8-oxodeoxyguanosine as a marker of oxidative DNA damage in children in relation to air pollutants and gene polymorphisms

Exposure to ambient air pollution has been associated with adverse health effects that could cause many diseases. Adverse effects of different pollutants on human health have been well documented in Europe and other parts of the world. Oxidative stress is believed to be one of the mechanisms of effects of air pollution to human health. We investigated variability of 8-oxodeoxyguanosine (8-oxodG), a marker of oxidative damage to DNA, in urine samples of 500 children from Teplice district with higher air pollution and 426 children from Prachatice district with lower air pollution as a background of the Czech Republic. For the analysis of 8-oxodG levels ELISA technique was used. We analyzed the association between exposure to particulate matter PM2.5, PM10, carcinogenic polycyclic aromatic hydrocarbons (cPAHs), benzo[a]pyrene (BaP) and 8-oxodG levels with individual characteristics from human life style as ethnicity, smoking, education level, maternal height and weight, type of heating, vitamins content etc. The concentrations of environmental pollutants (PM2.5, PM10, cPAHs and BaP) were monitored continuously by stationary monitors. The mean levels (SD) of 8-oxodG in Teplice children vs. Prachatice children were as follows: 17.2 (±17.4) vs. 17.3 (±12.0) nmol/mmol creatinine (p=0.37); so there was not a significance difference between these two districts. The high levels of 8-oxodG were connected mainly with cotinine levels, ethnicity, mother¢s education level, mother¢s high, mother¢s weight and children's age. Because it is expected that metabolic and DNA repair gene polymorphisms may modulate individual susceptibility to PAH exposure the relationship between 8-oxodG and polymorphisms of metabolizing (CYP1A1*2A, CYP1A1*2C, GSTM, GSTP, GSTT, EPHX1) genes and DNA repair genes (XRCC1, XPD6, XPD23, hOGG1) was investigated. The PCR-based FRLP assays were used. However, no consistent effect of genetic polymorphisms was observed. Levels of PM2.5 and PM10 measured in a 3-day period 6 days before collection of urine significantly increased 8-oxodG levels. The significant relationships were observed between 8-oxodG levels and respiratory illnesses in children. The study was supported by the grant VaV-SL/5/160/05, VaV-SP/1b3/50/07 of the Czech Ministry of Environment and AVOZ50390512 of the Academy of Sciences of the Czech Republic.

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