Lack of association between cancer incidence and residence near petrochemical industry in the San Francisco Bay area.

Estimated age-adjusted incidence rates for cancer during 1971--77 among Kaiser Foundation Health Plan (KFHP) members living in a portion of the San Francisco Bay area (SFBA) characterized by a heavy concentration of petroleum and chemical industries were compared to estimated rates among KFHP members in the remainder of the SFBA. One hundred fifty-four comparisons were done for 41 selected cancer sites. The number of significant differences did not appear inconsistent with what might be expected by chance alone; furthermore, in most of these instances the so-called exposed area showed the lower rate. These findings provided some assurance that place of residence near petrochemical industries is not associated with increased cancer risk.