Farm fires contributed to up to 32 per cent of the tiny PM 2.5 lung-damaging pollutants in Delhi's air - the highest in the past two years during the period of mid-October to early November, according to data from the Ministry of Earth Science. PM 2.5 are fine particles that are 2.5 microns or less in diameter and can travel deep into the respiratory tract, reaching the lungs and entering the bloodstream. "I have difficulty in breathing. I get asthmatic attacks. I think school should become online," said Arman Walia, 13, suffering from asthma due to air pollution.
