Environmental tobacco smoke (ETS) is an important indoor air pollutant. It is a mixture of thousands of different substances (both gases and particles), many of which are harmful to health and/or carcinogenic.
Compounds in ETS include carbon monoxide, formaldehyde, toluene, ammonia, hydrogen cyanide, nicotine, oxides of nitrogen, phenol and sulphur dioxide. ETS also contains numerous compounds, mainly bound to particles, that have been identified as known or probable human carcinogens, such as N-nitrosamines, PAHs (benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene) aromatic amines and benzene. Metals, including arsenic, nickel, cadmium and chromium, are also found in ETS.
Chronic exposure to ETS is associated with an increased risk of death due to lung cancer and death and ill health due to heart disease and stroke (these are diseases of the “cardiovascular” system). Infants and young children are more susceptible to the health effects of ETS and exposure increases the frequency and severity of asthma attacks, and the risk of respiratory infections (pneumonia, bronchitis) and other childhood infections such as those of the middle ear.