PM2.5 in Mumbai in 2017 was six times the safe limit: SAFAR study
WHO’s annual safe limit for PM2.5 is 10 µg/m3 and the annual limit for India is 40µg/m3.Updated: May 07, 2018 10:05 IST
The level of particulate matter (PM) 2.5 – a pollutant that can enter the lungs and cause health ailments – in the city in 2017 was 60µg/m3, six times the World Health Organization’s (WHO) permissible limit, according to a three-city pollution study.
WHO’s annual safe limit for PM2.5 is 10 µg/m3 and the annual limit for India is 40µg/m3.
As part of the study, System of Air Quality Weather Forecasting and Research (SAFAR) studied the pollution levels across 30 stations in Mumbai, Delhi and Ahmedabad (10 stations in each city). Season-wise PM2.5 levels showed Mumbai recorded 82µg/m3 during winter, 68µg/m3 in summer and 30µg/m3 in monsoon in 2017.
The study found average PM2.5 level in Delhi was 99µg/m3, and Ahmedabad was 71 µg/m3. The level of PM2.5 in Delhi and Ahmedabad was much higher than Mumbai through all three seasons.
Last week, WHO ranked Mumbai the fourth most polluted on the list of 10 mega cities in the world with more than 14 million habitants from 2010 and 2016. Mumbai stood fourth after Delhi, Cairo, and Dhaka. WHO data found PM2.5 levels in Mumbai was 68µg/m3 in 2015 and 64µg/m3 in 2016. “Our data for 2017 indicates that PM2.5 levels in Mumbai were much lower than what was observed by WHO in 2015 and 2016. While there is pollution during winter and there is no denying that, it is doubtful that the city can be ranked the fourth most polluted globally during summer and monsoon. Here, the sea breeze disperses pollutants much faster than in Delhi, Ahmedabad and all other land-locked cities,” said Gufran Beig, project director, SAFAR. “WHO should consult independent stakeholders and government agencies before releasing such results that are indicative of few stations as it might create panic among citizens.”
Other researchers said instead of questioning the authenticity of the global data, citizens and the government need to accept that metropolitan cities are facing a pollution crisis. “Mumbai should not make northern India the benchmark for comparison. The benchmark should always be the standard, and despite being a coastal city, Mumbai is exceeding even the Indian standard according WHO and SAFAR data,” said Anumita Roy Choudhury, executive director, Centre for Science and Environment, Delhi. “This means there is very high exposure to these small pollutants and there is need for a strong action plan to bring back clean air.”
HT had reported in February this year that a source analysis of PM2.5 by SAFAR for 2016 had revealed that emission from industries (26.43%), power (9.39%), transport (15.93%) and the residential sector (27.05%) accounts for more than 80% of particulate pollution in Mumbai. “The main contributors to PM2.5 are thermal and coal-based units located in Navi Mumbai, Thane, Dombivli, Kalyan and surrounding areas of Mumbai. Slum areas in the city, responsible for biofuel burning, emit a cocktail of pollutants from kerosene, wood burning, cow dung and biomass burning,” said Beig. “It is vital to keep both these factors in check while ensuring clean fuel for vehicles by complying with Bharat Stage V and VI standards soon.”
In 2017, the Maharashtra Pollution Control Board (MPCB), based on the National Clean Air Programme initiated by the Centre, started the process of formulating an action plan to mitigate air pollution for multiple cities in the state. They will set up 11 new air monitoring stations in Mumbai along with existing 18 stations (10 from SAFAR, 3 from MPCB and 5 stations in Chembur Industrial area), making it the largest air quality monitoring network in India after Delhi.
“Within the next two to three months, the draft action plan put together with help from stakeholders such as Brihanmumbai Municipal Corporation, National Environmental Engineering Research Institute and the Indian Institute of Technology, Bombay (IIT-B) will be ready. Suggestions and objections will be invited then. This plan will help identify micro-pollution sources for PM1 and PM2.5,” said a senior MPCB official.
He said six other real-time air quality monitoring stations will be inaugurated in the Mumbai Metropolitan Region, with one each in Thane, Navi Mumbai, Dombivli, and Vasai.