Case-control study of radon and lung cancer in New Jersey.

Radon is known to cause lung cancer in humans; however, there remain uncertainties about the effects associated with residential exposures. This case-control study of residential radon and lung cancer was conducted in five counties in New Jersey and involved 561 cases and 740 controls. A year long alpha-track detector measurement of radon was completed for approximately 93% of all residences lived in at the time of interview (a total of 2,063). While the odds ratios (ORs) for whole data were suggestive of an increased risk for exposures >75 Bq m(-3), these associations were not statistically significant. The adjusted excess OR (EOR) per 100 Bq m(-3) was -0.13 (95% CI: -0.30 to 0.44) for males, 0.29 (95% CI: -0.12 to 1.70) for females and 0.05 (95% CI: -0.14 to 0.56) for all subjects combined. An analysis of radon effects by histological type of lung cancer showed that the OR was strongest for small/oat cell carcinomas in both males and females. There was no statistical heterogeneity of radon effects by demographic factors (age at disease occurrence, education level and type of respondent). Analysis by categories of smoking status, frequency or duration did not modify the risk estimates of radon on lung cancer. The findings of this study are consistent with an earlier population-based study of radon and lung cancer among New Jersey women, and with the North American pooling of case control radon seven studies, including the previous New Jersey study. Several uncertainties regarding radon measurements and assumptions of exposure history may have resulted in underestimation of a true exposure-response relationship.

Outdoor exposure to airborne polycyclic organic matter and adverse reproductive outcomes: a pilot study.

BACKGROUND: To investigate the association between outdoor airborne polycyclic organic matter (POM) and adverse reproductive outcomes in New Jersey, we used a cross-sectional design combining air quality data from the USA EPA Cumulative Exposure Project and individual data on pregnancy outcomes from birth and fetal death certificates at the census tract level. METHODS: After excluding plural births and chromosomal anomalies, 221,406 live births and 1,591 fetal deaths registered in New Jersey during the years of 1990 and 1991 were included. The exposure estimates were derived from modeled average POM concentrations for each census tract in the state. RESULTS: After adjustment for potential confounders, the odds ratios (OR) for very low birth weight for the highest exposure compared to the lowest exposure group was 1.31 (95% CI 1.15-1.51); among term births, high POM exposure was associated with low birth weight OR = 1.31 (95% CI 1.21-1.43), with fetal death OR = 1.19 (95% CI 1.02-1.39) and with premature birth OR = 1.25 (95% CI 1.19-1.31). The univariate stratified analyses suggested effect modification of all observed associations by maternal alcohol consumption. CONCLUSIONS: This study found associations between outdoor exposure to modeled average airborne POM and several adverse pregnancy outcomes. The data and methods utilized in this pilot study may be useful for identifying hazardous air pollutants requiring in-depth investigation.

Associations of polycyclic organic matter in outdoor air with decreased birth weight: a pilot cross-sectional analysis.

The association between births that are small for gestational age and outdoor airborne polycyclic organic matter (POM) was examined in New Jersey, a highly urban state. This pilot study utilizes a cross-sectional investigation combining maternal and pregnancy outcome information from birth certificates with air toxics data from the U.S. Environmental Protection Agency Cumulative Exposure Project and census data at the census tract level. The exposure categories were based on tertiles of modeled average POM concentrations for each census tract in New Jersey. High POM exposure was positively associated with delivery of "small for gestational age" (SGA) births. After adjustment for potential individual-level confounding factors, the odds ratios for term, preterm, and all SGA were 1.22 (1.16-1.27), 1.26 (1.07-1.49), and 1.22 (1.17-1.27), respectively, for the highest exposure tertile in the urban population of the state (89% of the state's birth population). For group-level variables, the corresponding ORs were 1.12 (1.07-1.18), 1.23 (1.02-1.47), and 1.13 (1.07-1.18). The results of this study suggest that residential exposure to airborne polycyclic organic matter (POM) is associated with increased prevalence of "small for gestational age" births among urban population. Cross-sectional investigations combining air dispersion models with routinely collected population-based health and census data could be a useful approach for identifying the hazardous air pollutants of greatest public health concern.

Neural tube defects and drinking water disinfection by-products.

We conducted a population-based case control study of neural tube defects and drinking water contaminants, specifically, disinfection by-products. We used public monitoring records concurrent with the first month of gestation to assess exposure. The prevalence odds ratios (PORs) for the highest tertile of total trihalomethanes compared with the lowest was 1.6 (95% confidence interval [CI] = 0.9-2.70). Surface water source was also associated with neural tube defects (POR = 1.5; 95% CI = 0.9-2.5). Sensitivity analyses restricted to isolated neural tube defect cases and mothers with known residence at conception yielded stronger associations [total trihalomethanes, POR = 2.1 (95% CI = 1.1-4.0); surface water, POR = 1.7 (95% CI = 0.9-3.2)]. Other major groups of disinfection by-products (haloacetic acids and haloacetonitriles) showed little relation to these defects.

Evaluation of biomarkers of environmental exposures: urinary haloacetic acids associated with ingestion of chlorinated drinking water.

A study was conducted to determine if DCAA and TCAA urinary excretion rates are valid biomarkers of chronic ingestion exposure to these disinfection by-products of chlorination of drinking water. Entire first morning urine voids, time-of-visit urine samples, and tap water samples were collected from 47 female subjects. In addition, a 48-h recall questionnaire was administered to determine the amounts and types of liquids ingested by each subject as well as other exposures that could lead to DCAA and TCAA urinary excretion. The TCAA excretion rate for the first morning urine samples was significantly correlated with the estimated 48-h TCAA ingestion exposure for 25 subjects whose ingestion exposures primarily occurred at home, while the DCAA excretion rate was not correlated with the DCAA ingestion exposure. Thus, urinary TCAA appears to be a valid biomarker of chronic ingestion exposure to TCAA from chlorinated water, while urinary DCAA is not. It is proposed that the difference in the biological half-lives between these two compounds is the rationale for this finding. The biological half-life of TCAA is longer than successive exposure intervals; thus TCAA accumulates until it reaches a steady state. The half-life of DCAA is shorter than successive exposure intervals; thus DCAA is almost completely metabolized following an exposure and is eliminated from the body. This study suggests that biological half-life, exposure interval, and sample collection interval should be considered in selecting biomarkers and designing studies to validate them.

Exposure estimates to disinfection by-products of chlorinated drinking water.

Exposure to disinfection by-products (DBPs) of drinking water is multiroute and occurs in households serviced by municipal water treatment facilities that disinfect the water as a necessary step to halt the spread of waterborne infectious diseases. Biomarkers of the two most abundant groups of DBPs of chlorination, exhaled breath levels of trihalomethanes (THMs) and urinary levels of two haloacetic acids, were compared to exposure estimates calculated from in-home tap water concentrations and responses to a questionnaire related to water usage. Background THM breath concentrations were uniformly low. Strong relationships were identified between the THM breath concentrations collected after a shower and both the THM water concentration and the THM exposure from a shower, after adjusting for the postshower delay time in collecting the breath sample. Urinary haloacetic acid excretion rates were not correlated to water concentrations. Urinary trichloroacetic acid excretion rates were correlated with ingestion exposure, and that correlation was stronger in a subset of individuals who consumed beverages primarily within their home where the concentration measurements were made. No correlation was observed between an average 48-hr exposure estimate and the urinary dichloroacetic acid excretion rate, presumably because of its short biological half-life. Valid biomarkers were identified for DBP exposures, but the time between the exposure and sample collection should be considered to account for different metabolic rates among the DBPs. Further, using water concentration as an exposure estimate can introduce misclassification of exposure for DBPs whose primary route is ingestion due to the great variability in the amount of water ingested across a population.

Public drinking water contamination and birth outcomes.

The effects of public drinking water contamination on birth outcomes were evaluated in an area of northern New Jersey. After excluding plural births and chromosomal defects, 80,938 live births and 594 fetal deaths that occurred during the period 1985-1988 were studied. Information on birth outcome status and maternal risk factors was obtained from vital records and the New Jersey Birth Defects Registry. Monthly exposures during pregnancy were estimated for all births using tap water sample data. Odds ratios of > or = 1.50 were found for the following: total trihalomethanes with small for gestational age, central nervous system defects, oral cleft defects, and major cardiac defects; carbon tetrachloride with term low birth weight, small for gestational age, very low birth weight, total surveillance birth defects, central nervous system defects, neural tube defects, and oral cleft defects; trichloroethylene with central nervous system defects, neural tube defects, and oral cleft defects; tetrachloroethylene with oral cleft defects; total dichloroethylenes with central nervous system defects and oral cleft defects; benzene with neural tube defects and major cardiac defects; and 1,2-dichloroethane with major cardiac defects. Total trihalomethane levels > 100 ppb reduced birth weight among term births by 70.4 g. By itself, this study cannot resolve whether the drinking water contaminants caused the adverse birth outcomes; therefore, these findings should be followed up utilizing available drinking water contamination databases.

Assessing human health effects from chemical contaminants in drinking water.

Epidemiologic studies in New Jersey have examined the relationship between exposure to water contaminants and the occurrence of leukemias, non-Hodgkin's lymphomas, and adverse reproductive outcomes. Public drinking water supplies need to be monitored on a continual basis.

Radon exposure in residences and lung cancer among women: combined analysis of three studies.

Lung cancer risk in relation to indoor radon was examined in three case-control studies in Stockholm (Sweden), New Jersey (United States), and Shenyang (People's Republic of China). Year-long measurements of radon gas were made in current and past homes of 966 women who developed lung cancer and of 1,158 control women, included in the combined analysis. Nearly 14 percent of the participants were estimated to have a time-weighted, mean, radon concentration in their homes of more than 4 pCi/l (150 Bq/m3) during the period from five to 35 years prior to the date of lung cancer diagnosis (or comparable date for controls). There was a tendency for risk to increase with increasing levels of radon in NJ and Stockholm, but the trends for individual studies and overall were not statistically significant. The estimates of the excess relative risk for indoor exposure per pCi/l were 0.18 (95 percent [CI] = -0.04-0.70) in NJ, 0.06 (CI = -0.05-0.34) in Stockholm, and -0.02 (CI = -infinity-0.03) for Shenyang; these estimates did not differ significantly from each other. The overall excess RR per pCi/l was 0.00 (CI = -0.05-0.07); the confidence limits were sufficiently broad, however, that the overall estimate was still compatible with extrapolations of risks from miners. Cigarette smoking was the predominant cause of lung cancer with the RR significantly elevated in all studies. Within smoking categories, the trend in risk with increasing mean radon concentration was inconsistent. Analyses of data from several studies are complicated by the possibility that there may exist important differences in study bases which might affect results, and which may be controlled only partially through adjustment procedures. Future efforts to combine various residential studies will need to be attentive to the intrinsic limitations of studies to detect low levels of risk as well as the unique uncertainties associated with estimating, accurately, cumulative exposure to indoor radon.

Relationship among short- and long-term radon measurements within dwellings: influence of radon concentrations.

As part of a retrospective epidemiologic study of lung cancer in women, alpha-track and charcoal canister radon measurements were made in a sample of New Jersey residences. The alpha-track measurements were designed to yield estimates of annual average exposures of dwelling occupants, while charcoal canister measurements were designed to yield "worst case" concentrations for screening purposes. The year-long living area and basement screening measurements had geometric means of 19 Bq m-3 (0.52 pCi L-1) and 56 Bq m-3 (1.5 pCi L-1), respectively. Measurements of radon gas with different detectors and on different floors were compared to each other within residences. Ratios of screening to annual average results became more extreme as the measured concentrations increased; the mean ratio of basement canisters to year-long living area alpha-track detectors was 5.6 vs. 2.7 for houses that screened above and below 150 Bq m-3 (4 pCi L-1), respectively. Although the residence sample from which these data were drawn is not necessarily representative of either state or national housing stock, these observations, if verified, may have important implications for procedures and decision strategies designed to reduce individual and population exposures to radon.

Case-control study of residential radon and lung cancer among New Jersey women.

To evaluate the association of indoor radon exposure with lung cancer risk, yearlong alpha track detector measurements of radon were conducted in dwellings which had been occupied for at least 10 years by 433 New Jersey female lung cancer cases and 402 controls who were subjects in a larger population-based study. Adjusted odds ratios were 1.1 (90% confidence interval, 0.79-1.7), 1.3 (90% confidence interval, 0.62-2.9), and 4.2 (90% confidence interval, 0.99-17.5) for exposures of 1.0-1.9, 2.0-3.9, and 4.0-11.3 pCi/liter, respectively, relative to exposures of less than 1.0 pCi/liter, showing a significant trend (1-sided P = 0.04) with increasing radon concentration. The trend was strongest among light smokers (less than 15 cigarettes/day, 1-sided P = 0.01). The trend for lung cancer risk with estimated cumulative radon exposure was slightly weaker (1-sided P = 0.09). The increase in relative risk for each unit of cumulative exposure, 3.4% (90% confidence interval 0.0-8.0%) per working level month, was consistent with the range of 0.5-4.0% per working level month generally reported for underground miner studies, supporting the extrapolation of the occupational data to the residential setting. However, the possibility of selection biases, the small number of high exposures, and other uncertainties necessitate caution in interpretation of these data.

Mortality of a residential cohort exposed to radon from industrially contaminated soil.

A historical cohort mortality study was conducted in three neighborhoods of Essex County, New Jersey, to investigate the mortality patterns of persons who had inhabited 45 homes documented to be contaminated by radon gas emanating from radium processing waste. Residency history and vital status were collected for 752 persons, comprising 91% of the subjects enumerated who had resided in the index homes for at least one year during the years 1923-1983. Standardized mortality ratios (SMR) were used to compare the death rates of the study group with the death rates of the United States and New Jersey. While there were no statistically significant excesses of lung cancer for the cohort or its subgroups, an elevated mortality rate for lung cancer was found for white males in the comparison of lung cancer mortality rates in the United States (SMR = 1.5, 95% confidence interval (CI) 0.7-2.7) and New Jersey (SMR = 1.7, 95% CI 0.8-3.2). No excess of lung cancer was observed in females or nonwhites. The small size of the cohort and the inability to collect smoking histories or complete occupational data limited the study. Nevertheless, the degree of excess lung cancer among white males was in agreement with both the attributable and relative risk estimates per unit of exposure derived for radon from mining studies.