Abstract:

Air pollution problem is increasing day by day. In Pakistan, the major air pollution problems are due to high levels of smoke, particulate matter, nitrogen oxides and sulfur oxides mainly in big cities like Lahore, Karachi, Rawalpindi and Peshawar. These high levels of pollutants may be attributed to rapid urbanization and industrialization, increase of vehicles. Besides these, very important factor that affect the air quality of a specific region, is the contribution of transboundary pollution. The northeastern region of Pakistan is witnessing increased winter fog phenomenon since 1997. The problem lasts for 2-3 months (Dec.– Feb.) resulting in increased rates of accidents, damage to crops and human health. The reason is mainly assigned to high sulfur contents in the atmosphere of local as well as of transboundary origin. The northeastern region of Pakistan is found to be under maximum acid deposition and sulfur pollution indicating a strong correlation between fog formation and sulfur pollution.

In this work we have studied effect of transboundary air pollution on air quality of northeastern region of Pakistan using Regional Air Pollution Information and Simulation (RAINS-Asia) Model developed by IIASA. Two scenarios, "Business As Usual (BAU)"and "Maximum Feasible Reduction (MAXF)," have been studied for the year 2000 to assess the acid deposition and SO2 concentration in the region. Experimental results of air quality of northeastern Pakistan region are obtained from Pak EPA (2000). The model predictions are compared with the observed data. It was found that there is 8-10 % contribution from known sources of other countries in sulfur pollution of northeastern region of Pakistan. Future scenarios for the years 2010, 2020 and 2030 have been developed using RAINS-Asia model. The high values of SO2 concentration suggest a more extensive investigation of chemistry of atmosphere and transport processes.