Several of the world’s most polluted cities are found in South Asia which lies in the downstream of the Himalayas. These growing cities produce unacceptably high emissions of health endangering gaseous and particulate matter. Pollution from these regions can very well have an effect on the region due to uniquely positioning of the high mountains and associated atmospheric circulation. Studies on chemical analysis in this region have indicated that aerosols in remote regions originate from a variety of primary emissions (dust, biomass burning, sea spray and anthropogenic sources) and are produced by secondary formation within the atmosphere from precursors both natural and anthropogenic. The transboundary effects of this pollutant have threaten the environment, humans and other living organisms in the HKH region and ICIMOD is implementing two programmes related to the transboundary air pollution namely:
Atmospheric Brown Clouds (ABC) programme deals with study of layer of air pollution containing aerosols such as soot, sulphates, nitrates, fly ash and many other pollutants that absorb as well as scatter incoming solar radiation, leading to regional and global climatic effects and posing risks to human health and food security.
The Malé Declaration on Control and Prevention of Air Pollution and Its Likely Transboundary Effects for South Asia” is a regional programme lunched in 1998 by eight countries of South Asia including Bangladesh, Bhutan, India, Iran, Maldives, Nepal, Pakistan, and Sri Lanka which was also the first inter-governmental environment agreement among the SAARC countries.