Novel Approaches for Determining the Occurrence, Biogeochemical Cycling, and Biological Exposure of Phthalate Esters in Urbanized Marine Settings
EPA Grant Number: F07E20888Title: Novel Approaches for Determining the Occurrence, Biogeochemical Cycling, and Biological Exposure of Phthalate Esters in Urbanized Marine Settings
Investigators: Ellefson, Anne Cooper
Institution: Stony Brook University
EPA Project Officer: McClure, Karen
Project Period: January 1, 2007 through January 1, 2010
RFA: STAR Graduate Fellowships (2007)
Research Category: Academic Fellowships , Aquatic Ecology and Ecosystems , Fellowship - Oceanography
Description:
Objective:Phthalate di-esters are commonly used plasticizers that have recently been found to affect endocrine systems in wildlife and humans. Their presence in humans and the environment has been hard to monitor due to contamination during analysis from laboratory air, solvents, and other supplies. A method to assess mammalian exposure to phthalates which largely avoids this contamination has been developed that relies on determining relatively persistent metabolites of phthalate di-esters (mono-esters and their oxidation products). This method will be utilized to learn more about the distributions, sources, and fate of phthalate di-esters and their metabolites in surface waters and sediments. In addition, it will be determined if this method can be used to understand exposure of aquatic organisms collected in areas most contaminated by phthalates.
Approach:Phthalate mono-esters are also products of microbial transformation of phthalate di-esters, so it is hypothesized that they will be useful indicators of phthalate di-ester inputs and/or distributions in surface waters and sediments. To address this hypothesis, existing methods for measuring phthalate mono-esters in body fluids will be adapted for use in water as well as sediments. Method development will be aided through collaborations with Center for Disease Control investigators who developed the approach. A method for phthalate di-ester analysis will be developed that minimizes blanks as much as possible for comparison to mono-ester analyses. This will involve extractions performed in the field as well as a reduction of extraction and clean up steps. These methods will be used to determine the distribution of phthalate di- and mono-esters in samples throughout the urbanized NY/NJ harbor complex to assess likely sources and fates of the phthalate esters and their metabolites. The relationship between di-ester and mono-ester abundance will be determined in wastewater, surface water and sediments. Mono-ester levels will be measured in serum and tissues of different species and compared to levels in water, diet, and sediments as measures of possible exposure.
Expected Results:These results are expected to enable a better understanding of the distribution of phthalate di- and mono-esters in urban estuaries. Sampling in areas with different contaminant source inputs will enable determination of the sources and sinks of phthalate di- and mono-esters. The input from sewage treatment plants is expected to be the major source. It will be of interest to compare serum levels of phthalate metabolites in marine vertebrates to those that cause effects in mammals. These results will be used to determine if mono-ester analysis can provide useful understandings of phthalate di-ester sources and fates in receiving waters.
Supplemental Keywords:Phthalate esters, mono-ester, endocrine disruptor, plasticizer, metabolite,