Assessment of Polycyclic Aromatic Hydrocarbon Contamination in Smoked Fish Products from Riverine Markets in Rivers State and Associated Human Health Risk

Smoked fish is a dietary staple across South South Nigeria, particularly in the riverine communities of Rivers State where both artisanal fishing and traditional wood-smoking methods are practised extensively. Polycyclic aromatic hydrocarbons generated during incomplete combustion of biomass fuels are known to contaminate smoked food products and are classified as probable human carcinogens. This study quantified PAH concentrations in twenty smoked fish samples from five riverine markets in Rivers State and conducted a human dietary cancer risk assessment for local consumers. Sixteen priority PAHs were determined by gas chromatography-mass spectrometry following saponification and liquid-liquid extraction. Benzo[a]pyrene equivalent concentrations were calculated as a composite carcinogenic risk metric. Health risk assessment was performed using the EPA incremental lifetime cancer risk model. Total PAH concentrations ranged from 12.4 to 187.6 micrograms per kilogram across samples. Benzo[a]pyrene was detected in 85% of samples, with 40% exceeding the EU maximum residue limit of 2 micrograms per kilogram. Incremental lifetime cancer risk estimates exceeded the 10 to the power of negative 4 threshold of concern in high consumption scenarios. Samples smoked over direct open flame showed significantly higher PAH loads than indirect-heat smoked samples. These findings identify artisanal fish smoking practices in Rivers State as a significant dietary PAH exposure route requiring technological and regulatory intervention. Keywords: polycyclic aromatic hydrocarbons, smoked fish, cancer risk, Rivers State, GC-MS.