Abstract

In many developing countries including Bangladesh great urban conurbation’s of extremely high population density have emerged. Uncontrolled emission from motor vehicles and other economic activities to provide services to such urban areas give rise to severe air and other forms of pollution. In the capital city (Dhaka), blackening of the city air and reduced visibility can be observed in the some areas at times even with unaided eyes. Episodes of choking smells and irritating eyes are common. These happen when the capacity of self purification of the local atmosphere through dilution and dispersal is exceeded. The role of airborne particulate matter (APM) commonly referred to of the aerosol is increasingly being recognized to be extremely important. APM effect human health, welfare and the environment from local to global scale.

From the data obtained in the present studies we can make some conclusions which are given below.

• Dhaka has a significant level of air pollution due to particulate matter. During low rainfall period (Nov-Jan), the average suspended particle load for PM10 particles reach as high as 227 ìg/m3 compared WHO advised maximum yearly averaged value for TSP of 60-90 ìg/m3.
• Lead level for PM2.5 particles in Dhaka during LRF period reaches to one of the highest known values in the world. This shows that low level of industrialization does not necessarily translate to low pollution due to uneven distribution of population and industries and lack of emission controls. Immediate action is needed to reduce Pb level in air because of its health implications.
• In general rural air is much cleaner as the suspended particle masses are lower specially in the LRF seasons and in particular rural air has much less Pb in it.