Origin, distribution and toxicological potential of polycyclic aromatic hydrocarbons in surface sediments from the Bushehr coast, The Persian Gulf

•Recorded moderate level of PAHs pollution in Bushehr coastal zones.•Predominance of high molecular weight PAHs originated mainly from fuel combustion.•Occasionally harmful biological effects related to Ace, Fl and D(a,h)A concentrations.•Representing the concentration of dibenz(a,h)anthracene as a toxicity index.•Bioaccumulation capability of carcinogenic benz(a)pyrene in the surficial sediments. To evaluate the hazards of polycyclic aromatic hydrocarbons (PAHs) in the Bushehr coastal zones, 12 surface sediments were analyzed. The ∑14PAHs concentrations varied from 371 to 611ngg−1 dw. The primary sources of the observed PAHs were pyrolytic processes, demonstrating the dominance of petroleum-related combustion inputs. The ERL/ERM and TEL/PEL values showed that there was a moderate level of toxicity risk for some PAHs. The toxicological significance of the pollutants was assessed using the toxic equivalency factor (TEF) to calculate both the toxic equivalent for dioxins (TEQTCDD) and the TEQ carcinogenic risks. Dibenz(a,h)anthracene exhibited the highest proportion in the TEQs, ranging from 49% to 56% (TEQcarc) and from 29% to 39% (TEQTCDD) regarding the overall toxicity in the sampled sediments. This result suggests that the ambient dibenz(a,h)anthracene concentration represents the risk posed by PAHs in the sediments. Moreover, using a specific sediment criterion demonstrated the bioaccumulation potential of benzo(a)pyrene for humans in the sampled sediments.