PCDD/Fs and DL-PCBs in Chinese Mitten Crab (Eriocheir sinensis) and Its Farming Environment in Shanghai, China

Abstract

Most polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in the human body are acquired from dietary intake. The chronic exposure of humans to PCDD/Fs and DL-PCBs is a major health concern, and these compounds are strictly controlled in many areas. This study measured the levels of PCDD/Fs and DL-PCBs in Chinese mitten crab (Eriocheir sinensis) farms in Shanghai and determined potential sources. The mean concentrations of PCDD/Fs and DL-PCBs in the studied crab samples were 264.20 ± 260.14 and 506.25 ± 226.80 pg/g ww (wet weight), respectively. The range of the toxic equivalent (TEQ) for the total PCDD/Fs and DL-PCBs in the crab samples was 1.20–29.04 pg TEQ/g ww. Further analysis revealed that the TEQ input to crabs in aquacultural water was 1.6 times higher than the TEQ in edible crab parts. Aquatic plants, shore plants, and feed contributed about 0.05% of the total TEQ input to crabs. The TEQ contribution from sediment was 317 times that found in edible crab parts, and sediment may be the most prevalent source of PCDD/Fs and DL-PCBs in farm crabs. The evaluation of the Shanghai market crab revealed different levels of PCDD/Fs and DL-PCBs. The TEQs for the mean PCDD/F and DL-PCB levels were 1.55 ± 1.96 and 1.05 ± 0.55 pg TEQ/g ww, respectively. The tolerable daily intake (TDI) levels of adults and children were lower than the prescribed range (1–4 pg TEQ/kg (weight)·d), indicating no significant chronic or acute ingestion risk for adults and children.

Effects of prior acclimation on the survival, feed intake and salinity preference of a freshwater-adapted euryhaline crab

“…In the complex life cycle of the Chinese mitten crab, juveniles initiate upstream migration toward the limnic parental habitat after metamorphosis (Herborg et al, 2003). Similar behaviour of preferring fresh water was found in the megalopa of the Chinese mitten crab (Wang, 2012). Our experiment eliminated the influence of organic matter and the smell of natural seawater by using seawater solution mixed with sea salt and fresh water.…”

“…Most studies of Chinese mitten crabs were limited in salinity tolerance and stress in embryos, zoeae and adults (Normant et al, 2012;Wang et al, 2019). A previous study on the salinity preference of Chinese mitten crabs revealed that adult males did not demonstrate any preferences in the salinity range of 0-35 , but females preferred 21 (Wang, 2012). Although adult salinity selection and stress are documented, knowledge on juvenile salinity selection and other behavioural responses to salinity changes, especially the change in salinity selection after acclimation, is scant.…”

Developing an Improved Strategy for the Analysis of Polychlorinated Dibenzo-p-Dioxins/Furans and Dioxin-like Polychlorinated Biphenyls in Contaminated Soils Using a Combination of a One-Step Cleanup Method and Gas Chromatography with Triple Quadrupole Mass Spectrometry

“…More than 90% of human exposure to PCDDs/Fs and dl-PCBs originates from food, which has the lowest governmental regulatory concentration restriction among different media [ 53 , 54 ]. In the case of soil, the regulation level differs depending on the country or land use.…”