Wintertime PM2.5 in the Kathmandu Valley and Terai Region of Nepal. MD. ROBIUL ISLAM, Nita Khanal, Khadak Mahata, Siva Praveen Puppala, Narayan Babu Dhital, Michael Giordano, Benjamin Werden, Anobha Gurung, Arnico Panday, Robert J. Yokelson, Peter DeCarlo, Elizabeth Stone, University of Iowa