Sources identification of ammonium in PM during monsoon season in Dhaka, Bangladesh.

Ammonia (NH) is taken up by fine particulate matter (PM), and there are concerns about its impact on the environment and health. The source of NH, which was thought to be of agricultural sources, has recently been suspected to be non-agricultural sources in urban areas. Here, we collected PM during the monsoon season in Dhaka, Bangladesh, the most polluted city in the world, and analyzed the δN-NH in PM.