Exposure and cancer risk assessment of polycyclic aromatic hydrocarbons (PAHs) in River Nile of Egypt

Abstract

Distributions of 16 PAHs in 50 samples collected from the Nile River in Egypt through 1 year were investigated to understand the carcinogenic risk. Determination of PAHs through the validated method with LOQ 0.01 µg/l, RC% ranged from 95% to 114%, RSD% ranged from ±4–9% using HPLC, and results showed that (∑PAHs) were ranged from 0.01 to 0.87 ±0.26 μg/L in which the highest in Giza and the dominant of PAHs was fluoranthene. Fifty per cent of the total analysed PAHs were from 4-rings and 5-rings PAHs. Toxicity was expressed by the presence of PAHs in terms of benzo(a)pyrene (BaP) concentration by establishing toxic, mutagenic equivalency factors (TEFs, MEFs) for PAHs. ΣTEQ and ΣMEQ for seven PAHs were 0.070 μg/L and 0.086 μg/L respectively. These compounds are considered traces, but exposure to it impacts mutagenic risk greater than carcinogenic risk. Incremental Lifetime Cancer Risk (ILCR) was 2*10−4 to 6*10−4 for adults and 2*10−4 to 7*10−4 for children, there is a chance for cancer risk except for ILCR of BaP 4*10−3 has no carcinogenic risk. Hazard Index (HI) <1, but we should not be ignored in the long-term our results provided useful information for decision-makers to control carcinogens PAHs and establish a standard national programme for permissible levels with treatment advanced technology.