Mawu a M'munsi

a PCBs (polychlorinated biphenyls), amene wakhala akugwiritsidwa ntchito chiyambire m’ma 1930, ali mitundu 200 ndipo amagwiritsidwa ntchito monga kufeŵetsera zinthu, popanga mapulasitiki, zokutira zipangizo zamagetsi, mankhwala ophera tizilombo, sopo wotsukira mbale, ndi zinthu zina. Ngakhale kuti PCB analetsedwa m’mayiko ambiri, wapangidwa wokwana matani miliyoni imodzi kapena mamiliyoni aŵiri. Poizoni wake amapezeka m’chilengedwemu chifukwa cha PCB wotayidwa.