler of UNM-EpiCC.

United States Department of Commerce, Economics and Statistics Administration, Bureau of the Census. (1990a). 1990 Census of Population: Social and Economic Characteristics, New Mexico. Washington, DC: US Government Printing Office.

United States Department of Commerce, Economics and Statistics Administration, Bureau of the Census. (1990b). 1990 Census of Population: Summary Population and Housing Characteristics, New Mexico. Washington, DC: US Government Printing Office.

United States Department of Commerce, Economics and Statistics Administration, Bureau of the Census. (1990c). 1990 Census of Population: Population and Housing Characteristics for Census Tracts and Block Numbering Area, New Mexico. Washington, DC: US Government Printing Office.

United States Department of Health and Human Services, Public Health Service, National Center for Health Statistics (NCHS). (1987). Anthropometric Reference Data and Prevalence of Overweight, United States, 1976-80. DHHS Publication No. (PHS) 87-1688. (October).

University of New Mexico, Bureau of Business and Economic Research (BBER). (1995). The Census in New Mexico, Volume IV: Social and Economic Characteristics for the State and Counties from the 1980 and 1990 Censuses. Albuquerque, New Mexico. (August).

Westinghouse for the United States Department of Energy. (1995). Waste Isolation Pilot Plant Safety Analysis Report.. DOE/WIPP-95-2065. Revision 0. (November).

LIST OF TERMS

Bias: Systematic errors in collecting, analyzing, or interpreting data.

Bioassay: Measurement of techniques to determine the concentration of a substance, such as radionuclides, in the human body.

Confounding: Effects of factors, beyond those studied, that are associated with, or responsible for, the results of a study.

Ethnicity: Belonging to a particular cultural group that may share a social, as well as genetic, history. Ethnicities may be self-defined. The race category white includes the ethnicities Hispanic and non-Hispanic white.

Hispanic White: Of Spanish, Mexican, Latino, Chicano, etc. origin excluding individuals who are of non-white racial groups.

Non-Hispanic White: Of Caucasian, Anglo, European, etc. origin; not of Spanish, Mexican, Latino, Chicano, etc. origin.

First Head of Household: Adult survey participants who considered themselves to be the head of their household. These individuals answered general questions about the household and for children (under 18 years of age) living in the household.

Radiation: Energy emitted from a source.

Electro-magnetic: Energy emitted as a result of the acceleration of electric charges and the interaction of associated electric and magnetic fields. Some researchers believe that exposure to electro-magnetic energy, such as that emitted by electric appliances and power lines, may increase the risk of developing certain cancers.

Ionizing: Energy that causes ionization (i.e., the displacement of electrons from atoms or molecules, thereby producing charged particles).

Radioactivity: The property of certain nuclides of spontaneously emitting radiation in the form of rays or particles.

Radionuclides: A type of atom that loses particles and energy through the process of radioactivity, and decays or transforms into other elements.

Radon: A colorless, naturally occurring, radioactive gas, formed during the disintegration of the element radium.

Stratify: To divide a sample into homogeneous categories. This is a technique used to eliminate the effect of confounding on study results associated with particular characteristics of the sample.

Waste:

Hazardous: A solid, liquid, or gaseous chemical material of negligible economic value that poses a potential hazard to human health or the environment when improperly managed. Hazardous wastes, as defined by the US Environmental Protection Agency, usually possess at least one of four characteristics: 1) ignitability, 2) corrosivity, 3) reactivity, and 4) toxicity.

Mixed: Waste contaminated by radioactive and chemically hazardous materials.

Radioactive: A solid, liquid, or gaseous material of negligible economic value that contains radionuclides in excess of threshold quantities defined by regulation.

Transuranic : With a few regulatory exceptions, waste contaminated with transuranic isotopes (i.e., radioactive nuclides that are heavier than uranium) that emit more than 100 nanocuries of alpha particles per gram of waste and have half-lives longer than 20 years.

WIPP: Acronym for the U.S. Department of Energy Waste Isolation Pilot Plant

Carlsbad Environmental Monitoring & Research Center
1400 University Drive Carlsbad, NM 88220 (505) 887-2759

Related Files:

Related Links: