RADON SURVEY OF RECENT HOME BUYERS Michael Kitto Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201 School of Public Health, State University of New York, Rensselaer, NY 12144 ABSTRACT In an effort disclosure during to evaluate real-estate the prevalence transactions, of radon surveys of recent home buyers regarding radon awareness, testing, and remediation were conducted in 26 counties in four regions of New York State. A 1999 survey, canvassing 2220 buyers in 12 counties, produced 647 responses. The 2002 survey, canvassing 5299 buyers in 14 different counties, produced an additional measurements 705 responses. during real-estate Radon disclosure transactions and were infrequent in counties with low radon potential, but quite prevalent in higher-risk counties. Overall, radon played a minimal role in buyers’ decisions regarding home purchase. As a free radon test kit and analysis were provided with each completed compared with survey, the estimated corresponding counties. measurement radon results potentials could for be the INTRODUCTION Radon (222Rn) is a gaseous decay product of radium, a naturally soils. occurring radionuclide found in all rocks and Radon typically enters homes at the soil-foundation interface, and it contributes over half of the radiation dose received by the public from all sources. epidemiological studies have linked Extensive inhalation of the radioactive decay products of radon to an increased risk of lung cancer, attributed and to nearly radon 22,000 annually in lung-cancer the United deaths States are (1). While a substantial fraction of all indoor-radon testing and mitigations in some States occurs during real-estate sales of exists on single-family i) who houses conducts the (2), little information measurements, ii) the likelihood of radon disclosure during home sales, and iii) the radon-reduction strategies implemented at these newly acquired homes. Previous data regarding buyers’ consideration of radon during house obtained sales through in New York interviews State (NYS) conducted questionnaires sent to home owners (3). have with been and Among owners of 1,113 homes in NYS, that had been measured at >4 pCi/L of radon, 60% reported that they had taken action to reduce radon exposure. The actions included reduced time spent in the basement, increased ventilation, and installation of an active mitigation system. The authors of that study noted that this action rate was extraordinary, compared to rates observed elsewhere. The current project has surveyed homeowners involved in recent house sales. An objective of this study was to obtain information from four regions of NYS regarding the occurrence of radon disclosure, measurements, and remediations during the recent sales transactions, as well as the influence posed by the presence of radon, on the purchase of a home. home buyers radon, who are The survey provided data on whether receiving provides this information information, regarding and indoor whether the information provided is accurate. EXPERIMENTAL During two studies conducted in 99-00 and 01-02, home buyers in a total of 26 counties in four regions of NYS (Figure 1) were targeted, to examine the prevalence of radon disclosures during realestate transactions. and, as shown in These regions encompass much of NYS Table 1, include counties with low population and low radon potential (Region 3), as well as counties with high population and substantial radon potential (Region 4). Information on single-family homes sold in 12 counties from March 1 to May 30 in 1999 and in 14 additional counties from March 1 to May 30 in 2001, was extracted from the NYS Office of Real Property Services (ORPS) tax necessary database. to verify The the ORPS-derived location of each addresses house were in the county, as zip codes often cross county borders and cannot be used to locate houses within political boundaries. For the two 3-month periods, the number of eligible home buyers for this study ranged from 26 in Lewis County to 1309 in Orange County, county. an average of about 380 homes per The survey and measurements were done during the 1999-2000 home with and received explaining the 2001-2002 a heating package study, a seasons. containing page Each a describing cover radon targeted letter and its risks, a dated detector application, and a survey form. Participants returning the applications were mailed a 3” charcoal detector; this, following exposure, was mailed by the home buyer to the contracted, certified laboratory for analysis. Radon concentration results were sent to the participating home buyer. All homes with >20 pCi/L radon were provided with two follow-up detectors. RESULTS AND DISCUSSION 1999 Home buyer measurements Of the 2551 detector applications mailed during the 3month period counties, errors to 331 or single-family letters delivery were homes returned problems, and located due 647 in to the 12 addressing surveys and 588 detector applications were completed by the homeowners and returned to us. The results are summarized in Table 2. Radon detectors were mailed to responding participants, but only 218 detectors were properly exposed and returned for measurement to the contracted laboratory. The primary reason for exclusion of deployed detectors from the data set was overexposure of the canister by the homeowner (>7 days). Although instructions were included with the charcoal canisters, it appears that many home buyers either did not read or did not fully understand them. Overall, the return rates for the applications and questionnaires were about 27% and 29%, respectively. Cortland County had the highest return rate of the questionnaires (39%), while Allegany County residents returned only 12%. counties are high-risk areas for indoor Both of these radon. Among returned surveys, radon measurements were completed about 37% of the time, ranging from a 47% completion rate for Steuben County to 15% for Essex County. About 76% of the measurements were conducted in basements; and these data are included below, in a comparison of the survey results to estimates of radon potential based on surficial geology correlations. Basement measurement results, summarized in Figure 2, were log-normally distributed, with a geometric mean of 3.4 pCi/L and a maximum of 72 pCi/L. (48%) the basements had radon Overall, nearly half concentrations >4 pCi/L. About 17% of the basements had concentrations >10 pCi/L. None of the 13 exceeded 2 pCi/L. measurements in the low-risk Region 3 Living-area (i.e., non-basement) radon concentrations for the participating homes had an overall geometric mean of 2.1 pCi/L and a maximum of 17 pCi/L. About 33% of the first-floor (and above) measurements were >4 pCi/L, and 9% of the concentrations were >10 pCi/L. 2001 Home buyer measurements For the 3-month study period (March 1- May 30, 2001), a total of 5299 detector applications were mailed to buyers of single-family homes located in 14 counties. In response, there were 713 applications for the free radon detector, and 705 surveys were returned within the 2-month deadline. The return rates for the applications varied from 10% for Jefferson and Ontario Counties, to 22% for Genesee County. Results of the mail-out and measurements are included in Table 2. Of the radon detectors mailed to respondents who had mailed back the detector application, only 372 detectors were properly exposed and mailed back for measurement to the contracted laboratory. Successful completion of the measurements varied from 33% in Lewis County to 72% in Jefferson County, and averaged 52%. About 73% of the radon measurements were conducted in basements. Results of the 271 basement measurements, shown in Figure 3, were log-normally distributed, with a geometric mean of 2.2 pCi/L and a maximum of 25 pCi/L. county-wide from 1.1 geometric pCi/L for mean basement low-risk The average measurements counties (Oswego ranged and St. Lawrence Counties) up to 5.7 pCi/L for high-risk Chemung County. Nearly 70% of the measurements in the latter were >4 pCi/L. 1 were conducted Most (50 of 57) measurements in low-risk Region <4 in pCi/L, Oswego including and Lewis all of the Counties. measurements In the study overall, 29% the basements had indoor radon concentrations >4 pCi/L, and 5% had concentrations >10 pCi/L. Results of the 101 living-area radon measurements were also log-normally distributed, with a geometric mean of 0.7 pCi/L, but a larger maximum (42 pCi/L) than was observed for the basement measurements. Average county-wide geometric-mean living-area concentrations ranged from 0.3 pCi/L for Ontario County to 2.8 pCi/L for high-risk Chemung County. homes Orange County had the largest number (five) of with living area radon concentrations >4 pCi/L. None of the 23 measurements in the four low-risk counties of Region 1 was >4 pCi/L. had radon Overall, 11% the living areas concentrations >4 pCi/L, and 3% had concentrations >10 pCi/L. Comparison of measurement results and radon-potential maps The NYS Department of Health has estimated and mapped radon concentrations for every town and city in the State (4 ,5). Figure 4 provides a comparison of the radon potential estimated from nearly 44,000 measurements with the measurement results obtained from this study. The available number of measurements was inadequate to allow comparisons to the radon-risk maps on the township level; therefore, county summaries are provided. The correlation coefficients (r2) of 0.68 and 0.52 for the basement and living the area, small study. respectively, number of are satisfactory, measurements obtained considering through this The existing identification of counties as having a high (e.g., Chemung) or low (e.g., Oswego) potential for indoor radon was supported by the measurement data from the study. Home buyer survey The results of the 647 questionnaires returned by home purchasers in 1999 are tabulated by county and region in Table 2. The number of questionnaires returned for Regions 1 through 4 were 118, 186, 80, and 263, respectively. In 2001, 705 questionnaires were returned by home purchasers; the results are included in Table 2. the number Regions 1 of questionnaires through respectively. 4 While were there In the 2001 study, returned 149, were by 143, 1360 homeowners 148, and in 273, questionnaires returned, not all respondents answered every question, and not all questions were the same in both years. Lastly, the reader must bear in mind the bias inherent in surveys. Since home buyers who live in an area of high radon potential are likely to be more aware of radon and its health risks (due to various outreach activities), they are more likely to respond to the survey, thus biasing its results. In contrast, home buyers who live in a an area of low radon potential are less likely to be familiar with radon and its health risks (due to the lack of outreach activities) and may be more likely to discard the survey as “junk mail”. Below are the summary results for many of the key questions used in the surveys. Question: Have you ever heard of the health risk associated with radon? Overall, about 77% of respondents claimed to have heard of radon and its health respondents who resided Regions in were risk. The familiar 1 and 2, largest with both percentage radon’s areas of of health risk high radon potential. Question: How have you heard about radon? Radon information reached the home from newspapers and radio/TV. estate less agents provided frequently the (~15% equally (~22%) Home inspectors and real- buyer each). buyer with radon Respondents information noted that doctors had rarely supplied any radon information. Question: Do you believe that exposure to radon is unhealthy? An overwhelming majority (98%) of respondents understood that exposure to radon should be minimized. As mentioned above, people who live in an area of high radon potential are more likely to be familiar with radon health issues and more likely to respond to the survey, thereby biasing the results. Question: Was any radon during the purchase of your home? information given to you Radon information was provided to the home buyer about 44% of the time. On a regional scale, home buyers in Regions 2 and 4 were provided with radon information at about 60% of sales. Provision of radon information is nearly nonexistent in the low-risk counties of Region 3 (e.g., Clinton (3%), Essex (7%), and Franklin (5%)). replies indicated that less than 25% of Region 1, comprising of high radon However, the home buyers in risk counties, were provided with radon information. Question: Who provided you with the radon information? It is important to determine who provides home buyers with radon information, so that these groups can be targeting for additional training. who did receive radon Overall, among those home buyers information during the sale, the information was provided by home inspectors about 50% of the time, and real-estate agents about 30% of the time. In Regions 1 and 3, real-estate agents often provided radon information to the contributing little, home if buyers, any, to with the inspectors dissemination. However, for Region 4, inspectors were the primary source (61% of the time) of the radon information to home buyers, with real-estate agents contributing 22% of the time. most knowledgeable group, radon contractors, are The rarely involved in the initial discussion of radon with the prospective home buyers; such contractors provide the radon information only 4% of the time. In nearly every case in which the seller provided radon information to the buyer, the home had been measured prior to the sale. Question: What were you told about radon during the sale? As some home buyers may not be familiar with the topic of radon, the information provided by the home professional must be accurate and reliable. According to the survey, home buyers were told that i) the home should be tested (34%), ii) that radon is a health problem (19%) and iii) a radon contingency clause should be added to the contract (15%). These are all valid assertions. However, 67 home buyers were told that radon is not a problem or were told not to worry about it, with most of these (65%) located in the high-risk counties. In three of the regions, 31-35% of home buyers were advised to have their homes tested, while none in low-risk Region 3 were advised to test. Half of the respondents were told that radon is not a problem in Region 3, an assertion which may be generally correct but is not acceptable, considering that homes containing >20 pCi/L are located in these counties. Very few home buyers were informed of the potential for the seller to tamper with the test. Question: Has your house ever been tested for radon? Of the 1333 responses to this question, 28% reported that the home had a radon measurement, with most of these done during the sale. Over half of the buyers did not know whether the home had been previously measured. Many of the home buyers (38-50%) in Broome, Dutchess, and Rensselaer Counties had the homes tested for radon during the sale. Only about 20% of homes in the two highest-risk counties (Cortland and Steuben) were measured during the sale. A similar trend is evident in the regional breakdowns, with 39% of the homes in Regions 2 and 4 having been measured, but only 2% of those in low-risk Region 3 and 12% of homes in high-risk Region 1. About 75% of the home buyers who reported having received radon information also reported that the home had a radon measurement during or prior to the sale. This implies that buyers who receive radon information are much more likely to conduct a measurement as a stipulation of the sale. Question: When was the house tested? The majority (83%) of radon tests were done during the sale of the home, emphasizing both the need to provide radon information to buyers early in the sale process, and the role played by real-estate transactions in promoting radon measurements. (17%) of previous In tests Dutchess were County, conducted ownership), suggesting a significant before a the history sale of number (during past radon measurements during real-estate transactions in this area. Few respondents from Regions 1 and 3 reported that their homes had ever been measured, demonstrating the lack of radon measurements in both regions, even counties contain homes with >20 pCi/L. though the Only a few home buyers (4%) conducted radon measurements after the sale. Question: About 74% of Where was the radon measurement taken? the measurements were conducted in the basements of homes, suggesting that it is often used as the lowest habitable area of the home. Most of the remaining measurements were conducted on the first floor. Only in Columbia and Cattaraugus Counties were there more firstfloor than basement measurements. About 20 respondents reported dual measurements, and two respondents reported that multiple radon measurements had been conducted. Question: Home Who did the radon measurement? inspectors measurements of conducted these about homes. 70% This of the illustrates radon the importance of training and certification of home inspectors with respect to radon. The most knowledgeable group, radon contractors, provided about 15% of the measurements, and home buyers conducted about 7% of the tests themselves. Measurements by radon contractors were most prevalent (82%) in Region 4, an area that is relatively well informed on the topic of indoor radon. Surprisingly, real-estate agents conducted very few (3%) of the measurements. Question: Was the radon measurement above 4 pCi/L? Of the 359 replies to this question, 35% stated that the measured radon concentration was above 4 pCi/L. About 24% of the respondents could not recall the measurement value. Home buyers in Cortland, the highest radon-risk county in the State, pCi/L. this reported 60% of measurement results above 4 It has been estimated (4,5) that 74% of homes in County have radon concentrations >4 pCi/L basement (39% above 4 pCi/L in the living area). in the However, home buyers in other high-risk counties, such as those in Regions 1 and 4, reported that radon concentrations >4 pCi/L about 31% of the time. were Region 2 had the greatest proportion (41%) of homes reported to be above 4 pCi/L. In Region 3, <10% of the homes had a measurement conducted during the 3-month period for both years. Question: measurement? What actions resulted from this radon Nearly half of the respondents to this question stated that they purchased a home with a radon concentration>4 pCi/L without changing the price. This attitude may indicate ignorance of or apathy toward indoor radon, but it more likely reflects a desire not to complicate or compromise the home purchase. About 19% of home buyers required the seller to install a remediation system as a condition of the sale, primarily in Region-4 counties. About 18% required a reduction in the home's price, presumably to offset the cost of installation of a radon mitigation system. Home buyers in Region 1 were likely to request a price reduction, while 30% of buyers in highly populated Region 4 required that a system be installed. most buyers would have purchased the home Overall, regardless, without requesting an alteration in price, indicating that indoor radon plays a minor role in selection of a home. Question: Was a follow-up test conducted to confirm the initial measurement? The USEPA recommends a confirmatory measurement for results >4 pCi/L, prior to initiation of remediation. nearly 70% of the buyers with initial However, indoor radon measurements above 4 pCi/L did not conduct a confirmatory measurement. measurement. Thus, The lack few of homes had follow-up more than measurements one places undue reliance on the initial measurement, especially in high-risk counties, since remediation is contemplated based on a single measurement. Residents conducted follow-up measurements most often (67%) in Region 4, while those in Region 1, another high-risk area, had reported only 13% follow-up measurements. Question: Who did the follow-up measurement? Over half (~57%) of the follow-up conducted by radon contractors. measurements were This is likely due to the contractors’ involvement in home remediations following an initial result >4 pCi/L. the follow-up Home inspectors conducted 25% of measurements, and real-estate agents conducted very few (~2%). Question: Was the follow-up measurement below 4 below 4 pCi/L? Most (61%) pCi/L. of Given the follow-up that the measurements two were measurements were often conducted by different individuals, on different dates, a lack of Regions agreement 2 measurements and 4 below of had 4 the 60% pCi/L, results and 81% is not surprising. of the follow-up respectively. No follow-up measurements were conducted in Region 3 during either study year. Question: Were actions taken to reduce levels in your house? Roughly half of the respondents reported taking some action to reduce their household radon concentration. The majority of these were in Broome and Rensselaer Counties. Nearly half of the respondents in Dutchess County failed to attempt to reduce indoor radon concentrations. percentage of homes that received no The highest remediation action were in Region-3 counties. Question: What steps were taken to lower your exposure to radon in your home? This question provides an indication of the number mitigation systems installed during the home sales. of The most prevalent (40%) action to reduce indoor radon levels was to install a mitigation system. This approach was followed by the less-effective methods of sealing cracks (23%), opening windows (17%), and increasing ventilation (9%). Most of the remediation systems were installed in Regions 2 and 4. Among the 1333 responses, mitigation systems were installed in 43 houses (3.2%). Considering that 111,700 existing single-family homes were sold in NYS in 2002 (excluding New York City) (6), it can be estimated that ~3,600 conducted radon that mitigations year as a (111,700 result x of 3.2%) were real-estate transactions. Sales in New York City were excluded due to the large number of houses, the very low radon potential, and the likelihood that very few mitigation systems are installed there annually. Question: If radon levels in the home were higher than recommended limits, what actions would you have taken? Of the 1468 responses to this question, 43% of the home buyers stated that they would require the seller to install a remediation system, 22% would request a price reduction, and 19% would have canceled the purchase. Home buyers in Chenango and Clinton Counties were most willing to cancel the purchase due to elevated radon concentrations, while those in Cattaraugus County were most likely to take no action. While similar trends are observed at the regional level, only buyers in Region 3 were more likely to cancel the purchase than to seek a reduced price. buyers would have purchased the home A few (4%) home regardless of the indoor radon concentrations. Question: Are you interested in having a free radon measurement of your home? An overwhelming 97% of home buyers requested a radon measurement, regardless of the previous measurement history of the house. As described above, a few home buyers, primarily in Allegany and Broome Counties, were indifferent to radon's health effects and did not want to measure or re-measure their homes. It is interesting to note that, while very few homes in low-risk Region 3 were measured during the sale, >95% of the respondents from this region requested a radon measurement as part of our program. buyers from the higher-risk areas (Regions 2 declined the radon detector offer most often (8%). Home and 4) About 40% of the detector requests came from Region 4. Question: What type of home did you purchase? The majority of respondents (93%) purchased single-family homes, although 7% were mobile homes, two-family, or other residential building types. The prevalence of mobile-home purchases was highest in Regions 1 and 3, and none of the buyers of mobile homes reportedly measured during the purchase. Question: Which best describes your home? Unfinished basements (35%) were more common than finished construction (22%), although the latter implies that the owners are likely to spend more time in the higher-radon environment of the basement. Block wall construction, which can serve as a conduit for radon migration into a home, was more prevalent than poured foundation. Crawl spaces and slab-on-grade construction were reported for 10 and 7% of the homes, respectively. Crawl spaces were more common in Regions 1 and 3, and finished basements were more common in Regions 2 and 4. Question: Have you ever conducted a radon measurement in your previous residence(s)? This question sought information regarding radon awareness of the home buyer. of respondents had not the previous A large majority (83%) previously conducted a radon you conducted a radon measurement of their home. Question: Why have never measurement in past residence(s)? About 35% of respondents had previously rented a residence and had not conducted a radon measurement. respondents were not aware of radon and Another 32% of the need to Surveys were returned by 1333 home buyers in NYS. Of measure. CONCLUSIONS the 330 home buyers who reported discussing radon information during the sale in 1999, 194 either conducted a radon measurement or were provided results by the previous owners. Similarly, 251 home buyers reported receiving radon information during the sale in 2001, and most (174) conducted a radon measurement. This implies that many prospective buyers, if informed and assisted, will conduct radon testing of the house. "getting the However, radon message out" measurements Therefore, the importance of cannot and be overemphasized. disclosure nonexistent in the low-risk counties. were nearly Home inspectors are the primary providers of radon information to home buyers, but they often have little formal instruction or experience in matters regarding indoor radon. About 30% of responding home buyers had radon measurements done in the house either prior to, during, or after the sale. homes with initial radon levels Of the 129 reports of >4 pCi/L, only 20 had confirmatory results >4 pCi/L, and 43 (corresponding to ~3% of all respondents) had mitigation systems installed to reduce elevated concentrations (27 others had plans to have mitigation systems installed). the radon detectors was While interest in receiving evident from the survey’s high response rates, the improper exposure and return of these detectors to the analytical reduction in the proportion laboratory of resulted measurements that in a were valid. Acknowledgements paper was - Although partially funded the work described by the U.S. in this Environmental Protection Agency as part of the State Indoor Radon Grants (SIRG) Program, the contents do not necessarily reflect the views of the Agency, and no official endorsement should be inferred. REFERENCES 1. National Research Council, Health Effects of Exposure to Radon, BEIR VI, National Academy Press, Washington DC, 1999. 2. Kopera, A., “NJDEP Radon Section”, http://www.nj.gov/dep/rpp/radon, 2004. 3. Wang, Y., Ju, C., Stark, A.D., Teresi, N., “Radon Mitigation Survey Among New York State Residents Living in High Radon Homes”, Health Physics, 77(4), 403, 1999. 4. Kitto, M.E., Kunz, C.O., Green, J.G., "Development and Distribution of Radon Risk Maps in New York State", J. Radioanal. Nucl. Chem., Articles, 249(1) , 153, 2001. 5. Kunz, C.; Kitto, M.; Schwenker, C.; Green, J.; Regilski, E., "Identifying High-Risk Areas in New York State: Mapping Indoor Radon Data", SIRG V Final Report, 1999. 6. New York State Office of Real Property Services, private communication, 2003. 7. “Radon in New York State”, http://www.nyradon.org, 2004. 8. U.S. Census Bureau, http://www.census.gov, summary file 3, 2000. FIGURE CAPTIONS Figure 1. Counties in four regions of NYS that were targeted to examine differences in real-estate disclosures by region. Figure 2. Distributions of basement and living-area radon concentrations in homes measured in 1999 were Figure 3. log-normally distributed. Distributions of basement and living-area radon concentrations in homes measured in 2001 were log-normally distributed. Figure 4. Comparison of initial measurement results from this study with estimates from statewide mapping in NYS. Table 1. Counties in NYS targeted in the studies. Radon potentiala Year Region housesb Counties 1999 65,412 1 Allegany, Cattauragus, Steuben 50-66 2 Broome, Chenango, Cortland 36-74 3 Clinton, Essex, Franklin 91,869 9-15 45,817 4 150,563 Columbia, Rensselaer, Dutchess 41-46 No. of 2001 80,057 1 Genesee, Livingston, Ontario, Wyoming 33-48 2 Chemung, Schuyler, Tioga, Tompkins 35-71 3 Jefferson, Lewis, Oswego, Saint Lawrence 14-30 Orange, Putnam 33-35 75,064 97,960 4 126,894 a Percentage of homes estimated to have basement radon concentrations >4 pCi/L (7). b Detached houses occupied by 1-4 families (8). Table 2. Summary of radon surveys sent to NYS home buyers. 1999 County Surveys Completed name Sent Rec’d a measurements Region 1 Allegany 82 (72%) Cattaraugus 183 (33%) Steuben 238 (57%) (51%) Region 2 Broome (67%) Chenango (49%) Cortland (38%) (68%) Region 3 Clinton (52%) Essex (57%) Franklin (56%) 2002 Completed measurementsa County Surveys Name Sent Rec’d Jefferson 174 18 13 26 3 1 301 37 21 St. Lawrence 559 89 45 Genesee 158 33 22 Livingston 275 47 23 Ontario 404 39 15 Wyoming 156 22 15 10 4 (40%) 47 15 (35%) Lewis 61 24 (47%) Oswego 465 116 36 (35%) 127 26 9 (41%) 113 44 18 (39%) 127 34 11 (27%) Chemung 245 29 15 97 27 4 (15%) Schuyler 42 7 4 75 19 9 (47%) Tioga 280 32 18 Tompkins 499 78 45 (58%) Region 4 Columbia 177 (52%) Dutchess 619 (47%) Rensselaer 248 37 16 (52%) Orange 1309 151 79 164 51 (34%) Putnam 871 120 56 62 21 (39%) Totals (53%) a b 2551b 647 218 (37%) 5299 705 372 Percentage of completed measurements, based on number of detectors requested. 331 letters returned to sender due to delivery problems.