Seasonal variation of DNA adduct pattern in human lymphocytes analyzed by 32P-HPLC

Abstract

32P-HPLC is a recently published method to generate DNA adduct profiles after exposure to a complex of genotoxic substances. The low detection limit enables characterization of individual DNA adducts in the general population. The 32P-HPLC method was applied to human lymphocytes and granulocytes from Silesia, a polluted industrial region in the south of Poland. Human samples were collected at the end of winter and summer to investigate the seasonal influence on DNA adduct formation. In lymphocytes a strong seasonal variation was seen in total DNA adducts, with winter values exceeding the summer values by 7.33 +/- 3.56 times. Granulocytes did not show any seasonal variation. In winter-collected lymphocytes the DNA adduct levels were 21.4 +/- 16.6/10(8) normal nucleotides (NN) while the summer values were 2.96 +/- 2.46/10(8) NN. Granulocytes had 8.06 +/- 7.76 and 9.59 +/- 6.19 DNA adducts/10(8) NN during winter and summer respectively. The lymphocyte DNA adduct profile consisted of at least 16 individual or clusters of DNA adducts. All 16 had a clear winter influence, with a winter:summer ratio of 1.6-15.3, indicating exposure to a complex mixture of genotoxic substances. The DNA adducts analyzed in human lymphocytes had retention times similar to DNA adducts generated by polycyclic aromatic hydrocarbons. The suggested candidates for DNA adducts displayed a similar seasonal variation in airborne particles to that found in DNA adducts in lymphocytes of humans living in the area. This is the first application of the 32P-HPLC method to analysis of DNA adducts in human tissues.