Gravel road cover may be a health risk in Iowa

Friday, January 11, 2019

Dust from waste material used to cover gravel roads in Iowa could be hurting the health of children and adults who are exposed, according to a report from a state toxicologist.

Toddlers and developmentally disabled children would only need to play near the “slag dust” - which include high levels of manganese - for a few days a year to suffer, Iowa Public Health Department toxicologist Stuart Schmitz wrote in his report.

“I would say that any child playing or living very close to areas where slag is deposited could reasonably be expected to experience adverse health impacts,” Schmitz said.

Buena Vista County Engineer Bret Wilkinson said he has already been aware of the concerns, but that slag dust is not being used in the immediate area.

“To my knowledge Buena Vista doesn’t have any of that down. We haven’t been using it since I’ve been here, though I’m not saying it hasn’t been used in the past.”

The material is sometimes used in place of gravel to cut costs, or in asphalt mixes, he said. “I’ve heard of it being a problem. It’s always a concern when you use products when you don’t know for sure what goes into them,” he said.

“I like to know where my products are coming from, and we try to be cognizant of the environment. But I do understand the mindset of trying to find uses for waste products, especially in those areas around a large foundry or some place that might produce a lot of that dust.”

Slag is a byproduct of steel manufacturing, and contains metals at levels that are harmful especially for those up to 18 years old. Children exposed to high levels of manganese could experience learning disabilities and adverse behavioral changes, according to a U.S. Department of Health report.

Slag dust is also dangerous for adults who are exposed to levels nearly twice what’s considered safe, though adults would have to work “an entire workday, most days of the year,” to be harmed, the report said.

People exposed to high manganese levels can experience mild neurological damage that could lead to confusion, balance issues and coordination problems, Schmitz said. The effects would be temporary and likely wear off once a person is no longer exposed.

Muscatine County officials say they have only learned this week of the health concerns involving slag, and one supervisor there plans to introduce a motion immediately to ban use of the material there.

Slag is cheaper than gravel and has saved the county an estimated $1 million, according to officials. The county had previously relied on two decade-old state reports to show that the material was safe.

Edward Askew, a chemist who is a member of the local opposition group, is concerned that the health issues could be worse than the report illustrates. He urged counties to continue researching the type of slag used to learn if other hazardous materials are present, such as cadmium, arsenic or mercury.

• With local and AP reports

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