‘Mumbai needs to handle solid waste well to make air less toxic’Updated: Jan 14, 2020 23:59 IST
With 25 years of experience in studying particulate matter (PM), Professor Mike Bergin from Duke University, in the United States of America, has some idea of the challenges facing the city, which according to the World Health Organisation (WHO), ranked as the fourth most polluted megacity in the world, in 2018. Bergin spoke to Hindustan Times while he was in Mumbai, explaining why Mumbai was more polluted than Beijing and the challenges the city faces towards improving air quality. Bergin has studied the impacts of PM across Greenland, the Himalayan belt, as well as high air pollution areas in the world (including China and India) and in other megacities. His research has helped governments develop policies to address air pollution, especially in China.
Q. Air quality in 2019 was much better than in previous years. Do you think Mumbai has worked towards removing its tag from being the fourth most polluted megacity globally?
A. Mumbai currently has quite unhealthy levels of particulate matter. This is as a result of increased precipitation combined with weather patterns that affect the mixing and transport of pollutants. While the same could be said about Beijing a decade ago, today, severe constraints on pollution sources and effective policies have ensured cleaner air quality. Even going by low numbers recorded in Mumbai in 2019, air pollution is substantially higher than Beijing, and much higher than what was recorded by WHO in 2018.
Q. The Central government has said data linking death to air pollution is inconclusive. Do you agree?
A. There is overwhelming proof and no doubt that air pollution can lead to deaths. There are too many peer-reviewed publications on this. Studies carried out by universities like Harvard, done almost 25 years ago, conclusively proved air pollution led to deaths in America. Anybody who has spent time with the facts wouldn’t believe otherwise. India has a diverse group of talented and wealthy entrepreneurs. I would challenge those folks to come together to make the air and water better and improve health. This can be done in ways that allow them to generate revenue and employ people.
Q. What are the critical source areas (in terms of local sources) Mumbai needs to address urgently?
A. Proper handling of municipal solid waste is one of the primary sources which can reduce the toxicity in Mumbai’s air. We need more waste to energy plants. Restrictions on industries and power generators followed by converting heavy-duty diesel vehicles into cleaner fuels, and regulating localised road dust problems. Emissions from within the air shed, but coming from outside the city, carried to Mumbai when the wind direction changes, leading to sudden spikes in air quality needs to be studied using satellite data.
Q. Mumbai’s air quality monitoring network has 40 monitors and PM is the focus pollutant. Do you think the network is sufficient and should more pollutants be monitored?
A. The current monitoring network in Mumbai is sufficient. Current data needs to be connected with a sensor network combined with satellite mapping to come up with trends. We need to understand personal exposure to air pollution more than just urban background levels. PM is the main pollutant, and once we can tackle it, we can have answers for other pollutants too.