Air pollutants in Indian cities are rising rapidly, as per scientists. The study is based on observations made using instruments on satellites that scan the global skies continuously.
Researchers used the data gathered by space-bound instruments to examine the trends in air pollutants from 2005 to 2018, timed to coincide with rapid development in India.
Lack of air pollution policies
The study was led by the University of Birmingham and UCL, and also features an international team from Belgium, India, Jamaica, and the UK. Their findings were published in the journal Atmospheric Chemistry and Physics. The study notes that PM2.5 particles and nitrogen oxide (NO2), both hazardous to health, are on the rise in Delhi and Kanpur.
Delhi is a metropolitan city, while Kanpur was ranked the most polluted city in the world by WHO in 2018. The researchers believe the surge in PM2.5 particles is due to increased vehicle ownership, industrialization, and lack of air pollution policies.
Formaldehyde on the rise
Researchers also found that air pollutant formaldehyde is on the rise in Delhi and Kanpur. Formaldehyde is a marker for emissions of volatile organic compounds. A large chunk of it comes from vehicle emissions in the country.
“We were surprised to see the increase in formaldehyde above Delhi, Kanpur and London—a clue that emissions of other volatile organic compounds may be changing, potentially driven by economic development and changes in domestic behaviour. Our results emphasise the need to monitor our air for the unexpected, and the importance of ongoing enforcement of measures for cleaner air,” said Karn Vohra, study lead author and Ph.D. student at the University of Birmingham.
“There is more than a decade of freely available observations from instruments in space to monitor and assess air quality in cities throughout the world. Greater use of these in the UK, India, and beyond is paramount to successful air quality policies”, stated Dr. Eloise Marais, Earth observation expert at UCL and conceptual lead of the study.
