Tetrachlorobiphenyl

Old transformers/capacitors, fluorescent light ballasts, caulk, sealants, paints; leaks, spills, and contaminated soils/sediments can release it to air and dust [1][2].

Eating contaminated fish, meat, or dairy; breathing indoor air/dust in older buildings; handling old electrical gear; living near hazardous waste sites; transfer during pregnancy and through breast milk [1][2].

PCBs are known human carcinogens and linked to reduced immune response, hormonal/thyroid changes, liver effects, skin rashes/chloracne, and learning/behavior problems in children [1][3][4].

Pregnant people, fetuses, infants/children; people who frequently eat locally caught fish or wild game from contaminated waters; demolition/electrical workers; residents in older schools/buildings or near contaminated sites [1][2].

Follow local fish advisories; don’t disturb old caulk/ballasts—use trained pros; wet-wipe and HEPA vacuum dust; wash hands before eating; dispose of PCB equipment properly; check your water report and consider a certified filter if needed [1][2].