Assessment of Polycyclic Aromatic Hydrocarbons Concentration in Surface Water, Sediment and Blue Crab, Callinectes Amnicola (De Rochebrune, 1883) from Buguma Creek, Rivers State, Nigeria

Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic contaminants that pose ecological and human health risks. This study assessed PAH levels in surface water, sediment, and Callinectes amnicola from Buguma Creek, Rivers State, Nigeria. Surface water, sediment and C. Amnicola samples were collected bimonthly from three stations between May and September 2022 for PAHs analysis by gas chromatography. Physico-chemical parameters such as temperature (°C), salinity (‰), pH, dissolved oxygen (DO, mg/L), and biological oxygen demand (BOD, mg/L) were measured in surface water. Data were statistically analysed by Analysis of Variance (ANOVA). Results showed significant no spatial but temporal variations in DO, BOD, and salinity, with the highest values recorded for DO (5.3±0.4 mg/L) and BOD (5.9±0.3 mg/L) in July, while salinity peaked in May (19.0±0.0 ‰). Of the 17 PAHs listed by the agency of toxic substances and disease registry, 12 (including Naphthalene which was not listed in ATSDR) were detected, excluding benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, dibenzo(a,h)anthracene, and benzo(g,h,i)perylene. PAHs concentration followed the trend: sediment > water > C. amnicola, with the highest levels recorded in July. PAH sources were both petrogenic and pyrogenic, with petrogenic inputs dominating surface water, pyrogenic sources in C. amnicola, and both contributing equally to sediment contamination. Biota-water accumulation factor (BWAF) and biota-sediment accumulation factor (BSAF) indicated C. amnicola primarily accumulated PAHs from water rather than sediment. PAHs concentrations in all matrices exceeded by several magnitude the US Environmental Protection Agency’s limits (<1000 ng/g for sediment, <1000 ng/L for water). The presence of carcinogenic PAHs, including benzo(a)anthracene, benzo[b]fluoranthene, and benzo(a)pyrene in water and sediment, and chrysene and benzo[b]fluoranthene in C. amnicola, raises concerns over bioaccumulation and trophic transfer. In conclusion, Buguma Creek is polluted with PAHs from both pyrogenic and petrogenic sources. Given the potential ecological and human health risks associated with PAHs, regular monitoring and pollution prevention measures are essential for mitigating anthropogenic impacts and ensuring sustainable ecosystem.