Seasonal variations in the level of mutagenicity: an assessment of respirable particulate matter in Rio de Janeiro, Brazil

Abstract

Respirable particles (PM2.5) can become associated with organic matter containing several compounds such as polycyclic aromatic hydrocarbons (PAHs). Many PAHs have been identified as cancer-inducing chemicals. The mutagenicity of airborne particles is generally associated with PAHs, but recent reviews show that PAHs may not be the predominant mutagens in atmospheric pollution, and that nitroaromatic compounds, aromatic amines and aromatic ketones, often found in moderately polar or highly polar organic fractions, are potent mutagens. Nitro-polycyclicaromatics (nitro-PAHs) are persistent environmental mutagens and can be found in airborne suspended particles from direct sources such as diesel and gasoline exhausts, or may be products of atmospheric reactions in the presence of NO 2 and NO 3 radicals. In the present work we compared PAH levels and mutagenicity using gas chromatography spectrometry and the Salmonella/microsome assay on organic extracts of PM2.5 for Salmonella typhimurium strain TA98. The samples were collected in two periods: (I) July to October 2010 and (II) November 2010 to May 2011 at three sites in Rio de Janeiro -(1) low urban traffic at the University campus; (2) heavy . Mutagenic frameshift responses in the absence of metabolic activation were detected at all the sites in periods I and II. In the presence of metabolic activation this response was observed for all three sites in period I, but only for site 3 in period II. Nitroarenes and dinitroarenes were detected at all three sites in period I. In period II, the presence of nitroarenes was also detected at all sites, but dinitroarenes were only detected at sites 2 and 3. The information generated in this study shows that different levels of PAHs and nitroderivatives, influenced by seasonal variations in climatic conditions, probably contribute to the detected airborne mutagenicity.

Biomonitoring of genotoxic risk of workers exposed to heavy air pollution

“…In this study, we analyzed the effect of exposure to environmental pollutants in Rebouças tunnel workers using different exposure biomarkers. Rebouças tunnel has heavy traffic, and has high ambient air concentrations of PM 2.5 (141 µg/m [7,18,19]. Fifteen of the fifty Rebouças tunnel workers agreed to participate in this study, although N is small, it represents 30% of the population.…”

“…In 2010, we conducted a PM2.5 monitoring study at three sites of the city of Rio de Janeiro: the campus of the Rio de Janeiro State University (moderate traffic 119,000 vehicles/day), Avenida Brasil express way (has heavy traffic, ~250,000 vehicles/day and is the city's biggest highway) and Rebouças tunnel (heavy traffic, ~190,000 vehicles/day) [7,18,19]. In these studies we detected PM2.5 values that exceeded the levels established by the World Health Organization, [20] mainly in Rebouças tunnel.…”

“…In these studies we detected PM2.5 values that exceeded the levels established by the World Health Organization, [20] mainly in Rebouças tunnel. Furthermore, this site showed highest concentrations of PAHs and nitro-PAHs, and the highest mutagenicity values for Salmonella typhimurium strain TA98 and its derivatives, YG1021 and YG1024, both sensitive to nitro-compounds [7,18,19]. The aim of the present study was to investigate the genotoxic effects on Rebouças tunnel workers exposed to PM2.5.…”