Uduti two gukaraba (amabara yo ku zuba) dutanga imirasire ya ultraviolet (UV), cyane cyane mu buryo bwa UVA (315–400 nm), no ku rugero ruto rwa UVB (280–315 nm). Nubwo urumuri rw'izuba rusanzwe rufite ingano ingana y'ubwoko bwombi bw'imirasire, ibikoresho byo gukaraba ubusanzwe bitanga urugero rwinshi rwa UVA, rushobora kugira ingaruka zitandukanye ku ruhu no ku buzima muri rusange. Iyi nkuru irasuzuma ingaruka ku buvuzi no ku ndwara z'uruhu bitewe n'ikwirakwizwa rya UVA na UVB bivuye mu duti two gukaraba.
1. UVA na UVB: Itandukaniro ry'ingenzi
| Ibiranga | UVA (Umuraba muremure) | UVB (Umuyoboro mugufi) |
|---|---|---|
| Ubujyakuzimu bw'Ibyinjira | Ubujyakuzimu (dermis) | Imbere (epidermis) |
| Ingaruka zo gukaranga ibara ry'uruhu | Ako kanya (okisidati) | Gutinda (gutera melanin imbaraga) |
| Gutunganya Vitamine D | Gito cyane kugeza kuri nta na kimwe | Isoko y'ibanze |
| Uburyo bwo kwangiza ADN | Indirect (gukora ROS) | Ingano ya thymine (dimer) itaziguye |
| Kansinogeni | Bifitanye isano na melanoma | Bifitanye isano na kanseri y'uturemangingo twa squamous (SCC) |
| Kugabanya ubudahangarwa bw'umubiri | Ikomeye (ishingiye kuri sisitemu) | Iciriritse (iherereye mu gace runaka) |
2. Ingaruka z'ubuvuzi za UVA mu mashini zikora ibara ry'uruhu
A. Gusaza k'uruhu (gufotora):
UVA yinjira cyane mu ruhu, igasenya kolajeni na elastine binyuze mu bwoko bwa ogisijeni (ROS).
Ibi biganisha ku minkanyari, uruhu rusa n'uruhu ndetse no gusaza imburagihe.
B. Kugabanya ubudahangarwa bw'umubiri:
UVA ihindura imikorere y'uturemangingo twa Langerhans, bityo ikagabanya ubudahangarwa bw'uruhu.
Ibi byongera ibyago byo kwandura indwara z'uruhu (urugero: HPV na herpes) kandi bishobora gutuma uburyo bwo gukingira bugabanuka.
C. Ingaruka za Melanoma
UVA itera kwangirika kwa ADN, ibi bikaba byibasira melanoma mbi (ubwoko bwa kanseri y'uruhu yica cyane).
Ubushakashatsi bwerekana ko abantu bakoresha utubari two gusiga ibara ry’uruhu bafite ibyago byinshi byo kurwara melanoma ku kigero cya 59% (JAMA Dermatology, 2014).
D. Nta vitamine D ikorwa cyane
Bitandukanye na UVB, UVA ntabwo ihindura 7-dehydrocholesterol mo vitamine D₃, bivuze ko ahantu ho gusiga ibara ry'uruhu ntacyo bikora mu gukora vitamine D.
3. Ingaruka z'ubuvuzi za UVB mu mashini zikora uruhu
A. Gutwikwa n'izuba no kwangirika kwa ADN
UVB itera impinduka za ADN zitaziguye (thymine dimers), ibyo byongera ibyago byo kurwara kanseri y’ururenda rwa squamous (SCC) na kanseri y’ururenda rwa basal (BCC).
Uburiri bwo gutwika uruhu bufite UVB butera indwara yo gutwika izuba.
B. Gutunganya Vitamine D (bigarukira gusa mu duce two gusiga ibara ry'uruhu)
Nubwo UVB ari ngombwa mu gukora Vitamine D₃, imashini nyinshi zikoresha uruhu zigabanya ibyago byo gutwika UVB, bigatuma zidakora neza muri urwo rwego.
C. Guhagarika ubudahangarwa bw'umubiri ahantu runaka
UVB igabanya umubare w'uturemangingo twigaragaza mu ruhu, ariko igatera kugabanuka guke k'ubudahangarwa bw'umubiri kurusha UVA.
Uburyo bwo guhangana n'ibyangiritse kuri UV:
Ambara indorerwamo z'izuba zirinda.
Koresha amavuta akingira izuba afite uburinzi bwa UVA/UVB.
Hitamo ibikoresho bifite imirasire mike.