Influence of meteorological variables and forest fires events on air quality in an urban area (Córdoba, Argentina)

Abstract

Extreme environmental events, such as forest fires, are a major emission source of aerosols into the atmosphere. Thus, to investigate the contribution of local forest fires to urban particulate matter, we selected several forest fire indicators, such as number of heat sources, fire events, and burnt area, and collected particles smaller than 2.5µm (PM2.5) during a 2.5-year period in Cordoba City (Argentina). Temporal variation of PM2.5 concentration and composition was described consider-ing fire and nonfire periods, and the influence of meteorological variables was estimated as well. On average, PM2.5 levels registered in Córdoba city during the study period were lower than values reported for other similar cities in Latin America, despite the fact that during wintertime an increase in PM2.5 levels was observed due to the occurrence of thermal inversions. Several fire events taking place in the nearby hills around the city during winter and spring 2013 suggest that biomass burn-ing was a strong contribution to urban particles levels, which is consistent with the significant correlation between PM2.5 concentration and heat sources number. During fire periods, levels of Fe, Ca, and K, were significantly higher than in the nonfire periods, suggesting that these elements can be reliable forest fire markers.