Background: This study aimed to comprehensively evaluate the toxicity exerted by zinc oxide nanoparticles (ZnO NPs) on rat testis and its effects on fertility and progeny development. Methods: Different concentrations of ZnO NPs were administered by gavage to Sprague Dawley (SD) rats to examine the adverse effects resulting from pre- and post-natal exposure. Systemic distribution of ZnO NPs, developmental performance, sperm parameters, reproductive performance, histopathological examination, and sex hormone levels were determined scheduled in the experimental rats and their male offspring. The comparative in vitro cytotoxicity of the ZnO NPs was determined among C18-4, TM3, and TM4 cells. The toxicity exerted by ZnO NPs on germ cells in vitro and the effects on the expression of cytoskeleton and blood-testis barrier (BTB)-related proteins were also determined. Results: After oral gavage, ZnO NPs mainly accumulated in the liver and testes of rats; 350 mg/kg ZnO NPs adversely affected the epididymal weight, sperm motility, and hormone levels but did not affect the fertility of rats. In addition, 350 mg/kg ZnO NPs significantly reduced the reproductive and developmental performance of offspring male rats. Testicular histopathological and electron microscopic ultrastructure examinations showed more significant abnormal structural changes than those observed in parental rats. The results of in vitro cell experiments further showed that ZnO NPs exerted cytotoxic effects on germ cells, and led to DNA damage, nucleoskeleton and cytoskeleton alterations, and could regulate actin changes through changes in LC3B. Conclusions: It is possible that ZnO NPs act directly on TM4 cells by penetrating the BTB, causing damage to the cytoskeleton and disrupting the dynamic balance of the BTB, thereby destroying the microenvironment necessary for spermatogenesis, which may lead to poor reproduction in rats.

As regulations ban legacy PFASs, many emerging PFASs are being developed, leading to their release into the aquatic environment and drinking water. However, research studies on these emerging PFASs in drinking water are limited, and current standards only cover a few legacy PFASs, leaving many emerging PFASs unregulated and their toxicity unknown. Therefore, a machine learning-based suspect screening combined with target screening was employed to comprehensively identify and quantify both legacy and novel PFASs in drinking water from the Yangtze River Delta, and their potential sources of contamination were determined through pollutant profile analysis. A total of 30 PFASs were identified, including 16 legacy and 14 novel PFASs, categorized into 11 classes. Quantitative and semi-quantitative analyses revealed that the maximum concentrations of 30 PFASs ranged from <LOQ (limit of quantification) to 48.92 ng/L. Notably, PFPeA (48.92 ng/L), perfluorobutanoic acid (PFBA, 44.83 ng/L), perfluorooctanoic acid (PFOA, 37.72 ng/L), perfluorobutanesulfonic acid (PFBS, 26.77 ng/L), and bis(trifluoromethanesulfonyl)imide (HNTf2, 15.02 ng/L) exhibited higher concentrations compared to other PFASs. The pollutant profile analysis suggested that PFASs in the Yangtze River Delta’s drinking water are more likely to originate from pollution in the upper and middle reaches of the Yangtze River rather than from local industrial emissions. Then, the identified PFASs were prioritized by integrating the PBT (persistence, bioaccumulation, and toxicity) properties of PFASs with environmental exposure data. In the prioritization and risk assessment process, ten high-concern PFASs had Risk Indexes (RIs) higher than those of ref-PFOA and ref-PFOS, including eight legacy PFASs and two novel PFASs. The drinking water of the Yangtze River Delta originates from the surface water of the lower Yangtze River, which accumulates pollutants from its upper and middle reaches, affecting the health of over 20 million people. Our findings indicated the presence of emerging PFASs in the region’s drinking water and demonstrated conceptual models for integrating chemical information from suspect screening with toxicity prediction and risk assessment. Although the current levels of emerging PFASs are relatively low, legacy PFASs still dominate. Further research is needed to identify, monitor, and assess the health and environmental risks of emerging PFASs.

Natural pyrethrins (NPs), one kind of bio-pesticide, have been widely used in organic agriculture and ecological environment studies. Studies have shown that NPs may affect the metabolism of rat liver and human hepatocytes; nevertheless, the toxic effects of NPs on the liver and the related mechanisms are still incompletely understood. In this research, we utilized three types of human liver cells to investigate the mechanism of NPs’ induction of oxidative stress. The results showed that NPs exhibit noteworthy cytotoxic effects on human liver cells. These effects are characterized by the induction of LDH release, mitochondrial collapse, and an increased production of ROS and MDA content, subsequently activating the Kelch-like ECH-associated protein 1/Nuclear factor erythroid 2- related factor 2 (Keap1/Nrf-2) pathway. The ROS inhibitor N-acetyl-L-cysteine (NAC) can alleviate ROS/Nrf2-mediated oxidative stress. In addition, the siRNA knockdown of Nrf-2 exacerbated the injury, including ROS production, and inhibited cell viability. In summary, the ROS-mediated Keap1/Nrf-2 pathway could be an important regulator of NP-induced damage in human liver cells, which further illustrates the hepatotoxicity of NPs and thereby contributes to the scientific basis for further exploration.