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The Hudson River PCB Problem

The Hudson River PCB Problem

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The Hudson River PCB Problem

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  1. The Hudson River PCB Problem Ben Jewell Przemyslaw Bosak

  2. PCB Intro • Molecular structure: • Two benzene rings linked by a single bond • Chlorine replacement of some Hydrogen atoms • Characteristics • Nearly insoluble in water • Difficult to burn • Low vapor pressure • Good electrical insulators • Sources • Synthetic, used as a coolant fluid • US production ended in 1977, still in use in transformers • Disposal • Incineration

  3. PCBs in the Environment • Where does it go? • Deposition in river/lake sediments • Enters food stream, bio accumulation • Volatilization • Life span • Do not readily degrade • Can exist in environment for decades

  4. PCB Health Effects • Not acutely toxic to humans • Chloracne • most common sympton of organochlorine exposure • Disfiguring, painful analog to acne • Cancer • the types of PCBs likely to be bioaccumulated in fish and bound to sediments are the most carcinogenic PCB mixtures • found through animal and exposure studies • Immune System • increasing risk of non-Hodgkins lymphoma • Neurological • learning deficits and changes in activity associated with exposures to PCBs • most strongly associated with newborn children • Reproductive • decreased birth weight • significant decrease in gestational age • Exposure studies

  5. Hudson River History • General Electric: 1950s, 60s and 70s • Uses • Capacitors, power transformers • Discharge • Two capacitor manufacturing plants released between 209,000 and 1.3 million pounds • Leaking devices

  6. Clean Up Efforts • Past Clean up • Dredging of 180,000 cubic yards of contaminated sediments in 1977-78 • Capping of remnant deposits with a geosynthetic clay liner and a 2-foot layer of soil, • Stabilization of river banks with rock • Continuous monitoring of PCB level in the river

  7. Hudson River Now • Peak PCB level in 1991 • Clean up efforts lowered the concentration of PCB in the water and have kept it at pre-1991 level • Catch-and-release fishing allowed

  8. What is next? • Dredging of 2.65 million cubic yards of PCB-contaminated sediments using environmental techniques to minimize resuspension of sediments • Covering dredged areas with one foot of clean soil to isolate residual PCBs • Restoration of aquatic vegetation • Monitoring system recovery

  9. Aquatic Chemistry Implications • Dredging • Disruption to aquatic system • Increased turbidity • Release of trapped minerals and nutrients • Bioaccumulation effects on river fauna • Hazardous to health • Disruption to aquatic system

  10. Thank you for listening, we will now take any questions