State health officials investigating the cause of a cluster of childhood cancers in southeastern Kern County have moved their focus away from industrial sites and into the community. "We are really more preoccupied with routes of exposure," state epidemiologist Martha Harnly said. "What are the levels (of carcinogens) in communities where children live?" Officials have tested soil in Mojave and Rosamond for levels of dioxin, a man-made toxic chemical linked to birth defects and cancer. Results will be released at a series of meetings Wednesday and Thursday.