The Link Between Air Pollution and COVID-19 Infection: Maharashtra Study
Maharashtra recorded the second-highest annual PM2.5 emission load in India while also recording the highest Covid-19 deaths indicating a link between air pollution & Covid-19’.
A first of its kind Pan-India study has highlighted- Mumbai and Pune among hotspots in the country, where high air pollution from the transport and industrial sectors are having a visible relationship with a higher number of Covid-19 cases and casualties.
The study titled - Establishing a link between fine particulate matter (PM2.5) zones and COVID -19 over India based on anthropogenic emission sources and air quality data - provided the first evidence about how people living in highly polluted areas are vulnerable to Covid-19 infection.
Air has suspended particulate matter (PM) of different sizes. Many of these are a complex mixture of dust, pollen, soot, and smoke and they are hazardous. Of this, PM 2.5 is the smaller kind, with a diameter, not more than 2.5 micrometers (fine particles). PM2.5 is considered to have a very significant health impact as it can stay in the air for days or weeks, and is small enough to invade the lung airways.
In the study, Covid-19 cases were observed between March 2020 to November 2020, while the national PM 2.5 emissions load was estimated from the base year 2019.
For the study authors divided specific areas into different hotspot zones across India. From16 cities across 36 states, Mumbai and Pune were the two cities picked from Maharashtra (falling under zone 6) for the study.
Authors calculated the load of total fine particle (PM 2.5) pollutants from various sources at a high-resolution (10km X 10km) grid across the country over a year's time. They also developed new emission data which was analyzed along with reported positive Covid 19 cases and casualties. Further, the study is supported by Air Quality Data collected over 16 stations across the country.
“Our findings suggest a significant correlation between the district-level air pollution data and Covid-19 cases. We found that regions with huge amounts of fossil fuel such as petrol, diesel, and coal, etc. combustion in transport and industrial activities, also experiences a lot more Covid-19 cases,” said Dr. Saroj Kumar Sahu, Lead Author of the study, adding that the health impacts of air pollution and Covid-19 also had similar linkages. “PM2.5 are small-sized particles affecting the upper respiratory system, and Covid-19 too has shown similar health impacts.”
Maharashtra recorded the second-highest emission load- 828.3 Gigagram per year (Gg/Yr) of PM2.5- in India (Uttar Pradesh was the highest) based on the National Emission Inventory developed by us, said Dr. Sahu.
During the same period-till November 5, 2020- Maharashtra recorded 17.19 lakh Covid-19 cases, which was the highest in the country. “However it is important to note that in terms of PM2.5 emission per person, Maharashtra is ahead of Uttar Pradesh,” said Dr. Sahu.
Among the 16 cities captured in the study, Mumbai and Pune recorded the third and fourth highest ‘bad air quality days’ respectively. For Mumbai, out of a total of 165 bad air quality days. Similarly, Pune saw a total of 117 bad air quality days. Parallelly, Mumbai recorded 2.64 lakh Covid-19 cases and 10,445 deaths during this period, which was the highest in the country while Pune recorded 3.38 lakh Covid-19 cases and 7,060 deaths.
Dr. Sahu highlighted that the study revealed that while Maharashtra was one of the leading industrialized and developed states with a high quantity of PM2.5 emissions, district-level emission estimation showed Mumbai was experiencing more pollution than Pune.
Apart from Mumbai and Pune, the study also presented two other hotspots - Nagpur and Chandrapur - in Maharashtra that witnessed high pollution as well as higher Covid-19 cases and casualties. “Though these cities were not directly part of our study, both locations have the presence of industrial units and power plants that aggravate air pollution making them hotspots in Maharashtra,” said Dr. Sahu.
The study identified that Maharashtra has emerged as a dominating polluting state where the road transport sector plays an important role followed by industrial, thermal power plants and biomass burning among others.
“What is worrying is that there is evidence that the Coronavirus sticks to fine particles like PM2.5 allowing them to move from one part to another by making the airborne transmission of Covid-19 more effective. Through our analysis, it has become clear that rising pollution load is becoming more of a catalyst to aggravate the Covid-19 cases,” said Dr. Sahu, adding that polluted hotspots are also triggering long-term effects and more studies are needed to understand this.
Dr. Gufran Beig, Senior Scientist & Founder Project Director, System of Air Quality Weather Forecasting and Research (SAFAR) and co-author of the paper said that at hotspots within Maharashtra exposure to daily air pollution can make a person's lungs weak. “When human-induced emissions are added combined with the double impact of the Covid-19 virus, the damage to lungs will be much faster and worsen health conditions,” Beig added.