Spatial and seasonal variation of lead in Cairo atmosphere

Abstract

Spatial and seasonal variation of lead concentrations were investigated in the Cairo atmosphere. It was found that the annual mean lead concentrations in the central and densely populated parts of Cairo exceeded the 2μm⁻³ recommended limit. In sharp contrast to data for European cities, summer lead concentrations were higher than those detected during winter. Calculated settling velocities of lead particles show that in the central urban district lead particles can stay suspended for long periods, and so are available for inhalation, as compared with particles found in the atmosphere of other parts of the city.