An analysis of airborne particulate matter by variation in size

Abstract

This study seeks to capture, identify and quantify the carbonaceous fraction of airborne pollutants known as black carbon; whilst considering the potential sources in the urban region of Msida in Malta. Furthermore, it discusses these findings in relation to impacts and influences on each sustainability pillar, both separately and holistically. Out of the summation of particulate matter (PM), the black carbon fraction generated through anthropogenic activity has been known to lead to numerous severe health effects. Natural fractions have been acknowledged in previous research; however, mitigation action is limited when compared to sources such as fossil-fuel combustion. A Hirst Burkard Trap, situated on a rooftop, was utilised to capture regional airborne matter, which was viewed under a light microscope. Manual counting of BC took place through the identification and classification into three sizes: fine, coarse and large, according to the geometric diameter observed. Meteorological variables that alter concentrations are discussed and tested for significance via statistical analysis. Additionally, potential stationary and mobile sources post wind sector analysis are presented as maps. Findings suggest that cumulative contribution from sources is plausible. Moreover, statistical significance between the fine size and wind direction, and the coarse fraction with temperature were identified. Trends in relation to xylene were further observed, as well as with wind speed. The potential sources from the region include vehicular traffic, marine vessels, construction machinery and industrial sectors (including incinerators and shipyards). Further research, conducted over a longer timeframe, is recommended to better understand the Maltese context.