CYTOGENETIC EFFECTS OF ULTRAVIOLET-IRRADI ATION OF HUMAN-LYMPHOCYTES

Over the last decade, a greater decrease in the ozone level has occurr ed in the Southern Hemisphere. For each 1% decrease in this level, a 2 % increase in biologically effective radiation occurs. Aiming to evalu ate the biological effect produced by UV radiation, 10 blood samples c oming from patients consulting for reproductive problems, were irradia ted with visible and ultraviolet radiation A (treatment A) and visible and ultraviolet radiation B (treatment B) during 1 to 5 minutes. This dosage is comparable to the radiation received in Santiago at 13:00 h in a summer day. After irradiation, lymphocytes were cultured during 72 h and the number of altered metaphases was quantified. There was a significant increase in chromosomal alterations with treatment A (2.61 , 2.43, 4.53 and 3.53 at 1, 2, 3 and 5 min respectively) and treatment B (3.06, 3.81, 3.3, 5.51, at 1, 2, 3 and 5 min respectively) compared with non-irradiated controls (0.8 and 0.72). There was a reduction in mitotic indices in irradiated cells. It is concluded that both types of UV radiation (A and B) produce chromosomal alternations in vitro, e ven using lower doses than those received during summer in the central region of Chile.