The weather office’s forecast of a weak monsoon this year could lead to a spike in air pollution in many Indian cities, including Delhi and its suburbs, for a second straight year, says a state weather analysis institute.
Pollution in Delhi jumped about 20% last year to the highest levels since 2010 partly because of patchy rains during the July-September monsoon season, adding to the woes of residents already choking from the city’s toxic air because of noxious fumes belched out by vehicles.
“The wash down impact on emissions was low because of lesser rainfall. The extension of dry weather contributed to higher pollution levels,” said Gufran Beig of the Pune-based Indian Institute of Tropical Meteorology (IITM), which monitors air quality at 10 locations in Delhi.
The institute has been monitoring air pollution since 2010 under a programme called System for Air Quality Weather Forecasting and Research (SAFAR) and found a link between a weak monsoon and a rise in air pollution levels.
It found that the overall level of minute particles called particulate matter (PM) 2.5 leapt to 115 Gegagrams (Gg) in 2014 from 94.26 Gg in 2010. During the monsoon months last year the level was around 100 Gg, almost one-third more than the previous year’s annual average during the three months.
The phenomenon is not limited to Delhi, which is one of the world’s most polluted cities where doctors say residents develop smokers’ lungs by the age of 35 without ever having smoked because of the city’s toxic air.
A Central Pollution Control Board official said many cities in west and north-west India such as Jaipur, Amritsar, Ludhiana, Agra and Chandigarh have also witnessed higher air pollution levels because of less rainfall during the monsoon months.
But the impact of air pollution on monsoon rains has not been conclusively established. “It is an area of research and debate. But a poor monsoon resulting in a spike in air pollution can happen in many cities, including Delhi," the CPCB official said.
Other weather scientists have also found a co-relation between monsoon rains and pollution levels.
A 2011 University of Edinburgh study on monsoon data for over 50 years showed higher air pollution-linked human activity had led to drier monsoon, affecting the lives of billions of people in South Asia.