Abstract
Studies have shown the concentrations of total suspended particulates in Lahore, Pakistan, to be among the highest in the world. Results are presented from a study that examined the suspended particulate matter loading of the air at various locations within the metropolitan region, and defined the chemical composition of these particles. The extraction and analytical procedures used are described. The data indicated extremely high concentrations of lead, elemental and organic carbon, cadmium, arsenic, chromium, and nickel. The yearly mean concentration of benzo(a)pyrene was 9.32 ng/m super(3), with high levels even found at the rural sites, due to a plethora of brick kilns. At the city and industrial sites, the major source of higher-molecular-weight PAH species was vehicles burning leaded fuels. The minerals identified by X-ray diffraction were basically in line with those found at other urban locations.