Cancer mortality in U.S. counties with chemical industries.

Geographic analysis of U. S. cancer mortality, 1950–1969, revealed excess rates for bladder, lung, liver, and certain other cancers among males in 139 counties where the chemical industry is most highly concentrated. The correlation could not be explained by confounding variables such as urbanization, socioeconomic class, or employment in nonchemical industries. If the excess cancer mortality in these areas is due to industrial exposures, the actual risk of cancer among certain chemical workers must be very high. The correlation was limited to counties associated with specific categories of the chemical industry; many involve known occupational hazards, while others suggest new leads to chemically induced cancer in man.     

Air pollution and daily mortality in three U.S. counties

I used generalized additive models to analyze the time-series of daily total nonaccidental and cause-specific (cardiovascular, cerebrovascular, and chronic obstructive pulmonary disease) deaths over the period 1987-1995 in three major U.S. metropolitan areas: Cook County, Los Angeles County, and Maricopa County. In all three counties I had monitoring information on particulate matter [less than/equal to] 10 microm (PM(10)), carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone. In Los Angeles, monitoring information on particulate matter [less than/equal to] 2.5 microm (PM(2.5)) was available as well. I present the results of both single and multi-pollutant analyses. Air pollution was associated with each of the mortality end points. With respect to the individual components of the pollution mix, the results indicate considerable heterogeneity of air pollution effects in the different geographic locations. In general, the gases, particularly CO, but not ozone, were much more strongly associated with mortality than was particulate matter. This association was particularly striking in Los Angeles County.     

Cancer mortality in U.S. counties with shipyard industries during World War II

Respiratory cancer mortality, 1950–1969, was consistently high in U.S. counties where shipyards were engaged in the construction and repair of large naval and cargo vessels during World War II. Over three-fourths of the shipyard counties had elevated rates (in comparison to rates in counties of similar population size in the same region of the country) for lung and laryngeal cancer among white males, with the excess particularly evident in the South. Mortality from lung cancer was high also among white females, and the rate of increase in both sexes was greater than recorded nationally. In addition, rates for oropharyngeal, esophageal, and gastric cancers tended to be elevated in the shipyard counties, but mortality from other tumors was roughly comparable to national levels. A causal relation to asbestos exposures in shipyards cannot be inferred from this correlational analysis, but the unusual mortality patterns underscore the need for broadly based analytic studies to evaluate the risk of cancer in persons with wartime shipyard employment.     

Selenium in forage crops and cancer mortality in U.S. counties

The potential protective effect of selenium status on the risk of developing cancer has been examined in animal and epidemiologic studies. This ecological study investigated the association between U.S. county forage selenium status and site- and sex-specific county cancer mortality rates (1950-1969) using weighted least squares regression. Consistent, significant (p less than .01) inverse associations were observed for cancers of the lung, rectum, bladder, esophagus, and cervix in a model limited to rural counties and for cancers of the lung, breast, rectum, bladder, esophagus, and corpus uteri in a model of all counties. No consistent significant positive associations were observed in the rural county models. This remarkable degree of consistency for the inverse associations strengthens the likelihood of a causal relationship between low selenium status and an increased risk of cancer mortality.     

Cancer incidence and mortality around a hazardous waste depot

The Castlereagh Regional Waste Disposal Depot (CRWDD) has been the focus of community concerns regarding the impact of hazardous waste disposal on their health and that of their local environment. As part of a phased epidemiological approach to investigate the levels of illness in people living in the vicinity of the CRWDD, routinely collected data were used to determine the rates of cancer and mortality in the area around the site and whether these rates were higher than expected when compared with New South Wales (NSW). The area investigated was based on eight census collection districts around the boundary of the CRWDD. Cancer incidence and mortality in the study area were calculated and compared to NSW using the indirect method of age and sex standardisation. Over an 18–year period, brain cancer in males (six cases) was the only cancer where the incidence in the study area was significantly higher than expected (SIR 380, 95% CL 139.4,826.6). When this data were examined over smaller (arbitrary) time periods, there was an apparent cluster of brain cancer in males (three cases) between 1989 and 1991 (SIR 905, 95% CL 187,2646). There was a significant concentration of cases of cancers of the breast in females and cancers of the uterus over the smaller time periods. Although continued surveillance of these cancers is recommended, there are several basic limitations associated with small area data analysis that prevent a clear interpretation of these results. This limits our ability categorically to resolve the concerns of those living in the vicinity of the CRWDD.     

Environmental health and hazardous waste issues related to the U.S.-Mexico border.

Environmental health and environmental quality issues along the U.S.-Mexico border have been of concern for several years. The enactment of the North American Free Trade Agreement and the presence of the maquiladoras (foreign-owned industries using imported raw materials) have intensified those concerns recently. Efforts to assess these issues are complicated by the fact that many of the issues affecting the border region are within federal jurisdiction, but the problems are regional and local in nature. Thus, state and local governments become involved with public concerns about real and potential problems. One major problem is that environmental health data from this region are lacking, particularly from Mexico. Some new agencies such as the Border Environment Cooperation Commission, the United States-Mexico Border Health Commission, and the North American Commission on Environmental Cooperation have joined several existing agencies at the federal and state level to address environmental quality and health. Several studies have been initiated to determine air and water quality, but little is being done in the areas of hazardous waste and health assessment. Several problems are anticipated in the generation of such data, such as its format and accessibility. Data gaps and research needs are discussed.     

Cancer mortality among women employed in fast-growing U.S. occupations.

Our study examined cancer mortality before the age of 65 for women employed in the fastest growing and/or traditionally female occupations. Analysis of mortality data from 28 U.S. states for 1984-1995 revealed elevated proportionate cancer mortality ratios (PCMRs). The highest PCMRs observed were thyroid cancer among health aides, lymphatic and multiple myeloma among computer programmers, and brain cancer among actresses and directresses. Some of the excess mortality occurred for occupations that have been previously cited. These included elevated breast and ovarian cancer among teachers, Hodgkin's disease among hairdressers and cosmetologists, and thyroid cancer among health aides and therapists. A few of the associations were new, i.e., had not been previously observed. These included cancer of the connective tissue and lymphatic system among computer programmers, ovarian cancer and leukemia among secretaries, and lymphatic cancer and multiple myeloma among child care workers. These findings should be further investigated with epidemiologic and environmental studies.     

Risk of congenital malformations associated with proximity to hazardous waste sites.

Concern about environmental pollutants has increased; however, it remains unclear whether chronic exposures to toxic chemicals in the environment occur at doses sufficient to produce adverse health effects in humans. To date, community studies have not adequately addressed this question. In this study, the authors linked two existing data bases of the New York State Department of Health to evaluate the relation between congenital malformations and residential proximity to hazardous waste sites in New York State. A total of 9,313 newborns with congenital malformations and 17,802 healthy controls living in proximity to 590 hazardous waste sites in 1983 and 1984 were evaluated. After the authors controlled for several possible confounding factors, results indicated that maternal proximity to hazardous waste sites may carry a small additional risk of bearing children with congenital malformations (odds ratio (OR) = 1.12, 95% confidence interval (Cl) 1.06-1.18). Higher malformation rates were associated with both a higher exposure risk (no exposure risk: OR = 1.00; low exposure risk: OR = 1.09, 95% Cl 1.04-1.15; high exposure risk: OR = 1.63, 95% Cl 1.34-1.99) and documentation of off-site chemical leaks (not exposed: OR = 1.00; exposed, but no leaks at site: OR = 1.08, 95% Cl 1.02-1.15; exposed, and leaks found at site: OR = 1.17, 95% Cl 1.08-1.27). The increased rates detected may be important in terms of their public health implications. Further research is necessary to strengthen causal inferences regarding the teratogenicity, of waste site exposure.     

Simultaneous smoothing and adjusting mortality rates in U.S. counties: melanoma in white females and white males

Detecting patterns in health-related data for geographic areas is facilitated with the use of exploratory methods, especially smoothing. In addition, these data often must be adjusted for known prognostic factors such as age and gender. The analysis in this paper focuses on mortality rates due to malignant melanoma in White males and White females; these data are adjusted for both age and latitude, separately for males and females, and then smoothed using (a) a non-linear smoother known as weighted head-banging, and (b) a new method that incorporates the adjustment and the smoothing simultaneously. Maps of the continental United States show regions of high rates, even after having adjusted for age and latitude, and suggest the possibility of other variables that may influence the rates.     

Ischemic heart disease and ambient air pollution of particulate matter 2.5 in 51 counties in the U.S

OBJECTIVE: Ischemic heart disease (IHD) is one of the most common health threats to the adult population of the U.S. and other countries. The objective of this study was to examine the association between exposure to elevated annual average levels of Particulate matter 2.5 (PM2.5) air quality index (AQI) and IHD in the general population. METHODS: We combined data from the Behavioral Risk Factor Surveillance System and the U.S Environmental Protection Agency air quality database. We analyzed the data using SUDAAN software to adjust the effects of sampling bias, weights, and design effects. RESULTS: The prevalence of IHD was 9.6% among respondents who were exposed to an annual average level of PM2.5 AQI > 60 compared with 5.9% among respondents exposed to an annual average PM2.5 AQI < or = 60. The respondents with higher levels of PM2.5 AQI exposure were more likely to have IHD (adjusted odds ratio = 1.72, 95% confidence interval 1.11, 2.66) than respondents with lower levels of exposure after adjusting for age, gender, race/ethnicity, education, smoking, body mass index, diabetes, hypertension, and hypercholesterolemia. CONCLUSIONS: Our study suggested that exposure to relatively higher levels of average annual PM2.5 AQI may increase the likelihood of IHD. In addition to encouraging health-related behavioral changes to reduce IHD, efforts should also focus on implementing appropriate measures to reduce exposure to unhealthy AQI levels.     

Arsenic in drinking water and bladder cancer mortality in the United States: an analysis based on 133 U.S. counties and 30 years of observation

This study analyzes the relationship between arsenic exposure through drinking water and bladder cancer mortality. The county-specific white male bladder cancer mortality data (1950-1979) and county-specific groundwater arsenic concentration data were obtained for 133 U.S. counties known to be exclusively dependent on groundwater for their public drinking water supply. No arsenic-related increase in bladder cancer mortality was found over the exposure range of 3 to 60 microg/L using stratified analysis and regression analyses (both unweighted and weighted by county population and using both mean and median arsenic concentrations). These results, which provide a direct estimate of arsenic-related cancer risk for U.S. residents, exclude the National Research Council's 2001 risk estimate that was based on Southwest Taiwan data and required adjusting for differences between the body mass and water consumption rates of U.S. and Taiwanese residents.     

Family planning clinic services in U.S. counties, 1983

Organized family planning clinics are a major source of contraceptive services for low-income women, who are less likely than higher income women to be using a contraceptive method. A 1983 study estimated that 9.5 million U.S. women with family incomes below 150 percent of poverty were at risk of unintended pregnancy, and identified a network of 5,106 clinics providing them with services. Seventy-six percent of all counties in the United States have organized clinics that offer family planning services; almost all of those without services are nonmetropolitan counties. An estimated 52 percent of low-income women at risk of unintended pregnancy were served by organized family planning clinics in 1983, while the rest either went unserved or sought care elsewhere. Ten percent of low-income women not served by clinics live in counties that have no family planning clinics, but 67 percent live in counties where existing clinics reach fewer than half of potential low-income patients. More sites may be needed, particularly in counties without clinics, to effectively serve low-income women at risk of unintended pregnancy. However, since the majority of unserved women live in counties where at least one clinic exists, coverage might be improved through increased accessibility and outreach.     

Using quantile regression to examine the effects of inequality across the mortality distribution in the U.S. counties

The U.S. has experienced a resurgence of income inequality in the past decades. The evidence regarding the mortality implications of this phenomenon has been mixed. This study employs a rarely used method in mortality research, quantile regression (QR), to provide insight into the ongoing debate of whether income inequality is a determinant of mortality and to investigate the varying relationship between inequality and mortality throughout the mortality distribution. Analyzing a U.S. dataset where the five-year (1998-2002) average mortality rates were combined with other county-level covariates, we found that the association between inequality and mortality was not constant throughout the mortality distribution and the impact of inequality on mortality steadily increased until the 80th percentile. When accounting for all potential confounders, inequality was significantly and positively related to mortality; however, this inequality-mortality relationship did not hold across the mortality distribution. A series of Wald tests confirmed this varying inequality-mortality relationship, especially between the lower and upper tails. The large variation in the estimated coefficients of the Gini index suggested that inequality had the greatest influence on those counties with a mortality rate of roughly 9.95 deaths per 1000 population (80th percentile) compared to any other counties. Furthermore, our results suggest that the traditional analytic methods that focus on mean or median value of the dependent variable can be, at most, applied to a narrow 20 percent of observations. This study demonstrates the value of QR. Our findings provide some insight as to why the existing evidence for the inequality-mortality relationship is mixed and suggest that analytical issues may play a role in clarifying whether inequality is a robust determinant of population health.     

Fetal deaths and proximity to hazardous waste sites in Washington State

BACKGROUND: The in utero period is one of increased susceptibility to environmental effects. The effects of prenatal exposure to environmental toxicants on various adverse pregnancy outcomes, including fetal death, are not well understood. OBJECTIVE: We examined the risk of fetal death in relation to maternal residential proximity to hazardous waste sites. METHODS: We conducted a population-based case-control study using Washington State vital records for 1987-2001. Cases were women with fetal deaths at > or = 20 weeks (n = 7,054). Ten controls per case were randomly selected from live births. Locations of 939 hazardous waste sites were identified from the Department of Ecology registry. We measured distance from maternal residence at delivery to the nearest hazardous waste site, and calculated odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The risk of fetal death for women residing < or = 0.5 miles, relative to > 5 miles, from a hazardous waste site was not increased (adjusted OR = 1.06; 95% CI, 0.90-1.25). No associations were observed for any proximity categories < or = 5 miles from sites with contaminated air, soil, water, solvents, or metals; however, fetal death risk increased among women residing < or = 1 mile from pesticide-containing sites (OR = 1.28; 95% CI, 1.13-1.46). CONCLUSION: These results do not suggest that fetal death is associated with residential proximity to hazardous waste sites overall; however, close proximity to pesticide-containing sites may increase the risk of fetal death.     

Surveillance around hazardous waste sites: geographic information systems and reproductive outcomes.

The purpose of this paper is to discuss the potential for integrating surveillance techniques in reproductive epidemiology with geographic information system technology in order to identify populations at risk around hazardous waste sites. Environmental epidemiologic studies have had problems with estimating or measuring exposures to individuals, and of detecting effects when the exposure is low, but continuous. In addition, exposures around hazardous waste sites are complex and frequently involve chemical mixtures. The birth weight of human babies has been reported to be sensitive to many environmental influences. Birth weight can be analyzed as a continuous variable or as a dichotomous one using the standard cutpoint of 2500 g or less to indicate low birth weight. It has the potential to be a powerful surveillance tool since exposures to the fetus reflect maternal and paternal exposures. The advent of recent environmental regulations pertaining to hazardous waste sites has greatly increased the availability of environmental data for many sites. The major problem with incorporating these data into epidemiologic studies has been with the logistics of data management and analysis. Computer-assisted geographic information systems hold promise in providing capabilities needed to address the data management and analysis requirements for effective epidemiologic studies around to hazardous waste sites.     

Detecting spatiotemporal clusters of accidental poisoning mortality among Texas counties, U.S., 1980 – 2001

Background  

Accidental poisoning is one of the leading causes of injury in the United States, second only to motor vehicle accidents. According to the Centers for Disease Control and Prevention, the rates of accidental poisoning mortality have been increasing in the past fourteen years nationally. In Texas, mortality rates from accidental poisoning have mirrored national trends, increasing linearly from 1981 to 2001. The purpose of this study was to determine if there are spatiotemporal clusters of accidental poisoning mortality among Texas counties, and if so, whether there are variations in clustering and risk according to gender and race/ethnicity. The Spatial Scan Statistic in combination with GIS software was used to identify potential clusters between 1980 and 2001 among Texas counties, and Poisson regression was used to evaluate risk differences.     

Detecting spatiotemporal clusters of accidental poisoning mortality among Texas counties, U.S., 1980 - 2001

BACKGROUND: Accidental poisoning is one of the leading causes of injury in the United States, second only to motor vehicle accidents. According to the Centers for Disease Control and Prevention, the rates of accidental poisoning mortality have been increasing in the past fourteen years nationally. In Texas, mortality rates from accidental poisoning have mirrored national trends, increasing linearly from 1981 to 2001. The purpose of this study was to determine if there are spatiotemporal clusters of accidental poisoning mortality among Texas counties, and if so, whether there are variations in clustering and risk according to gender and race/ethnicity. The Spatial Scan Statistic in combination with GIS software was used to identify potential clusters between 1980 and 2001 among Texas counties, and Poisson regression was used to evaluate risk differences. RESULTS: Several significant (p < 0.05) accidental poisoning mortality clusters were identified in different regions of Texas. The geographic and temporal persistence of clusters was found to vary by racial group, gender, and race/gender combinations, and most of the clusters persisted into the present decade. Poisson regression revealed significant differences in risk according to race and gender. The Black population was found to be at greatest risk of accidental poisoning mortality relative to other race/ethnic groups (Relative Risk (RR) = 1.25, 95% Confidence Interval (CI) = 1.24 - 1.27), and the male population was found to be at elevated risk (RR = 2.47, 95% CI = 2.45 - 2.50) when the female population was used as a reference. CONCLUSION: The findings of the present study provide evidence for the existence of accidental poisoning mortality clusters in Texas, demonstrate the persistence of these clusters into the present decade, and show the spatiotemporal variations in risk and clustering of accidental poisoning deaths by gender and race/ethnicity. By quantifying disparities in accidental poisoning mortality by place, time and person, this study demonstrates the utility of the spatial scan statistic combined with GIS and regression methods in identifying priority areas for public health planning and resource allocation.     

Air pollution attributable postneonatal infant mortality in U.S. metropolitan areas: a risk assessment study

Background  

The impact of outdoor air pollution on infant mortality has not been quantified.