Polychlorinated Biphenyls (PCBs)
PCBs·Affects liver, reproductive, brain
Industrial coolants and insulating fluids banned in 1979. PCBs persist in the environment for decades, bioaccumulate in fat tissue, and concentrate up the food chain.
PCBs
EPA limit
0.0005 mg/L (MCL)
Most at risk
Communities near legacy industrial sites, anglers, infants, pregnant women
Found in
City water · Well water · Industrial areas
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
The EPA classifies PCBs as a probable human carcinogen. Long-term exposure is associated with elevated rates of liver cancer, melanoma, and non-Hodgkin lymphoma. The liver is the primary target organ, with documented enzyme changes and fatty-liver progression in chronically exposed workers and contaminated-community populations.
PCBs are endocrine disruptors. They interfere with thyroid hormone signaling and reproductive hormones, and they cross the placenta. Prenatal and early-life PCB exposure is linked to lower IQ, attention deficits, and motor-skill delays in children of mothers who consumed contaminated fish.
The toxicology that matters most is bioaccumulation. PCBs are fat-soluble and resist metabolic breakdown, so the body stores them for decades. Even very low water concentrations contribute to a lifetime body burden that is hard to eliminate once it's there.
Where it comes from
How it gets into your water
PCBs were manufactured from 1929 until the US ban in 1979 for use as electrical-transformer coolants, capacitor dielectrics, hydraulic fluids, and carbonless copy paper. They were valued for chemical stability and fire resistance, which is exactly what makes them so persistent in the environment now.
The dominant exposure pathway is legacy contamination: river sediment near old industrial sites, soil at former manufacturing facilities, and aging electrical equipment that still contains PCB fluids. The Hudson River, the Great Lakes, and the Housatonic River are well-documented contamination zones where PCBs continue to leach into water decades after production stopped.
Groundwater near Superfund sites, landfills that accepted PCB-containing equipment, and industrial corridors can carry PCBs into both municipal source water and private wells.
Legacy industrial sites
Transformer + capacitor manufacturing
Contaminated river sediment
Hudson, Great Lakes, Housatonic
Old electrical equipment
Pre-1979 transformers can still leak
Landfill leachate
Pre-ban disposal sites
Find out for yourself
Is it in your water?
Municipal utilities test for PCBs and report results in the annual Consumer Confidence Report (CCR). Most US systems show non-detect, but levels can rise sharply in source water near contaminated rivers and Superfund sites. Cleveland, Hudson Valley communities, and parts of New England have documented elevated PCB profiles.
Private well owners near former industrial sites, electrical substations, or hazardous-waste landfills should request a PCB-specific test from an EPA-certified lab. Standard well-water panels don't include PCBs.
The fix
How AquaOx filters it
PCBs are non-polar, fat-soluble organic compounds, which is exactly the chemistry activated carbon is designed to capture. The coconut shell carbon and Centaur catalytic carbon stages in The AquaOx adsorb PCB molecules as water passes through the bed.
Because PCBs bioaccumulate over a lifetime, the whole-house filtration model matters: showering, bathing, and cooking water are all exposure pathways. If you live near a known contamination site we recommend pairing The AquaOx with under-sink RO at the kitchen tap for a second barrier.