The current issue of the Journal of Rural Health includes 4 papers that highlight the importance of environmental health for people who live in rural settings. Much environmental health research, such as exposure to automobile or industrial pollution, or exposure related to housing or neighborhood conditions (lead-based paint, neighborhood safety, etc), has a predominant urban focus. Rural environmental health research has focused primarily on exposures related to agricultural or animal husbandry activities as well as activities typically occurring in rural settings such as mining.
One of the papers included in this section, on coal mining and public health, reflects this pattern. However, 3 of the 4 papers extend research into previously under-recognized rural environmental areas. The first paper1 provides a broad, “bird's eye view” of the distribution of toxic chemical releases across rural and urban settings nationwide. The study uses data from the Toxics Release Inventory (TRI) program combined with mortality data from the Centers for Disease Control and Prevention and other data sources for covariates. The results show that greater levels of toxic chemical releases are related to higher total age-adjusted mortality rates. Significant statistical associations with mortality are present in rural areas for greater releases of chemicals into both air and water. The study demonstrates that exposure to potential industrial pollutants with corresponding health implications is not solely an urban phenomenon. Given that the design is county-level and ecological, the study is exploratory only. However, the data indicate that further research into the impacts of chemical releases on rural public health is warranted.
The second study, led by Luo,2 explores that next research step. The study investigates how TRI releases of recognized carcinogens are related to adjusted lung cancer mortality rates. The results demonstrate that releases of carcinogenic chemicals, especially those released into the air, are related to higher lung cancer death rates. Furthermore, the study finds this effect specifically in smaller metropolitan areas or larger nonmetropolitan areas as opposed to the largest cities or most rural settings. The authors suggest that larger urban area effects may be masked by additional pollution sources or other population risk factors, but that small metropolitan or nonmetropolitan environments containing TRI facilities may be more independently affected by these facilities. This paper is also an ecological, county-level study (in fact, all 4 studies in the section are), so confirmatory research must be undertaken to determine the impact of specific releases on the health of individuals residing in these areas.
As illustrated in the third and fourth papers, the environment includes the social, economic, and human-made features that impact human health. The third paper, lead authored by Esch,3 documents both socioeconomic and potential environmental pollutant influences on cardiovascular mortality in areas of central Appalachia where mountaintop coal mining takes place. These mining areas are characterized by higher behavioral and economic risks (eg, smoking, poverty, and lower educational attainment) related to higher mortality. However, after controlling for these and other risks, a unique environmental effect of living in a mountaintop mining area remained a significant indicator of higher cardiovascular death rates. Although this paper does not include direct environmental quality data, other research referenced in this paper documents air and water quality problems that result from mountaintop mining and suggests a link between mining pollutants and human health.
In the final paper, Ahern et al4 illustrate how features of the human-made environment may influence population health in rural areas. The study shows that the availability of various food sources is related to population health outcomes in both rural and urban settings. Better outcomes (lower obesity, diabetes, and mortality rates) are related to access to a richer variety and better quality of food sources. For example, higher diabetes rates in rural areas correlate to greater per capita numbers of fast food restaurants and convenience stores. Lower mortality rates relate to greater access to products sold directly from local farms. Problems such as obesity or diabetes in rural settings will not be solved by focusing only on individual behavioral or health services interventions. The physical infrastructure also has to allow rural residents the opportunity to make healthy behavioral choices such as eating a healthy diet.
What are the general implications or lessons that we can take from these studies? First, more work must be done to understand individual-level environmental exposures, doses, and impacts on rural populations. The studies here all use secondary analyses of existing data, much of it at the county level. The results should be followed by field studies identifying environmental exposures and health consequences for individuals. This type of research is commonly done in the environmental health field, but a focus on rural-based exposures remains underdeveloped.
Second, the availability of comprehensive environmental quality data for rural areas needs to be improved. To cite one key example, the Environmental Protection Agency (EPA) offers a county database for air quality standards (ie, levels of air particulates, lead, carbon monoxide, ozone, nitrogen oxides, and sulfur dioxide are measured daily, converted to annual summaries, and flagged if they exceed established thresholds). However, not every county has a monitoring station, not every monitoring station includes every pollutant, and the public maps on the EPA Web site make no distinction between areas where standards are met and areas where there are no data. The stations that do exist are often located in urban areas. Two illustrations of data shortcomings are offered here. First, EPA air monitoring stations are absent in areas in rural southern West Virginia where mountaintop mining is concentrated, and air quality there is subsequently unknown. Second, there are a total of 7 ozone monitoring stations in Arkansas, located in 5 of the state's 75 counties, including only 2 of the state's 62 nonmetropolitan counties. Many other examples of missing rural air quality data could be given nationwide. At the very least, there should be distinctions made between areas where air quality is known to be good, and areas where data are simply missing, as the presumption of good air quality differentially impacts rural areas. Better still would be to establish monitoring stations in additional rural environments.
Improving the availability of data on aspects of the built environment would also be of value. Data to distinguish between different types of full-service restaurants that may vary in quality, or data on food co-ops, community gardens, or organic food outlets, could help to understand the availability of high-quality foods across rural and urban settings. For all of these data issues, data available at a scale finer than the county, such as the census tract, could be used in relation to demographic data to better understand population exposure and access to resources.
Third, the problem of how rural is defined is raised. The county-level studies in the special section use rural-urban continuum codes and urban influence codes to identify rural or urban environments. This may entail treating counties as equally rural whether they are adjacent to large metropolitan areas or remote, and treating as the same rural areas that vary in population size. This problem is closely linked to accessing data at sub-county scales.
Fourth, and in summary, these studies clearly show that environmental health is a rural issue as well as an urban one. The Office of Rural Health Policy, within the Health Resources and Services Administration, funds 6 rural health research centers nationwide. In the most recent funding cycle, 1 of those centers is focused on environmental health. This financial support of rural environmental health studies speaks to a need to understand the unique environmental threats in rural areas, and the preventive steps that may be taken to reduce harm to rural communities. As our population grows, there will be greater pressure on natural resources and increased threats to environmental quality, such that environmental health issues are likely to gain in importance in coming years. Research to understand these issues for rural populations will be a valuable contribution to scientific inquiry.