Urban dwellers in developed countries have been estimated to spend ∼90% of their time indoors (home, commuting, office),¹  where they are exposed to an ever-increasing number of chemicals from a wide range of sources. The problem dates back – at least in part – to the oil embargo in the 1970s, when increased energy efficiency measures were adopted, including making buildings more airtight and reducing ventilation rates. Consequently, pollutants generated indoors are increasingly likely to stay there, leading to elevated indoor air pollutant concentrations.

Sources of indoor pollution are diverse, as seen in preceding chapters. Some pollutants are generated...