The relationship between toxics release inventory discharges and mortality rates in rural and urban areas of the United States

Background: Potential environmental exposures from chemical manufacturing or industrial sites have not been well studied for rural populations. The current study examines whether chemical releases from facilities monitored through the Toxics Release Inventory (TRI) program are associated with population mortality rates for both rural and urban populations. Methods: We used the TRI database, Centers for Disease Control and Prevention age‐adjusted mortality data, and additional county‐level covariate data to conduct a national study at (N = 3,142) of the association between amounts of on‐site TRI air and water releases for the years 1988‐2006 and total age‐adjusted mortality rates for the years 1999‐2006, after controlling for the effects of other risk variables. Results: Results of multiple linear regression analyses indicated significantly higher adjusted mortality rates associated with greater water and air releases in both rural and urban counties. The strongest associations between TRI releases and rural mortality rates were found when 8 or more prior years of TRI release data were used to study subsequent mortality. Conclusion: The results support the use of the TRI as a public reporting tool and a research tool, and demonstrate that greater amounts of air and water TRI releases are related to mortality outcomes for both rural and urban populations.     

Cancer hospitalizations in rural–urban areas in relation to carcinogenic discharges from Toxics Release Inventory facilities

This paper examines whether carcinogenic pollutants discharged from US Toxics Release Inventory (TRI) facilities are related to cancer hospitalization rates among the general population in rural and urban areas. We analyzed cancer hospitalizations (N = 440,061) across 20 states to find age- and sex-adjusted population cancer hospitalization rates. Multiple regression models were used to determine whether cancer hospitalization rates at the county level (N = 1102 counties) were associated with higher levels of carcinogenic discharges from TRI facilities, controlling for other risks. Significantly higher hospitalization rates were found in relation to higher TRI discharges for several cancer types that varied from urban to rural setting. Carcinogenic discharges from TRI facilities were associated with excess inpatient cancer treatment costs of $902.8 million in 2009. Future research may strive to move beyond ecological designs to examine cancer risks from TRI releases to better our understanding of cancer etiology and to establish appropriate environmental safeguards as indicated by the evidence.     

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.     

Differences in Late‐Stage Diagnosis,Treatment, and Colorectal Cancer‐Related Death Between Rural and Urban African Americans and Whites in Georgia

Purpose: Disparities in health outcomes due to a diagnosis of colorectal cancer (CRC) have been reported for a number of demographic groups. This study was conducted to examine the outcomes of late‐stage diagnosis, treatment, and cancer‐related death according to race and geographic residency status (rural vs urban). Methods: This study utilized cross‐sectional and follow‐up data from the Surveillance, Epidemiology, and End Results (SEER) Program for all incident colon and rectal tumors diagnosed for the Atlanta and Rural Georgia Cancer Registries for the years 1992‐2007. Findings: Compared to whites, African Americans had a 40% increased odds (OR, 1.40; 95% CI, 1.30‐1.51) of late‐stage diagnosis, a 50% decreased odds (OR, 0.50; 95% CI, 0.37‐0.68) of having surgery for colon cancer, and a 67% decreased odds (OR, 0.33; 95% CI, 0.25‐0.44) of receiving surgery for rectal cancer. Rural residence was not associated with late stage at diagnosis or receipt of treatment. African Americans had a slightly increased risk of death from colon cancer (HR, 1.11; 95% CI, 1.00‐1.24) and a larger increased risk of death due to rectal cancer (HR, 1.24; 95% CI, 1.14‐1.35). Rural residents experienced a 15% increased risk of death (HR, 1.15; 95% CI, 1.01‐1.32) due to colon cancer. Conclusions: Further investigations should target African Americans and rural residents to gain insight into the etiologic mechanisms responsible for the poorer CRC outcomes experienced by these 2 segments of the population.     

Urbanisation and coronary heart disease mortality among African Americans in the US South.

STUDY OBJECTIVE: Despite significant declines since the late 1960s, coronary mortality remains the leading cause of death for African Americans. African Americans in the US South suffer higher rates of cardiovascular disease than African Americans in other regions; yet the mortality experiences of rural-dwelling African Americans, most of whom live in the South, have not been described in detail. This study examined urban-rural differentials in coronary mortality trends among African Americans for the period 1968-86. SETTING: The United States South, comprising 16 states and the District of Columbia. STUDY POPULATION: African American men and women aged 35-74 years. DESIGN: Analysis of urban-rural differentials in temporal trends in coronary mortality for a 19 year study period. All counties in the US South were grouped into five categories: greater metropolitan, lesser metropolitan, adjacent to metropolitan, semirural, and isolated rural. Annual age adjusted mortality rates were calculated for each urban status group. In 1968, observed excesses in coronary mortality were 29% for men and 45% for women, compared with isolated rural areas. Metropolitan areas experienced greater declines in mortality than rural areas, so by 1986 the urban-rural differentials in coronary mortality were 3% for men and 11% for women. CONCLUSIONS: Harsh living conditions in rural areas of the South precluded important coronary risk factors and contributed to lower mortality rates compared with urban areas during the 1960s. The dramatic transformation from an agriculturally based economy to manufacturing and services employment over the course of the study period contributed to improved living conditions which promoted coronary mortality declines in all areas of the South; however, the most favourable economic and mortality trends occurred in metropolitan areas.     

The residential radon-lung cancer association in U.S. counties: a commentary

There is little doubt that underground miners exposed to radon and its progeny have increased rates of lung cancer. Residential radon exposures should carry a possibly smaller risk of increased cancer. When it became possible to collect radon data in a large number of U.S. homes and the data were aggregated by counties, the apparent association with lung cancer was a negative one, even when many other variables were taken into account. Residential radon levels are higher in suburban residences leading to a negative association with population density. Population density is strongly positively associated with lung cancer. It follows that aggregate residential radon and lung cancer rates should be negatively associated for reasons having nothing to do with the possibility of radon being carcinogenic to the lung. A second problem presented by the data is the one of sampling bias since the county lung cancer data are from the whole county population, but only a few residences are tested. Examples of other inherent associations in environmental epidemiology are cited. One strategy is to study areas of the same population density but with radon exposure gradients. This is approximated by choice of rural high radon states. Counties in such states have weak and inconsistent associations between radon and lung cancer, some of which are positive. I conclude that counties are generally inappropriate units for study of radon and lung cancer associations.     

Edentulism in High Poverty Rural Counties

Purpose: To examine the differences in oral health status among residents of high‐poverty counties, as compared to residents of other rural or urban counties, specifically on the prevalence of edentulism. Methods: We used the 2005 Behavioral Risk Factor Surveillance System (BRFSS) and the 2006 Area Resource File (ARF). All analyses were conducted with SAS and SAS‐callable SUDAAN, in order to account for weighting and the complex sample design. Findings: Characteristics significantly related to edentulism include: geographic location, gender, race, age, health status, employment, insurance, not having a usual source of care, education, marital status, presence of chronic disease, having an English interview, not deferring care due to cost, income, and dentist saturation within the county. Conclusions: Significant associations between high‐poverty rural and other rural counties and edentulism were found, and other socioeconomic and health status indicators remain strong predictors of edentulism.     

Influence of Place of Residence in Access to Specialized Cancer Care for African Americans

Context: Disparities in cancer care for rural residents and for African Americans have been documented, but the interaction of these factors is not well understood.
Purpose: The authors examined the simultaneous influence of race and place of residence on access to and utilization of specialized cancer care in the United States.
Methods: Access to specialized cancer care was measured using: (1) travel time to National Cancer Institute (NCI) Cancer Centers, academic medical centers, and any oncologist for the entire continental US population, and (2) per capita availability of oncologists for the entire United States. Utilization was measured as attendance at NCI Cancer Centers, specialized hospitals, and other hospitals in the Surveillance, Epidemiology, and End Results (SEER) program Medicare population from 1998-2004.
Findings: In urban settings, travel times were shorter for African Americans compared with Caucasians for all three cancer care settings, but they were longer for rural African Americans traveling to NCI Cancer Centers. Per capita oncologist availability was not significantly different by race or place of residence. Urban African American patients were almost 70% more likely to attend an NCI Cancer Center than urban Caucasian patients (OR = 1.66; 95% CI 1.51-1.83), whereas rural African American patients were 58% less likely to attend an NCI Cancer Center than rural Caucasian patients (OR = 0.42; 95% CI 0.26-0.66).
Conclusions: Urban African Americans have similar or better access to specialized cancer care than urban Caucasians, but rural African Americans have relatively poor access and lower utilization compared with all other groups.     

White infant mortality in Appalachian states, 1976-1980 and 1996-2000: changing patterns and persistent disparities

Purpose: Appalachian counties have historically had elevated infant mortality rates. Changes in infant mortality disparities over time in Appalachia are not well‐understood. This study explores spatial inequalities in white infant mortality rates over time in the 13 Appalachian states, comparing counties in Appalachia with non‐Appalachian counties. Methods: Data are analyzed for 1,100 counties in 13 Appalachian states that include 420 counties designated as Appalachian by the Appalachian Regional Commission. Area Resource File data for 1976‐1980 and 1996‐2000 provide county‐ and city‐level infant mortality rates, poverty rates, rural‐urban continuum codes, and numbers of physicians per 1,000 residents. Multiple regression analyses evaluate whether Appalachian counties are significantly associated with elevated white infant mortality in each time period, accounting for covariates. Findings: White infant mortality rates decreased substantially in all sub‐regions over the last 2 decades; however, disparities in infant mortality did not diminish in Appalachian counties compared to non‐Appalachian counties. After accounting for poverty, rural/urban status, and health care resources, Appalachian counties were significantly associated with comparatively higher infant mortality during the late 1970s but not in the late 1990s. At the more recent time point, higher poverty rates, residence in more rural areas, and lower physician density were associated with greater infant mortality risk. Conclusion: Appalachian counties continue to experience relatively elevated infant mortality rates. Poverty and rurality remain important dimensions of health service need in Appalachia.     

Primary care, social inequalities and all-cause, heart disease and cancer mortality in US counties: a comparison between urban and non-urban areas

OBJECTIVE: The objective of this study was to test whether the association between primary care and income inequality on all-cause, heart disease and cancer mortality at county level differs in urban (Metropolitan Statistical Area-MSA) compared with non-urban (non-MSA) areas. STUDY DESIGN: The study consisted of a cross-sectional analysis of county-level data stratified by MSA and non-MSA areas in 1990. Dependent variables included age and sex-standardized (per 100,000) all-cause, heart disease and cancer mortality. Independent variables included primary care resources, income inequality, education levels, unemployment, racial/ethnic composition and income levels. METHODS: One-way analysis of variance and multivariate ordinary least squares regression were employed for each health outcome. RESULTS: Among non-MSA counties, those in the highest income inequality category experienced 11% higher all-cause mortality, 9% higher heart disease mortality, and 9% higher cancer mortality than counties in the lowest income inequality quartile, while controlling for other health determinants. Non-MSA counties with higher primary care experienced 2% lower all-cause mortality, 4% lower heart disease mortality, and 3% lower cancer mortality than non-MSA counties with lower primary care. MSA counties with median levels of income inequality experienced approximately 6% higher all-cause mortality, 7% higher heart disease mortality, and 7% higher cancer mortality than counties in the lowest income inequality quartile. MSA counties with low primary care (less than 75th percentile) had significantly lower levels of all-cause, heart disease and cancer mortality than those counties with high primary care. CONCLUSIONS: In non-MSA counties, increasing primary physician supply could be one way to address the health needs of rural populations. In MSA counties, the association between primary care and health outcomes appears to be more complex and is likely to require intervention that focuses on multiple fronts.     

Receipt of cancer screening services: surprising results for some rural minorities

Background: Evidence suggests that rural minority populations experience disparities in cancer screening, treatment, and outcomes. It is unknown how race/ethnicity and rurality intersect in these disparities. The purpose of this analysis is to examine the cancer screening rates among minorities in rural areas. Methods: We utilized the 2008 Behavioral Risk Factor Surveillance System (BRFSS) to examine rates of screening for breast, cervical, and colorectal cancer. Bivariate analysis estimated screening rates by rurality and sociodemographics. Multivariate analysis estimated the factors that contributed to the odds of screening. Results: Rural residents were less likely to obtain screenings than urban residents. African Americans were more likely to be screened than whites or Hispanics. Race/ethnicity and rurality interacted, showing that African American women continued to be more likely than whites to be screened for breast or cervical cancer, but the odds decreased with rurality. Conclusions: This analysis confirmed previous research which found that rural residents were less likely to obtain cancer screenings than other residents. We further found that the pattern of disparity differed according to race/ethnicity, with African Americans having favorable odds of receipt of service regardless of rurality. These results have the potential to create better targeted interventions to those groups that continue to be underserved.     

Chronic cardiovascular disease mortality in mountaintop mining areas of central Appalachian states

Purpose: To determine if chronic cardiovascular disease (CVD) mortality rates are higher among residents of mountaintop mining (MTM) areas compared to mining and nonmining areas, and to examine the association between greater levels of MTM surface mining and CVD mortality. Methods: Age‐adjusted chronic CVD mortality rates from 1999 to 2006 for counties in 4 Appalachian states where MTM occurs (N = 404) were linked with county coal mining data. Three groups of counties were compared: MTM, coal mining but not MTM, and nonmining. Covariates included smoking rate, rural‐urban status, percent male population, primary care physician supply, obesity rate, diabetes rate, poverty rate, race/ethnicity rates, high school and college education rates, and Appalachian county. Linear regression analyses examined the association of mortality rates with mining in MTM areas and non‐MTM areas and the association of mortality with quantity of surface coal mined in MTM areas. Findings: Prior to covariate adjustment, chronic CVD mortality rates were significantly higher in both mining areas compared to nonmining areas and significantly highest in MTM areas. After adjustment, mortality rates in MTM areas remained significantly higher and increased as a function of greater levels of surface mining. Higher obesity and poverty rates and lower college education rates also significantly predicted CVD mortality overall and in rural counties. Conclusions: MTM activity is significantly associated with elevated chronic CVD mortality rates. Future research is necessary to examine the socioeconomic and environmental impacts of MTM on health to reduce health disparities in rural coal mining areas.     

Health Care Utilization Patterns for Young Children in Rural Counties of the I‐95 Corridor of South Carolina

Objective: The objective of this study was to assess health care utilization patterns for young children with Medicaid insurance in the rural counties of the I‐95 corridor in South Carolina relative to other regions of the state. We hypothesize that young children received less well care and higher levels of tertiary care in the rural counties along the I‐95 corridor (I‐95) of South Carolina. Design/Methods: A Medicaid cohort of children less than 3 years of age was used to compare Early, Periodic, Diagnosis, Screening and Treatment (EPSDT) visits; preventable emergency department (ED) visits; and inpatient visits between I‐95, other rural and urban county groupings. Results: The adjusted odds of a child having had 80% of the recommended EPSDT visits were reduced for I‐95 compared to other rural counties. The odds of a preventable inpatient or ED visit were increased for all rural counties, with the highest rates in the other rural counties. Conclusions: Children accessed well care less in the I‐95 corridor compared to other rural areas of South Carolina. Rural children accessed tertiary care more often than urban children, a finding most prominent outside the I‐95 corridor, likely attributable to more available access of tertiary care in rural counties outside the I‐95 corridor.     

Patterns of infant mortality and cancer death in Alabama, USA

Aim  To use recent information of infant and cancer mortality in Alabama counties of the USA to test their relationships with social, economic, and environmental conditions at a large scale to identify potential public health issues. Subjects and methods  The data of infant mortality rates and cancer deaths in the recent years, biodiversity, including species number of plants, fishes, reptiles, and amphibians, roadless areas, metropolitan areas, river basins, African-American and minority populations, and per person income for all 67 Alabama counties were obtained and organized by geographic information system. The relationships between infant mortality rates and cancer deaths and social, economic, and environmental conditions at a large scale were analyzed. Results  Infant mortality was significantly higher in African-American and other minority populations than in white populations, but cancer mortality was higher in white populations than in African-American and minority populations. There was no significant difference in infant mortality rate between populations in the urban areas and the rural areas, but the mortality rate of cancers was significantly higher in the rural population than in the urban population. Mortality rates for cancers in wealthy counties were lower than in poorer counties. The incidences of infant and cancer mortality were lower in counties with higher biodiversity. The emergent spatial pattern suggests that the incidences of infant and cancer mortality were higher in the Sipsey/Warrior River Basin, Coosa/Tallapoosa River Basin, and Conecuh River Basins. Conclusion  This study indicates that ethnic disparities in infant and cancer mortality still exist in Alabama. This study also suggests that pattern analyses at larger scales can provide new insight for understanding public health.     

Difference in rural and urban mortality: implications for health education and promotion.

Rural health care delivery is often inferior to that of urban areas. Although health services do not have to be identical in the two settings, quality services appropriate for the needs of rural communities are imperative. Moreover, health education and promotion should be seen as an immediate and viable strategy for (a) reducing risk factors and health care needs, and (b) increasing the cost effectiveness of existing services. The appropriateness and prioritization of health care services and health education/promotion can only be realized if health professionals are aware of rural versus urban needs. To facilitate our knowledge of such differences, the mortality rates of the 10 leading causes of death were compared for each county in Ohio and differences between rural and urban mortality were analyzed. Counties were categorized according to "density" (persons per square mile) and "percent urban" (percent of county area classified as urban). The analysis demonstrated that there were no significant differences between rural and urban counties in mortality due to cancer, pulmonary disease, diabetes mellitus, atherosclerosis, and suicide. Mortality related to cardiovascular disease, cerebrovascular disease, accidents, and influenza/pneumonia was significantly higher in rural counties, while deaths due to chronic liver disease were significantly greater in urban counties.     

Race, rural residence, and control of diabetes and hypertension

PURPOSE: African Americans are at increased risk for diabetes mellitus and hypertension, and rural residents have historically had decreased access to care. It is unclear whether living in a rural area and being African American confers added risks for diagnosis and control of diabetes and hypertension. The purpose of this study was to examine the prevalence of diagnosed diabetes and hypertension, as well as control of both conditions, among rural and urban African Americans and whites. METHODS: We conducted an analysis of the Third National Health and Nutrition Examination Survey (1988-1994). Non-Hispanic African Americans and non-Hispanic white adults 20 years and older were classified according to rural or urban residence (n = 11,755). Investigated outcomes were previously diagnosed diabetes mellitus and hypertension and control of diabetes and hypertension. RESULTS: The prevalence of diagnosed diabetes was 4.5% for urban whites, 6.5% for rural whites, 6.0% for urban African Americans, and 9.5% for rural African Americans. Among patients with diagnosed diabetes, 33% of rural whites, 43% of urban whites, 45% of urban African American, and 61% of rural African Americans had glycosylated hemoglobin (HbA(1c)) levels of 8% or higher (P < .01). Among patients with diagnosed hypertension, 11% of rural whites, 13% of urban whites, 20% of urban African Americans, and 23% of rural African Americans had diastolic blood pressure greater than 90 mmHg (P < .01). In regression models controlling for relevant variables, including body mass index, health status, access to care, education, income, and insurance, compared with rural African Americans, rural and urban whites were significantly more likely to have better glycemic control and diastolic blood pressure control. Urban African Americans also had better diabetes control than rural African Americans. CONCLUSIONS: In this nationally representative sample, rural African Americans are at increased risk for a lack of control of diabetes and hypertension.     

Prostate cancer incidence and agriculture practices in Georgia, 2000–2010

Background:

Georgia has prostate cancer incidence rates consistently above the national average. A notable portion of Georgia''s economy is rooted in agricultural production, and agricultural practices have been associated with an increased risk of prostate cancer.

Methods:

Statistical analyses considered county age-adjusted prostate cancer incidence rates as the outcome of interest and three agricultural variables (farmland as percent of county land, dollars spent per county acre on agriculture chemicals, and dollars spent per county acre on commercial fertilizers) as exposures of interest. Multivariate linear regression models analyzed for each separately. Data were obtained from National Cancer Institute Surveillance, Epidemiology and End Results (SEER) 2000–2010, United States Department of Agriculture (USDA) 1987 Agriculture Survey, and 2010 US Census.

Results:

In counties with equal to or greater than Georgia counties'' median percent African-American population (27%), dollars per acre spent on agriculture chemicals was significantly associated (P = 0.04) and dollars spent of commercial fertilizers was moderately associated (P = 0.07) with elevated prostate cancer incidence rates. There was no association between percent of county farmland and prostate cancer rates.

Conclusion:

This study identified associations between prostate cancer incidence rates, agriculture chemical expenditure, and commercial fertilizer expenditure in Georgia counties with a population comprised of more than 27% of African Americans.     

Geographical differences of cancer incidence in Costa Rica in relation to environmental and occupational pesticide exposure.

BACKGROUND: This study describes geographical differences in cancer incidence in Costa Rica, and investigates if some of these differences may be related to pesticides. METHODS: Data were combined from the cancer registry (1981-1993), the 1984 population census, the 1984 agricultural census, and a national pesticide data set. The 81 counties of Costa Rica were the units for the ecological analyses. Adjacent counties were grouped into 14 regions (3 urban and 11 rural) with relatively similar socioeconomic characteristics. County indices for population density and agricultural variables were constructed and categorized. Differences across regions and categories were assessed by comparing observed numbers of incident cases to expected values derived from national rates. Within the tertile of most rural counties, rate ratios between categories of high and low pesticide use were calculated. RESULTS: In urban regions, excesses were observed for lung, colorectal, breast, uterus, ovary, prostate, testis, kidney, and bladder cancers; and in rural regions for gastric, cervical, penile, and skin cancers. Skin cancers (lip, melanoma, non-melanocytic skin and penile cancer) occurred in excess in coffee growing areas with extensive use of paraquat and lead arsenate. In the most rural subset, heavy pesticide use was associated with an increase of cancer incidence overall and at a considerable number of specific sites, including lung cancer (relative risk [RR] 2.0 for men and 2.6 for women) and all female hormone-related cancers (RR between 1.3 and 1.8). CONCLUSIONS: Regions and populations at high risk for specific cancers were identified. Several hypotheses for associations between pesticides and cancer emerged. The findings call for studies at the individual level.     

Premature mortality in the United States: the roles of geographic area, socioeconomic status, household type, and availability of medical care.

OBJECTIVES: This study examined premature mortality by county in the United States and assessed its association with metro/urban/rural geographic location, socioeconomic status, household type, and availability of medical care. METHODS: Age-adjusted years of potential life lost before 75 years of age were calculated and mapped by county. Predictors of premature mortality were determined by multiple regression analysis. RESULTS: Premature mortality was greatest in rural counties in the Southeast and Southwest. In a model predicting 55% of variation across counties, community structure factors explained more than availability of medical care. The proportions of female-headed households and Black populations were the strongest predictors, followed by variables measuring low education, American Indian population, and chronic unemployment. Greater availability of generalist physicians predicted fewer years of life lost in metropolitan counties but more in rural counties. CONCLUSIONS: Community structure factors statistically explain much of the variation in premature mortality. The degree to which premature mortality is predicted by percentage of female-headed households is important for policy-making and delivery of medical care. The relationships described argue strongly for broadening the biomedical model.     

Bladder cancer mortality in New Jersey counties, and relationship with selected environmental variables

Age-adjusted mortality rates for bladder cancer were calculated for the 21 New Jersey (NJ) counties (USA) during the period 1968-1977, and compared with the period 1950-1969, with the Surveillance, Epidemiology and End Results (SEER) survey and with cancer mortality in the US 1973-1977. The county rates were also correlated with: the rates of low birth weight, birth defects, infant mortality; chemical waste disposal sites; annual per capital income; per cent of the population working in the chemical industries; density of population and urbanization indices of 21 NJ counties. Age-adjusted bladder cancer mortality rates in 95% of NJ counties were higher than national and SEER area rates. The overall NJ State rates for four subgroup populations were highly significantly (p less than 0.001) greater than the national rates. There was a statistically significant correlation between bladder and lung cancer mortality among females in 21 NJ counties which may suggest a common risk factor--namely cigarette smoking. There was no such correlation between bladder and lung cancer mortality among males. There was a statistically significant association between bladder cancer mortality in individual counties and the percentage of the adult population working in the chemical industries.