Meteorological factors contributing to organic and elemental carbon concentrations in PM10 near an open-pit coal mine.

Abstract

Variations in the carbonaceous aerosol contents, organic carbon (OC) and elemental carbon (EC), in particulate matter less than 10 μm in size (PM10), were analyzed at sites influenced by coal mining in an open-pit mine located in northern Colombia. Samples were collected during different seasonal periods throughout 2015. Meteorological variables for each site were examined during the different seasons. Aerosols were detected using a thermal-optical reflectance protocol method. The highest PM10 concentrations, between the ranges of 28.2 ± 8.2 μg m-3 and 75.0 ± 36.5 μg m-3, were recorded during the dry season. However, the highest concentrations of OC (4.8-14.2 μg m-3) and EC (2.9-13.9 μg m-3) in PM10 were observed during the transition period between the dry and wet seasons. The strong correlation between OC and EC in PM10 (r = 0.6-1.0) during the transition season indicates a common primary combustion source. High OC (> 8.3 μg m-3) and EC (> 6.9 μg m-3) concentrations were associated with low wind speeds (< 2.1 m s-1) moving in different directions. Analyses of the sources of atmospheric aerosol pollutants in the mining area in northern Colombia showed that the daily maximum total carbon concentrations were mainly associated with regional atmospheric transport of particulate matter from industrial areas and biomass burning sites located in the territory of Venezuela.