London: A analysis conducted in the United Kingdom and published in the journal Atmospheric Chemistry and Physics discovered that unseen air contaminants such as small particles- PM2.5 and nitrogen dioxide (NO2), both of which are harmful to health, are increasing in Indian cities.
Observations from instruments on satellites that search the global sky every day, according to scientists,
Kanpur and Delhi are the top two cities in India where air pollution is quickly expanding.
Researchers used a long record of data collected by space-based instruments to predict developments in a variety of air contaminants from 2005 to 2018, which coincided with well-established air quality policies in the United Kingdom and rapid growth in India.
The research was conducted by the Universities of Birmingham and UCL, and it involved a multinational team of contributors from Belgium, India, Jamaica, and the United Kingdom. Delhi is a rapidly expanding megacity, and Kanpur was named the world’s most filthy city by the WHO in 2018. The researchers hypothesised that rising levels of PM2.5 and NO2 in India were due to increased vehicle ownership.
To date, air quality policies have had only a small impact due to industrialization.
This coincides with developments in the UK cities of London and Birmingham, which display small but continuing decreases in PM2.5 and NOx, owing to the effectiveness of policies targeting sources of these contaminants.
In addition, they discovered spikes in the air pollutant formaldehyde in Delhi, Kanpur, and London.
Formaldehyde is a symbol for volatile organic compound emissions, which have a significant contribution from automotive emissions in India and a growing contribution from personal care and cleaning goods and a variety of other household sources in the UK.
Karn Vohra, lead author of the thesis and a PhD student at the University of Birmingham, commented:
“We decided to show how satellite observations can be used to detect city-wide air quality in the UK, where ground-based measurements are plentiful, and in India, where they are not.” In cities with insufficient surface monitoring capacities, our solution would be able to provide valuable knowledge about air quality patterns.
This is important since the World Health Organization reports that urban air pollution kills 4.2 million people per year.
“Study co-author Professor William Bloss of the University of Birmingham said, “We were shocked to see the spike in formaldehyde above Delhi, Kanpur, and London –
a sign that emissions of other volatile organic compounds are changing, perhaps as a result of economic growth and improvements in domestic behaviour Our findings highlight the urgency of continuously monitoring our environment for the unexpected, as well as the importance of enforcing cleaner-air policies.” –
“More than a decade of free measurements from space sensors have been made available to track and measure air quality in cities around the world. Greater use of these in the UK, India, and elsewhere is critical to the effectiveness of air quality policies “, according to Dr. Eloise Marais, a UCL Earth observation specialist and the study’s conceptual lead.