india

Updated: Sep 27, 2019 02:58 IST

India has one air quality monitoring station for every 7 million people while China has over eight times that number, according to top environmental scientists who believe that the scale of the air pollution problem affecting Indians may be more severe than understood due to lack of adequate monitoring.

India will need at least 1,600 more monitoring stations to make up for the shortfall, according to a projection by a team made up of scientists from Indian Institute of Technology (IIT) Delhi, IIT Kanpur and Indian pollution research group UrbanEmissions.info, and Canadian academicians.

“What we cannot monitor we cannot maintain — be it health, economy or air quality. At present the number of air quality monitoring stations is inadequate in India and therefore it is very difficult to get a proper picture,” said SN Tripathi, head of the civil engineering department at IIT-Kanpur and one of the scientists involved in the report.

Much of north India, especially the Indo-Gangetic plains, reels under hazardous levels of pollution for most of the winter months. The air pollution in the national capital of Delhi, where the crisis triggered closure of schools and advisories to avoid the outdoors in recent years, has been linked to shorter life spans by several studies.

The condition in other cities may also be alarming.

“Only about 5% of our census towns are monitored now. Alternative methods such as satellite monitoring and low-cost monitoring can help us do better mapping of pollution and exposure to inform action. But cities will still need some reference regulatory monitors to assess trend and compliance with clean air targets,” said Anumita Roy Chowdhury, executive director (research and advocacy), of Centre for Science and Environment.

At present, India has a little less than 1,000 monitoring stations across 339 cities. The Union government has drawn up a National Clean Air Programme (NCAP), setting 2024 as the year by which pollution levels must be cut by 20-30% in 102 cities that were found to be highly polluted in 2017. But the scientists indicated that the lack of proper data would militate against achieving this goal.

A new automated air quality monitoring system will require approximately ₹1.8 crore to set up and run for seven years, according to an official of the Central Pollution Control Board (CPCB), who asked not to be named.

“We compared the density of India’s monitoring network with that of comparator countries and find large differences. To address these gaps... India will require 1,600-4,000 monitors (1.2 to 3 monitors per million people),” said Sagnik Dey, an associate professor of IIT Delhi’s Centre for Atmospheric Sciences and the coordinator of Centre of Excellence for Research on Clean Air (CERCA).

According to the analysis, the density of air quality monitoring stations in India (between 2010 and 2016) was around 0.14 monitors per million people. Most European countries have 2-3 monitors per million people; China, which also faces the challenge of bad air and high population density, has 1.2; Brazil has 1.8 monitors per million people; and USA has around 3.4 monitors per million people, said the report.

The report has been published in Atmospheric Environment, a peer-reviewed scientific journal of the Elsevier Group.

In order to make the expansion financially easier, the experts suggested using a mix of high-end and low-cost sensors, satellite monitoring and modelling to attain the clearer picture it needs of the issue.

China, for instance, has deployed 10,000 low-cost sensors and London uses at least 100 of them. “Same goes with California where a hybrid system of monitoring is being deployed to have a better understanding of the air quality and the pollution sources,” said Tripathi.

The senior CPCB official quoted above said that the agency has proposed that there is one monitor deployed for every million people, but suggested that simply increasing numbers may not be the answer. “In most developed countries like the USA and in Europe, authorities first try to get an idea of vulnerable pollution. Monitoring stations are then deployed accordingly,” this person said.