Toxicogenetic monitoring in urban cities exposed to different airborne contaminants.

Microparticles found in the air may be associated with organic matter that contains several compounds, such as Polycyclic Aromatic Hydrocarbons (PAHs) and nitro-PAHs, and may pose a significant risk to human health, possibly leading to DNA mutations and cancers. This study associated genotoxicity assays for evaluating human exposure with the atmospheric air of two urban areas in southern Brazil, that received different atmospheric contributions. Site 1 was under urban-industrial influence and the other was a non-industrial reference, Site 2. Organic extracts from the airborne particulate matter were tested for mutagenicity via the Salmonella/microsome assay and analyzed for PAH composition. Cells samples of people residing in these two cities were evaluated using the comet and micronucleus assay (MN).Concentrations of the individual PAHs ranged from 0.01 ng/m(3) (benzo[a]anthracene) to 5.08 ng/m(3) (benzo[ghi]perylene). As to mutagenicity analysis of airborne, Site 1 presented all the mutagenic responses, which varied from 3.2±1.22 rev/m(3) (TA98 no S9) to 32.6±2.05 rev/m(3) (TA98, S9), while Site 2 ranged from negative to minimal responses. Site 1 presented a high quantity of nitro and amino derivatives of PAHs, and peaked at 56.0±3.68 rev/µg (YG1024 strain). The two groups presented very low DNA damage levels without intergroup difference. Although Site 1 presented high mutagenic responses in the air samples, high PAH levels, healthy people exposed to this environment did not show significative damage in their genetic material. However, the evaluation of different environmental and genetic damage in such population is necessary to monitor possible damages.

Salmonella mutagenicity assessment of airborne particulate matter collected from urban areas of Rio Grande do Sul State, Brazil, differing in anthropogenic influences and polycyclic aromatic hydrocarbon levels.

Urban areas are both major sources and major targets of air pollution. The atmospheric environment receives diverse chemical substances, including genotoxic agents that may affect human health. The purpose of this study was to evaluate and compare the atmospheric quality in two urban areas in Rio Grande do Sul State (Brazil), under the influence of greater (Site 1) or lesser (Site 2) anthropogenic sources. Polycyclic aromatic hydrocarbons (PAHs) of environmental interest were quantified and the Salmonella/microsome assay was used for the measurement of mutagenicity. Organic compounds extracted from the airborne particulate matter were analyzed by high-performance liquid chromatography (HPLC) to detect PAHs of interest (known or possible carcinogens). The organic extracts were also tested for mutagenic and cytotoxic activity in the Salmonella/microsome assay with strains TA98, TA100, YG1021 and YG1024, with or without S9 activation. At Site 1, benzo[ghi]perylene (BghiP) and indeno[1,2,3-cd]pyrene (IP) were found at higher concentrations and mutagenicity (revertants per µg extract) varied from 1.0±0.25 (TA98, no S9) to 5.2±0.45 (TA98, S9). At Site 2, BghiP and IP were present in larger amounts and the mutagenic responses ranged from 0.6 to 3.7 revertants per µg (both in TA98, S9). The occurrence of BghiP and IP may be related to vehicular emissions. These and the other PAHs studied, as well as the nitro compounds, may contribute to the mutagenicity found in these airborne particles.

Genetic biomonitoring of an urban population exposed to mutagenic airborne pollutants.

Biomonitoring studies have increased as a consequence of risks and effects to human health on exposure to environmental contaminants, mainly air pollutants. Genetic biomarkers are useful tools for the early assessment of exposure to occupational and environmental pollution. The objective of the present study was to investigate genotoxic effects on people residing and/or working downwind from an oil refinery in southern Brazil and the mutagenic activity of airborne particulate matter (PM10). Samples of peripheral blood and buccal mucosa cells were evaluated using the single-cell gel electrophoresis assay (comet assay) and the micronucleus (MN) assay, respectively. PM10 samples were collected in the target site and the organic matter extraced with dichloromethane was assessed for mutagenic activity in the Salmonella/microsome assay. The exposed group (n=37) was compared to a reference group (n=37) of subjects living in an urban area with limited traffic and industrial influence, located far from the main industrial areas. All PM10 organic extracts showed mutagenic positive responses and the effect decreased in the presence of S9 mix indicating that the predominant compounds present were direct-acting mutagens. The responses of YGs strains are consistent with aromatic amines and nitroarenes being present in the PM10 extracts. The group in the area under the influence of the oil refinery (exposed group) showed significantly higher DNA damage in lymphocytes than the reference group. The MN frequencies in buccal mucosa were very low for both groups and no difference between groups was observed. No association was found between age and tobacco smoking habit and level of DNA damages measured by the comet assay. The results indicate that the comet assay was a sensitive tool to detect DNA damage in subjects under the influence of an oil refinery, with marked genotoxic activity in the atmospheric environment.