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Abstract
DDT analysis of wetland sediments in upper Escambia Bay, Florida
American Geophysical Union Fall Meeting, Vol.2017, abstract #ED11D-0162
American Geophysical Union 2017 fall meeting (New Orleans, LA, 12/11/2017–12/15/2017)
12/2017
Abstract
Dichlorodiphenyltrichloroethane (DDT) was a commonly used pesticide from World War II through the 1960's. DDT is generally used to control mosquito populations and as an agricultural insecticide. The pesticide and its degradation products (DDD and DDE) can bioaccumulate within ecosystems having negative implications for animal and human health. Consequently, DDT usage was banned in the United States in 1973. In a contaminant study performed in Escambia Bay, Florida, in 2009, DDT was present in 25% of study sites, most of which were located in the upper bay wetlands. Concentrations were well above the Florida Department of Environmental Protection's (FDEP) Probable Effect Level (PEL) and ratios of DDT and its metabolites indicated a recent introduction to the system. A follow-up study performed in 2016 found no DDT, but did show DDE at several sites. The current study repeated sampling in May 2017 at sites from the 2009 and 2016 studies. Sediment samples were collected in triplicate using a ponar sampler and DDT, DDD and DDE were extracted using EPA methods 3540c and 3620c. Extracts were analyzed using a gas chromatograph with electron capture detection (GC-ECD) as per EPA method 8081c. Sediment was also analyzed for organic carbon and particle size using an elemental NC analyzer and a laser diffraction particle sizer. Results show the presence of breakdown products DDE and DDD at multiple sites, but no detectable levels of DDT at any site. Sampling sites with high levels of DDT contamination in 2009 show only breakdown products in both 2016 and 2017. Particle size has little influence on DDD or DDE concentrations but OC is a controlling factor as indicated for contaminated sites by Pearson correlations between OC and DDE and DDD of 0.82 and 0.92, respectively. The presence of only DDD and/or DDE in the 2016 and 2017 studies indicates that the parent, DDT, has not been re-introduced into the watershed since 2009 but is degrading in the environment.
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Details
- Title
- DDT analysis of wetland sediments in upper Escambia Bay, Florida
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2017, abstract #ED11D-0162
- Resource Type
- Abstract
- Conference
- American Geophysical Union 2017 fall meeting (New Orleans, LA, 12/11/2017–12/15/2017)
- Publisher
- American Geophysical Union
- Copyright
- © American Geophysical Union
- Identifiers
- 99380185568806600
- Academic Unit
- Hal Marcus College of Science and Engineering ; Chemistry; Earth and Environmental Sciences
- Language
- English