Preliminary results from an ongoing federal air quality study show manganese levels ranging between 0.02 and 0.33 micrograms per cubic meter of air sampled between April and November of 2007.
The highest level was 0.28 micrograms above the 0.05 mcg/cubic meter reference level set by the U.S. Environmental Protection Agency, but it’s not a large difference, according to Stephanie Davis, epidemiologist with the federal Agency for Toxic Substances and Disease Registry.
“We’re not drawing any firm conclusions from these results at this time,” she said. “There’s a high degree of variation in the data we’ve collected, and we want to collect at least 12 months of data before making any analysis.
“We’re seeing levels that seem to be above the U.S. EPA reference level, but that level is very conservative, and it is not regulatory,” Davis said. “And we really don’t know if the EPA reference level is too protective, or if it’s not protective enough at this time. There’s a lot we just don’t know about the effect on humans.”
Although trace amounts of the substance are needed in the human body, excessive manganese exposure is thought to have an effect on the human nervous system. Health studies have been limited, but Davis has said that some studies have shown older people may have mood and movement problems associated with exposure.
The information released by ATSDR last week showed results of eight month’s worth of air sampling from four monitoring stations located in the Marietta, Boaz and Vienna areas in proximity to the Eramet Marietta plant along Ohio 7 south.
Eramet is the only manganese refinery in the United States.
The highest manganese sample, 0.33 mcg/cubic meter, was collected by a monitoring device at Neale Elementary School in Vienna on May 30, 2007.
The lowest sample taken at the Neale school was 0.047 collected on Oct. 27.
The lowest reading overall, 0.024 mcg/cu. meter, was collected June 29 from a station at the Washington County Educational Service Center, 115 Victory Place, in the Harmar area of Marietta.
Davis said after 12 months worth of data is collected from the monitoring sites, probably by the end of April this year, ATSDR officials will use the information to help determine if a human health study is warranted to analyze the effects of manganese on the local population.
A health study could provide a better definition of what the EPA reference levels, if any, should be in relation to protecting workers and the surrounding community, Davis said.
Dick Wittberg, executive director of the Mid-Ohio Valley Regional Health Department, who has researched manganese for more than a decade, said the results of the ATSDR study so far are troubling.
“I’m very concerned about these levels. In my mind these readings are high,” he said. “And the higher readings in the Vienna area (at Neale Elementary) are definitely a concern as it’s a more heavily populated area and there are a lot of families in that area.”
Wittberg is participating in a joint effort with the University of Cincinnati and Washington State Community College to obtain federal funding for an estimated $2 million study of area children to see if they are affected by exposure to manganese.
He noted this study would be separate from any human health study resulting from the ATSDR investigation.
Wittberg said he expects to learn if the federal funding will be awarded for the study within the next two weeks.
“We’ve looked at manganese levels up and down the valley, and I’ve never been able to convince myself that the substance is safe,” he said. “And I’m not out to shut Eramet down. I think they have gotten much better at filtering their emissions. But I think they have the ability to control the emissions more tightly.”
Joy Frank-Collins, public relations and communications representative for Eramet, said Monday that she had not seen the latest ATSDR monitoring results.
“But we appreciate that the ATSDR is taking the extra time to look at the results for a full year before coming to any conclusion,” she said. “We’re following the research and will be interested to see their results.
“Eramet is always interested in any studies that may impact us and the community,” Frank-Collins added.
Davis said sometime after the final air quality collections are made at the end of April, a public meeting would be scheduled to share the information, possibly in late summer or early fall.
