Concentrations of lead in ambient air

There is no simple relationship between the source strength and ambient concentration of an atmospheric pollutant, since dispersion of the pollutant between source and receptor is a process which is dependent upon meteorological conditions and is hence very variable. For this reason, concentrations measured over a short time period at only one site may not be representative of ambient concentrations in that region, and longer-term average concentrations measured at carefully selected sites are to be greatly preferred. 

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The approach to air pollution control in the US is very different to that in the UK. Rather than controlling lead via an effluent quality standard as in Britain, an ambient air quality standard is applied. The standard, set recently [11] applies to both industrial and vehicular sources of lead and is described in more detail in Section 5.5. Under this standard it is necessary for industrial sources to control emissions, and if necessary raise chimney heights to limit concentrations of lead in ambient air within the vicinity. 

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