Measurement of Major Ambient Air Pollutants in Sindh Industrial Trading Estate (SITE), Karachi, Pakistan

摘要

Continuous measurements of major ambient air pollutants such as O_3, SO_2, CO, NO, NO_x PM10, methane and nonmethane hydrocarbons as well as meteorological parameters was carried out to obtain baseline data for the Sindh industrial trading estate (SITE) in Karachi. The total average concentration of O_3 was determined to be 13.3 ppb, SO_2 24.9 #mu#g/m~3, CO 0.7 ppm, NO 31.6 ppb, NO_x 44.3 ppb, PM10 177.8 #mu#g/m~3, methane 16.31 ppm, and nonmethane hydrocarbon 0.4 ppm. The average wind speed during the measurement was 2.2 m/sec, wind direction 169.6 degrees, humidity 45.2%, temperature 22.6 deg C, barometric pressure 1012.4 mBars, and solar flux 215.0 W/m~2. SO_2 and PM10 show similar variation which indicate that both pollutants originate from the same source. The results also suggest that the O_3, NO and NO_X found in this area were mainly emitted from a small power generation plant and boiler of a nearly pharmaceutical industry, where as methane and nonmethane hydrocarbons were mostly emitted from nearby agricultural farms. The measurement of major ambient air pollutants and their dispersion trends in the atmosphere with respect to microclimatic effects is discussed.