What substance was discharged into the Hudson River for 30 years from two GE plants before cleanup began?

• A. Dioxins
• B. PCBs
• C. Lead
• D. Mercury

Answer: (B)

Polychlorinated biphenyls, or PCBs, are synthetic chemicals that were widely used as insulating and coolant fluids in electrical equipment. General Electric discharged PCB waste into the Hudson River from two plants for about 30 years, and it wasn’t until cleanup began decades later that the full extent of the contamination was addressed. PCBs are highly persistent in the environment and resist natural degradation, meaning they stay in sediments and fish for long periods. They bioaccumulate in aquatic organisms and magnify up the food chain, creating long-term health risks for wildlife and humans who consume contaminated fish. That combination of persistence and bioaccumulation is why PCBs became the defining pollutant of that Hudson River contamination and the focus of the subsequent cleanup.

Dioxins, lead, and mercury are different pollutants with separate histories and sources. Dioxins can be toxic byproducts but aren’t the substance primarily associated with the GE Hudson River discharge, and lead and mercury are heavy metals with different industrial contexts.