Occurrence and distribution of polycyclic aromatic hydrocarbons in surface microlayer and subsurface seawater of Lagos Lagoon, Nigeria

Abstract

Polycyclic aromatic hydrocarbons (PAHs) in surface microlayer (SML) and subsurface water (SSW) of Lagos Lagoon were investigated using gas chromatography-electron capture detector (GC-ECD) technique to ascertain their occurrence and spatial distribution, origin, enrichment, and carcinogenicity. Total PAH (ΣPAH) concentrations ranged from 9.10 to 16.20 μg L(-1) in the SML and 8.90 to 13.30 μg L(-1) in the SSW. ΣPAH concentrations were relatively higher in the SML than the underlying SSW samples. The enrichment factors (EFs) of ΣPAHs ranged from 0.76 to 1.74 while the EFs of the individual PAHs varied from 0.50 to 2.09. In general, the EFs values calculated in this study were consistent or slightly less than the EFs reported for similar coastal seawater ecosystems. A correlation between the EFs of fluoranthene and pyrene indicated a positive significant value (R = 0.9828, p < 0.0001, n = 6). Source analyses using the phenanthrene/anthracene and fluoranthene/pyrene ratios indicated the dominance of petrogenic-derived PAHs. Furthermore, enhanced concentrations of BaP (strong carcinogenicity) in SML and SSW samples, which resulted in higher EFs, could pose serious ecological and human health risks.

Occurrence and distribution of microplastics-sorbed phthalic acid esters (PAEs) in coastal psammitic sediments of tropical Atlantic Ocean, Gulf of Guinea

“…The highest number of MPs was found at the EG and OR sites with 1196 particles/m 2 and 1730 particles/m 2 , while the site BG recorded the lowest MPs with 36 particles/m 2 . The enhanced concentration of MPs at the EG and OR sites may be attributed to the proximity of these locations to industries, recreation and tourist hotspots, trading and religious activities, shops, bars, and residential areas, where piles of plastic litters are indiscriminately discarded by humans, and transported and distributed along the coast by ocean waves (Benson et al, 2014). The comparatively low amount of microplastic particles at Badagry (BG) site could be attributed to the routine sanitary management practices by small scale businesses located around the beach.…”

Microbial Communities in Sediments of Lagos Lagoon, Nigeria: Elucidation of Community Structure and Potential Impacts of Contamination by Municipal and Industrial Wastes

“…The lagoon is also industrialized, and is the location of Africa’s largest port, as well as the location of extensive petroleum tank farms ( Obafemi, 2008 ). Other areas of the lagoon boarder the forest belt, and are less intensively impact by urban and industrial activities ( Alani et al, 2012 ; Nsikak et al, 2014 ; Adama et al, 2015 ; Amaeze et al, 2015 ). Thus, Lagos lagoon has areas that range from severely impacted by anthropogenic activities to those having comparatively low levels of direct impact.…”

Spatial distribution of benthic foraminifera in the Lagos Lagoon (Nigeria): Tracing the impact of environmental perturbations

“…uncontrolled chemicals used by local fisherman, ineffective sewerage systems, industrial discharges, heavy metal pollution, wood residue leachates, and sand dredging activities [1,56,[59][60][61][62] and pose a serious threat to biodiversity and the aquatic ecosystem.…”

“…These led to high concentrations of heavy metals (e.g., copper, zinc, manganese, lead, iron, nickel) in the lagoon environment. Polycyclic aromatic hydrocarbons (e.g., naphthalene, phenanthrene, pyrene) have been found at considerable levels within the polluted western section of the lagoon (e.g., [1][2][3][4]). Excessive sand mining and dredging activities contribute more to the disruption of the ecosystem in the lagoon.…”