Origin, toxicological and narcotic potential of sedimentary PAHs and remarkable even/odd n-alkane predominance in Bushehr Peninsula, the Persian Gulf

Surface sediments (n = 17) were collected from 6 sites located in the coasts of the Bushehr Peninsula. ∑16PAH concentrations were in the range of 285.9-1288 ng g− 1 dw and the sediments were moderately polluted. Py, Ph, B(a)A and Flu showed > 70% of the detected values in order of the mentioned rank. 4-ring PAHs were the dominant compounds and the molecular ratios presented the dominant pyrolytic source. The toxicity of PAHs for sediment dwelling life was averagely equivalent to occurrence of 0.08 ng g− 1 of Dioxin in dw of the examined sediments. The evaluated narcotic potential (confidence level of 99%) was 0.027-3.04 and upper part of the Bushehr Peninsula, where the human population is more concentrated, showed more narcotic potential. ∑ n-alkane concentrations (n-C15 − n-C32) were in the range of 3.10-35.6 μg g− 1 dw. The dominant distribution of even carbon number n-alkanes was traced back to a possibly autochthonous source.