An update on Erin Brockovich's War on Science:

From 1996 to 2008, 196 cancers were identified among residents of the census tract that includes Hinkley — a slightly lower number than the 224 cancers that would have been expected given its demographic characteristics, said epidemiologist John Morgan, who conducted the California Cancer Registry survey.

The survey did not attempt to explain why any individual in Hinkley contracted cancer, nor did it diminish the importance of Pacific Gas & Electric Co. cleaning up a plume of groundwater with elevated levels of chromium 6, Morgan said.

"In this preliminary assessment we only looked at cancer outcomes, not specific types of cancer," Morgan said. "However, we did look at a dozen cancer types in earlier surveys of the same census tract for the years between 1988 and 1998. Overall, the results of those surveys were almost identical to the new findings, and none of the cancers represented a statistical excess."