Introduction The ongoing development in the third world countries has led to understanding the repercussions of environmental hazards that are prevailing in such countries. Similar is the case with Pakistan, which with the help of a number of international organizations has started addressing the aforementioned issue. On the basis of this review it is possible to assess the status and to determine the trends in air pollution sources, emissions, concentrations, and exposures in four metropolitan cities (Karachi, Lahore, Rawalpindi, and Peshawar) of Pakistan. Environmental pollution in these cities is analyzed in terms of – Particulate Matter (PM) and derived particle mass concentrations. – Heavy metal concentrations.

Metropolitan cities of Pakistan PM Karachi193μg m-3 Lahore200 μg m-3 Peshawar219 μg m-3 Rawalpindi185 μg m-3 The particulate matter concentration is major cities of Pakistan such as Such high levels of pm concentrations can result in a number of respiratory and nervous diseases. The origins of this high concentration pm can vary from anthropogenic to natural. Natural sources include sea salt particles and dust of minerals while anthropogenic sources include road dust, construction, burning of biomass and emissions from industries and vehicles.

PM2.5/PM10 ratio In mentioned cities, the pm 2.5/pm10 ratio was 0.4 in Karachi, 0.45 in Lahore, 0.31 in Rawalpindi and 0.30 in Peshawar. The astronomic ratios as opposed to the standards set by WHO leaves a lot to be desired in terms of environmental conditions improvement. The metropolitan cities have been plagued by environmental hazards due to vehicular emissions, industrial emissions, construction and dust from roads. The industrial area in these cities has been close to the townships which has caused the direct diffusion of hazardous chemicals into the atmosphere in which people breath.

Heavy Metal Concentration

Government Regulations The government has been taking drastic steps for the relocation of industrial areas to places which would have minimal effect on the quality of life. similarly, the environmental authorities have been striving to implement stringent regulations regarding vehicular emissions and the construction of roads, which would go a long way towards improving environmental condition of metropolitan cities in Pakistan. The government of Pakistan has initiated a clean air programme and has also set up monitoring stations for air quality. Although the desired standards in terms of air quality have not been established as yet, the government is heading in the right direction towards achieving the standards set by WHO. The government is also allowing a number of international organizations for conducting scientific studies, which would help the authorities understand the measures that need to be taken for the improvement of air quality.

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