STUDY OF AEROSOLS PARTICULATES COMPOSITION OF MONSOON RAIN WATERS IN THE VALLEY OF QUETTA‪.‬

Byline: Manzoor Iqbal Khattak Abstract: Rain water samples were collected at Quetta Valley during the monsoon of 2010. The cations (Ca, Mg, Na, K and NH4) and anions (F, Cl, NO3, SO4, acetate and formate) along with pH and conductance were measured. The percentage contribution of soil components (Ca, Mg, Na and K) and NH4 are observed to be higher than the acidic substances. The ratios of Mg/Ca, NO3/Ca and F/Ca in precipitation indicates that 50-75 percentile of rain water correspond to respective ratios in the local soil. Significant correlation of NO3 with NH4, Ca and Mg (0.56, 0.52 and 0.62) and of SO4 with Ca and Mg (0.65 and 0.66) and neutralization factor for NH4, Ca and Mg suggests that these are the neutralising constituents. Hence, it has been hypothesized that neutralization by NH4 is an incloud process, while that by Ca and Mg is a below cloud process.