You may think the air is bad in Los Angeles, but researchers say it's worse in India and Bangladesh. A new study released at the World Economic Forum in Davos, Switzerland, found that India had the worst air pollution in the world, followed by Bangladesh and Nepal. The United States ties with a slew of other countries for first place, including Japan and Argentina. Other interesting tidbits from the rankings include:

-- Ecuador was the most improved country when it came to air quality; Russia and Iraq had the biggest drops in the effects of their air on human health.

-- The worst countries for air pollution are clustered in South Asia and Central Africa.

You can delve deeper into the study and explore an interactive map of the findings using the Yale University Environmental Performance Index.