DNA damage in Mexican children living in high-risk contaminated scenarios Article uri icon


  • The aim of this study was to evaluate the deoxyribonucleic acid (DNA) damage (as a biomarker of biological effects) in children living in areas at high risk of contamination in Mexico using the comet assay. The alkaline comet assay was performed in order to assess DNA damage levels in blood cells of 276 children living in eleven communities in four states of Mexico. Moreover, levels of arsenic and 1-hydroxypyrene (1-OHP) in urine and lead and total DDT [sum of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT)] in blood were quantified. We found urinary 1-OHP levels between < LOD and 14.5. μmol/mol creatinine; for arsenic, the urinary levels were 3.5-180. μg/g creatinine (range). Lead levels in blood ranged from 0.5 to 24. μg/dL and finally, the levels of total DDT (DDE and DDT) ranged from < LOD to 32,000. ng/g lipid. Regarding DNA damage (comet assay), the most important finding in our study was that children exposed to a chemical mixture [high levels of exposure to polycyclic aromatic hydrocarbons (PAHs) and DDT were found] had the significant highest DNA damage level (p. < 0.05) in their blood cells (olive tail moment. = 7.5 ± 3.5), when compared with DNA damage levels in children living in the other scenarios assessed in this work. Finally, significant correlations were observed between urinary arsenic levels (r = 0.32, p. < 0.05); urinary 1-OHP levels (r = 0.65, p. < 0.01); total DDT in blood levels (r = 0.59, p. <. 0.01) and DNA damage. In conclusion, the data indicates that children living in areas which are at high risk of contamination showed high levels of biomarkers of exposure in urine or blood. Moreover, the exposure levels contribute to DNA damage and suggest an increased health risk in studied sites at risk of great pollution. © 2015 Elsevier B.V.

publication date

  • 2015-01-01