Chemical composition of particulate matters in Makkah - Focusing on cations, anions and heavy metals

Abstract

The size of particles mainly determines where the particle is deposited in the respiratory system, whereas the composition determines the type of body response. This study analyses Total Suspended Particles (TSP), Particulate Matter with aerodynamic diameter up to 10 micron (PM10) and 2.5 micron (PM2.5) and their chemical compositions. TSP, PM10 and PM2.5 samples were collected from August 2012 to September 2013 in Makkah, Saudi Arabia. Composition of PM was analysed, focusing on heavy metals, cations and anions. The heavy metals considered in this study were Lead (Pb), Nickel (Ni), Cadmium (Cd), Chromium (Cr), Vanadium (V), Arsenic (As), Mercury (Hg) and Aluminium (Al). Cations and anions considered were Chloride (Cl-), Bromide (Br-), Fluoride (F-), Ammonium (NH4+), Phosphate (PO43-), Sulphate (SO42-), Nitrate (NO3-) and Nitrite (NO2-). Average TSP, PM10 and PM2.5 (μg m-3) levels were 366.38, 233.38 and 143.49, respectively. The ratios of PM2.5/PM10, PM2.5/TSP and PM10/TSP were 0.61, 0.39, and 0.64, respectively. NO3- and SO42- were the most abundant anions in all three types of PM. NO3- contents (%) were 28.53, 39.79, and 30.77 in TSP, PM10 and PM2.5, whereas SO42- contents (%) were 22.52, 17.02 and 21.37, respectively. In TSP and PM2.5, As showed the highest content, which was about 42% and 43%, whereas in PM10, Al showed the highest content (47%).