Part 2: Health Effects Institute researcher Pallavi Pant speaks about air pollution and its health impact
A recent global study by the United States-based Health Effects Institute (HEI) identified Delhi as the highest polluted city globally, followed by Kolkata among the most populous 103 cities out of 7,200. Here is the second part of Jayanta Basu speaking to HEI scientist Pallavi Pant, who was pivotal in preparing the Air Quality and Health in Cities: A State Of Global Air Report.
Jayanta Basu: There has been a lot of controversy around the report in some of the cities analysed in the report. Institutions that monitor pollution levels in the cities like Kolkata have raised questions over the sources of the data and its calculations.
Pallavi Pant: It was tough to get ground-based air quality monitoring data from all the 7,200 plus cities.
Fortunately, over the last few years, satellite technology has improved and expanded, so now we can use those at a very fine scale. India’s air quality monitoring stations have also increased significantly in the last 10 years.
We combined satellite data, ground monitoring data and chemical transport models to produce the report’s estimates. We followed a consistent methodology in all the cities globally for our calculations.
Premiere institutes like IIT-Delhi also use satellite data to identify pollution hotspots.
JB: There are allegations that only the United States’ consulate data was used in cities like Kolkata.
PP: No, we didn’t just use consulate data, we used other available monitoring data as well. Central Pollution Control Board website has a lot of data, especially on suspended particulate matter (PM) 2.5 and other key pollutants.
One of our major ideas behind the report was to make all information and dynamic data available in public space because we know that the city and state governments ultimately need to take action.
Read more: Step towards transparency: Rajasthan pollution control board shares emissions data online
JB: Do you think we should have a regional air pollution combat policy or some kind of institutional structure to combat air pollution in South Asia?
PP: This is an excellent idea, considering the common good for the region and the fact that every South Asian country has similar air pollution-related problems. If we combine resources for a regional action plan, it is possible we can save both money and time.
The solutions can be similar and we can chase them together. UN agencies are also thinking about pushing regional air pollution agreements of cooperative nature and we have to see where that effort goes.
But generally, scientists across South Asia have to come together and think of what evidence can be generated collectively. Hopefully, administrators and policymakers will follow suit with joint action plans that would benefit all.
JB: There seems to be a disparity between the air pollution data and mortality in different regions. For example, cities with high PM 2.5 pollution seem to have far less mortality.
PP: The relationship between air pollution levels and health impacts cannot be linear as several factors are involved. Particularly, demographic variances like age play a role in community vulnerability to air pollution.
JB: The report attributes mortality to specific categories to air pollution. How did you link ischemic heart attack with PM 2.5 when there are so many other factors?
PP: We followed a very structured method to assess the air pollution impact on the health of the exposed population. In the case of air pollution, we have very strong and consistent evidence across the globe to link six diseases with air pollution exposure.
We may include more diseases as being strongly linked with air pollution in future within that list, such as Type-II diabetes, infant health, neurodegenerative diseases and likewise.
But clear scientific evidence is available now to attribute a specific percentage of mortality for particular diseases to exposure to critical air pollutants like PM 2.5.
Read more: Climate change-driven wildfires, heatwaves to worsen air quality & levy additional ‘climate penalty’
JB: How do you see the marriage of problems like air pollution and climate change? Are combined strategies a possibility to handle this dual menace?
PP: We do need to think about combined strategies to address air pollution and climate change. One example is heat waves that have been happening in different parts of the world in the last few months during summer.
We consistently find that every place with heat waves also has higher ozone levels, as the levels are generally higher in the summer. I think this is a very direct link in front of us.
If we want to reduce the impact on people’s health, we will connect air pollution and climate change actions.
(This is the part 2 of the interview with Pant, click here to read the first part)
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