What we know and what we do not know about pollution in India
Last week, AIADMK parliamentarian A Navaneethakrishnan demanded shifting of Parliament’s winter session outside Delhi due to high levels of pollution in the national capital.
The demand captures the inadequacy of society’s response to the problem of air pollution. Everybody worries about pollution during winter but disregards it once things improve because of climatic factors. Even Google search data suggests that online searches regarding pollution peak in winter months.
It is a known fact that peninsular India is much better in terms of air quality than the northern parts.
For 11 cities in the north, including Gurgaon, Delhi and Lucknow, the air quality index (AQI) – a measure of pollution – was either ‘poor’, ‘very poor’ or ‘severe’ on 47% days in 2017, Hindustan Times’s analysis of daily PM2.5 data shows. (PM refers to minute pollutants called particulate matter that lodge deep in the lungs.)
In 12 cities lying in the peninsular region – that includes Mumbai, Chennai, Pune, Bengaluru and Hyderabad – the air quality was ‘poor’ or worse on just 4% of the days. On 96% of the days, the air was either ‘good’, ‘moderate’ or ‘satisfactory’.
Not all people living in north India can think of migrating to cleaner places in winter despite the fact that health hazards due to air pollution are too dangerous to ignore.
This underlines the need for putting in place a holistic strategy to deal with air pollution. The first prerequisite of formulating any such strategy is the availability of detailed data, across time and regions, on pollution. An HT analysis shows there are big gaps on all counts.
The online portal of the Central Pollution Control Board (CPCB) provides air quality data from government-operated air quality monitoring stations across the country.
According to data on the CPCB website, there are 94 such monitoring stations across 53 cities. But not all of them function regularly. In 2017, at least 54 stations functioned for more than nine months. But 26 stations had data for less than three months. Still, this is an improvement. In 2015, just 19 stations functioned for more than nine months.
Defunct stations are not a problem in just smaller cities. For instance, in Kolkata, no PM2.5 data for 2017 is available on the CPCB website.
Most cities neither have enough stations nor do they cover all pollutants. For example, only 23 cities had at least one monitoring station providing PM2.5 data for more than 80% of the days.
Of this, 17 had just one station. Delhi had the most: nine active monitoring stations, as per the CPCB portal. Other organisations, such as SAFAR, have their own monitors but are not part of the CPCB portal.
The lack of stations is problematic: a single station doesn’t capture the spatial distribution of pollution in the city.
“This (single stations) is inadequate as it generates a statistically insignificant sample to represent the city or the range of sources contributing to the air pollution problem in the city,” says the website of Urban Emissions (India), an independent research group on air pollution.
Based on a thumb rule proposed by CPCB and the district-level urban and rural population (as per 2011 census), Urban Emissions estimate “the need for 4,000 continuous monitoring stations (2,800 urban and 1,200 rural) to spatially, temporally, and statistically represent the PM2.5 pollution in the urban and the rural areas of India.”
Sarath Guttikunda, the director of Urban Emissions, estimates that the government would need to spend Rs 7,500 crore every year for the next ten years. Here’s hoping that the New Year would see parliament demanding more funds for improving pollution monitoring than seeking greener pastures during Delhi’s toxic winter.