Routes of exposure

Human exposure to chemical releases can occur through air, food and drink, water or direct dermal contact with the chemical. Chemical fires and releases into the air due to failures of production, storage containers, road and rail tankers or pipelines are the most common incidents involving human exposure. This book therefore focuses on these as the most important public health risks.

Incidents involving drinking-water supplies have not been very important worldwide because most chemical contaminants are readily detectable by smell or taste, and thus people usually avoid drinking water containing them. Foodborne incidents, on the other hand, have given rise to major outbreaks of chemical-induced disease, such as toxic oil syndrome (see Annex) and organic mercury poisoning. Epidemiologists need to be aware that apparently inexplicable disease outbreaks may be the first evidence of a toxic release into the community.