An Integration of Copepod-Based BAFs, Lifecycle Toxicity Testing, and Endocrine Disruption Methodologies for Rapid Population-Level Risk Assessment of Persistent Bioaccumulative ToxicantsEPA Grant Number: GR832211
Title: An Integration of Copepod-Based BAFs, Lifecycle Toxicity Testing, and Endocrine Disruption Methodologies for Rapid Population-Level Risk Assessment of Persistent Bioaccumulative Toxicants
Investigators: Chandler, G. Thomas , Ferguson, P. Lee
Institution: University of South Carolina at Columbia
EPA Project Officer: Carleton, James N
Project Period: May 16, 2005 through November 15, 2007
Project Amount: $298,907
RFA: Greater Research Opportunities: Persistent, Bioaccumulative Chemicals (2004) RFA Text | Recipients Lists
Research Category: Land and Waste Management , Safer Chemicals , Hazardous Waste/Remediation , Health Effects
The general objectives of the proposed research are to:
- Develop a new integrated lifecycle toxicity testing system for PBTs that will provide concurrent data on PBT bioaccumulation, endocrine activity, reproductive effects, and population-level impacts using meiobenthic copepods, 96-well microplate culture (per a new ASTM standard), and Leslie-matrix population growth modeling.
- Focus on environmentally realistic mixtures of persistent chlorinated pesticides (PCPs) found commonly in SC, particularly with regard to a model PCP-contaminated SuperFund salt-marsh site in Shipyard Creek, SC. Applicability of project is broader than PCPs, but PCPs are a good model toxicant group with which to begin.
- Compare endocrine/reproductive health of field versus lab-exposed copepod populations as a function of lipid:carbon normalized body burdens (BAFs, BSAFs) of PCPs; hence a Critical Body Residue approach to predicting chronic PBT impacts.
- Use full lifecycle microplate test endpoints/data to robustly model multigenerational population-level effects of PCPs as a function of CBRs and endocrine health.
Our research plan will address these objectives through a series of experiments designed to provide a holistic picture of persistent chlorinated pesticide bioaccumulation and endocrine/reproductive effects on model ecologically-important crustaceans in estuarine environments. These experiments will include laboratory egg-to-egg lifecycle toxicity tests with DDT, chlordane and lindane (singles & mixtures) at concentrations 1X, 2X and 5X measured field values in our model Shipyard Creek system. Dose-response experiments will test the potential for PCPs to bioaccumulate, cause endocrine action, and directly cause adverse effects on sensitive estuarine infaunal crustaceans (meiobenthic copepods). Meiobenthic copepods are keystone species in food-webs and the trophic transfer of lipophilic contaminants from sediments to fish, shrimps and crabs.
The proposed work will, for the first time:
- address the potential for PCPs to bioaccumulate in trophically and ecologically important meiobenthic copepods;
- relate critical body residues of PCPs in field and lab populations to full lifecycle toxicity test endpoints of highest value to risk assessment (i.e., reproduction, population growth, population maintenance);
- and comprehensively evaluate endocrine disrupting potential of PCPs in crustaceans with regard to two hormonal systems intimately linked to growth and reproduction (i.e., ecdysone (molting) and vitellogenesis).
As copepod life-cycle testing is now before the OECD for adoption as a new endocrine disruptor screening tool, the information from this project will be of high value to OECD and environmental managers/agencies worldwide. Further, this work will generate new scientific knowledge related to the behavior of PCPs at the biochemical to whole organism to population levels.