Researchers from the International Food Policy Research Institute, University of Washington, USA, and Oklahoma State University, USA, have reported the economic losses and associated health risk caused by stubble burning in some parts of north India. 

According to the World Health Organization, the safe limit of PM_2.5 concentration for humans is 25 micrograms/cubic metre. But, the fact that at any given time, the  PM_2.5 levels in Delhi hover between 303.9 and 408.2 -- way above the safe level -- is no news! Newspaper headlines scream on toxic pollution levels and people wearing protective masks has become a common sight.