The age-old practice of sweeping roads with brooms significantly adds to morning haze in the Capital, reducing visibility that motorists struggle with almost everyday during winters, says a new study on air pollution.
Close to one lakh Municipal Corporation of Delhi workers sweep the streets of the Capital in the morning hours, contributing 25 per cent to the respirable suspended particulate matter (RSPM) in the air during that time, said Professor Arun Attri at Jawaharlal Nehru University’s School of Environmental Sciences.
The presence of RSPM in excess of 50g in one cubic metre of air increases the risk of cardiopulmonary diseases, stressed respiratory physiology, mortality and morbidity.
This winter, its level has hovered up to three times the 50g mark in Delhi’s air.
The study turns on its head the long-held belief that the main sources for morning smog were vehicle emission and industrial pollution.
The study, to be published in the next issue of global journal Atmospheric Environment, found a sudden jump in RSPM levels in the Capital’s air at the time when the roads are manually cleaned in the morning.
In cold winter mornings, the fine pollution particles remain suspended in the air we breathe for a longer time, causing low visibility and fuelling asthma attacks. “It is only when the sun filters through the thick morning smog and it becomes little warmer that the RSPM level goes down,” Attri said.