Cultured shrimp Penaeus vanmamei from eastern China accumulates PAHs and PYRs through different pathways: Water and food sources matter

Eastern China is an important area for aquaculture, but the aquaculture environment, as well as the aquatic product quality, are threatened by environmental pollutants such as polycyclic aromatic hydrocarbon (PAHs) and pyrethroid pesticides (PYRs). A three-month monitoring program for PAHs and PYRs throughout the whole culture processes of the shrimp Penaeus vanmamei was carried out. Specifically, concentrations of PAHs and PYRs ranged from 339 ± 19.5–631 ± 75.6 ng·L −1 and 65.3 ± 6.74–93.5 ± 10.8 ng·L −1 in water, 183 ± 33.8–369 ± 25.1 ng·g −1 dw and 441 ± 132–521 ± 62.8 ng·g −1 dw in sediments, while 416 ± 84.3–646 ± 19.7 and 483 ± 23.3–513 ± 22.1 ng·g −1 dw in suspended solids. Mean concentrations of PAHs and PYRs in the adult shrimp were 634 ± 82.3 ng·g −1 ww and 665 ± 58.1 ng·g −1 ww, respectively. A health threat would arise if men consume more than 28.8 g and women consume more than 24.4 g each day. PAHs in the aquaculture environment were generally from the influent water and rainfall, while PYRs were mainly introduced by feed. After entering the culture environment, PAHs primarily increased the water load, leading to more significant bioaccumulation of the shrimp from the water phase (72–95 %). For PYRs, the main sources were feed (44.4 %) and influent water (20.6 %), and they were accumulated in shrimp through feed assimilation directly (15.0 %–32.0 %). Additionally, feed waste containing PYRs increased the contamination burden of sediments and suspended solids, leading to bioaccumulation through assimilation (4.00 %–15.0 %) as well. Although the contribution of influent water to PYRs in the culture environment was lower than that of feed, the contribution of aqueous exposure to the enrichment of PYRs in the shrimp was higher (53.0 %–81.0 %) than that of food (feed, sediments, and suspended solid) intake (19.0 %–47.0 %). The hydrophobicity of PYRs led to an easier bioaccumulation from freely dissolved phase to biota. Therefore, it is important to pay attention to the water quality during the whole culture period, as well as feed quality, to ultimately improve the quality of aquaculture products. In summary, different pollutants in the aquaculture environment and products were from different sources and exposure pathways. Water quality monitoring and improvement are more efficient in decreasing PAHs in the shrimp, while PYRs reduction should be assisted with feed quality control.