Makemikolo—Ndi Othandiza Kapena Owononga?

TIMASANKHA zochita m’moyo mwakuona ubwino ndi kuipa kwake kwa chinthu. Mwachitsanzo, anthu ambiri amagula galimoto chifukwa chakuti imathandiza kuyenda mwamsanga. Koma ngakhale ndi choncho ayenera kulingalira za mtengo wogulira galimoto—inshuwalansi, kukalembetsa, kutha kwake—ndiponso kuisunga bwino kuti iziloledwa kuyenda pamsewu. Ayeneranso kulingalira zakuti akhoza kuvulala kapena kufa ngati atachita ngozi. Ziri chonchonso ndi zinthu zamakemikolo zopangidwa m’mafakitale—tiyenera kuona ubwino wake mosiyanitsa ndi kuipa kwake. Mwachitsanzo lingalirani za kemikolo yotchedwa MTBE (methyl tertiary butyl ether), yomwe amaiwonjezera ku mafuta a galimoto kupangitsa kuti aziyaka kwambiri ndiponso kupangitsa kuti galimoto isamatulutse utsi wambiri.

Chifukwa cha MTBE, mpweya m’mizinda yambiri ku United States ndi wabwinopo kuposa mmene unkakhalira zaka zambiri m’mbuyo. Komabe, kukhala ndi mpweya wabwino kumeneku kwachitika “kanthu kena katawonongeka,” inatero New Scientist. Ichi n’chifukwa chakuti MTBE amapangitsa matenda a kansa, ndipo amachucha m’mathanki ambirimbiri a pansi pa nthaka, ndipo kaŵirikaŵiri amaipitsa madzi a pansi pa nthaka. Zotsatira zake n’zakuti m’tauni ina 82 peresenti ya madzi amachita kukatenga kwina ndipo zimadya ndalama zokwana madola 3.5 miliyoni pachaka! New Scientist inati vuto limeneli “likhoza kukhala kuwonongeka kwa madzi a pansi pa nthaka kwakukulu kwambiri mu United States.”

Makemikolo ena analetsedwa ndipo anasiya kuwagulitsa chifukwa amawononga chilengedwe ndiponso thanzi. Mwina inu mungafunse kuti, ‘n’chifukwa chiyani zimenezi zimachitika? Kodi samayamba ayesa makemikolo onse kuti aone ngati ali abwino asanaloleze anthu kuyamba kuwagwiritsa ntchito?’

Vuto la Kuyesa Ngati Ali Abwino

Tikanena za kuyesa makemikolo kuona ngati ali abwino kapena oipa, amagwiritsa ntchito luso la sayansi ndipo zina amangoganizira. Joseph V. Rodricks m’buku lake lakuti Calculated Risks, anati, “Amene amaona za makemikolo alibe malire abwino osiyanitsira makemikolo kuti ndi ‘abwino’ kapena ndi ‘oipa.’” Zimenezi n’zomveka kwambiri makamaka ponena za mankhwala omwe amangopanga okha m’fakitale. The World Book Encyclopedia inati: “Ngakhale atayesa bwino kwambiri, si kuti nthaŵi zonse zimadziŵika kuti mankhwalawo angathe kuwononga mwanjira ina.”

Malabotale amakhala ndi makina ena opimira milingo yoyenera. Mwachitsanzo, iwo sangathe kupima bwino mmene makemikolo akakhalire kunja komwe kuli zinthu zosiyanasiyana. Kunja kwa labotale kumakhala zinthu mazanamazana, mwina zikwi za zinthu za makemikolo ongopanga m’fakitale, amene ambiri mwa iwo akakhalira pamodzi akhoza kumasinthasintha mwinanso kumasintha akakhudzana ndi zinthu zina zamoyo. Ena mwa makemikolo amenewa sangatiwononge pawokha, koma akakhala pamodzi ndi ena, kaya kunja kapena mkati mwa matupi athu, amatheka kusintha n’kukhala oipa owononga. Makemikolo ena amasanduka owononga, mwina kufika popangitsa kansa, panthaŵi imene thupi liyamba kugaya chakudya.

Kodi nanga amene amapima kuona ngati makemikolowo ali abwino angadziŵe bwanji pamene pali zovuta zonsezi? Njira yomwe kaŵirikaŵiri amagwiritsa ntchito m’labotale ndiyo kupatsa nyama mlingo wina wake wa mankhwalawo ndiye n’kuyerekezera zotsatira zakezo mmene zingakhalire kwa munthu. Kodi njira imeneyi ndi yodalirika nthaŵi zonse?

Kodi Kuyesera pa Nyama Nkodalirika?

Kuwonjezera pankhani yakuti kuteroko n’kuchitira nyama nkhanza, kuyesera makemikolo oopsa pa nyama kumabutsanso mafunso ena. Mwachitsanzo, nyama zosiyanasiyana zimachitanso mosiyanasiyana mutazidyetsa makemikolo. Mankhwala ochepa chabe a dioxin amapha kanyama kotchedwa guinea pig, koma kuti kanyama kotchedwa hamster kafe, muyenera kuŵirikiza mankhwala amenewo nthaŵi 5,000! Ngakhale nyama zofanana kwambiri monga makoswe ndi mbeŵa zimachita mosiyanasiyana zikadyetsedwa makemikolo osiyanasiyana.

Choncho ngati simungadziŵe kwenikweni mmene nyama ina ingachitire poona mmene ina yachitira, nanga ofufuza angatsimikizire bwanji kuti kemikolo yakutiyakuti anthu angagwirizane nayo? Chenicheni n’chakuti, njira imeneyi ndi yosadalirika.

Akatswiri opanga makemikolo alidi ndi ntchito yovuta kwambiri. Amafunikira kusangalatsa anthu amene amafuna zomwe amapangazo, kunyengerera amene amadera nkhaŵa za nyama, komanso iwo eni kuti adzisangalatse mwakukhala ndi chikumbumtima chabwino kuti makemikolo amene amapanga ndi abwino. Pazifukwa zimenezi, malabotale ena amayesera makemikolo awo pa maselo a anthu amene amasunga. Komabe zidzaoneka zokha m’tsogolo ngati njirayi ndi yodalirika yodziŵira kuti mankhwala ndi abwino kapena ayi.

Pamene Kuyesa m’Labotale Kulephera

Mankhwala ophera tizilombo otchedwa DDT, amene mpaka pano amapezekabe m’chilengedwemu, ndi amodzi mwa mankhwala omwe anatchulidwa kuti ndi abwino pamene anatulutsidwa koyamba. Koma pambuyo pake asayansi anadzatulukira kuti DDT amakhala nthaŵi yaitali m’zinthu zamoyo, ndipo ndi mmene zililinso ndi makemikolo ena oopsa. Kodi vuto la zimenezi n’chiyani? Ndi, mmene ndandanda ya kudalirana kwa nyama pachakudya yotchedwa food chain imakhalira, kuyambira pa mamiliyoni a tamoyo ting’onoting’ono, kenaka nsomba, mapeto ake mbalame, zimbalangondo, akatumbu, ndi zina zotero, mwanjira imeneyi zimapangitsa poizoni kuundana m’nyama zotsirizira kudya zinzawozo. Nthaŵi ina, mbalame za m’madzi zotchedwa grebes zinkalephera kuswa ngakhale mwana mmodzi kwa zaka khumi!

Pa ndandanda ya chilengedwe imeneyi kumapezeka kuti makemikolo ena, omwe amangopezeka ochepa m’madzi, amapezeka ochuluka kwambiri mu nyama zotsirizira kudya zinzawo. Chitsanzo chake ndi Beluga Whales zomwe zimapezeka ku North America mu Mtsinje wa St. Lawrence. Zili ndi poizoni wambiri mwakuti ngati zitafa ziyenera kutayidwa!

Makemikolo ena omwe amapezeka m’nyama aoneka kuti amafanana ndi mahomoni. Ndipo ndi chaposachedwapa pamene asayansi anayamba kuzindikira mmene makemikolo amenewa amawonongera.

Makemikolo Amene Amafanana ndi Mahomoni

Mahomoni ndi makemikolo ofunika amene amatumiza mauthenga m’thupi. Iwo amayenda m’magazi mwathu kupita ku mbali zina zathupi, kumene amakalimbikitsa kapena kulepheretsa ntchito zina, monga ngati kakulidwe ka thupi kapena zokhudza ziberekero. Koma modabwitsa, World Health Organization (WHO) inalengeza kuti “pali umboni wa sayansi womwe ukuwonjezekabe” umene ukusonyeza kuti makemikolo ena opangidwa m’mafakitale, ngati aloŵa m’thupi la munthu, amasokoneza mahomoni mwina mwa kutsanzira ntchito zake koma molakwitsa kapena amawatsekereza kuti asagwire ntchito bwino.

Makemikolo amenewa ndi monga PCBs,a dioxins, furans, ndi mankhwala ena ophera tizilombo monga zotsalira za DDT. Makemikolo amenewa amatchedwa kuti endocrine disruptors, (osokoneza ntchito za mahomoni) chifukwa ali ndi mphamvu yosokoneza mmene dongosolo lonse la mahomoni limayendera m’thupi.

Homoni imene kemikolo imeneyi imatengera ndi homoni yothandiza pa zakugonana ya akazi yotchedwa estrogen. Nkhani ya m’nyuzipepala yotchedwa Pediatrics inati zioneka kuti chifukwa cha mankhwala a tsitsi omwe amakhala ndi estrogen pamodzinso ndi makemikolo ena omwe amafanana ndi estrogen ndizo zikupangitsa kuti atsikana ambiri azitha msinkhu adakali ang’onong’ono.

Ngati mnyamata akhudzidwa ndi makemikolo ena panthaŵi ina pamene akukula ndiye kuti zinthu zikhoza kusokonezeka. Magazini otchedwa kuti Discover anati, “ofufuza apeza kuti ngati mutaika PCB m’thupi la afulu a m’madzi aamuna kapena nyama zina za mtundu wa ng’ona zotchedwa alligator panthaŵi ina yake yoyenera pamene zikukula zikhoza kusanduka zazikazi kapena kukhala ndi ziwalo ‘zachimuna ndi zachikazi zomwe.’”

Kuwonjezera apo, poizoni wa makemikolo amafooketsa mphamvu ya thupi yotetezera kumatenda, zikumapangitsa nyama kusachedwa kugwidwa ndi matenda oyambitsidwa ndi mavairasi. Ndipo zikuoneka kuti mavairasi akufalikira mwamsanga kwambiri kuposa kale, makamaka pakati pa nyama zotsirizira kudya zinzawo, monga ma dolphins ndi mbalame zam’nyanja.

Kunena za anthu, ana ndiwo amakhudzidwa kwambiri ndi makemikolo amene amatengera mahomoni. Ana obadwa kwa azimayi omwe anadya mafuta a mpunga okhala ndi PCB ku Japan zaka zapitazo “sanakule mwamsanga ndipo anali ndi malingaliro achibwana, analibe khalidwe labwino kuphatikizapo kuti amakhala ofatsa kwambiri kapena ochenjera kwambiri, amakhala ndi mpheto zachimuna zochepa kwambiri, ndipo I.Q. yawo imaperewera ndi mapointi asanu,” inatero magazini ya Discover. Atapima ana amene anakhudzidwa ndi PCB ku Netherlands ndi ku North America zotsatira zake zinasonyeza kuti anasokoneza kakulidwe ka thupi ndi malingaliro awo.

Bungwe la WHO linapereka lipoti lakuti chinthu chinanso chomwe chapangitsa kuti kansa “yokhudzana ndi mahomoni” iwonjezeke pakati pa abambo ndi amayi, monga kansa ya m’maŵere, m’mavalo, ndi m’ziwalo zina zoberekera za amuna ndi chifukwa cha kuchuluka kwa makemikolo. Kuwonjezera apo, m’mayiko ambiri, pali umboni wooneka bwino wakuti amuna akumatulutsa ubwamuna wochepa, ndipo sukhala wabwino kwenikweni, limenelinso n’kukhala vuto lodza chifukwa cha kuwonjezeka kwa kugwiritsa ntchito makemikolo. M’madera ena, pa avareji ubwamuna umene amuna amatulutsa unatsika kufika pa theka mkati mwa zaka 50!

M’nkhani yoyamba ija, dokotala wina anagwidwa mawu kuti “ndife mbadwo umene tionerepo zonse.” Zioneka kuti akukhoza. N’zoona kuti ambiri mwa makemikolo omwe apangidwa atithandiza kwambiri, koma ena sanatithandize. Choncho ndi chanzeru kupewa kukhudza makemikolo amene ali ndi mphamvu yotiwononga. Koma chodabwitsa n’chakuti, ambiri mwa amenewa amapezeka m’nyumba zathu. Nkhani yathu yotsatira inena zimene tingachite kuti tidziteteze ku makemikolo angozi.

[Mawu a M’munsi]

[Chithunzi patsamba 27]

Nsomba zotchedwa kuti whale izi zili ndi poizoni mwakuti siziyenera kudyedwa ngati zitafa

[Mawu a Chithunzi]

©George Holton, The National Audubon Society Collection/PR