Toxicity and distribution of polycyclic aromatic hydrocarbons in leachates from an unlined dumpsite in Nnewi, Nigeria

Abstract

ABSTRACT Leachates from dumpsites have been known to pollute the environment with deleterious effects. The study examined the levels of the sixteen United States Environmental Protection Agency polycyclic aromatic hydrocarbons (PAHs) in leachates from an unlined solid waste dumpsite using a gas chromatography incorporated with a flame ionisation detector (GC-FID). Possible sources of the PAHs were identified using diagnostic pair ratios. Toxicity and mutagenic health-related risk were extrapolated. The average levels of PAHs ranged from 0.03–147.85 µg/L. The anthracene value of 147.85 µg/L was the maximum PAH concentration recorded. The lowest PAH observed was 0.03 µg/L, which was found in benzo(k)fluoranthene. The 3 – ring PAHs matrix was the highest PAH observed and it followed a ring size decreasing order of 3 > 4 > 5 > 2 > 6 in the leachate sample. The diagnostic pair ratio suggested mixed sources with a slightly dominant petrogenic source identified. The cluster analysis showed different sources of the congeners in the leachate. The benzo(a)pyrene toxic and mutagenic risk quotients showed that the greater concentrations of benzo(a)pyrene and dibenz(a,h)anthracene can induce carcinogenic and non-carcinogenic related health risks to a living organism.