Double direction phototherapy and light-induced genetic abnormalities in human lymphocytes.

The irradiation of jaundiced infants with fluorescent lights is currently the most common method of treating neonatal hyperbilirubinemia. To investigate whether phototherapy is capable of damaging the genetic material, peripheral lymphocytes of ten jaundiced newborns were studied. Chromosomal analyses were carried out before and after 24 h of treatment with double blue light phototherapy at wavelengths from 420 to 500 nm. Using the BrdU technique for chromosomal culture, no detectable aberrations on genetic material of circulating lymphocytes were observed. This study doesn't, however, exclude potential deleterious effects of phototherapy on other tissues such as skin fibroblasts or immature ovaries in female infants.