Delhi's complicated air pollution problem

According to the World Health Organization, Delhi is the world's most polluted large city. And it's only going to get worse if something isn't done about it, say some experts in an article in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society.

Contributor Prachi Patel explains that air pollution in Delhi, India's capital, is a mixture of gases and small particulates. The largest source of these contaminants is burning—fires from power plants and landfills, as well as from individuals trying to keep warm and cook food, and the burning of fossil fuels to power vehicles. But pollution also comes from dust kicked up on roads and from construction sites. Getting a handle on real data has been difficult because, as experts say, official numbers can be erroneous, and it's impossible to count all of the small sources, such as fires that residents set.

Solving the pollution problem also is proving difficult. The government is taking steps to improve air quality, but critics maintain that these measures are too small and scattered to be of much help. And although there are some rules and laws on the books that should make things better, enforcement and implementation have been slow. In addition, Delhi often gets caught between national, state and local governments, all of whom point fingers at each other. But there's hope. Educational efforts targeting residents are building awareness, which will likely result in pressure on leaders to do what needs to be done. And modeling shows that if the right steps are taken, Delhi could meet air quality standards.