Clearing the air on air quality
While it is a truism that Indian cities suffer from extremely high levels of air pollutant concentrations, but to target industrial hubs alone, and holding them responsible for the poor ambient quality of air without any strong evidence, as is being done by activists across the political spectrum and state governments, is not only patently unfair but misleading too.-
While it is a truism that Indian cities suffer from extremely high levels of air pollutant concentrations, but to target industrial hubs alone, and holding them responsible for the poor ambient quality of air without any strong evidence, as is being done by activists across the political spectrum and state governments, is not only patently unfair but misleading too.
In fact, a recent report by three eminent scientists on the adverse impact on air quality because of Industrial emissions, has cleared many of the long-held misgivings. R.L. Verma of the Asian Institute of Technology, Bangkok, Thailand, J.S. Kamyotra, freelance consultant, New Delhi and Dr Balram Ambade, National Institute of Technology, Jamshedpur, Jharkhand, studied the air quality and Air Quality Index (AQI) of Thoothukudi (former Tuticorin), and compared it with other industrial clusters of Tamil Nadu and the four major metros on three different parameters.
It compared the status of ambient air quality in Thoothukudi on concentration levels of key air pollutants -- particulate matters (PM10, and PM2.5), sulphur dioxide (SO2), nitrogen oxide (NO2,) and the Air Quality Index (AQI) from January 2015 to December 2020 with Delhi, Mumbai, Kolkata, and Chennai and Manali, Cuddalore, and Coimbatore, industrial clusters of Tamil Nadu.
The study found the concentration levels of PM10, PM2.5, and NO2 in Thoothukudi were not only comparable to those observed in Mumbai, Kolkata, and Chennai because these cities have a costal environment but were comparable to those observed at Manali, Cuddalore, and Coimbatore too for the years 2015 and 2020.
Only Delhi was an outlier with double the concentration level of pollutants. For the authors of the report, it only proved the point that local meteorology plays an important role in the ambient concentration levels of air pollutants other than emissions. Even the AQI of Thoothukudi like other metros (except Delhi) and industrial hubs reported less than 100, which signifies good quality air.
Similarly, on the concentration level of air pollutants during the operation of Sterlite Copper in 2017 and 2018, and after the closure of the plant in 2018 and 2019 found no significant change in the concentration levels of SO2 in the ambient air quality at Thoothukudi before and after a year of the closure of the copper plant. Even during its operation, the SO2 levels were in the range of 13-15 ug/m3, well below the 24 hour ambient air quality standard of 80 ug/m3 and was comparable to other industrial clusters.
Strangely enough, other sources of air pollution like vehicle exhausts from burning of diesel, petrol and compressed natural gas, gases from thermal power plants, small scale industries including brick kilns, suspended dust on the roads due to vehicle forest fires etc have been glossed over or not given their due importance.
For instance, the past two decades have seen a seven-fold increase in the number of passenger cars on India's roads leading to significant increases in urban air pollution levels and associated health problems. "In terms of air pollution, road transportation was responsible for more than 40 per cent of total nitrous oxide (NOX) emission of 3.3 million tons and around 7 per cent combustion-related PM2.5 emissions in 2019," argues an International Energy Agency report titled 'Air Quality and Climate Policy Integration in India: Frameworks to deliver co-benefits'.
The strong economic growth witnessed between 2010 and 2019 too had a role in the worsening air quality because the country's total energy consumption increased by one-third in that period. "Given that India's energy sector is fossil fuel intensive, CO2 emissions increased by nearly 50 per cent over the same period, despite noted improvements to CO2-intensity and GDP energy-intensity," says the IEA study.
The heavy reliance on traditional biomass for cooking and heating in many of the poorer households in India, which have little to no access to clean cooking, results in high levels of harmful PM2.5 pollution and also contributes to a much lesser degree to NOX and SO2 emissions.
NOX emissions stem primarily from oil combustion in the transport sector and thermal power plants, which account for approximately 40 per cent and 25 per cent of India's NOX emissions, respectively. Half of India's SO2 emissions arise from thermal power plants and industrial activities add another third. Even agricultural activities produce two key pollutants namely ammonia (NH3) and nitrous oxide (N20) emissions.
Source : IANS