An international group of researchers, including NIEHS scientists and grantees, recommended targeted actions to reduce India’s national health burden from outdoor and household air pollution.
In a paper published in the October issue of Environment International, the collaborators called for a comprehensive nationwide air pollution monitoring network, training, ramping up data collection, and other actions to fill major knowledge gaps in how poor air quality affects health across India.

The authors are part of the Indo-U.S. Communities of Researchers, a group that formed after Srikanth (Sri) Nadadur, Ph.D., served as a U.S. Embassy Science Fellow in New Delhi. Nadadur oversees NIEHS research grants on air pollution and human health.
India’s air is worsening
According to the World Health Organization (WHO), 13 of the world's 20 cities with the highest annual levels of air pollution are in India, with New Delhi — the capital city — topping the list of Indian cities. The paper documents that the problem will continue to worsen due to regulatory challenges, a growing economy, and the rise of industrialization across the country.
The report on Global Burden of Disease estimates that air pollution contributes to the premature deaths of two million people every year. This distinction makes air quality near the top of the list — if not at the top — of all known health risks in the country. Air pollution ranks higher than smoking, high blood pressure, child and maternal malnutrition, and risk factors for diabetes.
Complex factors call for increased action
In India, untangling the link between poor air quality and poor health is not as simple as it may appear. “Air pollution sources can vary greatly across India, meaning that data collected in one area may not apply to another,” said Nadadur. “In order to create policy to help fix this problem, you need the data to support it.”
In urban areas, for example, most emissions come from vehicles and industry, whereas in rural areas, much of the pollution stems from biomass burning for cooking and keeping warm.
In the area known as the Indo-Gangetic Plain, brick kilns and coal burning are to blame. The country’s eastern states host massive coal mines and power plants. These sources combine to make the eastern states the most polluted places in India.
To further complicate matters, because most monitoring and data collection are done in urban centers, it is difficult for decision makers to understand population exposures in a way that includes rural residents.

One size does not fit all
“Being in New Delhi during a period of high air pollution levels brought home to me the severity of these issues for India,” said Gwen Collman, Ph.D., director of the NIEHS Division of Extramural Research and Training and co-author on the paper.
“Air pollution monitoring and health data collected across the spectrum is critical,” said Nadadur. “To identify best practices, we need the data from both places. There isn’t a one-size-fits-all way around this.”
Nadadur and colleagues at Indian and U.S. government agencies, alongside academic institutions in both countries, organized a conference in November of 2016 in New Delhi to think long and hard about this problem, and to identify ways to address it.

Research priorities include citizen science
For example, a recommended short-term goal is to analyze health data, like hospital visits or pulmonary infections, collected during a past smog episode in the National Capital area. A long-term goal would be to study the efficiency of different room filtration systems in areas where indoor air pollution is highest.
The authors also identified exposure research and communication priorities, such as effective ways to inform the public about air pollution data, and new citizen science programs to better document exposures.
Finally, the group identified other means, such as training the next generation of scientists in India, to continue these initiatives. Such training is known as building research capacity.
“We hope that our efforts help to develop research capacity and collaborations to support policymakers as they make strides to improve air quality, and respiratory and cardiovascular health in India,” said Collman.
Citation: Gordon T, Balakrishnan K, Dey S, Rajagopalan S, Thornburg J, Thurston G, Agrawal A, Collman G, Guleria R, Limaye S, Salvi S, Kilaru V, Nadadur S. 2018. Air pollution health research priorities for India: Perspectives of the Indo-U.S. Communities of Researchers. Environ Int 119:100-108.
(Sheena Scruggs, Ph.D., is the Digital Outreach Coordinator in the NIEHS Office of Communications and Public Liaison.)