An investigation of the relationship between air emissions of volatile organic compounds and the incidence of cancer in Indiana counties.

Cancer is a health endpoint influenced by a multitude of factors, including genetic history, individual behavior, and environmental insults. The ubiquity of toxicants in the environment has raised questions about the extent of their role in causing cancer in humans. More specifically, it is desirable to understand the cancer incidence due to airborne toxicants in anthropogenic pollution. One particular class of such pollutants is volatile organic compounds (VOCs). This paper reports an epidemiological investigation of the incidence of cancer in the 92 counties of Indiana. We evaluated the relationship between the amount of VOCs released in each county, as reported by the Toxic Release Inventory, and the county-by-county incidence of various types of cancer, especially those of less common organ systems not directly associated with the absorption or distribution of toxicants. Our evaluation considered chlorinated versus nonchlorinated emissions as well as stack versus fugitive emissions. We evaluated three models: linear, quadratic, and polynomial. Of these, the quadratic model appeared to be the best predictor (highest r2) for most endpoints for which there was a positive correlation. However, the linear model was the most sensitive (lowest P-value) for skin, melanoma, and endocrine-related cancers, including female genital system cancers. Our results indicate a relationship between emissions of VOCs and the incidence of some types of cancers. Most notable were strong correlations between VOC emissions and cancers of the brain, nervous system, endocrine system, and skin.

Use of biomarkers to indicate exposure of children to organophosphate pesticides: implications for a longitudinal study of children's environmental health.

Because of their history of widespread use in the United States and unknown long-term health effects, organophosphate pesticides (OPs) are being considered as a chemical class of interest in planning for the National Children's Study, a longitudinal study of children's environmental health. The availability and appropriate use of biomarkers to determine absorbed doses of environmental chemicals such as OPs are critical issues. Biomarkers of OP exposure are typically measured in blood and urine; however, postpartum meconium has been shown to be a promising matrix for assessing cumulative in utero exposure to the fetus, and studies are currently in progress to determine the utility of using saliva and amniotic fluid as matrices. In this article, we discuss the advantages and disadvantages of the currently available OP exposure monitoring methods (cholinesterase inhibition in blood, pesticides in blood, metabolites in urine and alternative matrices); study design issues for a large, long-term study of children's environmental health; and current research and future research needs. Because OPs are rapidly metabolized and excreted, the utility of one-time spot measurements of OP biomarkers is questionable unless background exposure levels are relatively stable over time or a specific time frame of interest for the study is identified and samples are collected accordingly. Biomarkers of OP exposure can be a valuable tool in epidemiology of children's environmental health, as long as they are applied and interpreted appropriately.