Professor Hassan’s research investigates groundwater arsenic poisoning, air quality monitoring, climate change, environmental health risk, and environmental justice. Apart from his recent book on “Arsenic in Groundwater: Poisoning and Risk Assessment†from CRC Press, he wrote a significant number of research papers and book chapters. In addition, he has also served as a consultant to several world bodies, including the Asian Development Bank, World Bank, UNICEF, and World Health Organization in the fields of climate change and human health, WASH, air quality monitoring, medical waste management, digital elevation model (DEM), EIA, EMP and so on.