I-Autism iwukukhubazeka okuthuthukayo okuyinkimbinkimbi futhi okudidayo, futhi kuyakhula.
ICenters for Disease Control and Prevention (CDC) isanda kumemezela ukuthi ukwanda kwe-autism kukhuphuke kwafinyelela kumntwana oyedwa kwabangama-1 abazalwa e-United States.
Ngo-2007, i-CDC yabika ukuthi ingane eyodwa kweziyi-150 yayine-autism (ngokusekelwe kudatha ka-2002 evela emiphakathini engu-14).
Akucaci ukuthi kungakanani kwalokhu kwanda kokuvama kungenxa yezibalo ezingcono ngokuqwashisa okwengeziwe nge-autism kanye nokufinyelela okungcono ezinsizeni.
Noma ngabe, ucwaningo oluningi lukhombisa ukuthi i-autism ayibangelwa imigomo, akukabikho imbangela eyodwa eyaziwayo.
Ososayensi baphenya izinto ezingenzeka njengezakhi zofuzo ezingazinzile, izinkinga ngesikhathi sokukhulelwa noma ukubeletha, nezici zemvelo ezifana nezifo ezibangelwa amagciwane kanye nokuchayeka kwamakhemikhali.
UDkt. Alan S. Brown, MPH, udokotela wengqondo kanye nodokotela wezifo eziwumshayabhuqe eNyuvesi yase-Columbia, uchithe ingxenye enkulu yomsebenzi wakhe ecwaninga izici eziyingozi ze-autism kanye nesifo sengqondo sokudangala nokuguquguquka kwengqondo.
Ucwaningo lwakhe lwakamuva nge-autism lungase lube phakathi kwakhe olubaluleke kakhulu.
UBrown nethimba lakhe lamazwe ngamazwe bahlola ukuxhumana okungenzeka phakathi kwe-autism nesibulala-zinambuzane i-DDT.
I-DDT (dichlorodiphenyltrichloroethane) yake yasetshenziswa kakhulu e-United States kodwa yavalwa ngo-1972 yi-Environmental Protection Agency (EPA) ngaphansi kukaMongameli u-Richard Nixon ngoba yayithathwa njengeyingozi emvelweni, izilwane futhi ingaba - ngisho nokuba abantu.
Pho kungani uBrown echitha isikhathi efunda isifutho sokuzivikela esasivinjelwe e-United States cishe eminyakeni engamashumi amahlanu edlule?
Ngenxa yokuthi i-DDT iphikelela ochungechungeni lokudla, esho. Kungathatha amashumi ambalwa eminyaka ukuba siwe, okuholela ekugcineni ukuxhumana nabantu, kuhlanganise nabesifazane abakhulelwe.
UBrown kanye nethimba lakhe lamazwe ngamazwe ucwaningo lokukhulelwa okungaphezu kwesigidi eFinland lubonise ukuxhumana phakathi kwamazinga aphezulu e-DDT metabolite egazini labesifazane abakhulelwe kanye nengozi eyengeziwe ye-autism ezinganeni zabo.
Uhlu lokuqukethwe
Okwavezwa ucwaningo
Imiphumela yocwaningo, eholwa nguBrown kanye nabanye abacwaningi base-Columbia University's Mailman School of Public Health kanye noMnyango Wezengqondo, ishicilelwe namuhla ku-American Journal of Psychiatry.
Lolu cwaningo olwenziwe ngokubambisana nabacwaningi baseNyuvesi yaseTurku kanye neNational Institute of Health and Welfare eFinland, lolu cwaningo lungelokuqala ukuhlanganisa isibulala-zinambuzane engozini ye-autism kusetshenziswa i-biomarkers yokuchayeka komama.
Lolu cwaningo luphinde lwabheka ukuchayeka komama kuma-PCB (polychlorinated biphenyls), elinye ikilasi lokungcolisa imvelo, futhi laphetha ngokuthi kwakungekho ukuxhumana phakathi kwalezi zinto kanye ne-autism.
UBrown uthe ithimba lakhe lihlonze izehlakalo ezingama-778 ze-autism ezinganeni ezizalwe phakathi kuka-1987 no-2005 phakathi kwabesifazane ababhalise eqenjini lababeletha baseFinland, abamele u-98% wabesifazane abakhulelwe eFinland.
Bamatanisa la mapheya kamama nengane neqembu elilawula inzalo yomama kanye nenzalo engenaso i-autism.
Igazi likamama elaqoqwa ekuqaleni kokukhulelwa lahlaziywa ukuze kutholwe i-DDE, i-metabolite ye-DDT, nama-PCB.
Abaphenyi bathi bathole ukuthi amathuba okuba ne-autism enokukhubazeka ngokomqondo ezinganeni akhuphuke ngokuphindwe kabili kumama onesilinganiso se-DDE esiku-quartile ephezulu.
Kuwo wonke amasampula ezimo ze-autism, amathuba ayecishe abe ngaphezulu kwesithathu phakathi kwezingane ezichayeke emazingeni aphezulu e-DDE kamama.
Imiphumela yaqhubeka ngemva kokulungiswa kwezici ezimbalwa ezifana neminyaka kamama kanye nomlando wengqondo. Kwakungekho ukuhlangana phakathi kwama-PCB kamama kanye ne-autism, kusho uBrown.
"Lolu cwaningo lusihlinzeka ngesici esisha sobungozi esivame kakhulu endaweni ezungezile futhi singase simelele idlanzana lamacala, kodwa hhayi idlanzana elincane mayelana nengozi," uBrown etshela i-Healthline.
Ngeshwa, uBrown uthe, la makhemikhali asekhona endaweni futhi atholakala egazini nasezicubu zethu.
"Kwabesifazane abakhulelwe, badlulela ku-fetus ekhulayo," esho. “Ngaphezu kwezakhi zofuzo nezemvelo, imiphumela yethu iphakamisa ukuthi ukuchayeka ebuthini i-DDT ngaphambi kokubeletha kungase kubangele i-autism.”
Ithimba likaBrown linikeze izizathu ezimbili zokuthi kungani libone ukuthi ukuchayeka komama ku-DDE kwakuhlobene ne-autism, kodwa ukuchayeka komama kuma-PCB kwakungenjalo.
Ama-PCB, noma ama-polychlorinated biphenyl, ayimikhiqizo yezimboni noma amakhemikhali avinjelwe e-United States ngo-1979.
Okokuqala, ithimba likaBrown lachaza, i-EDD kamama ihlotshaniswa nesisindo sokuzalwa esiphansi, isici esiyingozi esiphindaphindekayo se-autism. Ngokuphambene, ukuchayeka komama kuma-PCB akuzange kuhlotshaniswe nesisindo sokuzalwa esiphansi.
Okwesibili, ithimba likaBrown ligqamisa ukuboshwa kwama-androgen receptors, inqubo ebalulekile ekuthuthukisweni kwe-neurodevelopment.
Ucwaningo lwamagundane lwathola ukuthi i-DDE ivimbela ukubophezela kwe-androgen receptor, umphumela ubonakala futhi kumodeli yegundane ye-autism.
Ngokuphambene, ama-PCB akhulisa ukubhalwa kwe-androgen receptor.
Amazwana avela kwabanye ososayensi
Njengocwaningo oluningi olubandakanya i-autism, lolu cwaningo luletha ukungaboni ngaso linye okunenhlonipho phakathi kochwepheshe.
UTracey Woodruff, Ph.D., MPH, owenza izifundo zempilo yokuzala kanye nemvelo eNyuvesi yaseCalifornia, eSan Francisco, utshele iNature namuhla ukuthi lolu cwaningo “luyamangalisa ngempela. »
Uthe uhlabeke umxhwele ngenani kanye nekhwalithi yamasampula kusizindalwazi saseFinland futhi wathola ukuhlangana phakathi kwe-DDT ne-autism kumangalisa.
“Lokhu kuqinisekisa nje ukuthi ukuvinjelwa [kwe-DDT] bekuwumbono omuhle,” usho kanje
Kodwa uThomas Frazier, Ph.
Wayibiza ngokuthi ibalulekile kodwa hhayi eyenguquko.
"Lokhu kuphakamisa enye into engaba yingozi emvelweni, i-DDT, kodwa futhi ayifani nesici esiyingozi esihlonziwe ngaphambili, ama-PCB," etshela i-Healthline. “Lokhu kugqamisa isidingo sokuphindaphindwa kwesampula enkulu, ikakhulukazi ezicini eziyingozi ze-autism. »
UFrazier uthe indlela i-DDT engase yandise ngayo i-autism “ayaziwa, futhi kungase kungafaneleki ukuqagela kuze kube yilapho okutholakele kuphindaphindwa. Kungenzeka ukuthi i-DDT njengobuthi ithonya ukubonakaliswa kofuzo ebuchosheni obukhulayo. »
“Esinye isixwayiso esibalulekile kulolu cwaningo,” kwengeza uFrazier, “ukuthi ukuhlangana akusho imbangela. Nakuba ababhali bekhombe izimo ezifanayo nezilawuli futhi balungiselwa izici ezifanele, akunakwenzeka ukukhipha ezinye izincazelo. ”
"Umugqa ongezansi: Lolu cwaningo alunasisekelo, kodwa lwenziwe kahle futhi luphakamisa isidingo sokuphindaphinda nokucutshungulwa ngokucophelela kwe-DDT esikhathini esizayo," kusho uFrazier.
Impendulo evela kumholi wocwaningo
UBrown uthe uvumelana nokuningi okwashiwo uFrazier, kodwa hhayi konke.
"Ngiyavuma ukuthi kunesidingo sokuphindaphinda, kodwa kungakhathaliseki ukuthi ucwaningo luyi-groundbreaking noma cha, lokhu kuyisifundo sokuqala esisekelwe ku-biomarker, futhi lokho kufanele kuphawulwe," kusho uBrown.
UBrown uthe lolu cwaningo ludinga ukuthi kuqhutshekwe nocwaningo kubhekwe ezinye izindlela kanye namanye amakhemikhali, okuhlanganisa nezinye izibulala-zinambuzane.
"Lokhu, kanye nobunye ubufakazi, kuzosisiza ukuthi siqonde kangcono i-biology ye-autism," kusho uBrown. “Sifunda nsuku zonke futhi sinethemba lokuthi sizofunda kabanzi. »
UBrown uthe lolu cwaningo akumele luthuse abesifazane abalindile.
Uthe iningi labesifazane, ngisho namazinga aphezulu e-DDT metabolite, abanazo izingane ezine-autism.
Lokhu kuphakamisa ukuthi ukuze i-autism ithuthuke, ezinye izici zobungozi zizodinga ukuhlotshaniswa, okuhlanganisa ukuguqulwa kofuzo okungenzeka.
"Kungenzeka ukuthi udinga uhlobo oluthile lwezakhi zofuzo" oluhambisana nokuchayeka kwemvelo ukuze uthole i-autism, esho.
UBrown uthe lolu hlobo locwaningo lungagcina luholele ekwelashweni ngokuhlonza isigaba esincane sabantu abanezici ezithile zofuzo.
"Isihluthulelo siwukuhlonza okuhlosiwe, okungase kuyise ekwelashweni okunembayo," kusho uBrown.
Wengeze ngokuthi kukhona nobufakazi bokuthi ku-autism ingxenye yamasosha omzimba “ingase ingasebenzi kahle.”
I-Autism kanye namasosha omzimba
Olunye ucwaningo olubalulekile nge-autism, olushicilelwe emasontweni ambalwa edlule, lwaphetha ngokuthi ukukhula kwe-autism kunqunywa i-microbiome yowesifazane okhulelwe ngesikhathi sokukhulelwa.
Okutholwe kososayensi baseNyuvesi yaseVirginia (UVA) School of Medicine kusikisela ukuthi ezinye izinhlobo ze-autism zingagwemeka.
Ocwaningweni olushicilelwe ngenyanga edlule ku-Journal of Immunology, ososayensi baphethe ngokuthi ama-microorganisms kamama ngesikhathi sokukhulelwa alinganisa izimpendulo ze-interleukin-17A (IL-17A), ezidlala indima ebalulekile ekuthuthukiseni ukuphazamiseka kwe-autism.
I-Interleukin-17A iyi-molecule evuvukalayo ekhiqizwa amasosha omzimba.
Abacwaningi be-UVA baphethe ngokuthi imiphumela ye-microbiome ekuthuthukisweni kwe-autism ingavinjelwa ngokushintsha i-microbiome yomama okhulelwe ngokuthuthukisa indlela adla ngayo, ngokunikeza umama okhulelwe izithasiselo ze-probiotic, noma ngokufaka indle.
Esinye isisombululo kungaba ukuvimba ngokuqondile ukusayinda kwe-IL-17A, kodwa lokhu kungaba yinkinga kakhulu.
"Sinqume ukuthi i-microbiome iyisici esibalulekile ekunqumeni ukuthinteka [ekuphazamisekeni okufana ne-autism]. Ngakho-ke lokhu kuphakamisa ukuthi ungakwazi ukukhomba i-microbiome kamama noma le molecule evuthayo, i-IL-17A," kusho umcwaningi. uthishanhloko, uJohn Lukens, PhD, womnyango we-UVA Wesayensi Yezinzwa.
"Ungaphinda usebenzise le [IL-17A] njenge-biomarker yokuxilongwa kusenesikhathi," kusho u-Lukens esitatimendeni sabezindaba.
Wachaza ukuthi i-microbiome ingalolonga ubuchopho obukhulayo ngezindlela eziningi.
"I-microbiome ibaluleke kakhulu ekunqumeni ukuthi amasosha omzimba enzalo azosabela kanjani ekuthelelekeni, ekulimaleni noma ekucindezelekeni," esho.
Ucwaningo lukaLukens lubonisa ukuthi i-microbiome engenampilo kumama ingashiya inzalo yakhe engcupheni yokuphazamiseka kwe-neurodevelopmental, kodwa ingashintshwa kalula.
Lezi zindlela zonke zifuna ukubuyisela ibhalansi enempilo phakathi kwama-microorganisms ahlukene ahlala emathunjini, nakuba abacwaningi bengakenzi izincomo ezithile zokudla.
Ukuvimba i-IL-17A nakho kunganikeza indlela yokuvimbela i-autism, kodwa u-Lukens uthe lo mzila unengozi enkulu kakhulu.
“Uma ucabanga ngokukhulelwa, umzimba uyawamukela izicubu zangaphandle, okuyingane,” usho kanje. “Ngenxa yalokho, ukugcina impilo ye-embryonic kudinga ibhalansi eyinkimbinkimbi yokulawulwa kwamasosha omzimba, ngakho-ke abantu bavame ukugwema ukuphatha amasosha omzimba ngesikhathi sokukhulelwa. »
I-IL-17A isivele ifakiwe ezifweni ezifana ne-rheumatoid arthritis, multiple sclerosis kanye ne-psoriasis. Ikhona kakade imithi yokulwa nakho.
Kepha uLukens waphawula ukuthi i-molecule inenjongo ebalulekile ekulweni nezifo, ikakhulukazi izifo ezikhunta.
Ukukuvimba, uthi, “kungakushiya usengozini yazo zonke izinhlobo zezifo. Futhi ukwenza kanjalo ngenkathi ukhulelwe kungaba nemiphumela eyinkimbinkimbi ye-ripple ekukhuleni kwengane okuzodingeka ososayensi bayixazulule. »
Inkulumompikiswano mayelana nezibulala-zinambuzane nezibulala ukhula iyaqhubeka
Sekuyisikhathi eside kuxoxwa ngomonakalo obangelwa izibulala-zinambuzane nezibulala-zinambuzane kubantu.
I-DDT, eyaqala ukwakhiwa ngo-1874, yasetshenziswa amasosha phakathi neMpi Yezwe II ukulwa nomalaleveva, isifo sohudo, izintwala zomzimba kanye nesifo se-bubonic.
Abalimi babesebenzisa i-DDT ezitshalweni zokudla ezihlukahlukene e-United States nasemhlabeni wonke, kanti i-DDT nayo yayisetshenziswa ezakhiweni ukuze kunqandwe izinambuzane.
Emhlabeni jikelele, i-DDT isasetshenziswa ngamanani amancane emazweni ukuze ibulale omiyane, kuhlanganise nalabo abathwala umalaleveva.
I-DDT yayithandwa kakhulu ngoba iyasebenza, ayibizi kakhulu ukuyenza, futhi ihlala isikhathi eside endaweni ezungezile.
Ngo-2006, i-World Health Organization yasekela isibulala-zinambuzane njengendlela yokulwa nomalaleveva.
Amanye amaqembu ezemvelo asekela ukusetshenziswa okulinganiselwe kwe-DDT ukubhekana nenkinga kamalaleveva, kodwa amanye amaqembu athi ukufafaza kwe-DDT kuyingozi.
Abanye, njenge-Cato Institute, bafuna ukubuyisela i-DDT e-United States.
Kodwa-ke, ucwaningo luye lwabonisa ukuthi i-DDT kanye ne-DDE yayo ye-metabolite inemiphumela ehlukahlukene empilweni yabantu, okuhlanganisa ukuphuphuma kwezisu kanye nesisindo sokuzalwa esiphansi, ukulimala kwesistimu yezinzwa kanye nesibindi, nomdlavuza webele.
Ama-insecticide empini evela eMonsanto
I-Monsanto, inkampani yamakhemikhali ehileleke engxabanweni ngemikhiqizo yayo eminingi esekelwe kumakhemikhali - kusukela kuma-PCB kuya kumahomoni okukhula kwezinkomo, i-polystyrene ne-Agent Orange (dioxin) - yayingomunye wabakhiqizi bokuqala be-DDT.
I-Monsanto iphikelele amashumi eminyaka ukuthi i-DDT iphephile. Futhi manje enye i-Monsanto herbicide ivutha amalangabi ngezinsolo zokubangela umdlavuza.
Ngesonto eledlule, ijaji laseSan Francisco likhiphe isinqumo sokuthi i-Monsanto's Roundup, isibulala-khula esidayiswa kakhulu emhlabeni, yafaka i-non-Hodgkin lymphoma yangaphambili kubasebenzi basemagcekeni esikole.
UDewayne Johnson, okubikwa ukuthi usezobulawa wumdlavuza, ugixabezwe ngo-$289 million.
Ngemuva kwesinqumo, iMonsanto ikhiphe isitatimende yathi imile ezifundweni eziphakamisa ukuthi i-Roundup ayizange iwubangele umdlavuza.
"Sizokhalaza lesi sinqumo futhi siqhubeke nokuvikela ngamandla lo mkhiqizo, osetshenziswe ngokuphepha iminyaka engu-40 futhi uhlala uyithuluzi elibalulekile, eliphumelelayo neliphephile kubalimi nabanye," kusho uScott Partridge, iphini likamongameli weMonsanto.
Ukunqoba kukaJohnson kungase kube isibonelo ezinkulungwaneni zamanye amacala athi umuthi odumile weMonsanto udale i-non-Hodgkin's lymphoma.
Icala likaJohnson kwaba ngelokuqala ukuqulwa, njengoba wayesezoshona. E-California, abamangali abafayo bangacela ukuqulwa kwecala ngokushesha
I-Monsanto yayinokuzivikela okufanayo ku-Agent Orange, isibulala-khula esidume kabi uMnyango Wezindaba Zomakadebona manje osivumayo ukuthi kulimaze amashumi ezinkulungwane zomakadebona baseMelika.
"Inkampani yangaphambili yeMonsanto yakhiqiza i-DDT kusukela ku-1944 kuze kube yi-1957, lapho iyeka ukukhiqiza ngenxa yezizathu zezomnotho," inkampani ibhala kuwebhusayithi yayo.
“Lokhu kuvalwa kwenzeka kudala ngaphambi kokuba noma yikuphi ukukhathazeka kwezemvelo kulethwe etafuleni futhi, kuze kube namuhla, asikukhiqizi noma sisabalalisa. Kukhona, nokho, okumele kushiwo ngezinzuzo ze-DDT. I-World Health Organization iye yaphawula ukuthi i-DDT iyisinyathelo esiphumelelayo sokuvimbela umalaleveva, isifo esithwalwa omiyane esibulala izigidi zabantu unyaka ngamunye. »
I-Monsanto isanda kuthengwa yi-Bayer, inkampani yomhlaba wonke eyenza imithi ngonyaka odlule yathola imvume ku-Food and Drug Administration ukuze imakethe omunye wemithi yayo emisha nethembisayo kakhulu, i-Aliqopa, eyelapha i-non-Hodgkin's lymphoma .
