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Organochlorine pollutants in sediments in Escambia Bay and River Johan Liebens Dept. of Earth and Environmental Sciences Carl Mohrherr (ret.) Center for Environmental Diagnostics and Bioremediation University of West Florida
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Background EPA sponsored reconnaissance studies (PERCH) Assessed pollution in: –Three local bayous –Fish and shellfish –Humans (limited) –Air emissions –Surface soils –Escambia Bay and River Shrimp landings –900,000 pounds in 1968 –17,000 pounds in 1971
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1. Polychlorinated biphenyls (PCBs) –No natural source –12 congeners have dioxin-like toxicity –Production ban in 1970s 2. Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) –Byproduct –17 congeners are toxic 3. Organochlorinated pesticides –22 pesticides Introduction
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Methods 57 sites Stratified sampling design
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Methods Sediment sampling –Ponar grab sampler –Five-sample composites
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Methods (cont'd) Analytical methods: Standard EPA methods: –Extracted using USEPA Method 3550 –High resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). USEPA Method 1668A for PCBs USEPA Method 1613B for PCDD/PCDFs USEPA Method 8081A for pesticides
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Methods: Toxicity Toxic equivalence value TEQ = Σ (C o Congener i × TEF i) + (C o Congener j × TEF j) +.... + (C o Congener n × TEF n) –2,3,7,8-TCDD: TEF = 1
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Results 1: PCBs
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PCB concentrations Highest PCB concentrations in lower river and upper bay.
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Dioxin-like PCB abundance
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Dioxin-like PCB congeners 118 and 105 in sediment and Aroclors Sedim.
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Factor analysis of PCB profiles
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Results 2: Dioxins/furans
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Dioxin/furan concentrations 17 toxic congeners comprise 87% of total dioxin/furan mass OCDD is 93% of toxic dioxin/furan mass
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Dioxin/furan toxicity OCDD represents 22% of TEQ (93% of toxic dioxin/furan mass) 1,2,3,4,6,7,8 HpCDD represents 35% of dioxin/furan TEQ (5 % of dioxin/furan mass)
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Total combined TEQ (dl-PCBs+dioxins/furans) Dioxin-like PCBs only 8 % of total combined TEQ 56% of samples have TEQ above NOAA TEL (0.85 ng/kg) 23% of samples have TEQ above NOAA AET (3.4 ng/kg)
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Total combined TEQ Combined TEQ highest in upper river and wetlands
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Results 3: Pesticides
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DDT Endocrine disruptor Probably carcinogen Biomagnifies in food chain Structure of pp’ DDT
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DDT concentrations Most DDT concentrations in the bay are bdl. Most DDT concentrations in wetlands and river are above PEL.
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DDT concentrations DDD and DDE metabolites were not detected –Inaccurate analysis –DDT does not break down –DDT breaks down but DDD and DDE degrade at fast rate –DDT breaks down but DDD and DDE are removed at fast rate –DDT is recent
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Conclusions Potential impacts on the basis of SQAGs from: –Dioxin/furan TEQ Multisource origin –PCB concentrations A1254 component, multiple sources –DDT concentrations Probable impact upon fisheries Origin: old or new?
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Acknowledgments Student assistant –Jeffrey Jackson Project supported by EPA Cooperative Agreement X-97455002 with CEDB-UWF.
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Thank you. Questions?
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DDE DDD
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May not need this one
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Potential sources of pollution circa 1970 Source: Olinger et al., 1975
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Description of PCBs 209 congeners No natural source Used in transformer and other oils, stabilizers in plastics,... 12 congeners have dioxin-like toxicity Cause chloracne, cancer, liver damage,... Production ban in 1970s
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Description of dioxins/furans 210 congeners Byproduct 17 congeners are toxic Cause chloracne, cancer,... –Yuschenko, chicken and pigs in Belgium,... dioxin
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