“…Pristane and phytane can be used to assess the degradation level of petroleum residues (Samelak et al, 2020). Low values of Pristane/Phytane (Pr/Ph) ratios (0.9601-1.2771) were found in all samples; Pr/Ph values below or near 1 indicate the presence of anthropogenic organic substances of petroleum origin (Rushdi et al, 2017;Zhu et al, 2018;Gdara et al, 2020). Furthermore, based the UCM profile and the Pr/Ph ratios, it can be concluded that the samples are contaminated with fresh and partially biodegraded hydrocarbons (Cabrerizo et al, 2016;Iheonye et al, 2019;Zhu et al, 2018).…”