Abstract
The chemical nature of lead compounds in urban air is considered, and the available analytical methods for measurement of the organolead component are described. Reported concentrations of organolead compounds in urban atmospheres are critically assessed with regard to possible analytical errors and it is concluded that whilst elevated concentrations may exist in the vicinity of petrol stations and cold choked vehicles, tetraalkyl lead compounds typically account for only about 1–4% of total lead in urban air.