Elemental characterisation, potential sources and health risk assessment of ambient PM10 in urban Ghana during the dry season

Abstract

PM10 (particles with aerodynamic diameter ≤ 10 μm) is a carrier of toxic elements from diverse sources. This study examined the origin and potential health risks associated with trace elements in PM10 during the dry season in Ghana. A Gent sampler, equipped with a Gast pump and a stacked filter unit, was employed to collect airborne particulates at the Winneba Highway Intersection (WHI) and the Apam Fish-smoking Community (AFC). Sampling was conducted three times per week from November 2022 to March 2023, with each session lasting 24 h. The particulate samples were analysed for elemental and Black Carbon (BC) concentrations using Ag-anode X-ray tube spectrometer and a smoke stain reflectometer, respectively. The US EPA Air Quality Index (AQI) and health risk assessment models evaluated air quality and elemental toxicity risks, respectively. Notably, the average levels of Chromium (77 ng/m3) and Nickel (210 ng/m3) at WHI, and Chromium (310 ng/m3) and Nickel (470 ng/m3) at AFC, exceeded the US EPA threshold limits. Pearson’s correlation model linked BC, sulphur, and potassium to combustion-related emission sources. Principal Component Analysis (PCA) showed that PM10 at WHI originated from fugitive dust and sea salt, vehicular emissions, and minor industrial activities, whereas sea salt, dust, biomass burning, and vehicular emissions contributed to PM10 at AFC. AQI ratings indicated moderate air quality during December to February, implying potential health risks for sensitive populations. Cancer risk levels were relatively higher in adults than in children. Adopting clean fuels and sustainable transport is vital to reducing PM₁₀ health risks.