From 511CC:

“511 Contra Costa is proud to announce the release of its very first iPhone app – iSmog!

iSmog displays air quality information for the San Francisco Bay Area. With just a tap of the screen, users will see an easy-to-understand map of environmental quality in the Bay Area’s five air basins, built using data provided by the Bay Area Air Quality Management District (BAAQMD). With this information, commuters can make more informed choices about environmentally friendly transportation options, and members of sensitive groups will be better able to stay abreast of information that can be, literally, life-or-death.

Push notification alerts users with allergies or other environmental sensitivities when the air contains unhealthy levels of contaminants including ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and two sizes of particulate matter, all precursors of ozone. Notifications can be customized by level of sensitivity and by geographic area.”