Adverse effects of pollution on mental health: the stress hypothesis

Introduction Environmental contaminants are ubiquitous. Among the most studied environmental contaminants, lead, mercury, polychlorinated biphenyls and pesticides have been found to impact mental health. In particular, exposure to environmental contaminants has been related to executive functions and emotional/ behavioural maladjustment in children, and cognitive variability in elders. We hypothesise that the association between environmental contaminants and mental health, particularly in children and elders, could be explained by a disruption of the stress system. Discussion Environmental contaminants act at very low levels of exposure that are not reflected by high doses. Therefore, public regulation agencies are consistently reducing acceptable blood levels of exposure. For example, clinical management plans for children and elders at risk of toxicity are thus adapted to reflect the novel blood lead action level. Environmental contaminants acting at such low doses were found to be endocrinedisrupting chemicals, and most studies have thus focused on the sexual steroids system. However, the stress system, which produces glucocorticoids, has been overlooked. *Corresponding author Email: pierrich.plusquellec@umontreal.