The accumulation of polycyclic aromatic hydrocarbons in snails and soil in Igbekebo, Ondo State, Nigeria

Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) are harmful to human health and can cause cancer. The PAHs concentration in soil and snail samples collected from the Igbekebo region of Ondo state was measured in this study. Using metal spoons, soil samples were taken from five separate sites and placed in foil paper bags at a depth of 10 cm. For each type of snail under study, eight (8) samples were randomly taken from five distinct locations. Gas chromatography flame ionization detector (GC-FID) was used to analyze the samples. The estimated daily intake (EDI) and bioaccumulation factor (BAF) in the snail samples, as well as the toxic equivalence quotient (TEQ) and mutagenicity equivalence quotient (MEQ) in the soil samples, were calculated. This study showed that concentration levels of PAHs in soil, freshwater snail (Bulinus globosus), and land snail (Achatina marginata) samples were within the range of 0.1894–48.8063 μgkg−1, 0.15–40.14 μgkg−1, and 0.56–60.79 μgkg−1 respectively. Dibenzo(a,h)anthracene, anthracene, and Dibenzo(a,h)anthracene, respectively, were the most common PAHs found in soil, freshwater snails, and land snails. The total PAHs concentration in freshwater snail sample was lower when compared to other studies. The toxicity of each PAH in the soil sample was determined using Toxic Equivalent Factor (TEF) and Mutagenic Equivalent Factor (MEF) values, and the results were compared to the National Institute for Public Health and the Environment’s (Dutch: Rijksinstuut voor Volksgezondheid en Milieu (RIVM)) toxicity limits. It is advised to restrict crop and land snail consumption in Igbekebo since the soil samples from Igbekebo had a higher PAH toxicity value than the RIVM toxicity limit.