Integrated study of genotoxicity biomarkers in schoolchildren and inhalable particles in areas under petrochemical influence.

This study aimed to evaluate genotoxicity effects of inhalable particulate matter from areas influenced by a petrochemical complex on exposed children population. Peripheral blood and buccal mucosa exfoliated cells were collected from 54 children (5-12 years) at two public schools, 2.5 Km (Site NW) and 35 km (Site NWII) from the main industrial emission source. These areas lie in the first wind direction from a petrochemical complex. Blood samples were used to Comet Assay (CA) evaluating the tail intensity and to the cytokinesis-block micronucleus cytome assay (CBMN-cyt), assessing the frequency of micronucleus (MN), nuclear buds (NBUDs) and nucleoplasmic bridges (NPBs). Buccal micronucleus cytome assay (BMCyt) was used to detect MN and nuclear abnormalities. Mutagenicity of particulate matter (PM) organic extracts from these two sites, besides from one in the second wind direction (NE) was evaluated by Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024 with and without metabolic activation (S9). The site closest to the petrochemical complex (NW) presented worse air quality, evidenced by greater PM mutagenicity and more toxic PAHs profile (ΣTEQ). Also, Tail intensity was significantly higher at this site (10.65 ± 0.78) compared to site NWII (6.73 ± 0.92). MN frequencies in CBMN-cyt did not differ among groups, but was significantly higher than an external reference site. NBUDs were significantly higher at site NWII. BMCyt showed no difference among the groups for MNs and NBUDs. Site NWII showed higher frequencies of karyorrhexis and karyolysis. All samples, even within the PM limits, presented genotoxic potential. Results showed that the children are exposed to a mixture of contaminants from different sources, and that the proximity of the petrochemical industry gives a cause of concern. Actions must be taken to identify and reduce emissions and hazardous effects, since air quality standards are not enough to ensure the exposed population health.

Genotoxicity biomarkers for airborne particulate matter (PM2.5) in an area under petrochemical influence.

The effects of fine inhalable particles (PM2.5) were evaluated in an area under the influence of a petrochemical industry, investigating the sensitivity of different genotoxicity biomarkers. Organic extracts were obtained from PM2.5 samples at two sites, positioned in the first and second preferential wind direction in the area. The extracts were evaluated with Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024. The mammalian metabolization fraction (S9) was used to evaluate metabolite mutagenicity. The Comet Assay (CA) and Micronuclei Test were used in a Chinese hamster lung cell line (V79). All extracts showed mutagenicity in Salmonella, and nitrogenated compounds were strongly present. Genotoxicity were found in CA in almost all extracts and the micronuclei induction at the Site in the first (Autumn 1, Winter 1), and in the second (Spring 2) wind direction. V79 showed cytotoxicity in all samples. The three biomarkers were concordant in characterization Site NO with worse quality, compatible with the greater pollutants dispersion in the first wind direction. All PM2.5 concentrations were lower than those recommended by air quality standards but genotoxic effects were detected in all samples, corroborating that these standards are inadequate as quality indicators. The Salmonella/microsome assay proved sensitive to PM2.5 mutagenicity, with an outstanding influence of nitroarenes and aromatic amines. Analyses using CA and the micronucleus test broadened the levels of response that involve different damage induction mechanisms. Results show that the complex PM2.5 composition can provoke various genotoxic effects and the use of different bioassays is essential to understand its effects.