Tobacco and cigarette butt consumption in humans and animals.

Discarded cigarette butts may present health risks to human infants and animals because of indiscriminate eating behaviours. Nicotine found in cigarette butts may cause vomiting and neurological toxicity; leachates of cigarette butts in aquatic environments may cause exposure to additional toxic chemicals including heavy metals, ethyl phenol and pesticide residues. This report reviews published and grey literature regarding cigarette butt waste consumption by children, pets and wildlife.