Air pollution: Southern India witnesses higher rise in PM2.5 levels than Gangetic Plain in last decade

The Indo-Gangetic Plain, that is the northern Indian states guarded by the Himalayas and other mountainous ranges are often considered to be the most polluted region of the country for being away from the coastline but a recent study has found that the PM 2.5 level has been alarmingly higher in the southern and easter states of India in between 2000 and 2019 than the Gangetic Plain.

The study carried by IIT-Delhi and commissioned by Central Pollution Control Board also found that air pollution in rural India has increased at par with urban India, a concern that is neglected by air pollution policymakers who continue to focus on urban India. For example, the study found that while the national capital witnessed an increase in PM 2.5 level by 10.9 per cent between 2001 and 2005, rural centres had an 11.9 per cent jump in the pollutant level in the same period.

The first-of-its-kind study that relied on satellite data further found that while the increase in PM2.5 levels in less than 1.2 per cent in Gangetic plane during a specific period, it is more than 1.6 per cent in eastern and southern India, reported IE.

Fine particulate matter is a big contributor to air pollution affecting human health, environment and climate and the 20-year averaged pollutant level in India is 57.3 micrograms per cubic meter. The period of 2010 and 1019 had a larger share in pollution than 2000 and 2009. The study also found that 436 Indian cities with more than 1 lakh people exceeded the National Air Quality Standard in 2019.

The study author, Sagnik Dey, however, is hopeful that the pollution levels will come down in rural areas in a few years as more and more people will take up the Ujjwala scheme and shift to LPG connections as household emission is a major factor for increasing pollution levels in villages. The 2020 data is under the process of collating and analysis.

The study also establishes that the poor air quality at urban-rural shift is a problem in regional scale and often not discussed. Apart from Himachal Pradesh, Jammu and Kashmir and north-eastern states like Sikkim, Manipur, Nagaland, Arunachal Pradesh, the PM.25 exceeds the Ambient Air Quality Standard. In the Gangetic Plain and its western arid areas that are home to more than 70 crores people has double the Ambient Air Quality Standard as per WHO guidelines.

The PM2.5 levels increased significantly between 2010 and 2019 in eastern states like West Bengal, Telangana, Odisha and parts of Bihar, UP while a decline was recorded at J&K and parts of Rajasthan. The states that have shown the highest increase in PM2.5 over the last decade are Kerala, Goa, Andhra Pradesh, Maharashtra and Odisha.

The study found that household sources are the biggest contributor to ambient 2.5 in India and successful implementation of Pradhan Mantri Ujjwala Yojana with sustained usage can work on reversing the increasing levels of rural PM2.5.

The study aims at bringing the topic of rural air pollution to focus. According to Dey, as the focus is predominantly on controlling air pollution in Indi-Gangetic Plains, the rising pollutant levels in Southern Indian states and rural centres gets neglected, this can result in Southern India suffering from same problems as northern India in 10 years. Hence, he wants the authorities to start addressing pollution levels in all parts of India with equal emphasis. He also finds spatial mapping of pollution vital for government in designing policies under the National Clean Air Programme in future.