Report: Dust from steel manufacturing byproduct mixed with road gravel poses risks to rural children's health

In addition to the dust issue, residents say slag causes more
"washboarding" of roads. (Photo by Jean Forbes via DMR)

Dust from a waste product often mixed with gravel on roads in Iowa—and many other rural areas—could harm children's health, according to a newly published report by an Iowa Department of Public Health state toxicologist. "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," Donnelle Eller reports for the Des Moines Register. 

In the report, author Stuart Schmitz wrote that children ages three and under who live and play near slag gravel roads only a few days out of the year are exposed to 124 times more manganese than is considered safe. Children from ages 4 to 18 who are around slag gravel roads about once every five days are exposed to about 5 times what's considered safe. Adults face a little risk from slag dust too: those who work near such gravel all day, almost every day of the year, would be exposed to levels almost twice as much as is considered safe. The report also says slag dust could also hurt the health of nearby cattle and contaminate the soil, Eller reports.

Children exposed to too much manganese could experience learning disabilities and behavior problems, and people in general could experience mild neurological issues like confusion and coordination problems that end after exposure to manganese is halted, Eller reports. Schmitz wrote, "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."

States, counties, homeowners and businesses supplement gravel with slag since it is much cheaper. Not all slag has hazardous levels of manganese; Schmitz determined in 2008 that slag used in Washington County, Iowa, was safe to use, but said Muscatine County uses different processes with different levels of metals, Eller reports.

Chemist Edward Askew, a Muscatine chemist who leads a group lobbying the county to stop using slag, obtained a report from SSAB Americas, which operates a nearby steel mill and sells slag, that lists the amount of metals in the slag. But Askew worries that the report didn't include tests for some of the most hazardous metals such as cadmium, arsenic or mercury, Eller reports.

In addition to the potential health issues from slag, some Iowa residents complain that slag in gravel roads wears down their tires more quickly, puncture their tires, bounce up and break vehicle windows, and can make driving unsafe in other ways, Eller reports: "Residents say slag quickly leads to gravel roads 'wash-boarding,' or bumps across the road that can send vehicles skidding."