Chepfu Yomutobvu—Chinetso Chenyika Yose
BOKA rorwendo raChangamire John Franklin rwokundowana Northwest Passage yakarondedzerwa mungano rakanga riri muchinetso. Ngarava dzake mbiri dzakabatwa nechando, uye mwaka wechando wenguva refu weArctic wakanga uchangobva kuvamba. Mukwasvi mumwe akanga atofa nenzira yechienzi—pashoma napashoma akanga avamba kuva anopenga, akava anobvotomoka, uye pakupedzisira akaperezeka kusvikira afa. Ipapo upengo hwakapararira. Varume vakawanda vakafa. Pashure pokunge chiverengero chasvika makumi maviri navana pamakore maviri akatevera, mitezo yakasara yeboka rorwendo yakanga yakatsunga zvikuru kusiya ngarava dzayo zvokuti yakatanga rwendo rwokupererwa nezano rose yakananga kumaodzanyemba panyika yerenje ine chando, ichizvuva zvireyi zvihombe zvakazara nezvinhu zvakawanda zvisiri madikanwa, kunyange zvinhu zvoumbozha. Hapana nomumwe mutezo weboka rorwendo wakapukunyuka. Imomo makanga muri muna 1848. Kwaanenge makore 140, chisakiso choupengo hwavo chakanga chiri chakavanzika. Asi mumakore gumi apfuura, kunzverwa kwebvudzi uye zvimedu zvamapfupa kwakazivisa chisakiso chikuru chechakavanzika: mutobvu. Varume vakanga vadya nyama yakachengetwa mumagaba akanamwa nebhureza romutobvu. Vakanga vadya chepfu yomutobvu!
Chepfu yomutobvu yakanga iri chinetso kare kare pamberi pamazuva eboka iroro rorwendo rwakaparara, uye yakapinda mutyisidziro youtano hwenyika yose chifocho. Mumakore achangobva kupfuura aya mipumburu yakanyorwa pamusoro pengozi yechepfu yomutobvu. Masangano outano kupota nyika yose ari muchinetso pamusoro pokuti angagonana sei nayo. Zvikurukuru munyika, dzakadai seidzo dzomuLatin America uye Eastern Europe, uko kunongova bedzi noudzori hwemhoteredzo hwakaganhurirwa, chepfu yomutobvu yazova chinetso chinowedzera. Marudzi ane nzvimbo dzamabasa okugadzirwa kwezvinhu anoitirawo hanya.
Makore gumi akapfuura, vanyeverwa noufakazi hunowanda hwokuti chepfu yomutobvu yakanga yava hosha yakapararira, vakuru voutano muAustralia, Denmark, Germany, Mexico, Scotland, uye United States vakavamba kufunda kuti vawane kuti kunyange mwero yakaderera zvikuru yomutobvu ine ngozi zvakadini chaizvoizvo kuvanhu, zvikurukuru vana.
Une Ngozi Zvakadini?
Kuratidzirwa kusimbiwo zvayo, yenhando kungagona kuva chaizvoizvo kune ngozi zvikuru here? Dr. Richard Wedeen, munyori webhuku rinonzi Poison in the Pot: The Legacy of Lead, anodavira kuti mutobvu ungashatsa zvikuru kwazvo kushanda kuri kwose kwezvinhu zvipenyu zvomuviri womunhu. Naizvozvo iye anogumisa kuti “mutobvu ungabatanidzwa nesimba reropa rakakwirira, situroko, uye hosha dzemwoyo pamwe chete nehosha yeitsvo.” Wedeen anodavira kuti vamwe vakura vanotambura nechepfu huru yomutobvu vangatova zvidhakwa ndokuguma vava muzvipatara zvendangariro.
The World Book Encyclopedia rinoronga ndaza yezvimwe zviratidzo, zvakadai seperevedzo yamasero matsvuku, rukope, zvinyamunhari zvetsandanyama, kuneta, kuoma mitezo, marwadzo omudumbu, uye kurutsa. “Kuvadziko youropi, koma, uye kupfauma kunoitika mune zvinoitika zvakakomba, uye zvinoitika zvokunyanyisa zvechepfu yomutobvu zvakaparira rufu,” inoshuma kudaro enisaikoropidhia. Uye mwero unokosha waavo vanonaya pazvinoitika zvakakomba vanotambura kuvadziko youropi yechisaririra, anonyora kudaro chiremba mumwe akatanhamara.
Chii chaizvoizvo chinoita mutobvu kuti ubudise izvi zviratidzo? Kutaura idi, muviri unotora mutobvu secalcium, nokudaro hauiti nhamburiko dzokuubvisa. Uchidzungaira hawo mutsinga dzeropa, mutobvu unoparira kuvadziko kunenge kuri kwose kwaunoenda. Muropa, unodzivisa kugadzirwa kwehemoglobin, uchikuvadza simba rinotakura oxygen reropa. Muuropi nomugadziriro yetsinga, unozvinamatidza umene kumaprotein anokosha anonzi enzymes ndokuaita kuti ave asingashandi. Mapfupa anounganidza mutobvu ndokuuchengeta, padzimwe nguva achiubudisa gare gare zvikuru kuti aite kuvadziko yakakura.
Zvinhu zviviri zvechepfu yomutobvu zvinokuita kuve kune ngozi zvikurukuru. Kutanga, inogona kuva rudzi rwakavanzika, runooneka pashoma napashoma rwechirwere, rwakaoma kuwana. Chechipiri, zvikurukuru nemhaka yokuchinja kwenzvimbo dzamabasa okugadzirwa kwezvinhu, mutobvu uri munzvimbo iri yose chaizvoizvo mumhoteredzo yedu.
Simbi Iri Munzvimbo Iri Yose
Nhasi, kushandiswa kwomutobvu kwakaganhurirwa bedzi nefungidziro yomunhu. Chifo chama 1920 kusvikira pamisi ichangobva kupfuura iyi, somuenzaniso, mamirioni amatani omutobvu akawedzerwa kupeturo kuti uvandudze kushanda kweinjini. Mutobvu wakashandiswa zvakafara mupendi, kunyange zvazvo dzimwe nyika zvino dzakaganhurira nomutoo wakakomba uku kushandiswa.
Asi kunyange kana uchigara munyika umo mutobvu wanguve wakarambidzwa kushandiswa mupendi kana kuti peturo, ungave usina kukotsekana chose chose pakuratidzirwa kumutobvu. Somuenzaniso, ungagara muimba kana kuti kamuri rakapendwa mitemo yakadaro isati yashanda. Kana kuti zvimwe uko unogara, kune motokari dzomugadzirirwe wekare dzakawanda zvikuru dzichiri kushandisa peturo ine mutobvu, dzichiri kubudisa utsi hunonhuhwa hunoshatsa mhepo uye ivhu zvakakupota.
Ipapowo, mutobvu wakashandiswa zvakafara mukugadzirwa kwamapombi amatsvina nebhureza. Chidziviriro chomutobvu chinoshandiswa kudzivirira vashandi vane unyanzvi veX-ray navashandi vesimba renyukireya pamwaranzi inokuvadza. Zvibhorani zvemvura inonwiwa zvina matangi ane majoini akabhurezwa nomutobvu zvichiri kushandiswa, sezvakaita magaba ezvokudya ane majoini akabhurezwa nomutobvu. Mabwe omutobvu anozivikanwa mumagirazi ewaini namasefa. Kunyange mabhodhoro avacheche anoitwa namabwe omutobvu. Mumabhatiri emotokari muna mapureti omutobvu. Mabara omutobvu nembumburu dzezvifefe zvinoshandiswa namamirioni asingaverengeki. Ndaza inoratidzika kuva isingagumi.
Kunyange zvazvo chepfu yomutobvu pakati pavakura iri yeitiro hanya yakakomba kuna vanachiremba, vanyajambwa vanotapurwa zvikurusa veiyi hosha ndivo vana. Neiko vana? Uye unogona seiko kuvadzivirira uye iwe umene paiyi hosha inoparira kuneta munyama nomundangariro?
[Mashoko okukwezva vaverengi ari papeji 22]
Kuratidzirwa kusimbiwo zvayo kungagona chaizvoizvo kuva kune ngozi here?
[Mashoko okukwezva vaverengi ari papeji 22]
Wakasununguka kudzungaira mutsinga dzeropa, mutobvu unoparira kuvadziko kunenge kuri kwose kwaunoenda
[Mashoko okukwezva vaverengi ari papeji 23]
“Mutobvu ungabatanidzwa nesimba reropa rakakwirira, situroko, uye hosha dzomwoyo pamwe chete nehosha yeitsvo”
[Vakatipa Mufananidzo uri papeji 21]
Mufananidzo: Painting by Thomas Smith, courtesy of the Maritime Museum, Greenwich, England