Discovery of novel benzotriazole ultraviolet stabilizers in surface water.

The comprehensive understanding of the occurrence of benzotriazole UV stabilizers (BZT-UVs) in environmental surface water is imperative due to their widespread application and potential aquatic toxicity. We conducted an analysis of 13 traditional BZT-UVs in surface water samples collected from Taihu Lake (TL, n = 23) and Qiantang River (QR, n = 22) in China. The results revealed that 5­chloro-2-(3,5-di-tertbutyl-2-hydroxyphenyl)-benzotriazole (UV-327) was consistently the predominant BZT-UV in water samples from TL (mean 16 ng/L; detection frequency 96 %) and QR (14 ng/L; 91 %). Furthermore, we developed a characteristic fragment ion-based strategy to screen and identify unknown BZT-UVs in collected surface water, utilizing a high-resolution mass spectrometer. A total of seven novel BZT-UVs were discovered in water samples, and their chemical structures were proposed. Four of these novel BZT-UVs were further confirmed with standards provided by industrial manufacturers. Semi-quantitative analysis revealed that among discovered novel BZT-UVs, 2-(2­hydroxy-3­tert­butyl­5-methylphenyl)-benzotriazole was consistently the predominant novel BZT-UV in TL (mean 4.1 ng/L, detection frequency 70 %) and QR (2.8 ng/L, 77 %) water. In TL water, the second predominant novel BZT-UV was 2-(3-allyl-2­hydroxy-5-methylphenyl)-2H-benzotriazole (mean 3.9 ng/L,

Conjugated bisphenol S metabolites in human serum and whole blood.

Studies have shown that bisphenol S (BPS) is mainly present as its conjugated metabolites in human blood. However, the distribution of conjugated BPS metabolites in different human blood matrices has not been characterized. In this study, paired human serum and whole blood samples (n = 79) were collected from Chinese participants, and were measured for the occurrence of BPS and 4 BPS metabolites. BPS was detectable in 49% of human serum (

Evidence of promoting effects of 6:2 Cl-PFESA on hepatocellular carcinoma proliferation in humans: An ideal alternative for PFOS in terms of environmental health?

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic chemicals, encompassing compounds like perfluorooctane sulfonate (PFOS), which have widespread applications across various industries, including food packaging and firefighting. In recent years, China has increasingly employed 6:2 Cl-PFESA as an alternative to PFOS. Although the association between PFAS exposure and hepatocellular carcinoma (HCC) has been demonstrated, the underlying mechanisms that promote HCC proliferation are uncleared. Therefore, we aimed to investigate the effects and differences of PFOS and 6:2 Cl-PFESA on HCC proliferation through in vivo and in vitro tumor models. Our results reveal that both PFOS and 6:2 Cl-PFESA significantly contribute to HCC proliferation in vitro and in vivo. Exposure led to reduced population doubling times, enlarged cell colony sizes, enhanced DNA synthesis efficiency, and a higher proportion of cells undergoing mitosis. Furthermore, both PFOS and 6:2 Cl-PFES) have been shown to activate the PI3K/AKT/mTOR signaling pathway and inhibit necroptosis. This action consequently enhances the proliferation of HCC cells. Our phenotypic assay findings suggest that the tumorigenic potential of 6:2 Cl-PFESA surpasses that of PFOS; in a subcutaneous tumor model using nude mice, the mean tumor weight for the 6:2 Cl-PFESA-treated cohort was 2.33 times that observed in the PFOS cohort (p < 0.01). Despite 6:2 Cl-PFESA being considered a safer substitute for PFOS, the pronounced effects of this chemical on HCC cell growth warrant a thorough assessment of hepatotoxicity risks linked to its usage.

Presence of carbazole and polyhalogenated carbazoles in human urine.

Exposure to carbazole (CZ) and polyhalogenated carbazoles (PHCZs) may pose a threat to human health, owing to their potential dioxin-like toxicity. Until now, the presence of these chemicals in the human urine from the general population is still unclear. Human urine samples (n = 210) were taken from the general population in Quzhou, China in this study, and were analyzed for CZ and 14 PHCZs. CZ and nine PHCZs were detected in collected human urine. CZ (detection frequency 100 %), 3-chlorocarbazole (3-CCZ; 88 %), 3,6-dichlorocarbzole (36-CCZ; 84 %), and 3-bromocarbazole (3-BCZ; 80 %) were more frequently detected. Among detected PHCZs, 3-CCZ (mean 0.49 ng/mL, < LOD-4.3 ng/mL) had comparatively higher urinary levels, followed by 3-BCZ (0.30 ng/L, < LOD-1.9 ng/mL) and 36-CCZ (0.20 ng/L, < LOD-1.4 ng/mL). Urinary concentrations of CZ in male participants (1.3 ± 0.26 ng/mL) were significantly (p < 0.05) higher than that in female participants (0.92 ± 0.24 ng/mL). No obvious trend in urinary concentrations with the age of participants was found for CZ and detected PHCZs. The mean daily excretion was found highest for CZ (31 ng/kg bw/day), followed by 3-CCZ (19 ng/kg bw/day) and 3-BCZ (8.5 ng/kg bw/day). This study provides the first data, to our knowledge, on the presence and levels of CZ and PHCZs in human urine, which is necessary for conducting the human exposure risk assessment.

Sediment-seawater partitioning, bioaccumulation, and biomagnification of perfluorobutane sulfonamide in marine environment.

Environmental occurrence of perfluorobutane sulfonamide (PFBSA) has only been recently discovered. The current knowledge regarding the occurrence and environmental behaviors of PFBSA in the marine environment is still relatively limited. In this study, PFBSA and other 37 poly- and perfluoroalkyl substances were analyzed in seawater (n = 43), sediment (n = 43), and marine fish (n = 176) samples collected from East China Sea and Antarctic Ocean. PFBSA was detected in > 90% of seawater from East China Sea and Antarctic Ocean, with the concentrations of 1.0 - 19 ng/L and < LOD-228 pg/L, respectively. The field-based mean log-transformed sediment-seawater partitioning coefficients of PFBSA were 1.6 ± 0.19 L/kg dw and 1.1 ± 0.19 L/kg dw in East China Sea and Antarctic Ocean, respectively, which are lower than that of perfluorooctanoate and perfluorooctane sulfonate. This indicates its long-range transport potential in global oceans with ocean currents. The mean log-transformed bioaccumulation factor values of PFBSA determined in the multiple species of whole-body marine fishes from East China Sea and Antarctic Ocean were 2.3 L/kg ww and 2.4 L/kg ww, respectively, which are comparable to that of perfluoroheptanoate (2.3 L/kg ww) in marine fishes from East China Sea. We did not observe an obvious biomagnification or biodilution of PFBSA along the marine food chain in East China Sea or Antarctic Ocean. This study provides the first data on the environmental behaviors of PFBSA in the marine environment.

Identification of key factors affecting neonicotinoid residues in crops and risk of dietary exposure.

Neonicotinoids, widely used on farmland, are ubiquitous in food; however, their distribution among various crops and associated exposure risks at the provincial level in China remain unclear. We collected 19 types of crop samples (fruits, vegetables, and tea) from farmland in nine prefectural cities in Zhejiang Province, China. We analyzed nine commonly used neonicotinoids in the edible portions of these crops. A notable detection rate (42.1 %-82.9 %) and high residual neonicotinoid concentrations (278 ± 357 ng/g) were observed. Tea exhibited the highest residue, followed by fruits, and vegetables showed the lowest (P < 0.05). Neonicotinoid ratios in crops to soil (R_C/S) and soil to water (R_S/W) were defined to discern insecticide distribution across different environments. Increased water solubility leads to increased migration of neonicotinoids (R_S/W) from agricultural soils to water through runoff, thereby increasing the relative contribution of nitenpyram and dinotefuran in water. In comparison with other studied compounds, all crops demonstrated the strongest soil uptake of thiamethoxam, denoted by the highest R_C/S value. Elevated R_C/S values in tea, pickled cabbage, and celery suggest increased susceptibility of these crops to neonicotinoid absorption from the soil (P < 0.05). Estimated dietary intake for teenagers, adults and elders was 8.9 ± 0.5, 8.9 ± 0.6, and 8.8 ± 0.3 µg/kg/d, respectively, below the reference dose (57 µg/kg/d). Teenagers, compared to adults and elders, exhibited significantly higher neonicotinoid exposure through fruit consumption, emphasizing the need for increased attention to neonicotinoid exposure among vulnerable populations.

Distribution of parabens and 4-HB in human blood.

Human blood has been commonly and routinely analyzed to determine internal human exposure to parabens. However, data on the occurrence of parabens and their common metabolite, p-hydroxybenzoic acid (4-HB), in different human blood matrixes is still limited. In this study, 139 pairs of serum and whole blood samples were collected from Chinese adults, and then analyzed them for 5 parabens and 4-HB. Methylparaben (MeP) and propylparaben (PrP) were consistently the predominant parabens in human serum (mean 2.3 and 2.1 ng/mL, respectively) and whole blood (1.9 and 1.3 ng/mL, respectively). Mean concentrations of 4-HB in human serum and whole blood were 7.7 and 12 ng/mL, respectively. Concentrations of parabens, except benzylparaben (BzP), and 4-HB in human serum were significantly (p < 0.01) correlated with that in whole blood. Distribution pattern of parabens and 4-HB in human blood was evaluated, for the first time, based on their partitioning between human serum and whole blood (Kp). Mean Kp values of parabens, except BzP, increased with the alkyl chain length from 0.83 to 1.6. BzP (mean 1.4) had a comparable mean Kp value to PrP (mean 1.4). Among target analytes, 4-HB had the lowest mean Kp value (0.75). These data are important to select appropriate blood matrixes for conducting human exposure assessment and epidemiological studies on parabens.

Occurrence and partitioning of p-phenylenediamine antioxidants and their quinone derivatives in water and sediment.

p-Phenylenediamine antioxidants (PPDs) and PPDs-derived quinones (PPDQs) may pose a threat to the river ecosystem. However, the knowledge on the occurrence and environmental behaviors of PPDs and PPDQs in the natural river environment remains unknown. In this study, we collected paired water (n = 30) and sediment samples (n = 30) from Jiaojiang River, China and analyzed them for nine PPDs and seven PPDQs. Our results showed that target PPDs and PPDQs are frequently detected in water samples, with the dominance of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD; mean 12 ng/L, range 4.0-72 ng/L) and 6PPD-derived quinone (6PPDQ; 7.0 ng/L,

Occurrence of p-phenylenediamine antioxidants in human urine.

General populations are widely exposed to various p-phenylenediamine antioxidants (PPDs). N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), a typical p-phenylenediamine antioxidant, has been detected in human urine samples. However, the occurrence of other widely used PPDs in human urine is still unclear. This study comprehensively characterized the occurrence of 9 PPDs in human urine from 151 Chinese adults. Our results showed that all target PPDs were detected in human urine samples, with the total concentrations of PPDs ranging from 0.41 to 38 ng/mL. PPDs in human urine was dominated by 6PPD (mean 1.2 ng/mL, range < LOD - 3.8 ng/mL), followed by N-phenyl-N'-cyclohexyl-p-phenylenediamine (CPPD; 0.85 ng/mL,

Association of serum bisphenols, parabens, and triclosan concentrations with Sjögren Syndrome in the Hangzhou, China population.

Exposure to endocrine-disrupting chemicals (EDCs) has been linked to various immune deficiency disorders, including autoimmune diseases like Sjögren Syndrome (SjS). However, the detrimental effects of exposure to EDCs, including bisphenols, parabens, and triclosan (TCS), on SjS have been inadequately documented. Thus, we conducted a cross-sectional study that included both healthy individuals (controls) and patients with SjS (cases). We assessed serum concentrations of bisphenol A (BPA), bisphenol S (BPS), methyl parabens (MeP), ethyl parabens (EtP), and TCS. The relationship between the five EDCs levels and the risk of SjS was also explored. Additionally, we conducted an in-depth analysis of the collective influence of these EDCs mixtures on SjS, employing a weighted quantile sum regression model. Out of the five EDCs analyzed, EtP displayed the highest mean concentration (2.80 ng/mL), followed by BPA (2.66 ng/mL) and MeP (1.99 ng/mL), with TCS registering the lowest level (0.36 ng/mL). Notably, BPS exposure was significantly positively associated with the risk of being diagnosed with SjS (with an odds ratio [OR] of 1.17, p = 0.042). No statistically significant associations with SjS were observed for BPA, MeP, EtP, and TCS (p > 0.05). And we did not observe any significant effects of the EDCs mixture on SjS. To the best of our knowledge, this study is the first to suggest that BPS may potentially increase the risk of SjS. Although no significant effects were observed between other EDCs and SjS risk, we cannot disregard the potential harm of EDCs due to their non-monotonic dose response.

Environment relevant exposure of perfluorooctanoic acid accelerates the growth of hepatocellular carcinoma cells through mammalian target of rapamycin (mTOR) signal pathway.

Perfluorooctanoic acid (PFOA), a synthetic alkyl chain fluorinated compound, has emerged as a persistent organic pollutant of grave concern, casting a shadow over both ecological integrity and humans. Its insidious presence raises alarms due to its capacity to bioaccumulate within the human liver, potentially paving the treacherous path toward liver cancer. Yet, the intricate mechanisms underpinning PFOA's role in promoting the growth of hepatocellular carcinoma (HCC) remain shrouded in ambiguity. Here, we determined the proliferation and transcription changes of HCC after PFOA exposure through integrated experiments including cell culture, nude mice tests, and colony-forming assays. Based on our findings, PFOA effectively promotes the proliferation of HCC cells within the experimental range of concentrations, both in vivo and in vitro. The proliferation efficiency of HCC cells was observed to increase by approximately 10% due to overexposure to PFOA. Additionally, the cancer weight of tumor-bearing nude mice increased by 87.0% (p < 0.05). We systematically evaluated the effects of PFOA on HCC cells and found that PFOA's exposure can selectively activate the PI3K/AKT/mTOR/4E-BP1 signaling pathway, thereby playing a pro-cancer effect on HCC cells Confirmation echoed through western blot assays and inhibitor combination analyses. These insights summon a response to PFOA's dual nature as both an environmental threat and a promoter of liver cancer. Our work illuminates the obscured domain of PFOA-induced hepatoxicity, shedding light on its ties to hepatocellular carcinoma progression.

Occurrence of p-phenylenediamine antioxidants (PPDs) and PPDs-derived quinones in indoor dust.

The p-phenylenediamine antioxidants (PPDs) have been widely detected in various dust samples. Nevertheless, the knowledge on occurrence of their environmental transformation products, PPD-derived quinones (PPDQs), in indoor dust remains limited. In this study, indoor dust samples (n = 97) were collected from Hangzhou, China, and analyzed for PPDs and PPDQs. Results showed that nine PPDs were detected in indoor dust samples, with the total concentrations of 1.7-223 ng/g. N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD, mean 17 ng/g) was the predominant PPDs in indoor dust, followed by N, N'-di(o-tolyl)-p-phenylenediamine (DTPD, 8.6 ng/g) and N-(1,3-dimethylbutyl)-N'-(p-tolyl)-p-phenylenediamine (DMTPD, 4.7 ng/g). Five PPDQs were detected in indoor dust samples. Among detected PPDQs, 6PPDQ (14 ng/g, 0.33-82 ng/g) had the highest mean concentration, followed by DTPDQ (5.9 ng/g, < LOD-31 ng/g) and DPPDQ (2.2 ng/g, < LOD-11 ng/g). We also estimated the daily intake (DI) of PPDs and PPDQs through indoor dust ingestion. Infants had higher mean DIs of PPDs and PPDQs than children and adults. Notably, to our knowledge, this study first reports the occurrence of three novel PPDs and four novel PPDQs in indoor dust samples. More studies are needed to reveal the potential human health risks of exposure to these newly identified chemicals.

Occurrence of microplastics in Antarctic fishes: Abundance, size, shape, and polymer composition.

Presence of microplastics (MPs) in Antarctic ecosystems has attracted global attention, due to the potential threat to the Antarctic marine organisms. However, data on the occurrence of MPs in Antarctic fishes remains very limited. This study investigated the abundance and characteristics of MPs in four species of Antarctic fish (n = 114). The highest mean abundance of MPs was detected in Trematomus eulepidotus (1.7 ± 0.61 items/individual), followed by that in Chionodraco rastrospinosus (1.4 ± 0.26 items/individual), Notolepis coatsi (1.1 ± 0.57 items/individual), and Electrona carlsbergi (0.72 ± 0.19 items/individual). MPs in Notolepis coatsi (mean 747 µm) had the highest mean size, followed by that in Trematomus eulepidotus (653 µm), Chionodraco rastrospinosus (629 µm), and Electrona carlsbergi (473 µm). This is possibly attributed to the feeding habits and egestion behaviors of different Antarctic fishes. Fiber was consistently the predominant shape of MPs in Trematomus eulepidotus, Chionodraco rastrospinosus, and Electrona carlsbergi, accounting for 82 %, 76 %, and 60 % of total items of MPs, respectively. Polypropylene, polyamide, and polyethylene were the predominant polymer composition of MPs in Antarctic fishes, collectively contributed 63-86 % of total items of MPs. This may be because these types of MPs have been widely used in global household materials. To our knowledge, this is the most comprehensive study examining the occurrence of MPs in Antarctic fishes. This study provides fundamental data for evaluating the risks of MP exposure for Antarctic fishes.

The toxic mechanism of 6:2 Cl-PFESA in adolescent male rats: Endocrine disorders and liver inflammation regulated by the gut microbiota-gut-testis/liver axis.

In previous studies, 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA), a perfluorooctanesulfonate alternative, has been demonstrated to be toxic to mammals. However, the toxic mechanism of 6:2 Cl-PFESA in mammals is unknown. Herein, adolescent male rats were administered 50 µg/kg/Day 6:2 Cl-PFESA for 28 days (oral gavage) to estimate the toxicity of 6:2 Cl-PFESA and investigate its toxic mechanism. Significant changes in some hematological indicators (e.g., aspartate transaminase and neutrophils) and liver sections (inflammatory cell infiltration) indicated that 6:2 Cl-PFESA exposure caused rat hepatotoxicity. Six steroid hormones (e.g., testosterone, progesterone, and cortisol) in serum and thirteen genes in testicles (related to the pathway of steroid hormone biosynthesis) were significantly regulated in 6:2 Cl-PFESA-treated rats. This suggested that 6:2 Cl-PFESA induced rat endocrine disorders. Compared to the controls, the mean relative abundance of Ruminococcaceae, Pasteurellaceae, Micrococcaceae, and Desulfovibrionaceae was significantly regulated by 1.3-, 0.40-, 0.32-, and 3.2-fold in the 6:2 Cl-PFESA rats, respectively. The 6:2 Cl-PFESA treatment also significantly disturbed 47 gut metabolites (29 upregulated and 18 downregulated), mainly bile acids, short-chain fatty acids, and amino acids. In summary, 6:2 Cl-PFESA induced endocrine disorders and liver inflammation in rats by altering the gut microbiota-gut-testis/liver axis. This study first reveals the toxic mechanism of 6:2 Cl-PFESA in mammals through a multiomics approach and provides comprehensive insight into the toxic mechanism of 6:2 Cl-PFESA.

Organophosphate esters concentrations in human serum and their associations with Sjögren syndrome.

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers due to their excellent properties. The interference of OPEs on immune function has been proven, but the epidemiological data on OPEs exposure to related immune function diseases, such as sjögren syndrome (SjS), is limited. In cross-sectional study, 283 serum samples were collected from healthy individuals (n = 145) and patients with SjS (n = 138) in Hangzhou, China. Eight OPEs, triethyl phosphate (TEP), tributyl phosphate (TBP), tris (2-chloroethyl) phosphine (TCEP), triphenyl phosphate (TPHP), tri (1-chloro-2-propyl) phosphate (TCIPP), 2-ethylhexyldi-phenyl phosphate (EHDPP), tris (1,3-dichloro-2-propyl) phosphate (TDCIPP), and tri (2-butoxyethyl) phosphate (TBOEP), were frequently measured in serum samples. In addition, we explored the associations between the serum OPEs concentration and the risk of SjS. Results showed that TEP (mean controls 2.17 and cases 3.63 ng/mL) was the most abundant OPEs in the serum samples of the control and case groups, followed by TCIPP (mean controls 0.54 and cases 0.78 ng/mL). Serum TEP, TPHP, and EHDPP concentrations were positively correlated with SjS [odds ratio (OR): 1.97, 1.96, and 2.42, respectively; 95% confidence interval (CI):1.34-2.89, 1.34-2.87, and 1.34-2.87, respectively] in the adjusted model, and a negative correlation of TBP concentrations with SjS in the adjusted model (OR: 0.35, 95% CI: 0.17-0.70) was observed. Compared with the lowest quartile concentrations, the ORs of SjS at the highest quartile concentrations of TEP (OR: 4.93, 95% CI: 2.24-10.82) and TPHP (OR: 4.75, 95% CI:1.89-11.94) were significantly higher. This study suggests that human exposure to OPEs may increase the risk of SjS.

Microplastics in terrestrial insects, long-horned beetles (Coleoptera: Cerambycidae), from China.

Despite studies have proposed that microplastics (MPs) could exert adverse effects on terrestrial ecosystems and biota, the occurrence of MPs in wild terrestrial insects has been rarely investigated. This study examined MPs in 261 long-horned beetle (Coleoptera: Cerambycidae) samples collected from four different Chinese cities. Detection frequency of MPs in long-horned beetles from different cities was 68-88 %. Long-horned beetles from Hangzhou (4.0 items/individual) had the highest mean abundance of MPs, followed by that from Wuhan (2.9 items/individual), Kunming (2.5 items/individual), and Chengdu (2.3 items/individual). The mean size of MPs in long-horned beetles from four Chinese cities was 381-690 µm. Fiber consistently represented the major shape of MPs in long-horned beetles from different Chinese cities, contributing 60, 54, 50, and 49 % of total items of MPs in Kunming, Chengdu, Hangzhou, and Wuhan, respectively. Polypropylene was the major polymer composition of MPs in long-horned beetles from Chengdu (68 % of total items of MPs) and Kunming (40 %). However, polyethylene and polyester were the major types of polymer compositions of MPs in long-horned beetles from Wuhan (39 % of total MP items) and Hangzhou (56 %), respectively. To our knowledge, this is the first study investigating the occurrence of MPs in wild terrestrial insects. These data are important for evaluating the risks of exposure to MPs for long-horned beetles.

Mass spectrometry-based multimodal approaches for the identification and quantification analysis of microplastics in food matrix.

Background: Microplastics (MPs) and nanoplastics (NPs) have become emerging contaminants worldwide in food matrices. However, analytical approaches for their determination have yet to be standardized. Therefore, a systematic study is urgently needed to highlight the merits of mass spectrometry (MS) based methods for these applications. Purpose: The aim of the study is to review the current status of MS-based multimodal analysis for the determination of MPs in food matrices. Methods: Web of Science and Google Scholar databases were searched and screened until Jan. 2023. Inclusion criteria: "publication years" was set to the last decades, "English" was selected as the "language," and "research area" was set to environmental chemistry, food analysis and polymer science. The keywords were "microplastics," "nanoplastics," "determination," "identification/quantification," and "mass spectrometry." Results: Traditional spectrometry techniques offer good abilities to conduct the multimodal analysis of MPs in terms of color, shape and other morphologies. However, such technologies have some limitations, in particular the relatively high limits of detection. In contrast, MS-based methods supply excellent supplements. In MS-based methods, gas chromatographic-mass spectrometry (GC-MS), and LC-MS/MS were selected as representative methods for determining MPs in the food matrices, while specialized MS methods (i.e., MALDI-ToF MS and ToF-SIMS) were considered to offer great potential in multimodal analysis of MPs especially when interfaced with the imaging systems. Significance: This study will contribute to gaining a deeper insight into the assessment of the exposure levels of MPs in human body, and may help build a bridge between the monitoring studies and the toxicology field.

Metabolomics and transcriptomics reveal the toxic mechanism of Cd and nano TiO2 coexposure on rice (Oryza sativa L.).

Engineered nanoparticles (ENPs) can resist heavy metal toxicity in plants, but their coexposure still exhibits toxicity to plants compared to plants without exposure to ENPs and heavy metals. There have been few studies on the toxic mechanism of nano TiO2-heavy metal coexposure and the effect mechanism of nano TiO2 in plants. Thus, transcriptomics and metabolomics were used to study the toxic mechanism of rutile nano TiO2 or TiO2-Cd (rutile nano TiO2 and CdCl2 mixture) on rice (Oryza sativa L.). After 40 days of exposure, the plant height and root dry weight of rice were significantly decreased in the nano TiO2-Cd group compared to the blank group (nano TiO2 and CdCl2 free). After Cd treatment, 423 differentially expressed genes (DEGs) and 16 differential metabolites were identified. Nano TiO2 exposure induced significant regulation of 299 DEGs and 6 metabolites. After nano TiO2-Cd coexposure, 1660 DEGs and 181 differential metabolites were identified. Notably, the EDGs (e.g., chalcone isomerase and hydroxycinnamoyl transferase) and differential metabolites (e.g., chrysin and galangin) demonstrated the disruption of flavonoid biosynthesis in Cd-treated rice. After rice was exposed to nano TiO2, the DEGs were related to ribosome, whereas the differential metabolites were associated with pyruvate metabolism and valine, leucine, and isoleucine biosynthesis. Furthermore, 14 DEGs (e.g., asparaginyl-tRNA synthetase and methionyl-tRNA formyltransferase) involved in aminoacyl-tRNA biosynthetic pathways were significantly upregulated in rice treated with nano TiO2-Cd, in line with the changes in related metabolites (e.g., L-asparagine and 10-formyltetrahydrofolate). Our results show that it is necessary to pay close attention to the toxicity of nano TiO2-Cd coexposure in paddy ecosystems and use ENPs with caution to combat the phytotoxicity of heavy metals.

Influence of Gut Microbiota on Metabolism of Bisphenol A, a Major Component of Polycarbonate Plastics.

Bisphenol A (BPA) is a major component of polycarbonate plastics and epoxy resins. While many studies have investigated the effect BPA exposure has upon changes in gut microbial communities, the influence of gut microbiota on an organism's ability to metabolize BPA remains comparatively unexplored. To remedy this, in this study, Sprague Dawley rats were intermittently (i.e., at a 7-day interval) or continuously dosed with 500 µg BPA/kg bw/day for 28 days, via oral gavage. In the rats which underwent the 7-day interval BPA exposure, neither their metabolism of BPA nor their gut microbiota structure changed greatly with dosing time. In contrast, following continuous BPA exposure, the relative level of Firmicutes and Proteobacteria in the rats' guts significantly increased, and the alpha diversity of the rats' gut bacteria was greatly reduced. Meanwhile, the mean proportion of BPA sulfate to total BPA in rat blood was gradually decreased from 30 (on day 1) to 7.4% (by day 28). After 28 days of continuous exposure, the mean proportion of BPA glucuronide to total BPA in the rats' urine elevated from 70 to 81%, and in the rats' feces the mean proportion of BPA gradually decreased from 83 to 65%. Under continuous BPA exposure, the abundances of 27, 25, and 24 gut microbial genera were significantly correlated with the proportion of BPA or its metabolites in the rats' blood, urine, and feces, respectively. Overall, this study principally aimed to demonstrate that continuous BPA exposure disrupted the rats' gut microbiota communities, which in turn altered the rats' metabolism of BPA. These findings contribute to the better understanding of the metabolism of BPA in humans.

Development of QuEChERS coupled with UHPLC-MS/MS for simultaneous determination of eight neonicotinoid pesticides in breast milk.

A speedy and hypersensitive method was built to detect eight neonicotinoid insecticides (neonics) in breast milk by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The breast milk was extracted with a mixture of acetonitrile and water and purified with primary secondary amine (PSA) and C18. The recovery of the method ranged from 74.3 to 105.9% with relative standard deviations (RSDs) of less than 10%, and the limit of detection ranged from 0.05 to 0.18 ng/mL. Among 32 samples obtained from women 1 month postpartum, thiamethoxam and imidacloprid were the most frequently detected neonics. Moreover, thiacloprid and imidaclothiz were not detected in any samples. The concentrations of neonics in breast milk ranged from 1.90 to 149.95 ng/mL. Considering the toxic effects on mammals and even humans, infants who are exposed to neonics through ingestion of breast milk should receive extensive attention in future studies.