Neuropsychological effects of manganese exposure in smelter workers - 2 year follow-up

<p dir="ltr">Previous studies have suggested a causal link between low level occupational exposure tomanganese (Mn) dust and the development of neuropsychological deficits. In the present study employees of a Tasmanian manganese smelter were retested 24 months following initial assessment. A total of 133 employees from the TEMCO Bell Bay Mn smelter undertook a comprehensive battery of neuropsychological tests, with 82 having participated in the original study. For each employee a cumulative exposure index to Mn (inhalable and respirable) and level of Mn exposure for the 24 months between test sessions were calculated. Correlational analysesindicated no significant relationships between level of Mn exposure (24 month) and the differences in test performance between test sessions. Further, consistent with previous results, multiple regression analyses indicated no effect of low level chronic cumulative Mn exposure (inhalable or respirable) on neuropsychological function when covariates (age,education, IQ) were controlled for. The results of this study confirm our previous results indicating that the levels of exposure to Mn in an Australian smelter workforce are not associated with deficits to neuropsychological function.</p>