PCB anapezeka m’zaka za zana la 19. Panthawiyo, magalimoto anali kugwiritsidwa ntchito kwambiri ndipo mafuta anali kufunika. Mafuta amapangidwanso kuchokera ku mafuta osakomoka, ndipo mankhwala ambiri, monga benzene, amatulutsidwa. Benzene ikatenthedwa, klorini imawonjezeredwa kuti ipange mankhwala atsopano otchedwa Polychlorinated biphenyls (PCB). Pakadali pano, pali zinthu 209 zokhudzana ndi PCB, zowerengedwa molingana ndi kuchuluka kwa ayoni a klorini omwe ali ndi komwe adayikirako.

Chilengedwe ndi Ntchito

PCB ndi mafakitale omwe ali ndi izi:

1. Kutumiza kwa kutentha kumakhala kolimba, koma kulibe magetsi.

2. Sikophweka kuwotcha.

3. Khola, osasintha mankhwala.

4. Samasungunuka m’madzi, ndi chinthu chosungunuka ndi mafuta.

Chifukwa cha izi, ma PCB poyamba amawerengedwa kuti ndi godend ndi makampani ndipo amagwiritsidwa ntchito ngati dielectric, pazida zamagetsi monga ma capacitors ndi ma thiransifoma, kapena ngati madzi osinthira kutentha kuti aziwongolera kutentha komwe zida zimagwirira ntchito.

M’masiku oyambilira, anthu samadziwa za poyizoni wa PCBS ndipo samaziteteza, ndipo adataya zinyalala zambiri za PCB munyanja. Mpaka pomwe ogwira ntchito omwe adapanga PCB adayamba kudwala ndipo asayansi yachilengedwe adapeza zomwe zili mu PCB zomwe anthu adayamba kulabadira zovuta zomwe zimayambitsidwa ndi PCB.

Kodi PCB imalowa bwanji m’thupi

Zinyalala zambiri za PCB zimadziunjikira m’malo otayira zinyalala, omwe amatha kutulutsa mpweya. Popita nthawi, zinyalazi zimatha kumatha kunyanja kapena nyanja. Ngakhale ma PCBS samasungunuka m’madzi, amatha kusungunuka m’mafuta ndi mafuta, omwe amatha kudziunjikira m’zinthu zam’madzi, makamaka zazikulu monga shark ndi dolphins. Ma PCBS amapumidwa tikamadya nsomba zakuya kwambiri kapena zakudya zina zowononga, kuphatikiza zopangidwa ndi mkaka, mafuta amafuta ndi mafuta. PCB ingested imasungidwa mu minofu ya adipose ya munthu, imatha kupatsiridwa kwa mwana wosabadwayo kudzera pa placenta panthawi yoyembekezera, komanso kutulutsidwa mkaka wamunthu.

Zotsatira za PCB pathupi la munthu

Kuwonongeka kwa chiwindi ndi impso

Khungu limayambitsa ziphuphu, kufiira ndipo zimakhudza pigment

Maso ndi ofiira, otupa, osasangalala komanso kutulutsa kwachinsinsi

Mchitidwe wamanjenje kuchepa, kufooka kwa manja ndi mapazi kunjenjemera, kukumbukira kuchepa, kukula kwanzeru kutsekerezedwa

Ntchito yobereka imasokoneza kutulutsa kwa mahomoni ndikuchepetsa kubereka kwa achikulire. Ana amakhala ovuta kubadwa ndi zolepheretsa kubadwa komanso kukula pang’onopang’ono m’moyo

Khansa, makamaka khansa ya chiwindi. International Organisation for Research on Cancer yawonetsa PCBS ngati khansa

Kulamulira kwa PCB

Mu 1976, Congress idaletsa kupanga, kugulitsa ndikugawa PCBS.

Kuyambira zaka za m’ma 1980, mayiko angapo, monga Netherlands, Britain ndi Germany, akhazikitsa malamulo pa PCB.

Koma ngakhale ndi zoletsa zomwe zidalipo, kupanga kwapadziko lonse kunali akadali mapaundi 22 miliyoni pachaka mu 1984-89. Sizikuwoneka ngati zotheka kuyimitsa kupanga PCB padziko lonse lapansi.

mapeto

Kuwonongeka kwa PCB, komwe kwakundika pazaka zambiri, zitha kunenedwa kuti ndizapadziko lonse lapansi, pafupifupi chakudya chonse chaipitsidwa pang’ono, ndizovuta kupewa kwathunthu. Zomwe tingachite ndikumvetsera chakudya chomwe timadya, kuwalimbikitsa ndi kutisamalira poteteza chilengedwe, ndikuyembekeza kulimbikitsa opanga mfundo kuti azisamalira moyenera.