Levels of suspended particulate matter (SPM) — small-sized pollutants in the air that can get lodged in the lungs — were dangerously above safe limits across Mumbai between July 2015 and March 2016, an environment assessment report found.
The Brihanmumbai Municipal Corporation (BMC)’s Environment Status Report (ESR) 2015-16 said pollution levels measured at nine locations where air quality is monitored and forecasted by the System of Air Quality Weather Forecasting and Research (SAFAR), were above permissible limit for PM10 — particles smaller than 10 microns — and the more hazardous PM2.5.
PM stands for Particulate Matter. PM2.5 are fine particles of diametre 2.5 micrometers or less. These particles are invisible to a naked eye and can only be seen by using an electron microscope. They are found in the air, including dust, dirt, soot, smoke, and liquid droplets.
Similarly, PM10 are coarse dust particles of diameter ranging between 2.5 micrometers to 10 micrometers.
According to the report, Andheri and Bandra-Kurla-Complex (BKC) were the most polluted locations in the city, with levels more than twice the safe limit for PM10 and PM2.5. While some locations like Colaba and Worli recorded levels closer to safe limits owing to their proximity to the sea, other locations such as Chembur, Bhandup, Mazgaon and Malad also recorded high pollution levels.
“The average annual levels of PM10 were found to be in the range of 88–148 μg/m3, maximum at Andheri. Average annual levels of PM2.5 were in the range of 56-104 μg/m3, with the highest at BKC and Andheri,” read the report, adding that annual safe limits for PM10 is 60μg/m3 and PM2.5 is 40μg/m3.
Civic officials said dust pollution from vehicles was one of the main concerns the city is facing. “Areas such as BKC and Andheri have major traffic junctions where vehicular pollution gets trapped closed to the surface and owing to the presence of concrete structures, the pollutants do not get dispersed easily,” said a senior civic official.
“High pollution at Mazgaon was observed owing to the dockyard that has several diesel ships combined with pollutants emitted from vehicles on the Eastern Express Highway. However, for Andheri, we observed a mix of pollution from construction, choked traffic junctions and open burning at various areas,” said the official said.
According to the ESR report, there has been seen a 9% increase in total number of vehicles plying on city streets between 2015 (25,46,749 vehicles) and 2016 (27,86,512) with maximum number of two-wheelers (16,00,998 in 2016) that increased by 9.5% and increase in four-wheelers (8,84,882) by 7.3% since 2015.
Other causes were attributed to construction and open burning in the past year that led to air quality recorded by SAFAR falling under ‘moderate’ to ‘poor’ categories at these locations, exceeding national ambient air quality standards.
“Pollution from particulate matter mainly cause by dust and vehicular pollution leads to irritation and increased aggravation for patients suffering from asthma, bronchitis, chronic obstructive pulmonary disease (COPD) and other chronic respiratory problems. Symptoms of breathlessness is even felt by healthy people because of this pollutant,” said Dr Nilkanth Awad, head of department, pulmonary medicine, Sion hospital. “Particulate pollution combined with other pollutants in Mumbai’s air can even lead to cardiac problems for people suffering from respiratory ailments.”
Officials from the state environment department said high ambient air quality levels need to be curtailed through public awareness about the issue and the need for implementing measures such as car pools and cycling to reduce vehicular emissions.
“Additionally, the state pollution control board is purchasing 10 pollution monitoring systems that will help identify and mitigate pollution problems at specific traffic junctions and residential areas. The tender has already been floated and in a month we will be in a position to procure these instruments,” said Satish Gavai, principal secretary, state environment department.
During July 2015 to March 2016 air quality levels for PM10 and PM2.5 are measured at various monitoring sites by ‘SAFAR-Mumbai’.
PM 2.5 has a diameter not larger than 2.5 micrometers and smaller than 10 micrometers and “fine particles,” with diameters that are 2.5 micrometers and smaller.
PM 10 - These solid and liquid particles are less than 10 microns in diameter. PM10 particles can stay in the air for minutes or hours while PM2.5 particles can stay in the air for days or weeks.
|Site||Suspended particulate matter (PM10) (in microgrammes per cubic metre (μg/m3)||Small particulate matter (PM2.5) (in μg/m3)|
|Bandra Kurla Complex||135||104|
|Safe standards as per Central Pollution Control Board||60||40|
(Source: BMC Environment Status Report (ESR) 2015-16)
The SAFAR data was made available to the public in June last year, after nine automatic air quality monitoring stations were setup in Mumbai and one in Navi Mumbai that provided a real-time air quality index (AQI). However, this is the first time the day was accumulated over a span of nine months and correlated as a part of BMC’s ESR report.
ESR highlights other pollution problems in Mumbai
•The Brihanmumbai Municipal Corporation’s unreleased Environment Status Report (ESR) 2015-16 has pointed out the falling problems related to pollution in Mumbai –
•Levels of suspended particulate matter was above permissible limits at all pollution monitoring stations of the civic body – Worli, Khar, Bhandup, Andheri and Marvali
•Levels of ammonia (NH3) were almost three times the permissible limits at BMC’s Marvali station (representative of Chembur and surrounding areas)
•Levels of nitrogen oxides (NOx) were above safe limits at all locations (Khar, Bhandup, Andheri and Marvali) except Worli
•Pollution at traffic junctions such as Andheri and Wadala increased three times from last years levels for PM2.5 and PM10