Smoke from burning forests and grasslands kills on average 339,000 people a year worldwide, an international research team said Sunday in the first systematic global health study of air pollution from wildfires.
Every year, accidental and deliberate wildfires burn an area that, taken together, is larger than India. The dense plumes of fine particles and compounds released in the complex chemistry of combustion typically stay aloft for weeks and can travel hundreds of miles downwind. Smoke from fires in Central Siberia during 2003, for example, caused air pollution in the US.

Read more:
http://www.foxnews.com/us/2012/02/20/report-smoke-from-wildfires-kills-over-300000-per-year-worldwide/

This must be more deadly than all weather events put together.