NDCA

Spike in cancers probed

Possible environmental factors sought in Oroville-area cases

By Dorsey Griffith - dgriffith@sacbee.com

Published 12:00 am PST Tuesday, January 8, 2008
Story appeared in METRO section, Page B1

State and Butte County health officials will hunt for a possible environmental culprit in a cancer spike detected near Oroville.

The rare move comes on the heels of an analysis of state cancer data that found 23 cases of pancreatic cancer in 2004 and 2005, twice the number that would be expected for the neighborhood in question.

The decision to probe further in the Oroville area focuses attention on a now-shuttered wood preservation treatment plant, and whether contamination from the site may have caused long-term health problems for area residents.

State public health officer Mark Horton emphasized however that no link has been established between the 23 cases and any past or present environmental hazard in the area.

“We are going to proceed with further investigation to try to determine if there are any variables that may have contributed to this increase in cases,” he said in a telephone interview Monday. “I think there is absolutely no reason for community alarm, because there are many other explanations as to why this may have occurred.”

California health officials get about 100 public inquiries about possible cancer clusters every year, but most are quickly dismissed as “statistically insignificant.” Only one or two yield results that prompt follow-up action, according to a health department spokeswoman.

State and local health officials launched the initial analysis last May. It was spurred by a call to the state from a Butte County resident who had lost a friend to pancreas cancer and knew others who also had been diagnosed with the highly lethal disease.

The caller, who was not named, cited a fire in 1987 at nearby Koppers Industries Inc., a wood treatment facility south of Oroville. The plant was designated a Superfund site in 1983 by the federal Environmental Protection Agency.

An estimated 10,650 people live within a 3-mile radius of the plant, located a quarter-mile south of Oroville’s city limits.

Contamination from the plant was noted as early as 1973, when the pesticide pentachlorophenol (PCP) was discovered in nearby residential wells used for drinking water, according to the EPA.

Environmental officials later determined that the wood treatment operation had contaminated groundwater underneath the 40-acre industrial site and many nearby residential wells. In addition to PCP, chemicals found in the water included benzene, copper, chromium and arsenic.

After the fire, concerns were raised about potentially dangerous exposure to dioxins, highly toxic industrial byproducts known to cause cancer, which were found in high concentrations in the soil. That prompted the state to issue a health advisory warning residents to avoid consuming potentially contaminated food, including home-produced eggs and meat from chickens raised on soil.

Males, people with a history of diabetes, and smokers all are at higher risk for pancreatic cancer. The disease also has been linked to chemical exposures, including for those involved in the pulp and paper industry, state researchers found.

“It’s been a long-standing issue at the site, because some of the wood-treating chemicals are cancer-causing,” said Fred Schauffler, the EPA’s former site manager at Koppers and now a Superfund section chief.

The plant was closed in March 2001. Site cleanup included creating two lined and sealed landfills to contain contaminated soil, and a groundwater treatment system. Nearby residents were provided alternative water supplies until their own wells were deemed free of contamination.

Schauffler said the site continues to undergo inspections every five years to determine whether the remedy “remains protective of human health and the environment.”

In the meantime, a private development company plans to turn the site into an industrial park. The EPA will not remove the site from the Superfund list until the groundwater aquifer is restored, which Schauffler predicted will take several more years.

The state’s Horton said Butte County health officials will track down and conduct detailed surveys of surviving pancreatic cancer patients or their relatives.

State epidemiologists will collect demographic data including patients’ ages, sex, race or ethnicity, health status, smoking history, dietary and physical exercise practices and work history.

Investigators also will learn how long each patient has lived in the Oroville area.

Butte County Health Officer Dr. Mark Lundberg welcomes the investigation.

“A cancer cluster is always scary,” he said. “If we can identify it, we can eliminate it or provide advice to avoid that risk factor. We are very anxious and very motivated to look into it.”

Horton cautioned that investigators may never know the reason for the jump in pancreatic cancer rates in the Oroville area.

He said the two-year trend detected in the analysis is “short-lived,” and could represent a “statistic aberration.” He said cancer case data from 2006 and 2007 are not yet available.

“When these studies are undertaken, despite a thorough investigation,” he said, “we don’t always identify a specific cause.”