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Sex Differences in Neuropsychological Function and Manganese in Air, Blood, Hair, and Toenails in Ohio Residents
Gocheva, Y., Y. Kim, D. Lobdell, AND R. Bowler. Sex Differences in Neuropsychological Function and Manganese in Air, Blood, Hair, and Toenails in Ohio Residents. 28th Int Neurotoxicology Conf: Manganese Healt Effec on Neurodevelopment & Neurodegenerative Dis, New York, NY, September 25 - 28, 2016.
This study addresses research questions under Sustainable and Healthy Communities (18.104.22.168 lessons learned, best practices and stakeholder feedback from community and tribal participative case studies). This Regional Applied Research Effort project is a joint effort between Region 5 and ORD Scientists that examined neurotoxic effects of Mn within two communities: a high level air exposure community (East Liverpool, Ohio) and a mid to low range air exposure community (Marietta, Ohio). This work is important in that either positive results (differences between the high level air Mn exposure community and comparison communities) or negative results (little or no differences among communities) inform the issue of potential health effects of residential airborne Mn exposure, a recognized gap in Mn health effects literature. Both outcomes can also help inform the need for greater airborne Mn control.
Background: This study compares manganese (Mn) in air, blood, hair, and toenails and neuropsychological function of 110 women and 76 men, environmentally exposed to Mn in air (Mn-air) in two Ohio towns from a ferromanganese smelter and a soil Mn-packaging facility.Method: Biomarkers [blood (B), hair (H) and toenails (T)-H and T available only in one town] were analyzed for Mn and serum ferritin. Mn-air was estimated using AERMOD. Sex-stratified analyses examined age, ferritin, residential distance from the source, Mn-air, years residency and dietary Mn as biomarker predictors. Biomarker associations with neuropsychological tests of motor function, executive function, verbal and visuospatial learning and memory were examined. Results: Mn-air was similar for women: Mean (M) ± standard deviation=0.20 μg/m3±0.22 and men: M=0.26 μg/m3±0.34, p=0.25. Mn biomarkers did not differ by sex. Predictors of Mn/B for women (M=10.37 µg/L±3.91) included age (β=-0.26, p=0.02) and ferritin (β=-0.28, p=0.03). For men, Mn/B (M=9.36 µg/L±2.58) predictors included distance from the Mn source (β=-0.26, p=0.06). No significant predictors were obtained for Mn/T in either sex. Women’s Mn/H was associated with ferritin (β=0.28, p=0.02), years residency (β=-0.36, p=0.01). In men, the Mn/H-age association approached significance (β=-0.51, p=0.06). Women’s Mn/B was associated with Grooved Pegboard (dominant: β=-0.30, p=0.01; non-dominant: β=-0.96, p=0.03) and delayed NAB Daily Living Memory [DLM (β=1.02, p=0.02). For men, Mn/B was associated with non-dominant Fingertapping (β=1.45, p=0.03) and delayed DLM (β=0.24, p=0.03) was obtained. Associations with Mn/H were only observed in women for sematic clustering (β=-0.27, p=0.06) and List Learning Short Delay (β=-0.38, p=0.01). Mn/T was associated with neuropsychological scores only in men: clustering (β=-0.43, p=0.02), List Learning Short Delay (β=-0.52, p=0.01), Memory Index (β=-0.39, p=0.05).Conclusion: Women and men exposed to similar levels of Mn-air had similar neuropsychological function but different patterns of biomarker associations. More studies with varying Mn exposures are needed to examine sex differences.This abstract does not represent EPA policy.