Characteristics of Atmospheric Trace Gases, Particulate Matter and Heavy Metal Pollution in Karachi, Pakistan

This study was carried out for determination of Aerosol particulate matter (PM 10), trace gases (SO 2, NO 2, CO) and heavy metals (Zn, Pb, Mn, Cu, Ni and Cd) in the atmospheric air of Karachi city. Sampling has been done at thirteen locations between during the year of 2014. The total average concentrations of SO 2, NO 2, CO and PM 10 were 65.9, 98.7, 1.49 and 202.14μg m –3, respectively. An atomic absorption spectrophotometer (AAS) was used to determine the trace metal concentrations in the PM10 size fraction. The total average concentrations of Cd, Zn, Pb, Mn, Cu and Ni in PM 10 were 0.09, 2.55, 2.23, 1.92, 2.15 and 1.44μg m –3 respectively. The Pb concentration in Karachi shows a decreasing tendency, presumably due to the ban on the use of leaded fuel. The overall trace metal concentrations in Karachi are higher than those in European (e.g., Spain, Norway) and East Asian (e.g., Taiwan) locations, but lower than those measured in Southeast Asian (Kanpur, Delhi, Mumbai, India) cities.