Distribution, source apportionment and risk assessment of PAHs in the culture ponds of Macrobrachium rosenbergii in Jinshan, Shanghai

Abstract:

In order to study the pollution level and source of polycyclic aromatic hydrocarbons (PAHs) in the breeding environment of Macrobrachium rosenbergii in Jinshan district of Shanghai and to assess the food health risk, 16 kinds of optimal PAHs were detected by HPLC. The results showed that: In the cultivation area, the total PAHs content and the settling flux in the dry and wet deposition were 5.52-9.45 μg/g, 47.99-100.42 ng/L and 3.75-6.42 μg/m²·d, 83.32-174.36 ng/m²·d, respectively. In the dry deposition, the high ring was dominated, while in the wet deposition, the low ring was dominant. The total PAHs content in the water is 342.76-1 520.83 ng/L, which is mainly dominanted by low ring. Compared with other breeding areas in China, PAHs pollution in the water of research areas is at a medium level; the content of PAHs in soil and sediment was 1 000.45-2 138.46 ng/g and 1 763.70-3 656.97 ng/g, respectively. The content of PAHs in high ring was much higher than that in low ring, which was also higher than that in other aquaculture areas. The total PAHs contents in zooplankton and phytoplankton was 46.18-134.63 μg/g and 26.13-145.39 μg/g, respectively, which were dominated by 4-ring PAHs; The average total PAHs content in the three growth stages of Macrobrachium rosenbergii was 63.09 ng/g (Seeding stage), 111.89 ng/g(Growth stage) and 148.77 ng/g(Incubation stage), respectively, showing the existence of bioenrichment phenomenon. The PAHs content in the 3 and 4 cyclic PAHs in the shrimp meat was relatively high. Compared with aquatic products in other breeding areas, PAHs in the study area in Macrobrachium rosenbergii were at a lower level. The ratio method and principal component analysis method were used to analyze the pollution sources. The results showed that the air settlement in the breeding area coexisted with many pollution sources, and the pollution sources in the wet settlement were mainly petroleum sources. The main source of pollution in dry deposition was coal and wood combustion. The main pollution sources of water bodies were petroleum sources; the main source of coal combustion was in the soil. The pollution sources in sediments were similar to those in soil, mainly coal combustion and incomplete combustion of fossil fuels. The results of risk assessment showed that the lifetime cancer risk of Macrobrachium rosenbergii was 1.89×10^-8-1.37×10^-6, which was within the acceptable range and would not harm human health under normal eating conditions.