Report details health effects of exposure to common road material slag

Slag is used to cheaply supplement gravel on roads like this one (flickr). 

Julia Poska | January 11, 2019

A report from the Iowa Department of Public Health has stirred up concern in Muscatine County and around the state this week over the health effects of steel slag, a cheap waste product from steel manufacturing that’s used to supplement gravel on rural roads.

Muscatine County has used slag in county roads for over 5 years, and many private homes and businesses use the material as well. Residents have complained to the county about bits of metal in the roads and health concerns about slag dust for years, but this report was the first official indication of risk. It found that children up to 18 years old are exposed to potentially dangerous levels of metals like manganese when playing near slag-supplemented roads.

The Muscatine County Board of Supervisors will vote Monday on whether to stop using slag in county roads, and will likely formulate a plan to remove existing slag. A local slag opposition group will collect samples from households before then to determine current levels of dangerous metals.

Many people are upset that the state and county allowed slag to be used in roads to begin with, and are unhappy with Muscatine County’s initial response to the report.

“I suppose that all county boards and city councils have problems, but our county leaders just seem to care about making themselves look good and it makes all the people who they represent look like idiots,” one Muscatine woman write in a letter to the Des Moines Register, who wrote about the issue in depth earlier this week.

The news has alarmed people in other Iowa counties as well. Engineers in Marion, Warren, Winnebago and other counties have since conducted tests for dangerous slag on their own roads.


Iowa State University researchers find new potential in miscanthus

Nick Fetty | July 29, 2014
A miscanthus field in Japan. Photo via Wikipedia
A miscanthus field in Japan.
Photo via Wikipedia

Researchers at Iowa State University have discovered that Iowa’s soil may help miscanthus – a perennial tall grass – to produce higher yields of biomass than once thought.

Iowa State Agronomists think that this Asian plant will not only provide a source for biomass energy but will also help to protect the environment. The study focused specifically on miscanthus x giganteus, “a sterile hybrid of the plant that cannot reproduce from seed and spreads slowly.”

The study found that this hybrid plant has a low mortality rate even in Iowa’s harsh winters. Agronomists also found that crop yields in the second year were similar to yields in the third year, which is when the plant generally hits its peak production. The full report was published in June in the journal Industrial Crops and Products and additional information about biomass production from miscanthus is also available through the ISU Department of Agronomy.

The University of Iowa has utilized the plant as part of its Biomass Fuel Project which aims to achieve 40 percent renewable energy by 2020. In 2013, 16 acres of miscanthus were planted in Muscatine County and earlier this year an additional 15 acres were planted just south of Iowa City.