One might assume the executive is worse off---after all, Delhi has the world's worst air. Yet a village woman who cooks over a dung-fuelledchulha for several hours a day could be more exposed to hazardous pollutants than a Delhi office worker.

This distinction between ambient pollution levels and individual exposure lies at the heart of a new report from a Union health ministry committee that---correcting a historical focus on urban air pollution---highlights the importance of tackling pollution from the burning of dung and wood in village chulhas across India.

The report, made available on the health ministry's website this week, calls for an integrated approach to air pollution that focuses on "reducing exposures not emissions".

"All pollution is bad but, with the intention of eventually taking care of all of it, where do you focus your efforts first?" said AmbujSagar, committee co-chair and Vipula and Mahesh Chaturvedi Professor of Policy Studies at the Indian Institute of Technology in Delhi. "From a health standpoint, you prioritize reduction in areas and sources that most affect people directly."

Top of the committee's list: reducing household air pollution from cooking with biomass because the proximity to humans, especially women and children, makes stove smoke most harmful--- next only to cigarette smoking, in fact.

Household cooking is "probably the largest single source of exposure in the country, although only one of many contributors to ambient air pollution," the report said. Most rural households in India—an estimated 780 million people---continue to rely on wood, dung and other biomass for cooking, while a good percentage of urban households also use non-LPG stoves.

Next on the committee's priority list: pollution from vehicles, garbage burning, and diesel generator sets---all micro or local sources of pollution. Then comes road and construction dust, followed by brick kilns, local industries, and then power plants and other large industries.

Conventionally, environmental policy has focused on large-scale sources of ambient pollution. Road dust, for example, is thought to be a bigger source of pollution in Delhi than vehicles.

"The standard practice of ranking pollution sources on the basis of their contribution to ambient emissions ... may be creating distortions in their apparent relative importance from the health standpoint, although perhaps adequate for other purposes - visibility, for example," the report says.

"Evaluation by exposure will not only re-order the ranking of major outdoor emission sources but will reveal an entirely different landscape of sources; those that may significantly affect exposure without appreciably affecting ambient concentration."

Much more data and studies are needed to understand pollution patterns, Sagar said. Monitoring of air pollution is still largely confined to cities, the report notes, and monitors tend to be on rooftops "where people hardly ever are".

And in some ways, tackling the cooking or driving habits of millions of people can be as or more complicated as tackling single-point sources like factories, Sagar admitted.

To reduce household pollution, the report advocates expanding power and gas coverage as well as innovating cleaner stoves and running public health campaigns. Tackling air pollution should be part of the Swachh Bharat campaign, the committee said, and clean cooking stoves given as much importance as toilets.

Emissions from cooking with biomass also contribute a quarter of ambient PM2.5 levels in the country, the report notes. "Exposure to air pollution, be it ambient or household, is part of a continuum, and reinforces the need for an integrated approach towards mitigation and harm reduction."

Kirk Smith, a leading air pollution expert and the professor of global environment health at the University of California at Berkeley, described committee's focus on exposure management as well as on looking at indoor and outdoor air pollution together, as "pioneering".

"The new approach is facilitated by new technologies," he said, "We have ways to monitor individual pollution exposure that we didn't have before."

This is also the first time any country's health ministry is taking up air pollution, he noted, as the issue is usually handled by environment ministries.