Higher cancer rates not due to dioxin, study says

A June report by the Utah Department of Health confirmed the result of a cancer study the Davis County Health Department undertook in 2001: Higher rates of certain cancers were due to statistical variation, and there was no link to dioxin exposure.

The Utah Department of Health's study used a slightly different methodology and had a broader scope, checking 30 years of data instead of 10, but came back with the same answer as well as confirmation that none of the cancers associated with dioxin were found to be elevated, said Davis County Health Department director Lewis Garrett.

Dioxin, a known carcinogen, is produced at the Wasatch Integrated Waste Management District's Energy Recovery Facility, a garbage incinerator that uses heat to produce steam and electricity.

The facility came under fire in the late 1990s for excessive dioxin and carbon monoxide emissions. The district installed $7 million pollution-controlling "scrubbers" in 2001, reducing the facility's total emissions by 47 percent or 317.7 tons between 2000 and 2002.

In 2001, after residents in South Weber discovered an abnormally high incidence of brain cancer, the Davis County Health Department undertook a study to see what caused it.

After the study was completed, Garrett said, his department could come up with no plausible biological theory for the higher rates, which occurred in a three-year period.

Following the three-year period, the brain-cancer rates dropped and no elevated rate has recurred.

"Our conclusion was most likely statistical variation," Garrett said Tuesday. "To put it simply, that means sometimes the rate is going to be higher and sometimes lower."

Garrett said the Davis department's study didn't find higher rates of leukemia and Non-Hodgkin's lymphoma — cancers normally associated with dioxin.

The state study, completed this year, found the same results.

"The blip was apparent in their study, too," Garrett said.

According to the study, there were only two cancers (brain and lung/bronchus) that were statistically significantly elevated during the study period.

"There is no evidence in the scientific literature linking human exposure to (dioxin) and the development of brain cancer," the study states.

And as for the lung-bronchus cancer rates, which were found in Layton, those were attributed to statistical variation, as well, because the development of such cancers were inconsistent with any exposure to dioxin from the incinerator.

The Utah Department of Health's Environmental Epidemiology Program plans to follow up the study when more data are available.

The study can be found online at health.utah.gov/epi/enviroepi and click on the "Layton Health Consultation" link.

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E-mail: jdougherty@desnews.com