Prenatal Exposure to Industrial Chemicals and Pesticides and Effects on Neurodevelopment

Approximately 80 000 synthetic chemicals are in commercial use worldwide. Each year, hundreds of new chemicals are added to this list. For the majority of these materials, there are not even basic data available regarding developmental or pediatric toxicity. The developing human brain, particularly during the prenatal period, has been shown to be highly sensitive to toxic chemical insults. As was first demonstrated with lead, and then with polychlorinated biphenyls (PCBs) and methyl mercury, even low-level exposures in early life to neurotoxic chemicals - exposures at levels well below those associated with clinical signs of toxicity - can interfere with brain development and produce long-lasting detrimental effects on cognition and behavior. A new generation of chemicals termed endocrine disruptors - among them phthalates, bisphenol A, and certain pesticides - which can alter the availability and actions of endogenous hormones, is suspected of being capable of interfering with early brain development. It is hypothesized that certain chemical exposures in early life, perhaps acting in concert with genetic and social factors, may impact the prevalence of developmental disabilities across the population, and account in part for the apparent population-wide increases in neurodevelopmental abnormalities observed over recent years. In this article, the relevant literature concerning prenatal exposure to some of the more widespread industrial pollutants, their mechanisms of action, and their associations with adverse neurodevelopmental outcomes is reviewed.