The persistent, bioaccumulative, toxic, and resistance (PBTR) risk assessment framework of antibiotics in the drinking water sources.

Antibiotics are emerging pollutants largely considered to have a lower risk based on persistent, bioaccumulative, toxic (PBT) risk assessments. However, an increasing number of studies have illustrated that antibiotics are responsible for the global increase in antimicrobial resistance (AMR), which suggests that the risk of antibiotics has been largely underestimated by using PBT risk assessment. Here, we designed an integrated innovation risk assessment framework of persistent, bioaccumulative, toxic, and resistance (PBTR) that accounts for antibiotic resistance to better represent the antibiotic environmental risk. This novel antibiotic risk assessment framework was further verified via application to 39 target antibiotics in the 23 drinking water sources of the lower Yangtze River (LYR), China, during the normal and flood seasons. In contrast with the PBT assessment, single toxicity assessment and single resistance assessment, in the PBTR assessment, 7 of 39 target antibiotics with bacterial insensitivity were observed to represent a more prominent risk, as were the sites sampled during the flood season with low concentrations but high pollution loads, which confirmed that the sensitivity of PBTR risk assessment was instructive. The PBTR risk assessment for the screened priority antibiotics contributes not only representative data but also an innovative approach for identifying resistance risks. Using the positive matrix factorization (PMF) model, the sources of priority antibiotics can be predicted and thus supported the corresponding policy. Overall, this study first constructed a PBTR risk assessment framework, then applied it to facilitate the accurate management of antibiotic pollution at the basin level.

Comprehensive overview of antibiotic distribution, risk and priority: A study of large-scale drinking water sources from the lower Yangtze River.

Antibiotics have attracted widespread attention around the world because they are ubiquitous in the environment and can lead to antibiotic-resistant microbes developing and pose ecotoxicological risks. In this study, we determined the spatiotemporal distributions of 39 antibiotics in 19 drinking water sources in Jiangsu area of the lower Yangtze River and attempted to identify the sources of the antibiotics and to prioritize the antibiotics. The total antibiotic concentrations in spring and fall were 234.56-6515.99 and 151.12-2562.59 ng/L, respectively. In spring, the total antibiotic concentration gradually increased from upstream to downstream. In fall, the antibiotic concentration did not markedly vary upstream to downstream (total concentrations 151.12-432.17 ng/L) excluding site S9 and S10. Analysis using a positive matrix factorization (PMF) model indicated that the antibiotics had four main sources. Pharmaceutical wastewater was the main source, contributing 34.1% and 41.2% of total antibiotics in spring and fall, respectively, and domestic wastewater was the second most important source, contributing 24.4% and 43% of total antibiotics in spring and fall, respectively. Pharmaceutical wastewater was the main source from midstream to downstream, but the other sources made different contributions in different areas because of the various ranges of human activities. An ecological risk assessment was performed. Stronger risks were posed by antibiotics in spring than fall, and fluoroquinolone antibiotics posed the strongest risks. Optimized risk quotients indicated that norfloxacin was a high-risk contaminant. An assessment of the risk of resistance development indicated that norfloxacin, ciprofloxacin, and enrofloxacin posed moderate to high risks of resistance development and should be prioritized for risk management. The results of this study are important reference data for identifying key sources of antibiotics and developing strategies to manage antibiotic contamination in similar areas.

Spatiotemporal distribution and ecological risk assessment of pharmaceuticals and personal care products (PPCPs) from Luoma Lake, an important node of the South-to-North Water Diversion Project.

PPCPs (pharmaceuticals and personal care products) are widely found in the environment and can be a risk to human and ecosystem health. In this study, spatiotemporal distribution, critical risk source identification and potential risks of 14 PPCPs found in water collected from sampling points in Luoma Lake and its inflowing rivers in two seasons in 2019 and 2020 were investigated. The PPCPs concentrations ranged from 27.64 ng·L-1 to 613.08 ng·L-1 in December 2019, and from 16.67 ng·L-1 to 3287.41 ng·L-1 in April 2020. Ketoprofen (KPF) dominated the PPCPs with mean concentrations of 125.85 ng·L-1 and 640.26 ng·L-1, respectively. Analysis of sources showed that the pollution in Luoma Lake mostly originated from sewage treatment plant effluents, inflowing rivers and domestic wastewater. Among them, the inflowing rivers contributed the most (82.95%) to the concentration of total PPCPs. The results of ecological risk assessment showed that there was a moderate risk (0.1 < RQs < 1) from carbamazepine (CBZ) in December 2019 and a high risk (RQs > 1) from naproxen (NPX) in April 2020. The results of human risk assessment found that NPX posed a high risk to infant health, and we found that NPX was associated with 83 diseases according to Comparative Toxicogenomics Database. NPX was identified as a substance requiring major attention. The results provide an understanding of the concentrations and ecological risks of PPCPs in Luoma Lake. We believe the data will support environmental departments to develop management strategies and prevent PPCPs pollution.

Seasonal variability of the correlation network of antibiotics, antibiotic resistance determinants, and bacteria in a wastewater treatment plant and receiving water.

Sewage treatment plants are an essential source of antibiotics, antibiotic resistance determinants, and bacteria in environmental waters. However, it is still unclear whether they can maintain a relatively stable relationship in wastewater and environmental waters. This study analyzed the removal capacity of the above three pollutants in the sewage treatment plant in summer and their impact on environmental waters, and then examines the relationship between the three contaminants in the wastewater and environmental waters in summer and winter based on our previous study. The results found that the removal capacity of bacteria in summer was poor, the concentration of fluoroquinolone in the effluent was higher than that in influent, and the abundance of intI1, tetW, qnrB, and ermB increased after wastewater treatment. Proteobacteria and Bacteroides were the main bacteria that constitute the correlation network between bacteria, and they existed stably in summer and winter. However, fluoroquinolones occupied a significant position in the determinant network of antibiotics and antibiotic resistance in summer and winter. There are fewer correlation between antibiotics and antibiotics resistance determinants in winter. Interestingly, the relationship between bacteria, antibiotics, and antibiotic resistance determinants was a mainly positive correlation in summer and negative correlation in winter. This study analyzed the relationship between bacteria, antibiotics, and antibiotic resistance determinants that were stable in the wastewater and environmental waters and pointed out the direction for subsequent targeted seasonal control of novel pollutants in wastewater and environmental waters.

Distribution, abundance, and risk assessment of selected antibiotics in a shallow freshwater body used for drinking water, China.

With rapid improvements in industrialization and urbanization, antibiotics are now extensively used to prevent and treat human and animal diseases and husbandry and aquaculture. Some research has been conducted to assess the environmental distribution and risk level of antibiotics, but their distribution remains largely uncharacterized. Thus, this study investigated the distribution and abundance of 39 antibiotics belonging to five groups, and their associated risks in surface water around Luoma Lake in the north of Jiangsu province, China. Nineteen antibiotics were detected, at a detection frequency (DF) ranging from 2.27% to 100%. The total antibiotics (ΣABs) concentrations ranged from 34.91 to 825.93 ng/L, with a median concentration of 195.45 ng/L. Among these antibiotics, chlortetracycline (DF: 100%; median: 172.02 ng/L) was the dominant antibiotic, accounting for a median percentage of 91.0% of ΣABs concentrations. Spearman rank correlation method found a significant correlation between clindamycin (DF: 72.7%; median: 2.01 ng/L) and lincomycin (DF: 79.5%; median: 4.58 ng/L). The ecological risk quotient (RQ) values for two out of 44 sampling sites were higher than 1, indicating a high risk; 11.4% of the RQ values fell between 0.1 and 1, indicating a medium risk. Moreover, roxithromycin was found to be the dominant contributor to the ecological risk, accounting for a median of 79.7% of ΣABs. However, the total non-carcinogenic (<6.54 × 10-4) and carcinogenic risks (<1.64 × 10-7) of ΣABs were negligible at the detected concentrations.

Positive correlation between human exposure to organophosphate esters and gastrointestinal cancer in patients from Wuhan, China.

As kinds of endocrine disruptors, organophosphate esters (OPEs) pollution in the environment had received increasing attention recently. Food and water intake were two important exposure pathways for OPEs. However, the studies about the potential association between OPEs and gastrointestinal cancer were limited. This study investigated the possible association between OPEs and gastrointestinal cancer. All cancer patients were diagnosed with gastrointestinal cancer from a Grade 3 A hospital in Wuhan, China, while the control group was non-cancer healthy persons. The results showed that 6 OPEs were found in the control samples, while 8 in the samples from patients with gastrointestinal cancer. The detection frequencies of OPEs in gastrointestinal cancer patients were significantly higher than those in the control group (p < 0.05 or p < 0.01), except for triethyl phosphate (TEP) and tris (methylphenyl) phosphate (TMPP) in the gastric cancer group. The concentrations of OPEs in the control group were significantly lower than those in the gastric cancer group and colorectal cancer group (p < 0.01). In the control group and gastrointestinal cancer group, TEP was the dominant pollutant. Correlation analysis found that concentrations of TEP, tris(2-chloroisopropyl) phosphate (TCIPP), triphenyl phosphate (TPHP), TMPP, tris(2-ethylhexyl) phosphate (TEHP), and 2-ethylhexyl diphenyl phosphate (EHDPP) were associated with gastric cancer (p < 0.01), and concentrations of TEP, TCIPP, TPHP, TMPP and TEHP were associated with colorectal cancer (p < 0.01). A cluster analysis divided the 34 patients with gastric cancer and 40 patients with colorectal cancer in four groups. The results showed that the elderly male patients with gastric cancer were more sensitive to the exposure of EHDPP, while the TEP exposure was more sensitive to the relatively young gastrointestinal cancer patients. These findings indicated that OPEs might play a role in developing gastrointestinal cancer.

Occurrence and fate of antibiotics, antimicrobial resistance determinants and potential human pathogens in a wastewater treatment plant and their effects on receiving waters in Nanjing, China.

Antibiotics, antimicrobial resistance determinants and human pathogens are new types of environmental pollutants that pose a great threat to human health. Wastewater treatment plants (WWTPs) are important sources of novel pollutants; however, few studies have investigated their impact on surrounding natural water. Therefore, this study used a WWTP as the entry point to explore WWTP removal efficiency of antibiotics, antimicrobial resistance determinants and human pathogens and further analyze the impact of WWTP effluent on receiving waters. The investigated WWTP had a good removal effect on fluoroquinolones, macrolides, lincomycin, sulfanilamide, tetracycline and chloramphenicol antibiotics in wastewater, and the concentration of antibiotics in the WWTP's effluent was reduced by >80% relative to the influent. In addition to cmlA, the effect of the WWTP on antimicrobial resistance determinants removal was poor, although the effluent from the WWTP had no effect on the abundance of antimicrobial resistance determinants in the receiving water. However, with the dilution of receiving water, the abundance of antimicrobial resistance determinants gradually decreased. The WWTP could reduce the abundance of bacteria by 1000 times from influent water to effluent water. The major bacteria in the influent and effluent were Bacteroidetes and Proteobacteria. After effluent is discharged into receiving water, Cyanobacteria proliferate in large quantities, which can affect the microbial structure in the environment.The abundance of Acinetobacter, which was the predominant potential human pathogen in local wastewater, decreased dramatically after wastewater treatment. We also conducted an ecological risk assessment of the antibiotics identified and found that the ecological risk AZM and CLR posed to aquatic organisms was high. Overall, we identified the efficiency of WWTP control of antibiotics, antimicrobial resistance determinants and potential human pathogens and the impact of WWTP effluent on receiving water and provided data to support the control of the investigated pollutants.

Urinary levels, composition profile and cumulative risk of bisphenols in preschool-aged children from Nanjing suburb, China.

Due to the extensive use in consumer products, the bisphenols (BPs) pollution in the environments has aggravated and people are frequently exposed to BPs. In this research, four BPs, i.e., bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF), were determined in urine samples collected from Gaochun District preschool-age children and the concentrations, distribution profiles, potential sources and cumulative risk assessment of the target compounds were studied. Total concentrations of 4 BPs ranged from 2 to 3113.1 ng/L, with the average concentration of 648.6 ng/L. BPA was the predominant congener (accounting for 94%), followed by BPS. Correlation analysis indicated a negative relationship between BPA and BPAF (R = -0.273, p < 0.05). The estimated daily intakes suggested that young females were more sensitive to BPs. Moreover, the cumulative risk for hazard quotient (HQ) of BPA has been evaluated and the results showed that no high risk had occurred. It provided basic information on the occurrence and human exposure to urinary BPs of preschool aged children from Gaochun District.

Food up-take and reproduction performance of Daphnia magna under the exposure of Bisphenols.

Because the application of Bisphenol A (BPA) was restricted, many substitutes, such as Bisphenol F (BPF) and Bisphenol S (BPS), were developed as BPA substitutes. Therefore, environmental impacts of BPA and its substitutes on aquatic organisms should be concerned, especially their combined toxicity. In this study, the impacts of BPA, BPF, BPS and their mixture on the feeding behavior, reproduction and physiological function of daphnids were synthetically evaluated, involving the duration and mode of exposure. In short-term exposure tests, feeding rates of D. magna decreased after exposure to BPA, BPF, BPS and their mixture, while the inhibition reversed into stimulation in the recovery period. It may benefit from overcompensation of D. magna. In long-term exposure tests, the inhibition effect on the reproduction and growth of the exposed D. magna was difficult to recover, and only some experimental groups have a certain recovery. In conclusion, environmental risk of BPA, BPF, BPS and their mixture on the behavior of D. magna increased with prolonged exposure time. Moreover, relative activities of trypsin, amylase (AMS), acetylcholinesterase (AChE), carbonic anhydrase (CA), glutathione peroxidase (GPx) and super oxidase dimutase (SOD) of the exposed daphnids decreased in most treatment groups, indicating the disorder of digestive, nervous and antioxidative system of D. magna. Interestingly, inhibition of enzymes activities decreased with the increase of the exposure time, which implied the tolerance may be occurred.

Distribution and bioaccumulation of endocrine disrupting chemicals in water, sediment and fishes in a shallow Chinese freshwater lake: Implications for ecological and human health risks.

The occurrence, distribution and bioaccumulation of six endocrine disrupting compounds (EDCs) were investigated in water, sediment and biota samples from Luoma Lake, a shallow Chinese freshwater lake. Total concentrations of ∑phenolic EDCs were much higher than ∑estrogens EDCs in both waters and sediments. There were not obvious differences on the concentrations of target compounds [except nonylphenol (NP)] in upstream, lake and downstream locations, these may be suggested that they were mainly affected by non-point discharges in this area. However, the high concentration of NP in water may be associated with the discharge of rural domestic wastewater without thorough treatment. Furthermore, concentrations of NP were about 2-3 order magnitude higher than those of OP in both water and sediment compartments. Relatively higher bioaccumulation factors (BAF) were obtained for DES and EE2. Ecological risk assessment revealed greater risk of NP in surface water, which may pose a serious threat to aquatic ecosystems. The estrogen equivalent concentration (EEQ) of male were higher than those in female, and occurred in the order of city >rural-urban>countryside.

Occurrence, distribution and risk assessment of suspected endocrine-disrupting chemicals in surface water and suspended particulate matter of Yangtze River (Nanjing section).

The occurrence and distribution of eight selected endocrine-disrupting chemicals were investigated in samples of surface water and suspended particulate matter (SPM) in Nanjing section of Yangtze River over a year (the flow period, the wet period and the dry period). All target compounds were detected at least once in surface water with 4-tert-butylphenol (4-TBP), nonyphenol (NP) and bisphenol A (BPA) as the dominant compounds, with concentrations in the range of 225-1121ng/L, 1.4-858ng/L and 1.7-563ng/L, respectively. Except for December, all selected compounds for the other sampling times were not found in all sampling points. NP (mean concentration 69.8µg/g) and BPA (mean concentration 51.8µg/g) were also the dominant estrogens in SPM. In addition, the highest total compounds concentrations were found in December in both phases, which could be due to the low flow conditions and temperature during this season. Meanwhile, a significant positive correlation was found between the total compounds concentrations in the water phase and those in SPM phase. Risk assessment based on the calculated risk quotients (RQ) showed that low and moderate risk for the aquatic environment from presence of the target compounds at all sampling points with exception of 4-TBP and NP which might pose a high risk to aquatic organisms.

TBBPA induces developmental toxicity, oxidative stress, and apoptosis in embryos and zebrafish larvae (Danio rerio).

Tetrabromobisphenol A (TBBPA) is currently one of the most frequently used brominated flame retardants and can be considered as a high production volume chemical. In this study, zebrafish embryos and larvae served as a biological model to evaluate TBBPA-induced developmental toxicity, oxidative stress, oxidant-associated gene expression, and cell apoptosis. Abnormalities, including hyperemia and pericardial edema, were induced in zebrafish larvae. The results showed that toxicity endpoints such as hatching rate, survival rate, malformation rate, and growth rate had a significant dose-response relationship with TBBPA. Further studies revealed that TBBPA did not alter the enzyme activities of Copper/Zinc Superoxide dismutase (Cu/Zn-SOD), catalase (CAT), and glutathioneperoxidase (GPx) at 0.10 mg/L, but decreased activities following exposure to 0.40, 0.70, and 1.00 mg/L. Despite the significantly decreased gene expression of Cu/Zn-SOD, CAT, and GPx1a in the 1.00 mg/L treatment group, other treatments (0.10, 0.40, 0.70 mg/L) did not alter gene expression. Moreover, Acridine orange staining results showed that apoptotic cells mainly accumulated in the brain, heart, and tail, indicating possible TBBPA-induced brain, cardiac, and blood circulation system impairment in zebrafish embryos and larvae. Histological analysis also showed evidence of obvious heart impairment in TBBPA-treated groups. This study provides new evidence on the developmental toxicity, oxidative stress, and apoptosis of embryos and zebrafish larvae, which is important for the evaluation of environmental toxicity and chemical risk. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1241-1249, 2016.

Development of Quantitative Structure-Activity Relationship Models for Predicting Chronic Toxicity of Substituted Benzenes to Daphnia Magna.

The chronic toxicity of anthropogenic molecules such as substituted benzenes to Daphnia magna is a basic eco-toxicity parameter employed to assess their environmental risk. As the experimental methods are laborious, costly, and time-consuming, development in silico models for predicting the chronic toxicity is vitally important. In this study, on the basis of five molecular descriptors and 48 compounds, a quantitative structure-property relationship model that can predict the chronic toxicity of substituted benzenes were developed by employing multiple linear regressions. The correlation coefficient (R (2)) and root-mean square error (RMSE) for the training set were 0.836 and 0.390, respectively. The developed model was validated by employing 10 compounds tested in our lab. The R EXT (2) and RMSE EXT for the validation set were 0.736 and 0.490, respectively. To further characterizing the toxicity mechanism of anthropogenic molecules to Daphnia, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models were developed.

Seminal superoxide dismutase activity and its relationship with semen quality and SOD gene polymorphism.

PURPOSE: Superoxide dismutase (SOD) is an important component of antioxidative defense systems and plays an important role in protecting spermatozoa from oxidative damage. In this study, we assessed seminal SOD activity, its association with semen parameters, and also genetic and non-genetic factors contributing to the determination of SOD activity in infertile men. METHODS: Semen samples were obtained from 435 male infertility patients. Sperm DNA damage levels were detected with the Tdt-mediated dUTP nick end labelling (TUNEL) assay. Four single nucleotide polymorphisms (SNPs) in SOD2 and SOD3 genes were genotyped using OpenArray platform. RESULTS: We found that seminal SOD activity was positively associated with sperm concentration and overall motility, whereas inversely with sperm DNA fragmentation. In addition, infertile men with SOD2 rs4880 CC variants showed a low level of SOD activity when compared with TT carriers (Mean ± SD: 268.3 ± 102.3 and 342.8 ± 98.2, respectively, P = 0.005). Those who consumed vitamin C/E (≥3 times per week) had a significantly higher SOD activity level than those who did not (mean ± SD: 379.8 ± 93.3 and 332.2 ± 94.9, respectively, P = 0.001). CONCLUSIONS: Seminal SOD activity and other factors influencing SOD activity play a role in determining sperm fertilization potential and male infertility.

Efficient and durable oxygen reduction in alkaline media by doping heteroatomic boron into FeSA-NC catalyst.

Despite extensive research has been conducted on atomic dispersion catalysts for various reactions, altering the electronic structure of the central metal to enhance electrochemical reactivity remains a challenging task. Herein, the electrochemical reactivity was considerably enhanced by introducing heteroatomic B to adjust the d-band of single Fe center. In specific, the obtained FeSA-BNC catalyst demonstrated an outstanding ORR performance (E1/2 = 0.87 V) and exhibited greater long-term durability in alkaline media compared to Pt/C. The performance of FeSA-BNC in Zn-air battery was also higher than that of Pt/C. According to theoretical calculations, a downward shift in the d-band center of Fe was induced by introducing B, thereby improving the desorption of intermediates and facilitating the oxygen reduction reaction (ORR).

ACAT1 suppresses clear cell renal cell carcinoma progression by AMPK mediated fatty acid metabolism.

Renal cell carcinoma (RCC) stands as a prevalent malignancy within urological pathology, exhibiting a noteworthy escalation in its incidence. Despite being a mitochondrial enzyme, the precise role of Acetyl-CoA Acetyltransferase 1 (ACAT1) in RCC remains elusive. In this investigation, we employed bioinformatics methodologies to assess the expression patterns and prognostic significance across various RCC subtypes, encompassing clear cell renal cell carcinoma (ccRCC), papillary cell carcinoma, and chromophobe cell carcinoma. Our findings unveil a close correlation between ACAT1 expression and the prognostic implications specifically within ccRCC. Through both in vitro and in vivo overexpression studies, we delineated the functional and mechanistic facets of ACAT1 in impeding the progression of ccRCC. Our results unequivocally demonstrated that ACAT1 overexpression markedly curtailed proliferation, invasion, and metastasis of ccRCC cells in both in vivo models and cell cultures. Mechanistically, ACAT1's inhibitory effect on the AMPK signaling pathway orchestrated a regulatory role in modulating fatty acid metabolism, thereby effectively restraining the advancement of ccRCC. Collectively, our findings underscore ACAT1 as a pivotal tumor suppressor, instrumental in curtailing the proliferation, migration, and invasion of ccRCC by governing fatty acid metabolism through the AMPK signaling pathway. These insights posit ACAT1 as a potential predictive biomarker and therapeutic target warranting further exploration in RCC management.

Development of efficient and economic Bi2O3/BN/Co3O4 composite photocatalyst: Degradation mechanism, pathway and toxicity study of norfloxacin.

The production of cheap, efficient, and stable photocatalysts for degrading antibiotic contaminants remains challenging. Herein, Bi2O3/boron nitride (BN)/Co3O4 ternary composites were synthesized using the impregnation method. The morphological characteristics, structural features, and photochemical properties of the prepared photocatalysts were investigated via X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and ultraviolet-visible (Vis) diffuse reflectance spectrum techniques. BN was used as a charge transfer bridge in the ternary composites, which afforded a heterojunction between the two semiconductors. The formation of the heterojunction substantially enhanced the charge separation and improved the photocatalyst performance. The degradation activity of the Bi2O3/BN/Co3O4 ternary composites against norfloxacin (NOR) under Vis light irradiation was investigated. The degradation rate of NOR using 5-wt% Bi2O3/BN/Co3O4 reached 98% in 180 min, indicating excellent photocatalytic performance. The ternary composites also exhibited high photostability with a degradation efficiency of 88.4% after five cycles. Hydroxyl radicals (•OH), superoxide radicals (•O2-), and holes (h+) played a synergistic role in the photocatalytic reaction, where h+ and •O2- were more important than •OH. Consequently, seven intermediates and major photocatalytic degradation pathways were identified. Toxicity experiments showed that the toxicity of the degradation solution to Chlorella pyrenoidosa decreased. Finally, the ecotoxicity of NOR and its intermediates were analyzed using the Toxicity Estimation Software Tool, with most intermediates exhibiting low toxicity.

Unraveling drivers of per- and polyfluoroalkyl substances (PFASs) occurrence and removal in leachate: Insights from disposal methods, geo-climate, and biodegradation.

Leachate is a substantial reservoir of per- and polyfluoroalkyl substances (PFASs) within the environment. However, comprehensive information on the occurrence and fate of PFASs in leachate, particularly in semi-arid and moderate-elevation regions where PFASs may aggregate, is lacking. Here, 13 legacy PFASs were investigated in leachate from landfills and an incineration plant in such area. PFASs concentrations ranged from 6063 to 43,161 ng·L-1 in raw leachate, influenced by leachate origin, climate, wastewater disposal, and especially bacterial communities. Bacteroidetes and Firmicutes were enriched in raw leachate, while Proteobacteria dominated during leachate treatment processes, possibly due to PFASs selection pressure. In addition, top 20 biomarkers indicated the potential of these bacterial indicators for PFASs detection. Tracing analysis also suggested that PFASs in groundwater may have originated from leachate and effluent from wastewater treatment plants. PFASs levels in groundwater showed a significant correlation with the presence of Brevundimonas, Leptothrix, Malikia, and Sphaerotilus. The pathogenic bacterium Brevundimonas suggested potential human health risks, while Leptothrix, Malikia, and Sphaerotilus may serve as indicators of groundwater contamination. This study is believed to provide insights into how to prevent and control PFASs-related environmental pollution.

Bulky DNA adducts in human sperm associated with semen parameters and sperm DNA fragmentation in infertile men: a cross-sectional study.

BACKGROUND: DNA adducts are widely used marker of DNA damage induced by environmental pollutants. The present study was designed to explore whether sperm polycyclic aromatic hydrocarbon-DNA adducts were associated with sperm DNA integrity and semen quality. METHODS: A total of 433 Han Chinese men were recruited from an infertility clinic. Immunofluorescence was applied to analyze sperm PAH-DNA adducts. Sperm DNA fragmentation was detected by terminal deoxynucleotidyl transferase (Tdt)-mediated dUTP nick end labelling (TUNEL) assay. RESULTS: After adjustment for potential confounders using linear regression, sperm PAH-DNA adducts were negatively associated with sperm concentration, total sperm count, sperm motility, and curvilinear velocity (VCL). In addition, a positive relationship between sperm PAH-DNA adducts and sperm DNA fragmentation was found. CONCLUSIONS: Our findings suggested an inverse association between sperm PAH-DNA adducts and semen quality, and provided the first epidemiologic evidence of an adverse effect of PAH-DNA adducts on sperm DNA integrity.