Firing clay in unvented kilns may be a source of exposure to dioxins

Oct 23, 2007

Firing clay in unvented kilns could be a significant source of dioxins in people exposed regularly and over long periods, a new study suggests.

The results came out of follow-up interviews with subjects who participated in the University of Michigan Dioxin Exposure Study, which measured dioxin levels in residents in Midland and the Tittabawassee River flood plain between Midland and Saginaw.

The two-year study, commissioned by Dow Chemical Co., was to determine if elevated dioxin levels in the soil caused elevated levels of dioxins in residents' bodies.

A 35-year ceramicist had by far the highest blood dioxin levels in the study. Though the woman lived on contaminated soil, the contamination fingerprint of her blood was a closer match to the clay rather than the soil, said Dr. Alfred Franzblau, professor in the U-M School of Public Heath and co-principal investigator on the Dioxin Exposure Study. Franzblau said the woman worked with ball clay, which is used in ceramics.

Ceramics clay, sometimes referred to as ball clay, is known to be contaminated with dioxins, and Franzblau said the woman's clay displayed the same pattern of contamination shown previously to exist in ball clay tested in America and Europe. However, there are no previous reports suggesting that dioxins in clay can be a direct source of contamination for humans.

"We think they breathed it in from the volatilization when they fired the kiln," Franzblau said. The woman with the highest levels had three unvented kilns in her basement, so the fumes were released directly inside her home. Two other women who were ceramics enthusiasts also had elevated dioxin levels, though not nearly as high as the first woman. The two other women had kilns in their garages (not inside their homes), and did not use them as often.

Franzblau said it's important not to overreact to the findings, but that more study is needed to determine the impact. There may be thousands of unvented kilns being used in schools, pottery workshops and private homes.

"For most people this is not likely to result in any significant exposure," Franzblau said. "My case was somebody who did this regularly for 30 to 40 years. A child once a week in an art class is in a radically different realm. But there are other people like her and I think there needs to be more research to better characterize the danger."

The Dioxin Exposure Study did not measure health effects of dioxin on the 946 subjects who participated.

"Although we have been able to confirm that clay can be a dominant source of exposure to dioxins, you can't draw conclusions about health effects based on just three cases," said Franzblau, also an associate professor of emergency medicine.

Source: University of Michigan

Explore further: Computer-generated GI patient history deemed higher quality

add to favorites email to friend print save as pdf

Related Stories

Throwing money at data breach may make it worse

33 minutes ago

Information systems researchers at the University of Arkansas, who studied the effect of two compensation strategies used by Target in reaction to a large-scale data breach that affected more than 70 million customers, have ...

How will Google, Apple shake up car insurance industry?

43 minutes ago

Car insurance industry, meet potential disrupters Google and Apple. Currently, nearly all mainstream insurers that offer driver-monitoring programs use relatively expensive devices that plug into a portal under the dashboard. ...

Researchers on expedition to solve 'small island problem'

43 minutes ago

Researchers from the Department of Electronic & Electrical Engineering are starting their new year with an expedition to the island of South Georgia to carry out research into improving weather forecasting. You can follow the team's progress on their blog. ...

Recommended for you

'Tis the season to overeat

8 hours ago

(HealthDay)—Overeating is common during the holidays, but there are strategies that can help you eat in moderation, an expert says.

Don't let burns mar your holidays

9 hours ago

(HealthDay)—The risk of burns from fires and cooking accidents increases during the holidays, so you need to be extra cautious, an expert says.

Irish court mulls rights of dead woman vs. fetus

Dec 24, 2014

A lawyer representing a 17-week-old fetus living inside the clinically dead body of its mother told a Dublin court Wednesday that the unborn child's right to life trumps the woman's right to a dignified death.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.