Air pollution exposure and DNA damage in buccal mucosa cells of pre-school children

摘要

Background Child exposure to air pollution is a matter of concern due to the well-known health effects of air pollutants and the relevance of biological damage in childhood on the risk of developing chronic diseases in adulthood. Aim The aim of this study was to evaluate the early effects of air pollution on buccal mucosa cells of pre-school children using biomarkers of DNA damage. Methods This study was carried out on healthy 3-6-year-old children living in Brescia, a high polluted town in Northern Italy. DNA damage was investigated in buccal cells of children using the comet and micronucleus (MN) assays. Child exposure to urban air pollution was assessed by analysing PM0.5 samples collected in the school areas for polycyclic aromatic hydrocarbon (PAH) and heavy metal concentration and in vitro mutagenicity on bacteria, human leukocytes and Allium cepa cells. Data regarding other pollution sources (particularly indoor pollution) were collected using a questionnaire. Results A total of 152 children were enrolled and their biological samples were tested using the comet assay and MN tests. The results regarding the 40 subjects read so far show slightly high DNA migration (tail intensity: 6.34±5.53%; range=0.69-30.80%) and MN frequency (0.30±0.15%; range=0.09-0.99%). All PM0.5 samples show genotoxic activity in bacterial and human cells and a PAH concentration (range 5.2-6.7 ng/m3) higher than the annual law limit of 1 ng/m3. Conclusion Preliminary data concerning about a quarter of the enrolled subjects show that children living in an urban area are usually exposed to air mixtures with a high concentration of genotoxic pollutants and have slightly high DNA damage in their buccal mucosa cells. At the end of the study, all the data will be processed to investigate the associations between air pollution exposure and biomarkers of early effects. The interactions between factors will also be examined.