The Hudson River PCB Problem Ben Jewell Przemyslaw

The Hudson River PCB Problem Ben Jewell Przemyslaw Bosak

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

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

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

Hudson River History • General Electric: 1950 s, 60 s and 70 s • Uses – Capacitors, power transformers • Discharge – Two capacitor manufacturing plants released between 209, 000 and 1. 3 million pounds – Leaking devices

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

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

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

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

Thank you for listening, we will now take any questions