The Study of PM10 Concentration and Trace Metal Content in Different Areas of Karachi, Pakistan

Atmospheric particulate matter may exert serious health hazards because of its chemicalcharacteristics. Aim of this study was to determine the concentrations of particulate matter (PM) with anaerodynamic diameter <10 mm (PM10), and air transmitted particulate trace metals in different areas ofKarachi’s ambient air, for the period of 01 year viz. June 2011 to June 2012. Furthermore, the present workcompares the levels of particulate matter and trace metals with the proposed limiting values from the U.S.Environmental Protection Agency (65 mg/m3 for PM10). The sampling for PM10 was performed by usinga high volume air sampler. The PM10 levels were determined by gravimetry and the metals by graphitefurnace. Arithmetic means of 361.0 mg/m3 was determined for PM10 in commercial areas, 275.0 mg/m3 inresidential areas, 438.0 mg/m3 in industrial areas and 68.9 mg/m3 in background areas of Karachi. Tracemetal content in PM10, such as lead (Pb) and cadmium (Cd) were also analysed separately during the sameperiod using atomic absorption spectrometry. The average concentration of Pb were found in commercialzone 1.36 mg/m3, in residential zone 1.0 mg/m3, in industrial zone 1.46 mg/m3 and in urban backgroundzone 0.6 mg/m3, whereas; Cd concentration in commercial zone 0.10 µg/m3, in residential zone 0.02 µg/m3,in industrial zone 0.25 µg/m3 and in urban background zone 0.01 µg/m3, respectively.