Polycyclic Aromatic Hydrocarbons (PAH) in Atmospheric Particles (PM2.5 and PM2.5–10): Integrated Evaluation of the Environmental Scenario in Urban Areas

Abstract

The 16 United States Environmental Protection Agency (US EPA) priority polycyclic aromatic hydrocarbons (PAHs) are considered carcinogenic and mutagenic for humans and are emitted by anthropogenic sources mainly in urban areas. For this purpose, the carcinogenic risk in the Metropolitan Region of Porto Alegre/RS (RMPA), Brazil, was investigated due to its demographic density (421.8 inhabitants/km2), industrialization, and high flow of vehicles. The concentration of the 16 PAHs present in PM10–2.5 and PM2.5 was evaluated, and so their origins, the carcinogenic risk of inhalation, and their interaction with meteorological parameters. Dichotomous sampler was used to collect the PM10–2.5 and PM2.5 in the cities of Canoas (CA) and Novo Hamburgo (NH) in RMPA for having different industries and demographic densities. Extracts containing PAHs were analyzed by gas chromatography coupled to mass spectrometry to determine the concentration of PAHs. Thirteen PAHs were found, mainly in PM2.5. The carcinogenic risk was above the US EPA recommended safety range (1 × 10−6) in PM2.5 and PM2.5–10 at both NH and CA. Naphthalene obtained the highest concentration, but the presence of benzo[a]pyrene was determinant for the higher carcinogenic risk in PM2.5. PAHs in RMPA are emitted mainly from burning by vehicles, increasing concentrations in cold seasons. Due to anthropogenic similarities between CA and NH, the interactions among meteorological parameters and air pollutants were the same. High interaction was observed between PM2.5, naphthalene, and meteorological parameters. The integrated evaluation of the factors used by this study shows the relevance of obtaining these data for the prevention of human health.