2g?d?1. When the carcinogenic risk is 10?5, the calculated selleck chemical SV threshold is 0.67ng?g?1 (wet weight, the potency equivalent concentration) [36�C39], which is far higher than the wet weight contents of PAHs in various tissues and organs acquired from this research. Therefore, we can clarify that the carcinogenic risk from the four main fish species found in the Beijing market is significantly lower than 10?5 (Table 8).Table 8Risk assessment on BaP and potency equivalent concentration of PAHs for human consumption of fish.In addition, BaP equivalent concentrations of PAHs in the fish measured in this research were also below the national standards limiting pollutants, in which BaP equivalent concentrations are suggested below 5ng?g?1 for grain and meat and 10ng?g?1 for vegetables [35, 40].4.

ConclusionsThe residual levels of PAHs in fish on a wet weight basis ranged from 0.51ng?g?1 to 28.78ng?g?1, while the residual levels of PAHs on a lipid-normalized basis ranged between 93.62ng?g?1 and 8203.43ng?g?1. LMWPAHs took a dominant percentage of the total of the PAH residuals.The residual levels of PAHs in fish on a wet weight basis had no significant differences among various fish species but did show differences among the various fish tissues. The highest residual levels of total PAHs and LMWPAHs were found in the brain, they were lower in the roe and bladder, and they were the lowest in the liver and muscle. With regard to residual levels of MMWPAHs, the highest value was found in the bladder, lower values in the brain and roe, and the lowest values in the liver and muscle.

For HMWPAHs, the highest value was found in the roe, lower values in the brain, and the lowest values in the bladder, liver, and muscle. The residual levels of PAHs on a lipid-normalized weight basis had significant differences both for various fish species and for various fish tissues. In all of the four fish species, the highest total residual levels of PAHs was found in bighead carp, lower levels in crucian carp and the lowest values in carp, and grass carp. As for the five tissues, the highest residual levels Carfilzomib of PAHs were found in the liver, lower levels in the muscle, roe, and bladder, and the lowest levels in the brain. No significant differences were found for PAH distribution in HMWPAH, MMWPAHs, and LMWPAHs.The potency equivalent concentration of PAHs on a wet weight basis in various tissues was found to be lower than the SV value from USEPA (0.67ng?g?1, wet weight).