Water Resources Research Act Program

Details for Project ID 2004MN82B

Assessing the Exotoxicology of 4-Nonyphenol, A Ubiquitous Environmental Estrogen, in Two Organismal Bioassays

Institute: Minnesota
Year Established: 2004 Start Date: 2004-03-01 End Date: 2006-02-28
Total Federal Funds: $76,000 Total Non-Federal Funds: $90,416

Principal Investigators: Heiko Schoenfuss, Larry Barber, Matthew Julius

Project Summary: Alkylphenols (APs) were recently discovered in many surface water samples and even in some drinking water in Europe and North America. Wastewater effluent was identified as a major source of contamination and found to revert much of the metabolic products of these biologically active compounds back to their original form. Alkylphenols are used in large quantities (thousands of tons annually in North America) as surfactants in industrial and domestic settings and are know to bind to the estrogen receptor of mammalian cells. Environmental estrogens such as APs are known to disrupt normal endocrine hormone that are central to maturation and reproduction in fishes, and the ubiquitous presence of these biologically active compounds in surface waters should be of environmental and human health concern. In this study we propose to examine the effects of 4-nonylphenol exposure, the most potent AP, on two organismal bioassays. The first, a reproductive assay using the fathead minnow, would test whether male fathead minnows experience reduced reproductive success if exposed for 21 days to realistic concentrations of 4-nonylphenol, while the second bioassay would examine the physiological response of a diatom to 4-nonylphenol exposure. Fathead minnows are an important model for toxicological studies and an important ling to the aquatic food chain. The reproductive bioassay for fathead minnows proposed here, has been used successfully with endocrine disrupting compounds and takes into account all aspects of reproductive interactions between exposed and non-exposed fish. Diatoms represent a crucial nutrient supply to larval fish and fingerlings and have been used in previous studies to evaluate degradation of aquatic habitat through chemical contamination. The study of these two bioassays in the context of endocrine disruptive environmental estrogens would comprise the most comprehensive study of its kind and provide valuable and much needed information for the risk-assessment of these contaminants on surface waters. Furthermore, this study would also provide two tools in form of the developed bioassays to study other environmental estrogens whose ecological risk still needs to be assessed.