Neurobehavioral impairment in children occupationally exposed to mixed organic solvents

BackgroundOur previous work has demonstrated adverse effects on neuropsychological and neurobehavioral function in solvent-exposed working children compared to non-exposed working and school children. The aim of this paper was to examine the dose–response relationships between neurobehavioral function and solvent exposure in children.MethodsWe tested 120 male children aged 10–17 years (100 working solvent-exposed, 10 working children, 10 school children). Neurotoxic effects were assessed through a questionnaire and a selection of neurobehavioral tests. Workplace exposure to a mixture of solvents was measured using personal passive samplers.ResultsChildren with higher solvent exposure showed significantly higher reporting of neurotoxic symptoms (P = 0.02). Importantly, multiple regression models revealed significant dose–response relationships, with higher cumulative exposure associated with poorer performance on the Choice Reaction Time, Symbol Digit, Continuous Performance, Digit Span and Grooved Pegboard tests.ConclusionsThis study provides the first empirical evidence of a dose–response association between exposure to solvents and neurobehavioral performance in working children. This finding implies that solvent-exposed working children are at high risk of developing neurobehavioral impairments. These impairments are likely to interfere with their capacity to respond quickly and safely to new demands and to learn new information.