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Your Environment. Your Health.

Higher Manganese Levels Associated with Lower IQ in Children

Erin Haynes, Ph.D.
University of Cincinnati
R01ES016531, R21ES021106, P30ES06096

A new NIEHS-funded study revealed that children in East Liverpool, Ohio who had higher levels of manganese (Mn) in their hair had lower IQ scores. East Liverpool, the site of a hazardous waste incinerator and a Mn processor, has exceeded U.S. Environmental Protection Agency reference levels for Mn in the air for more than a decade.

Researchers analyzed blood and hair samples of 106 children, 7 to 9 years of age, from East Liverpool and surrounding communities, from March 2013 to June 2014. Participants and their caregivers received cognitive assessments and questionnaires at the time the samples were taken.

By adjusting for other factors, including lead exposure, the researchers found that increased Mn in hair samples was significantly associated with declines in IQ. Researchers did not see the same association with blood Mn levels, which they noted likely reflected previous findings that suggested that hair Mn might be a better reflection of long-term exposure, whereas Mn levels in blood might best represent current exposure.

This study was conducted in response to a request from the East Liverpool School District superintendent because of concerns about declining academic performance potentially related to high Mn concentrations in the area. According to the authors, community partners were essential to both the conception and implementation of the study.

Citation: Haynes EN, Sucharew H, Hilbert TJ, Kuhnell P, Spencer A, Newman NC, Burns R, Wright R, Parsons PJ, Dietrich KN. 2017. Impact of air manganese on child neurodevelopment in East Liverpool, Ohio. Neurotoxicology; doi: 10.1016/j.neuro.2017.09.001 [Online 6 Sept. 2017]