Neurotoxicity of chronic low-dose exposure to organic solvents: a skeptical review

The health effects of long-term, low-level exposure to organic solvents have been studied for many years. While the volume of literature is great, definitive conclusions regarding chronic neurobehavioral effects of environmental exposure are premature. Methodological shortcomings in research preclude confidence in studies allegedly supporting a causal link between chronic low-dose solvent exposure and lasting neurobehavioral deficits. In this article, the shortcomings reviewed include selection bias in recruitment of research subjects, overreliance on subjective recall in determining levels and duration of exposure, between-study variability in kinds of solvents examined, variability in tests selected to assess neurobehavioral functioning, and diversity in reported findings. The implications of these for characterizing the state of organic solvent research are discussed.