Several organisations that monitor air quality have expressed doubts in the World Health Organization’s (WHO) pollution report that ranked Mumbai as the fourth most polluted megacity in the world.

COMMERCIAL BREAK
SCROLL TO CONTINUE READING

The WHO report considered particulate matter (PM) pollutants and the rankings were based on pollutants that are PM 2.5 and PM 10 levels. While Mumbai’s PM 2.5 was recorded as 64 micrograms per cubic metre, PM 10 levels were recorded as 104 micrograms per cubic metre.

Particulate matter is the sum of all solid and liquid particles suspended in air many of which are hazardous. This complex mixture includes both organic and inorganic particles, such as dust, pollen, soot, smoke, and liquid droplets.

Experts raise questions

Dr Gufran Beig, the project director, System of Air Quality Weather Forecasting and Research (SAFAR) that records the air quality index (AQI) for Delhi, Mumbai, Pune and Ahmadabad said that he had reservations in the WHO report, sting that the organisation must consult Indian stakeholders before deriving such conclusions.  

He further stated that the WHO report was based on single station data, which in most cases is a traffic junction. He said that the AQI of a city is a combination of different micro-environments and added that the Indian citizen’s threshold limit for PM 2.5 is 40 microgram per cubic metre. The WHO standard is 10 microgram per cubic metre.

“SAFAR has been mapping Mumbai’s AQI for the past three years. Mumbai is not as polluted as stated in the WHO Pollution report. Pollution in Mumbai cannot build up significantly due to the coast and often gets swept away because of oceanic winds. The levels in the city fluctuate between moderate and poor. Only in winter do the levels go to the very poor category,” he stated.

According to SAFAR data, in 2016 the AQI in Mumbai for 330 days ranged between ‘good’ and ‘poor’, while it was ‘very poor’ for 34 days.

Dr Rakesh Kumar, director National Environmental Engineering and Research Institute (NEERI) agreed with Dr Baig, saying that the WHO pollution report was unrealistic. “We need to account for more factors when AQI studies are being carried out for any city in India. For instance, one has to understand that at times dust accounts for up to 50% of pollutants, but not all types of dust are harmful to health. Furthermore, readings cannot be drawn by a single reading at a selected spot,” he added, stressing on a more elaborate study.

A senior Maharashtra Pollution Control Board (MPCB) official further stated that Mumbai and Delhi are very different from each other when you study the AQI. “The WHO report has picked data from a couple of places in the city. If you need to give an overall picture of Mumbai, then you need to record it from all spots in the city,” he said. 

What is Choking Mumbai?

Data obtained from Central Pollution Control Board (CPCB) under a Right To Information (RTI) filed by NGO Praja Foundation in April 2018 stated that the highest average monthly AQI had increased from 170 in January 2016 to 186 January 2017, while the highest average monthly AQI in 2015 was 139 in October 2015.

Beig clarified that there was no doubt that air pollution was increasingly becoming a cause of worry specially in Indian metro cities and even in Mumbai.

A study by SAFAR carried out in 2016 said that one of the major contributors to the PM 2.5pollutant, which is the smaller size pollutant known to cause respiratory illnesses and worsens the condition of those suffering from ailments like asthma and bronchitis in Mumbai, is the burning biofuels by residents.

“It comprises 27% and is the biggest contributor for the poor AQI, particularly in winter. Other contributors are construction dust, industries located on the outskirts of Mumbai, as well as vehicular pollution,” said Beig.

While experts questioned the WHO pollution report, they also cautioned that it should not be ignored, but taken as a warning bell for Mumbai.  They also called for a panel of independent experts to study the present scenario, and monitor the future scenario.