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Abstract Background The aim of this article is to establish an external quality assessment (EQA) scheme for sperm Deoxyribonucleic acid (DNA) fragmentation (SDF) detection, and to assess the feasibility of the scheme. In addition, this article provides some case analysis of abnormal results in order to really help improve the performance of the laboratory. Results In 2021 and 2022, 10 and 28 laboratories in China volunteered to participate in the EQA program respectively. Two samples were selected for EQA each year, a large spread of results was obtained for the four samples, and the highest values were 13.7, 4.2, 8.0 and 4.0 times the lowest respectively. The coefficients of variation (CVs) were very high for the four samples, at 46.6%, 30.1%, 26.7% and 30.3%, respectively. The CVs of the samples with high SDF values were lower than those of the samples with low SDF values. There was no significant difference between the results of sperm chromatin structure assay (SCSA) and sperm chromatin dispersion (SCD). For the 10 laboratories that participated in EQA in 2021 and 2022, the CVs of low SDF value samples and high SDF value samples decreased from 46.6% and 30.1% in 2021 to 32.5% and 22.7% in 2022, respectively. Conclusion This is the first study to evaluate the EQA program on SDF, which involved a number of laboratories and was demonstrated to be feasible. It is recommended that all laboratories participate in the EQA of SDF to ensure the accuracy of the results.

Résumé Contexte Des études antérieures ont rapporté que certains patients qui avaient des spermatozoïdes sans tête présentaient une mauvaise qualité du sperme, mais il n’y a eu aucune analyse systématique publiée sur la qualité du sperme chez les patients ayant des proportions différentes de spermatozoïdes sans tête dans leur sperme. Nous avons cherché à explorer l’association entre syndrome des spermatozoïdes acéphaliques et qualité du sperme chez les hommes ayant des proportions distinctes de spermatozoïdes sans tête. Les valeurs des paramètres du sperme chez les patients pour lesquels des spermatozoïdes sans tête ont été trouvés dans l’éjaculat ont été étudiées et comparées à celles de 413 patients consultant pour un examen prénatal, appariés sur l’âge. Tous les échantillons de sperme ont été analysés selon la même méthodologie dans un seul laboratoire. Résultats Toutes les valeurs des paramètres du sperme, à l’exception du volume de sperme, étaient négativement (P 20% (n = 71, groupe C). Dans le groupe A1, une seule valeur de paramètre de sperme (motilité progressive) est. inférieure à celle du groupe témoin, mais dans le groupe A2, le nombre s’élève à cinq (vitalité des spermatozoïdes, morphologie normale des spermatozoïdes, mobilité des spermatozoïdes, VCL (vitesse linéaire curviligne) et ALH (amplitude du déplacement latéral de la tête)). Pire encore, toutes les valeurs des paramètres du sperme étaient significativement plus faibles dans les groupes B et C que dans le groupe témoin (P

Antibiotic resistance genes (ARGs) are widespread in aquaculture and pose a huge threat to aquaculture organisms and human health. In this study, occurrences and relative abundances of ARGs were analysed in the guts of products cultured in freshwater ponds in the Yangtze River Delta region in China. A total of 29 ARGs were found in the gut samples, with detection frequencies ranging from 4.8% to 81%, and the relative abundances (ARGs/16S rRNA) ranging from 10−7 to 1. In addition, the human dietary intake of ARGs via aquaculture products was assessed, where the daily intake of most ARGs via aquaculture products was higher than those via PM2.5 and drinking water, but lower than that via vegetables. The relative abundances of MGE (IS613, Tp614, tnpA and int1) were significantly correlated with those of multiple ARGs, indicating the horizontal gene transfer (HGT) of ARGs among gut microorganisms. Proteobacteria, Firmicutes and Actinobacteria were the dominated microbial communities found in the guts of aquaculture products. In addition, significant correlations were found between Cyanobacteria and int1, between Nitrospira and tetE, and between sul2 and aadA2, indicating potential same hosts of these genes. In addition, results from co-correlation indicated both HGT (dominated by MGEs) of ARGs and the enrichment of ARGs in bacteria. MGEs, mostly int1, were more effective than bacteria in increasing the ARG abundance. This study could provide a better understanding of the transmission of ARGs in the aquaculture environment and improve the quality of aquaculture products and the ecology. [ABSTRACT FROM AUTHOR]

Water quality in aquaculture farms is highly related to the quality of aquaculture products and the connected environment. Cadmium (Cd2+) and polycyclic aromatic hydrocarbons (PAHs) are two of the most common pollutants in the aquaculture water, while biochar derived from waste algae (Enteromorpha prolifera), namely BE, was applied in farms ponds to improve water quality. Firstly, the adverse environmental impact of BE was minor, while the concentrations of the heavy metal (Cd2+ in the present study) and PAHs (FLU, PHE, FLT and PYR) were removed with efficiencies of 49%, 88%, 90%, 91% and 88%, respectively. The ecological risk values (RQs) were reduced subsequently with a rate of 58 ± 11%. After dosing BE, the ecological risk values in all the studied ponds were lower than 1, indicating no ecological risk in the corresponding aquaculture environment. The sorption capacities (qm) of BE were 15, 12, 6.3, 0.41, 0.29 and 0.56 mg·g−1 for Cd2+, FLU, PHE, FLT, PYR and BaP, respectively. The sorption capacities were acceptable compared with those derived from other types of biomass. The removal mechanisms were partition (PAHs), complexation (Cd2+), π-π interaction (Cd2+ and PAHs), precipitation (Cd2+) and ion-exchange (Cd2+). Practically and theoretically, the algae biochar is applicable in the aquaculture environment, where Cd2+ and PAHs co-exist. [ABSTRACT FROM AUTHOR]

Equilibrium sampling based on silicone polydimethylsiloxane (PDMS) has been used to determine the concentrations of freely dissolved hydrophobic organic compounds (HOCs) and assess the thermodynamic potentials for bioaccumulation of these compounds in the aquatic environment. This allows the use of PDMS‐based sampling techniques in assisting conventional sampling and extraction methods for the determination of the concentrations of HOCs in aquaculture products. The present study is an ex situ demonstration of how well PDMS can inform the tissue residues and dietary risks of legacy or current‐use organic chemicals in aquaculture species from farm ponds in eastern China. For legacy contaminants such as polybrominated diphenyl ethers (PBDEs, n = 10), good agreement between the predicted concentrations based on PDMS and the measured lipid‐normalized concentrations was observed for 60% of the studied biota, including both pelagic and benthic species. For pesticides currently used, such as pyrethroid (PE) (n = 4) and organophosphate pesticides (OPPs, n = 7), the measured tissue residues were consistently higher than those predicted by PDMS, possibly caused by the continuous input from the surroundings. For the organochlorine pesticides (OCPs, n = 5), the only detected chemical was also underestimated. Adjusted by ingestion rates of aquaculture products and toxicology data, the target hazard quotients of these chemicals predicted from PDMS were generally comparable to those derived from measured concentrations in tissue because of the predominance of PBDEs. Overall, PDMS‐based equilibrium sampling offered an alternative approach for the prediction of tissue residues and dietary risks of PBDEs. Moreover, it should be applied with caution for PEs, OPPs, and OCPs. Improving the application of PDMS for these chemicals in farm ponds warrants future study. Environ Toxicol Chem 2021;40:79–87. © 2020 SETAC [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) are among the contaminants of concern in aquaculture ponds due to their frequent detection and high bioaccumulation in aquatic products and hence high dietary risks to human beings. In this study, magnetic activated carbon (MAC) was added as a stabilization and removal adsorbent to native pond sediment with known contamination of HMs and PAHs to reduce the tissue residues and dietary risks of HMs and PAHs in a model aquaculture species (Venerupis philippinarum) in the course of a 28-day bioaccumulation experiment. Meanwhile, passive sampling techniques based on diffusive gradient in thin films (DGT) and polydimethylsiloxane (PDMS) were applied to sense the bioavailable fraction of HMs and PAHs in sediment during the stabilization process. The results showed that 3% dosage of MAC to sediment achieved the most cost-effective stabilization for HMs and PAHs. A remarkable decrease was observed with the tissue residues of HMs and PAHs in V. philippinarum (28–47% for HMs and ~76% for ∑PAHs), which was quantitatively linked to the decline in their bioavailable concentrations in sediment pore water (31–46% for HMs and ~76% for ∑PAHs). Consequently, the target hazard quotients (THQs) posed by HMs and incremental lifetime cancer risks (ILCRs) by PAHs in V. philippinarum were reduced by 38% and 46%, respectively. Along with the magnetic recovery of ~70% MAC from the sediment, HMs (4.8–13%) and PAHs (2–60%) can be effectively removed. We further established a multi-domain equilibrium sorption model that was able to predict the optimal amendment of MAC for quantitative mitigation of bioavailable PAHs in sediment pore water within a certain range of MAC dosage. Future studies are warranted to explore the applicability domain of MAC for in situ remediation in aquaculture ponds to ensure the quality of farming organisms or to serve other purposes in aquatic systems. Unlabelled Image • A predictive model was established to inform the optimal MAC dosage. • 3% dosage of MAC had most cost-effective stabilization for heavy metals and PAHs. • Reduced contaminant bioavailability was linked to dietary risk reduction in clams. • 70% of MAC was recovered from sediment via magnetic separation. [ABSTRACT FROM AUTHOR]

The effect of zirconium-modified zeolite (ZrMZ) addition on the release and immobilization of phosphorus in heavily polluted river sediment was investigated using microcosm incubation experiments. Results showed that addition of ZrMZ to sediment greatly reduced concentrations of P in pore water and overlying water, also reducing the release flux of P across the interface between overlying water and sediment. The addition of ZrMZ to sediment resulted in the transformation of NH 4 Cl extractable P (NH 4 Cl-P), Na 2 S 2 O 4 /NaHCO 3 extractable P (BD-P), and HCl extractable P (HCl-P) into NaOH extractable P (NaOH-rP) and residual P (Res-P) in sediment, thereby leading to the reduction of mobile P (sum of NH 4 Cl-P and BD-P) in sediment. Content of bioavailable P (BAP) including water soluble P (WSP), readily desorbable P (RDP), iron oxide paper strip extractable P (FeO-P), and anion resin extractable P (Resin-P) in sediment also declined following addition of ZrMZ. Control of P release from sediment by ZrMZ could be due to reduction of P in pore water and immobilization of P in sediment. Results of this work indicate that ZrMZ is very promising for controlling P release from sediments in heavily polluted rivers.