Yini i-PTFE ne-PFOA?Zitholakalaphi?
I-PTFE igama lomkhiqizo wekhemikhali eyenziwe umuntu eyaziwa ngokuthi i-polytetrafluoroethylene (PTFE).Ibisetshenziswa kwezentengiselwano kusukela ngawo-1940.Inokusetshenziswa okunhlobonhlobo ngenxa yokuthi izinze ngokwedlulele (ayisabeli namanye amakhemikhali) futhi inganikeza indawo ecishe ingabi nakhuni.Abantu abaningi bajwayelene nayo njengendawo yokwemboza engagxili yamapani nezinye izinto zokupheka.Ibuye isetshenziswe kweminye imikhiqizo eminingi, njengezivikeli zendwangu.I-Perfluorooctanoic acid (PFOA), eyaziwa nangokuthi i-C8, enye ikhemikhali eyenziwe ngumuntu.Isetshenziselwa inqubo yokwenza i-polymer namakhemikhali afanayo (aziwa ngokuthi ama-fluorotelomers), nakuba ishiswa ngesikhathi senqubo futhi ingekho ngamanani abalulekile emikhiqizweni yokugcina.I-PFOA inamandla okuba ukukhathazeka kwezempilo ngoba ingakwazi hlala endaweni kanye nasemzimbeni womuntu isikhathi eside.Ucwaningo luthole ukuthi lukhona emhlabeni wonke emazingeni aphansi kakhulu cishe egazini lawo wonke umuntu.Amazinga aphezulu egazi atholwe kubahlali bomphakathi lapho amanzi asendaweni angcoliswe yi-PFOA.Abantu abachayeka ku-PFOA emsebenzini bangaba namazinga aphezulu ngokuphindwe kaningi.I-PFOA nezinye izinhlanganisela ezifanayo zingatholakala emazingeni aphansi kokunye ukudla, emanzini okuphuza, nasothulini lwasendlini.Nakuba amazinga e-PFOA emanzini okuphuza ngokuvamile ephansi, angaba phezulu ezindaweni ezithile, njengezitshalo zamakhemikhali eziseduze ezisebenzisa i-PFOA.Abantu bangaphinde bavezwe ku-PFOA kusuka ku-ski wax noma ezindwangu kanye nokhaphethi oye waphathwa ngendlela engazweli amabala. .I-cookware engagxili ayiwona umthombo obalulekile wokuchayeka kwe-PFOA.Ingabe i-PTFE ne-PFOA ziwudala umdlavuza?I-PTFEI-PTFEyona ngokwayo akusolwa ukuthi idala umdlavuza.PFOAUcwaningo oluningi eminyakeni yamuva lubheke ukuthi kungenzeka yini ukuthi i-PFOA ibangele umdlavuza.Abacwaningi basebenzisa izinhlobo ezi-2 eziyinhloko zezifundo ukuzama ukuthola ukuthi into enjalo ingabanga umdlavuza.Izifundo elebhuOcwaningweni olwenziwe elebhu, izilwane zichayeka entweni (ngokuvamile ngemithamo emikhulu kakhulu) ukubona ukuthi ingabe idala izimila noma ezinye izinkinga zempilo.Abacwaningi bangase futhi baveze amangqamuzana omuntu esitsheni selebhu entweni ukuze babone ukuthi ingabe ibangela izinhlobo zezinguquko ezibonakala kumaseli omdlavuza.Ucwaningo olwenziwe ezilwaneni zaselabhu luthole ukuchayeka ku-PFOA kwandisa ingozi yezimila ezithile zesibindi, amasende, ama-mammary glands (amabele), namanyikwe kulezi zilwane.Ngokuvamile, izifundo eziqhutshwa kahle ezilwaneni zenza umsebenzi omuhle wokubikezela ukuthi yikuphi ukuchayeka okubangela umdlavuza kubantu.Kodwa akucaci ukuthi indlela leli khemikhali elithinta ngayo ingozi yomdlavuza ezilwaneni izofana yini nakubantu.Izifundo kubantuEzinye izinhlobo zezifundo zibheka amazinga omdlavuza emaqenjini ahlukene abantu.Lezi zifundo zingase ziqhathanise izinga lomdlavuza eqenjini elichayeke entweni nezinga lomdlavuza eqenjini elingavezwanga kulo, noma liqhathanise nezinga lomdlavuza esibalweni sonke.Kodwa ngezinye izikhathi kungase kube nzima ukwazi ukuthi imiphumela yalezi zinhlobo zocwaningo isho ukuthini, ngoba ezinye izici eziningi zingase zibe nomthelela emiphumeleni.Ucwaningo lubheke abantu abachayeke ku-PFOA ekubeni behlala eduze noma besebenza ezitshalweni zamakhemikhali.Ezinye zalezi zifundo ziye zaphakamisa ingozi eyengeziwe yomdlavuza wamasende ngokuchayeka kwe-PFOA eyengeziwe.Ucwaningo luye lwaphakamisa izixhumanisi ezingase zibe nomdlavuza wezinso kanye nomdlavuza wegilo, kodwa ukwanda kwengozi kube kuncane futhi kungenzeka kube ngenxa yengozi.Olunye ucwaningo luye lwaphakamisa izixhumanisi ezingase zibe neminye imidlavuza, okuhlanganisa i-prostate, isinye, nomdlavuza wesibeletho.Kodwa akuzona zonke izifundo ezithole izixhumanisi ezinjalo, futhi ucwaningo olwengeziwe luyadingeka ukuze kucaciswe lokhu okutholakele.Okushiwo yizinhlangano zochwephesheAma-ejensi amaningana kazwelonke nakwamanye amazwe afunda izinto ezahlukene endaweni ukuze athole ukuthi zingawubangela yini umdlavuza.(Into ebanga umdlavuza noma esiza umdlavuza ukuthi ukhule ibizwa ngokuthi ai-carcinogenI-American Cancer Society ibheka lezi zinhlangano ukuthi zihlole ubungozi ngokusekelwe ebufakazini obuvela endaweni yaselabhorethri, ocwaningweni lwezilwane kanye nocwaningo lwabantu.I-International Agency for Research on Cancer (IARC)iyingxenye yeNhlangano Yezempilo Yomhlaba (WHO).Enye yezinhloso zayo ukuhlonza izimbangela zomdlavuza.I-IARC ihlukanise i-PFOA ngokuthi “mhlawumbe i-carcinogenic kubantu” (Iqembu 2B), ngokusekelwe ebufakazini obulinganiselwe kubantu bokuthi ingabangela umdlavuza wamasende nezinso, kanye nobufakazi obulinganiselwe ezilwaneni zaselabhu.(Ukuze uthole ulwazi olwengeziwe ngohlelo lokuhlukanisa olusetshenziswa yi-IARC, bheka I-Carcinogens Yabantu Eyaziwayo Nengenzeka.)I-USI-Environmental Protection Agency (EPA)igcina I-Integrated Risk Information System (IRIS), isizindalwazi se-elekthronikhi esiqukethe ulwazi ngemiphumela yempilo yabantu kusukela ekuchayekeni ezintweni ezihlukahlukene endaweni ezungezile.I-EPA ayizange ihlukanise ngokusemthethweni i-PFOA ngokuphathelene ne-carcinogenicity yayo.Embikweni osalungiswa (hhayi okokugcina), Ibhodi Lokweluleka Ngezesayensi le-EPA lihlole ubufakazi be-PFOA, ikakhulukazi ocwaningweni lwezilwane zaselabhu, futhi lathi “kunobufakazi obusikiselayo be-carcinogenicity, kodwa akwanele ukuhlola amandla omdlavuza womuntu.”Ibhodi livumile ukuthi ubufakazi obusha buzocatshangelwa njengoba butholakala.Ezinye izinhlaka azikakahloli ngokusemthethweni ukuthi i-PFOA ingawudala yini umdlavuza.Kwenziwani ngePFOA?Imiphumela yesikhathi eside ye-PFOA namakhemikhali afanayo awaziwa kakhulu, kodwa kube nokukhathazeka okwanele ukugqugquzela umzamo wokuqeda ukukhishwa kwezimboni kuwo.Izinkampani ezimbalwa kuphela ezisebenzise lawa makhemikhali ekukhiqizeni eminyakeni yamuva.Nakuba imiphumela yezempilo ye-PFOA engaba khona yesikhathi eside ingaziwa, lolu daba okwamanje lusacwaningwa yi-EPA nezinye izinhlaka.Ngaphezu kwalokho, ngo-2006, i-EPA kanye nabakhiqizi be-8 abasebenzisa i-PFOA ngaleso sikhathi bavuma "uhlelo lokuphatha."Izinhloso bekuwukuthi izinkampani zinciphise ukukhishwa kwefekthri kanye namazinga wokuqukethwe komkhiqizo we-PFOA ngama-95% ngonyaka ka-2010, futhi kuqedwe i-PFOA ekukhishweni nasekuqukethe okuqukethwe kwemikhiqizo ekupheleni kuka-2015. Izinkampani zithumele imibiko yonyaka ngenqubekelaphambili yazo ku I-EPA, kanye nemibiko yakamuva ibonise ukwehliswa okukhulu kokusetshenziswa kwalawa makhemikhali.Ukwehla kwesidingo se-PFOA kuphinde kwaholela ekutheni izinkampani eziningi ziyeke ukukhiqiza.I-EPA ayilawuli amazinga e-PFOA noma amakhemikhali ahlobene (njenge-perfluorooctane sulfonate, noma i-PFOS) emanzini okuphuza ngalesi sikhathi.Kodwa-ke, ngo-2009, i-EPA yakhipha izeluleko zezempilo zesikhashana (PHAs) ze-PFOA ne-PFOS emanzini okuphuza.Lezi zeluleko zincoma ukuthi izinyathelo kufanele zithathwe ukuze kuncishiswe ukuchayeka lapho ukungcola kudlula izinga elithile emanzini okuphuza - 0.4 µg/L (ama-micrograms ngelitha) ku-PFOA kanye no-0.2 µg/L ku-PFOS.Lezi zeluleko azizona izindinganiso zikahulumeni eziphoqelelwe ngokomthetho futhi zingashintsha njengoba ulwazi olusha lutholakala.Ingabe kufanele ngithathe izinyathelo zokuzivikela, njengokungawasebenzisi amapani ami ambozwe nge-polymer?Ngaphandle kwengozi engaba khona yezimpawu ezinjengomkhuhlane ngenxa yokuphefumula intuthu ephuma epanini eligcwele i-polymer egcwele ukushisa, azikho izingozi ezaziwayo kubantu ngokusebenzisaI-PTFE-isitsha sokupheka.Nakuba i-PFOA isetshenziswa ekwenzeni i-polymer, ayikho (noma ikhona ngamanani amancane kakhulu) emikhiqizweni embozwe nge-polymer.Ngenxa yokuthi imizila abantu abangachayeka ngayo ku-PFOA ayaziwa, akucaci ukuthi yiziphi izinyathelo abantu abangazithatha. ukunciphisa ukuchayeka kwabo.Ngokusho kwe-US Centers for Disease Control and Prevention (CDC), abantu abanomthombo wabo wamanzi okuphuza otholakala ukuthi banamazinga avamile we-PFOA noma amakhemikhali afanayo angase acabange ukusebenzisa amanzi asemabhodleleni noma ukufaka izihlungi zamanzi e-carbon activated.
Kubantu abakhathazekile kungenzeka ukuthi baye bavezwa emazingeni aphezulu e-PFOA, amazinga egazi angalinganiswa, kodwa lokhu akukona ukuhlolwa okujwayelekile okungenziwa ehhovisi likadokotela.Noma ngabe ukuhlolwa kwenziwa, akucaci ukuthi imiphumela ingasho ukuthini mayelana nemiphumela yezempilo engaba khona.
Isikhathi sokuthumela: Jun-14-2018