MUSCATINE, Ia. — Dust from waste material used to cover Muscatine County's gravel roads could be hurting the health of rural area children, a new report says.

Dust from the slag, a byproduct from steel manufacturing, contains metals at levels that are harmful to infants and toddlers but also for kids up to 18 years old, a state toxicologist report says.

"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," Stuart Schmitz, the Iowa Department of Public Health's toxicologist, wrote in a report for residents who oppose the county's slag use.

The report says:

Children 3 and younger are exposed to manganese levels that are 124 times what's considered safe. Those toddlers, along with developmentally disabled children, "would only need to play in that area several days per year" for adverse health impacts.

Kids from 4 to 18 have been exposed to manganese levels that are about five times what's considered safe. They would need to play in the area only "about once every five days" to exceed safety levels.

The slag dust also is dangerous for adults, who are exposed to levels nearly twice what's considered safe. However, adults would have to work "an entire workday, most days of the year," to be harmed.

"You've put this on the roads for the past five years, and you need to discontinue its use," Edward Askew, a chemist who is a member of the local opposition group, told county supervisors this week.

Askew said the problem could be worse than this one report shows. His group hasn't received data on the slag used over five previous years.

If it confirms the material is hazardous, officials should consider removing the existing slag to protect residents — and consider assessing if it has hurt area residents' health, he said.

"It's an environmental disaster," he said before the meeting. State and county officials have "acted like all slag is the same, and it's not."

It's unclear how many Iowa counties might use slag to supplement gravel.

Supervisor Nathan Mather, a Muscatine attorney, said it's also widely used by area homeowners and businesses.

Slag reduces county spending on gravel

Mather said Monday he would ask the board at the next meeting to no longer use slag to supplement gravel on rural county roads.

Slag is about one-fifth the cost of gravel, and using it has saved the county an estimated $1 million in gravel costs, officials have said.

Residents say supervisors have ignored their complaints about scrap metal in the slag flattening tires and bouncing up and breaking vehicle windows.

And they've questioned whether the slag dust could harm residents' health.

Mather said the county has addressed most residents' concerns. But it needed more information about health concerns. The new state report provides that.

"None of us want to expose the public to any kind of health risks," said Mather, the board's chairman.

County leaders have relied on two state reports, both at least a decade old, as proof the slag material was safe.

The county has spent close to $202,000 on slag. It stopped using the waste after 2008 but resumed doing so in 2013.

"We're not environmental scientists. We have to rely on authorities to tell us if something is good or not — if it's suitable for use," Mather said.

"This is the first time anybody in an official capacity has told us there's a concern," he said. "Before, people were just telling us their guesses."

Asked why the board didn't seek an analysis on the slag dust's safety, given residents' concerns, Mather said the county "isn't an environmental agency.

"It's a commonly accepted road material. We're not experts on slag composition," he said.

Children could experience learning disabilities

Slag threatens more than the health of kids and workers, opponents say.

Dust from metals in the slag also could be hurting the health of cattle and other livestock as well as contaminating the area's rich soil.

Askew said he's unsure what to tell parents concerned about their children's exposure.

He points to a U.S. Department of Health report on manganese, which says children exposed to high levels could experience learning disabilities and adverse behavioral changes.

Schmitz, the state toxicologist, said children in that report consumed high levels of manganese through water, which would be greater levels than Muscatine children would be exposed to.

He said people exposed to high manganese levels show mild neurological damage, such as confusion and balance and coordination problems.

Schmitz said the impact would be temporary and remedied once a person was no longer exposed to manganese, which is an essential nutrient that people need in small amounts.

Still, Schmitz recommends parents keep children away from dust exposure.

The county may want to consider removing slag if it's used near schools, he said, adding that the issue requires additional research and discussion.

"If parents notice any changes, they should have their children evaluated," Schmitz said.

'Nobody should be poisoned by a county road'

Askew is unsure if residents have received an entire accounting of the harmful metals contained in this year's slag, based on reports from SSAB Americas, which operates a steel mill near Muscatine.

Askew's group gave Schmitz the company's report that lists the amount of metals contained in the slag.

An independent laboratory assessed the metals from samples collected in May.

SSAB said its slag products have been used for "decades as an environmentally sound and cost-effective road material."

The company said it takes the "health and safety of our employees and communities seriously," and is working to provide "relevant, factual, scientific data to Muscatine County and other government officials regarding" the use of slag.

Askew is worried that SSAB's report didn't include tests for cadmium, arsenic or mercury, some of the most environmentally concerning metals.

"It's sad. The county has said it won't do anything until someone proves" the slag is unsafe, said Daryl Sywassink, a farmer who lives in rural Muscatine County and opposes slag use.

His family's 120-year-old home sits close to the road. But his children are grown and his grandchildren live outside the area.

He worries, though, about the impact on other families. "I'm concerned for the community," Sywassink said. "Nobody should be poisoned by a county road."

Jean Forbes, a former longtime teacher, remembers parents who came to one community meeting.

Living on the corner of two gravel roads, the parents described their children coming inside covered in black dust.

"The buses don't have air-conditioning in the warm months and there's a lot of dust coming through the windows," Forbes said. "It concerns me a lot.

"It makes me mad. It's frustrating that they (supervisors) would rather argue than listen," she said.

State law OKs slag use on roads

State oversight of slag is slim.

The Iowa Department of Natural Resources said state lawmakers exempted steel slag as a solid waste in 2014 as long as it was used in "a controlled manner," such as "Muscatine County officials are using it."

Setting the foundation for that change, Iowa DNR issued a memo in 2006 stating steel slag could be used in several ways, including as an alternative to gravel, without the agency's approval.

It replaced guidance from 2004 that prohibited slag's use on state and county roadsides.

The state agency is getting slag samples from SSAB for laboratory testing, and will send the lab data to Schmitz.

In 2008, Schmitz analyzed slag used in Washington County and determined that it was safe to use.

Iowa DNR said it wants to see if that health consultation is still valid.

Askew said the processes used to create slag in Washington and Muscatine are different — with different levels of metals.

Companies "couldn't sell it, so they basically gave it away," removing it from landfills and their responsibilities for it, he said.

'My tires were getting chewed up'

Sywassink, Doug Hoag and others initially opposed the slag because of its impact on pickups, cars, grain carts and other farm vehicles.

Forbes has collected bolts, nails and other sharp metal pieces on her family's dead-end gravel road.

She has long worried that a flat tire could lead to an accident.

Hoag, a farmer, said his pickup tires wear down quickly, and many residents complain about flat tires and broken windows from metal in slag.

"I sell seed on the side and drive quite a bit of the county. My tires were getting chewed up," he said.

Residents say slag quickly leads to gravel roads "wash-boarding," or bumps across the road that can send vehicles skidding.

The county thinks it's saving money, Hoag said, but officials have "passed ... those costs onto us. We need good county roads."