Low-level hydrocarbon solvent exposure and neurobehavioural effects

Studies of workers exposed to hydrocarbon solvents are reviewed in order to address the question, 'Does long-term human exposure to hydrocarbon solven ts at concentrations around occupational exposure limits result in clinical ly important neurobehavioural effects?' Studies selected evaluated exposure -response (E-R) trends with some control of potential confounders. Tests of neurobehavioural performance were classified into specific functional cate gories, within those of cognitive, psychomotor and sensory functions to inc rease specificity and power to detect patterns of effect. The weight-of-evi dence was evaluated with respect to criteria for determining causality. The temporality criterion was met as latency was adequate for the occurrence o f chronic effects. There were few significant associations, and when presen t, were consistently weak even in the most-exposed workers. Exposure respon se showed no consistent or significant pattern for any tests of functional mortality. The weight of evidence suggests that exposure to hydrocarbon sol vents at current limits does not appear to cause adverse neurobehavioural e ffects.