Superfund Research Program
Project Leader: Ellen B. Gold
Grant Number: P42ES004699
Funding Period: 2000-2010
This project provides epidemiologic evaluation of human health effects associated with exposure to environmental contaminants in residents adjacent to a Superfund site in Sacramento, California. Dr. Ellen Gold and Dr. Bill Lasley hope to accomplish this by evaluating physiologic dysfunction, specifically reproductive and other hormone-related health effects, in female adults (aged 20-50 years during the likely exposure period of 1988-96) residing downwind or in the groundwater plume of the Sacramento Superfund site and comparing the rates of these health effects to a non-exposed but similar population nearby and relating these rates to likelihood of exposure. In addition to interviewing women residing in these areas and in a comparison area, Gold and Lasley will use serum and urine biomarkers of exposure and of health effects that have been developed here.
Thus far, this project has identified over 5260 households, screened over 1460 women in the three study areas for eligibility in the study, interviewed over 800 women and obtained blood from the first 450 eligible women and daily urine samples for two menstrual cycles from 274 women who were still menstruating in the three areas. Blood collection was suspended a few years ago, having found no significant differences in serum parameters being measured among the three study sites. The three study areas appear comparable on a number of socioeconomic indicators, as well as on general community and women's health concerns (none of the top 4 of which include the Superfund site or endocrine/reproductive concerns, respectively).
Further, Gold and Lasley have observed no notable differences in thyroid hormone levels among the first 450 women examined in the three study areas, as expected, since the relevant exposure that might have affected thyroid function ended in 1996, and no prolonged adverse effect on the thyroid would be expected. The researchers have detected no evidence of environmental estrogens in any of the first 250 urine samples tested and thus suspended this testing several years ago as well. Largely, no notable differences are seen in reproductive health or endocrine effects, but further analyses with additional data are required from this ongoing project to determine any differences in health effects that might have occurred during the times of likely exposure. Finally, UC-Davis investigators have established several collaborations. First, Gold and Lasley are collaborating with The Fate and Transport project in assessing likelihood (realizations) of exposure in each of the households using GIS techniques and analyzing the findings in relation to outcomes ascertained in their interviews, which should result in a publication in the next year or so. Second, the project team has been collaborating with The Reproductive Biomarkers project in having laboratory assays of the urine samples conducted to assess ovarian function, which they will examine in relation to study area and likelihood of exposure, which should result in a publication in the next year or so. Third, this research group has collaborated with the CDC, which provided funds to have them assay the urine samples for perchlorate, iodide, nitrate and thiocyanate, and the team is using these values to assess the relation of the assay results to the endocrine and reproductive outcomes of interest, which should result in a publication or two in the next year or so. Fourth, junior faculty have become involved and will analyze the data in relation to fast food consumption, the built environment and opportunities for physical activity, and lifetime physical activity. These analyses should result in publications in the next year or two. Last, toxicology investigators at the University of Arkansas have submitted proposals to fund a collaboration with UC-Davis researchers to investigate trichloroethylene exposure in relation to autoimmune changes, and that collaboration awaits funding.
Applications of epidemiologic techniques in this project have not only facilitated applications of the biomarkers in humans in the exposed population and assessment of the relation of exposure to environmental contaminants to human health effects, but will also help to elucidate modification of these effects by host and lifestyle factors. In turn, this project has and will continue contribute to the other projects by providing epidemiologic expertise for developing further field applications of techniques developed in the UCD laboratories in the future. In this effort, this project has and will continue to interact with the cores mentioned above to evaluate exposures to endocrine disruptors as a result of residing downwind or in the groundwater plume of a Superfund site, to assess the likely routes of exposure, and to assess the relation of such exposures to adverse reproductive and other endocrine health effects.