Mu 2019, FDA yo muri Amerika yatangaje igitekerezo gishya kivuga ko mu bintu 16 bikora ku zuba biri ku isoko rya Amerika, zinc oxyde na titanium dioxide byongewe ku bicuruzwa bikingira izuba nka "GRASE" (Byemerwa ko bifite umutekano kandi bifite akamaro). PABA na Trolamine Salicylate si "GRASE" yo gukoreshwa mu bikingira izuba bitewe n'ibibazo by'umutekano. Ariko, ibi bikubiye muri iki gice byakuwe mu buryo bunyuranye, kandi byumvikana ko ibintu bikingira izuba gusa - nano zinc oxyde na titanium dioxide - ari byo bifite umutekano kandi bifite akamaro mu bibigize bikingira izuba, ibindi birwanya izuba ntabwo bifite umutekano kandi bifite akamaro. Mu by'ukuri, imyumvire myiza ni uko nubwo FDA yo muri Amerika ifata nano-zinc oxyde na titanium dioxide nk "GRASE", ntibivuze ko ibindi binini 12 birwanya izuba atari GRASE, ariko biracyafite amakuru ahagije y'umutekano yo kwerekana. Muri icyo gihe, FDA irimo gusaba amasosiyete abishinzwe gutanga amakuru menshi y'inkunga y'umutekano.
Byongeye kandi, FDA yakoze igerageza ku "kwinjizwa kw'imirasire y'izuba mu maraso binyuze mu ruhu" maze isanga bimwe mu bintu bikora ku mirasire y'izuba biri mu mirasire y'izuba, iyo umubiri winjijwe ku rwego rwo hejuru, bishobora guteza ibibazo by'ubuzima. Ibisubizo by'igerageza bikimara gusohoka, byakuruye ibiganiro bikwirakwira hirya no hino ku isi, kandi buhoro buhoro byateje ubwumvikane buke ku baguzi basanzwe batari bazi ukuri. Bemeraga mu buryo butaziguye ko mirasire y'izuba ishobora kwinjira mu maraso kandi ikaba iteje akaga ku mubiri w'umuntu, ndetse bakemeraga uruhande rumwe ko mirasire y'izuba yangiza ubuzima kandi idashobora gukoreshwa.
Byatangajwe ko FDA yashatse abakorerabushake 24, bigabanyijemo amatsinda 4, maze igerageza imiti irinda izuba irimo imiti 4 itandukanye irinda izuba muri formula. Ubwa mbere, abakorerabushake batanze 75% by'uruhu rw'umubiri wose, hakurikijwe igipimo gisanzwe cya 2mg/cm2, inshuro 4 ku munsi mu minsi 4 yikurikiranya kugira ngo bakoreshe imiti irinda izuba. Hanyuma, hakusanyijwe amaraso y'abakorerabushake mu minsi 7 yikurikiranya kandi ingano y'imiti irinda izuba mu maraso irapimwa. Ubushakashatsi bwagaragaje ko agace k'uruhu rw'umuntu mukuru kari hagati ya 1.5-2 ㎡. Dufashe agaciro k'impuzandengo ka 1.8 ㎡, iyo kabazwe hakurikijwe ingano isanzwe, ikoreshwa ry'imiti irinda izuba n'abakorerabushake ni hafi 2 × 1.8 × 10000/1000 = 36g mu igerageza, kandi ingano yayo inshuro 4 ku munsi ni 36 × 4 = 144g. Ubusanzwe, agace k'uruhu rwo mu maso kari hagati ya 300-350cm², gukoresha rimwe imirasire irinda izuba birahagije kugira ngo birinde umunsi wose. Muri ubu buryo, ingano y'ikoreshwa ryabazwe ni 2 × 350/1000 = 0.7g, nubwo irangi ryasubiwemo, ni hafi 1 .0 ~ 1.5g. Iyo ufashe ingano ntarengwa ya garama 1.5, ibarwa ni 144/1.5 = inshuro 96. Kandi ingano y'isuku ikoreshwa n'abakorerabushake mu minsi 4 yikurikiranya ni 144 × 4 = 576g, mu gihe ingano y'isuku ikoreshwa ku munsi n'abantu basanzwe mu minsi 4 ari 1.5 × 4 = 6g. Kubwibyo, itandukaniro riri hagati y'ingano ya garama 576 na garama 6 z'isuku ikoreshwa ni rinini cyane kandi ingaruka ziragaragara.
Imiti irinda izuba yageragejwe na FDA muri ubu bushakashatsi ni benzophenone-3, octoclilin, avobenzone, na TDSA. Muri yo, amakuru yo gupima benzophenone-3 ni yo yonyine arenze cyane "agaciro k'umutekano", inshuro zigera kuri 400 zirenze igipimo gisanzwe, octocrylene na avobenzone byombi biri mu nshuro 10, naho aside p-xylylenedicamphorsulfonic ntabwo iraboneka.
Mu buryo bw’imitekerereze, gukoresha cyane imiti irinda izuba ku ruhu ku buryo buhoraho bizagira ingaruka nyinshi. Ntibitangaje kuba n’imiti irinda izuba iboneka mu maraso mu bihe bikomeye nk’ibi byo gupimwa. Imiti irinda izuba imaze imyaka irenga mirongo yemejwe kandi ikoreshwa, ibihugu byinshi byagenzuye imiti irinda izuba nk’imiti, kandi kugeza ubu nta makuru ahagije y’ubushakashatsi agaragaza ko igira ingaruka mbi ku mubiri w’umuntu.
Igihe cyo kohereza ubutumwa: Nzeri-09-2022
