First data on concentrations and composition of polycyclic aromatic hydrocarbons in soil, bottom sediments and suspended matter of water throughout the whole Fatala River Basin (Republic of Guinea)

Abstract

The concentrations of polycyclic aromatic hydrocarbons (PAHs), their sources and toxic equivalent (TEQ) in soil, suspended matter and bottom sediments in the Fatala River Basin ecosystem were obtained for the first time to our knowledge. Determination of 14 PAHs (ΣPAHs) was carried out using high-performance liquid chromatography. The ΣPAH content in soil ranged from 13 to 50,920 (Me = 820) ng/g. The composition of PAHs (high proportion of low-molecular-weight compounds and values of individual PAHs ratios) reflected the significant oil pollution of soil. Contaminated soil was localated in the central part of the Fatala River Basin. The median benzo(a)pyrene toxic equivalent of soil at the study site was 1.08 (range, 0.05 to 53.16) ngTEQ/g, showing generally low soil toxicity. The ΣPAH content in suspended matter was in the range of 33 to 1316 (Me = 309) ng/L. The ΣPAH content in bottom sediments ranged from 36 to 6943 (Me = 478) ng/L, corresponding to clean and moderately contaminated sediments. The ΣPAH content in bottom sediments depended on the anthropogenic impact on the Fatala River Basin territory and the bottom sediment features. Bottom sediments and suspended matter had a low toxic equivalent.