Imichiza—Ngaba Iluncedo Okanye Ikukufa Kufunjiwe?

IZIGQIBO ezininzi esifikelela kuzo ebomini sizenza ngokuthelekisa iingenelo nxamnye nelahleko. Ngokomzekelo, abantu abaninzi bathenga inqwelo-mafutha ngenxa yokuba iluncedo. Kodwa iluncedo injalo, kuye kufuneke bacinge nangeendleko zokuba nenqwelo-mafutha—i-inshorensi yayo, ukubhaliswa kwayo, ukuhla kwexabiso layo—nokugcina le nqwelo-mafutha ikufanelekela ukuba sendleleni. Kwakhona kufuneka bacinge nangokwenzakala okanye ukufa ngenxa yeengozi. Yintw’ enye ke nangoozenzele bemichiza—ziyafuna ukuthelekiswa iingenelo zabo nxamnye nelahleko abayidalayo. Ngokomzekelo khawucinge nje ngomchiza ekuthiwa yiMTBE (imethyl tertiary butyl ether) ogalelwa kwipetroli ukuze iqhwithe iphungule nokuqhuma kwenqwelo-mafutha.

Tshotshw’ ibekho iMTBE le, kuba kaloku iwutsho wacoceka noko umoya kwizixeko ezininzi zaseUnited States kunokuba ubunjalo kwiminyaka ethile ngaphambili. INew Scientist iza nengxelo yokuba lo moya ucocekileyo “uqhwaye oluny’ ukhwembekhwembe.” I-MTBE le inokubangela umhlaza, ibe iye yavuza kumashumi amawaka eetanki zokugcina ipetroli ezingaphantsi komhlaba, apho ke iye yahlalela ukungcolisa amanzi angaphantsi komhlaba. Loo nto ke inyanzele enye idolophu ukuba ithenge ama-82 ekhulwini amanzi ayo kweminye imithombo engaphandle, nto leyo eyibethe yayikhukuza ii-$3,5 zezigidi (ii-R22,3 zezigidi) ngonyaka! Ithi ke iNew Scientist le ngxubakaxaka “inokuba kokona kungcoliswa kwamanzi angaphantsi komhlaba kutsib’ izicithi eUnited States okuza kuthabatha iminyaka kusenzeka.”

Ngenxa yeli lifu limnyama ke lilengalenga phezu kwemekobume nakwimpilo yethu, eminye imichiza iyingozi gqitha yaye ivaliwe ukuba ingenziwa ibe ayithengiswa nokuthengiswa. Usenokuba uyazibuza ukuba, ‘Kodwa kutheni kusenzeka le nto nje? Kanti le michiza mitsha ayibhilabhilwa xa iyonke na kuqala kukhangelwa ukuba ayingebi natyhefu na ngaphambi kokuba ithengiswe?’

Izinto Ezifika Zixabe Xa Kukhangelwa Ityhefu Ekuyo

Liyinene lona elokuba, xa kukhangelwa ityhefu kwimichiza kusetyenziswa ubuchule benzululwazi kuphinde kufuniselwe. Uth’ uJoseph V. Rodricks kwincwadi yakhe ethi Calculated Risks: “Abo bakhangela obu bungozi babamba beyeka kunzima ukwahlula kakuhle phakathi ‘kwendlela ekhuselekileyo’ ‘nengakhuselekanga’ yokusetyenziswa kwawo nawuphi na umchiza.” Imek’ iyafana ke nakuninzi lwamayeza angoozenzele. IThe World Book Encyclopedia ithi: “Kungaciciyelwa kubhilabhilw’ iyeza kuye kumiw’ apho kumiwa khona, kodwa zikho iingozi zalo eziya kuhlala zifihlakele zingaveli.”

Neelebhu zisikelw’ umda ngandlel’ ithile. Ngokomzekelo, ziyoyiswa kukuqikelela ngokupheleleyo indlela umchiza oya kusebenza ngayo xa usetyenziselwa iinjongo ezininzi ezahlukeneyo ngaphandle. Ngaphandle kwelebhu kukho amakhulu kwanamawaka emichiza engoozenzele uninzi lwayo olunokudala nto yimbi lwakudibana naxa ludibana nezinto eziphilayo. Eminye kule michiza ayinabungozi xa iyodwa, kodwa ithi yakudibana, ngaphakathi okanye ngaphandle kwemizimba yethu, ivelise imixube yemichiza emitsha nenetyhefu. Eminye ke imichiza iba yityhefu, de ibangele nomhlaza, emva kokuba sele icoliwe ngumzimba.

Aba bakhangela ubungozi baza kukwazi njani ke ngoku ukuthi imichiza ayinabungozi xa kukho iingxaki ezinjalo? Eyona ndlela ke ibisasetyenziswa yile yokunika izilwanyana eziselebhu umlinganiselo othile womchiza ize ke yonke into efunyenwe apho ithatyathwe ize kusetyenziswa ebantwini. Ngaba le yindlela enokusoloko ithenjwa?

Ngaba Kunokuthenjelwa Kuvavanyo Olwenziwa Kwizilwanyana?

Ngaphandle nje kokuzibuza ukuba azi le nto asikokukhohlakalelwa kwezilwanyana kusini na, ukuvavanya iityhefu kwizilwanyana kushiy’ eminye imibuzo ijinga. Ngokomzekelo imichiza isebenza ngeendlela ezahlukeneyo kwizilwanyana ezahlukeneyo. Uchatha nje wedioxin enetyhefu eninzi ungayibeth’ uyibulale imazi yeguinea pig, kodwa ukuze ubulale ihamster kungafuneka loo mlinganiselo uphindwe kangangama-5 000! Imichiza isebenza ngeendlela ezahlukeneyo nakwezona zilwanyana zihlobeneyo njengamabuzi neempuku.

Ngoko ke xa kunzima nokuqiniseka ukuba umchiza unokusebenza ngendlela efanayo kwizilwanyana ezahlukeneyo, abaphengululi banokuqiniseka njani ke ngoku ukuba umchiza othile unokubalungela abantu? Enyanisweni, soze baqiniseke kuphele.

Ngokuqinisekileyo iingcali zemichiza zikwembi inkathazo. Kufuneka zanelise abantu abafuna le michiza yazo, zixolise abo bangalali boya ngenxa yentlalo-ntle yezilwanyana zize ziqinisekise ukuba kuthe ngco kuzo ngaphakathi ukuba imichiza yazo ayinabungozi. Yiloo nto ke le ibangela ukuba, ezinye iilebhu zenze ulingelo lwemichiza kwiiseli zomntu eziphilayo. Noko ke, mhlawumbi ekuhambeni kwexesha kuya kutshiwo kuqinisekwe ukuba ayinabungozi.

Xa Ulingelo Olwenziwa Elebhu Lusiwa Nganeno

Isibulali-zinambuzane ekuthiwa yiDDT, nesikho kwiindawo ezininzi, singomnye wemichiza ekwathiwa ayinabungozi ukuqala kwaso ukukhululwa ukuba singasetyenziswa, phofu kubethw’ ecaleni kuyo yonke loo nto. Kamva izazinzulu zafumanisa ukuba iDDT iyathanda ukukhe inamathele kuloo nto ikuyo, ngokunjalo ke nangezinye iityhefu ezinobungozi. Le nto ibangele yiphi intlekele? Kaloku umjikelo wokutya, obunjwe zizigidi zezidalwa ezincinane uze ezintlanzini uze ugqibele ezintakeni, kwiibhere, iintini nezinye izilwanyana, udlulisela ityhefu kwizilwanyana ezisekugqibeleni kuwo. Kaloku kwakha kwenzeka ukuba, ezinye iintaka zasemanzini ekuthiwa ziigrebes kube nzima ukuba ziqandusele amantshontsho kangangeminyaka elishumi!

Oku kudluliselana ngetyhefu kuyinto ngobunto bayo, nangona eminye imichiza kunzima ukuyibona emanzini, kodwa iba yingozi kakhulu xa ifika kwisidalwa sokugqibela ukuyiginya. Loo nto ungayibona kakuhle kwiminenga ekuthiwa ziibeluga ekuMlambo iSt. Lawrence yaseMntla Merika. Inetyhefu kangangokuba xa ifile ibalelwa phakathi kwenkunkuma eyingozi!

Kuye kwafunyaniswa ukuba imichiza ethile ekwizilwanyana ezininzi xa uyijongile ungaqhatheka uthi yincindi yamadlala. Ibe izazinzulu zisandul’ ukuyibhenca kutshanje imiphumo emibi enokubangelwa yile tyhefu inamaqhinga.

Imichiza Ezifanisa Nencindi Yamadlala

Incindi yamadlala iphala phambili ekudluliseleni imichiza emzimbeni. Ityhutyha igazi lethu iye kwamanye amalungu omzimba, apho ifika incedise okanye inqande inkqubo ethile, njengokukhula komzimba okanye imijikelo enxibelelene nokuzala. Eyona nto ke ibangel’ umdla yile yokuba, inqaku leendaba lakutshanje elabhalwa yiWorld Health Organization (WHO) lathi “intaphane yezinto ezifunyaniswe yinzululwazi” ibonisa ukuba oozenzele bemichiza xa bengene emzimbeni bayaphazamisana nencindi yamadlala ngokuzifanisa nayo nto leyo eyingozi okanye bayivalele.

Phakathi kwale michiza kuthethwa ngayo kukho iiPCB,a iidioxin, iifuran nezinye izibulali-zinambuzane, kuquka namasalela eDDT. Le michiza ibizwa ngokuba ngabaphazamisi benkqubo yokusebenza kwamadlala iyakwazi ukuphazamisana nendlela eqhelekileyo yokusebenza kwenkqubo yomzimba yokusebenza kwamadlala, apho iphuma khona ke incindi yamadlala.

Enye incindi yedlala ethanda ukuzifanisa nayo le michiza yincindi yedlala lesini lebhinqa eliyiestrogen. Olunye uhlolisiso olwakhutshwa komny’ ulindixesha wezamayeza iPediatrics lubonisa ukuba ukukhawuleza kwamantombazana ukufikisa kurhanelwa ukuba kubangelwa sesinye isithambiso sentloko esine-estrogen kwakunye neminye imichiza ekhoyo efana ne-estrogen.

Ukufumana kwendoda umchiza othile ngexesha kanye elibalulekileyo ekukhuleni kwayo kusenokuba yingozi kuyo. Ithi ingxelo ekwiphephancwadi iDiscover: “Ulingelo luye lwabonisa ukuba iiPCB ezisetyenziswe ngexesha elithile lokukhula zinokuguqula iimfudo nee-alligator ezizinkunzi zibe ziimazi okanye ‘kuzenze zingaziwa nokuba ziinkunzi okanye ziimazi.’”

Phezu kwaloo nto, imichiza eyityhefu iyikhuph’ amazinyo inkqubo yomzimba yokuzikhusela, ishiya isilwanyana eso sisesichengeni sokuhlaselwa zizifo. Enyanisweni, kukhangeleka ngathi izifo zinwenw’ okomlilo wedobo yaye ziyagqugqisa, ingakumbi kwizilwanyana ezitshotsh’ entla kumjikelo wokutya njengamahlengesi neentaka zaselwandle.

Ebantwini ngabantwana abathanda ukuhlaselwa yimichiza efana neencindi zamadlala. Iphephancwadi iDiscover linikela ingxelo yokuba abantwana abazelwe ngabafazi abatya ioli ekuthiwa yirice oil enePCB eJapan kwiminyaka eyadlulayo “imizimba neengqondo zabo zakhula kade, baba neengxaki kwizimilo zabo ngxaki ezo eziquka ukunyaba nokudlamka ngokugqithiseleyo, iincanca zabo zazincinane ngendlel’ apha engaqhelekanga, nengqondo engaphantsi ngokuphindwe kahlanu kunento ebekumele ukuba iyiyo.” Uvavanyo oluye lwenziwa ebantwaneni abafumene iiPCB ezininzi eNetherlands nakuMntla Merika luye lwathi bhenqe iingozi ezifanayo ezinokuphazamisa ukukhula kwemizimba neengqondo zabo.

IWHO inikela ingxelo yokuba ezinye izinto ekurhanelwa ukuba zibangelwa yimichiza, zisenokuba ngumhlaza “obangelwa ziincindi zamadlala” phakathi kwamadoda namabhinqa, njengomhlaza wamabele, owamasende nowedlala lobudoda. Ngaphezu koko, kumazwe amaninzi, ingxaki ekubonakala ifuna ukuba yinto ngobunto bayo yile yokungabi namandla kwamadlozi emadodeni, kwakunye nokuhla komgangatho wamadlozi, nto leyo esenokubangelwa kukusetyenziswa kakhulu kwemichiza. Kwamany’ amazwe, amandla amadlozi ahle aya kutsho kwisiqingatha kwiminyaka engama-50!

Kwinqaku elandulelayo, kucatshulwe omnye ugqirha obesithi “siphila phakathi kwesizukulwana esihleli nje siyalinga.” Iyazicacela yona into yokuba uchan’ ucwethe ngotolo. Liyinyaniso elokuba, imichiza emininzi esiyivelisileyo iye yasinceda kodwa eminye ke iye yawa nganeno. Ngoko ke siya kuba silumkile xa singasebenzisi ngokungeyomfuneko imichiza enokusenzakalisa. Eyona nto ke imangalisayo yile yokuba uninzi lwale michiza ifumaneka kanye emakhayeni ethu. Inqaku elilandelayo liza kuxubusha ngento esinokuyenza ukuze sizikhusele kwimichiza enokuba yingozi.

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Le minenga inetyhefu kangangokuba ibalelwa phakathi kwenkunkuma eyingozi xa ifile

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©George Holton, The National Audubon Society Collection/PR