The Rodeo-Chediski Fire Complex began as a small blaze in a remote region of east-central Arizona and within days erupted into the largest wildfire in Arizona history. Fortunately, no lives were lost. However, from June 18, 2002 to the time of its containment on July 7, 2002, the Rodeo-Chediski fire destroyed over 490 structures and 467,000 acres of ponderosa pine and pinyon-juniper woodland—an estimated 500 million to 1.3 billion board feet of timber. Jurisdictions involved included the Fort Apache Indian Reservation, the Apache-Sitgreaves National Forest, the Tonto National Forest, and private lands adjacent to Highway 260, from the Town of Forest Lakes east to the City of Show Low. Virtually all of the acres burned were in Navajo County, with some damage in the contiguous counties of Coconino, Apache, and Gila Counties. This health assessment describes the fire events and summarizes the resulting public health impacts from the fire.

In May 2003, a Scottsdale, Arizona, resident asked the Agency for Toxic Substances and Disease Registry in Atlanta to investigate possible sewer gas exposures in a Scottsdale residential neighborhood. In June 2003, the Agency asked the Arizona Department of Health Services, to conduct an investigation to determine if sewer gas exposures were occurring. Because ambient and indoor air hydrogen sulfide data for the neighborhood were not available, the Arizona Department of Health Services and the resident collaborated in conducting an air monitoring investigation in the neighborhood from June 26, 2003, through July 15, 2003.