Trace element analysis of airborne particulate matter in relation to air pollution in Benin city, Nigeria.

The methods of neutron activation analysis (NAA) and atomic absorption spectrometry (AAS) have been employed to determine the concentration levels of 18 trace elements in filter-collected airborne aerosols over an urban area in Nigeria. The highest concentrations measured in the samples were for Cl, Na, Al, Pb, Ca and Zn. The aerosol particles were found to contain higher concentrations of soil-derived trace elements, such as Al, Ti, K and Na than those derived from combustion and industrial activities such as As, Cd, Mn, Zn, Pb, Ni and Sb. The average precision of measurements varied between +/- 5.2% and 13% for most elements. Possible sources of the elements are also discussed.