PIXE characterization of PM₁₀ and PM_2.5 particulates sizes collected in Ikoyi Lagos, Nigeria

Abstract

Ambient concentrations of PM₁₀ (x ≤ 10 µm) and PM_2.5 (x ≤ 2.5 µm) particulate fractions collected from Ikoyi Lagos, Nigeria, as well as their elemental compositions are presented in this study. Both size-segregated fractions were collected using a double staged ‘Gent’ stack filter unit sampler. Elemental characterizations of dust laden filters were carried out using proton-induced X-ray emission (PIXE) technique. Twenty-two elements (Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb, Br, Rb, Sr, Zr, Ag, Cd, and Ta) were detected as well as their concentrations and correlations were determined for both particulate size fractions. Their correlation matrix result indicates that some of the trace elements detected could have common source origins or similar chemical properties. The results were similar to the levels observed in moderately polluted urban areas and there is need for source identification and apportionment using receptor models in future studies.

Keywords:

• elemental
• characterization
• inhalable
• particulate matter

Acknowledgements

The authors wish to thank The Management of Voice of Nigeria (VON), Ikoyi, for granting us permission during sample collection. We are indeed indebted to Prof Taiwo and Mr I. Omoniyi of Lagos Metropolitan Transport Authority (LAMATA) for mobility assistance during field work. We are also grateful for the supports of Professor's E.I Obiajunwa, G.A Osinkolu, and D.A Pelemo as well as the entire accelerator staff team at CERD during PIXE analysis.