BACKGROUND: Carbon monoxide (CO), hypothetically linked to prebiotic biosynthesis and possibly the origin of the life, emerges as a substantive growth substrate for numerous microorganisms. In anoxic environments, the coupling of CO oxidation with hydrogen (H2) production is an essential source of electrons, which can subsequently be utilized by hydrogenotrophic bacteria (e.g., organohalide-respring bacteria). While Dehalococcoides strains assume pivotal roles in the natural turnover of halogenated organics and the bioremediation of chlorinated ethenes, relying on external H2 as their electron donor and acetate as their carbon source, the synergistic dynamics within the anaerobic microbiome have received comparatively less scrutiny. This study delves into the intriguing prospect of CO serving as both the exclusive carbon source and electron donor, thereby supporting the reductive dechlorination of trichloroethene (TCE).
RESULTS: The metabolic pathway involved anaerobic CO oxidation, specifically the Wood-Ljungdahl pathway, which produced H2 and acetate as primary metabolic products. In an intricate microbial interplay, these H2 and acetate were subsequently utilized by Dehalococcoides, facilitating the dechlorination of TCE. Notably, Acetobacterium emerged as one of the pivotal collaborators for Dehalococcoides, furnishing not only a crucial carbon source essential for its growth and proliferation but also providing a defense against CO inhibition.
CONCLUSIONS: This research expands our understanding of CO\'s versatility as a microbial energy and carbon source and unveils the intricate syntrophic dynamics underlying reductive dechlorination.

Synthesizing cubic spinel Cu2MnO4 with nanosheet structure (SCMO) aimed to construct a \"non-radical-mediated radical-oxidative reaction\", for increasing PMS utilization efficiency, and solving the defects of SO4•- and •OH through indirect PMS activation by electron transfer process. Compared with box-like Cu2MnO4 (11.1%, 0.0035 min-1) and ordinary Cu2MnO4 nanoparticles (21.3%, 0.0070 min-1), SCMO/PMS showed excellent trichloroethylene removal (98.8%, 0.1577 min-1). The pivotal role of Cu(III) was determined based on EPR analysis, quenching experiments, chemical probe experiments, hydrogen temperature-programmed reduction and Raman spectroscopy analysis, in-situ FTIR and Raman analyses. In brief, the interaction between PMS and SCMO could produce surface-bonded reactive complexes and the subsequent breaking of O-O bond in the sub-stable structure allowed the conversion of Cu(II) to Cu(III), which in turn facilitates the generation of •OH and SO4•-. The density functional theory (DFT) calculations provided supporting evidence for the electron donor role of SCMO and the increase of the electron acceptance capacity of PMS. SCMO/PMS system showed good resistance and degradation efficiency to complex composition and combined pollutants in actually contaminated groundwater, respectively. However, the coexistence of high concentrations of arsenic could significantly affect SCMO performance due to their adsorption on -OH groups, which still need in-depth study.

BACKGROUND: We recently reported an increased risk of Parkinson\'s disease (PD) in service members who resided at Marine Base Camp Lejeune, North Carolina, when water supplies were contaminated with trichloroethylene and other volatile organic compounds (VOCs). Prior studies suggest that environmental exposures may affect PD phenotype or progression, but this has not been reported for VOCs.
OBJECTIVE: The objective of this study was to test whether PD progression is faster in individuals exposed to VOCs in water at Camp Lejeune.
METHODS: A cohort of 172,128 marines residing at Camp Lejeune between 1975 and 1985 was previously assembled. We identified individuals with PD in Veterans Health Administration and Medicare databases between 2000 and 2021. Using estimates derived by the US Agency for Toxic Substances and Disease Registry, we classified individuals as exposed or unexposed to VOCs in residential water. We used Kaplan-Meier and Cox regression models to test differences between exposed and unexposed groups in the time from PD diagnosis until psychosis, fracture, fall, or death.
RESULTS: Among 270 persons with PD, 177 (65.6%) were exposed to VOCs in residential water. Median cumulative exposure was 4970 μg/L-months, >50-fold the permissible level. Time until psychosis, fracture, and fall were all shorter in the exposed group, with adjusted hazard ratios (HRs) exceeding 2: psychosis HR, 2.19 (95% confidence interval [CI]: 0.99-4.83); fracture HR, 2.44 (95% CI: 0.91-6.55); and fall HR, 2.64 (95% CI: 0.97-7.21). A significant dose response was observed for time to fall (P trend, 0.032). No differences were observed for time until death.
CONCLUSIONS: PD progression may be faster in persons exposed to trichloroethylene and other VOCs in water decades earlier. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

The coupling of microscale zero-valent iron (mZVI) and anaerobic bacteria (AB) has gained increasing attention due to its ability to enhance dechlorination efficiency by combining the advantages of chemical and microbial reduction. However, the implementation of these coupling technologies at the field scale is challenging in terms of sustainability goals due to the coexistence of various natural electron acceptors in groundwater, which leads to limited electron selectivity and increased secondary risk. Therefore, this study used trichloroethylene (TCE) as a probe contaminant and nitrate (NO3-) as a typical co-occurring natural electron acceptor to optimize the overall sustainable remediation performance of an mZVI/AB coupled system by adjusting the mZVI particle size and dosage. Results revealed that mZVI particles of different sizes exhibit different microorganism activation capabilities. In contrast to its 2 μm and 7 μm counterparts, the 30 μm mZVI/AB system demonstrated a strong dosage-dependency in TCE removal and its product selectivity. Finally, multi-criteria analysis (MCA) methods were established to comprehensively rank the alternatives, and 30 μm mZVI (15 g/L dosage) was determined to be the best remediation strategy with the highest total sustainability score under all studied hydro-chemical conditions when equal weights were applied to technical, environmental, and economic indicators. Our work provides a paradigm for comprehensively assessing the sustainable remediation performance of chlorinated aliphatic hydrocarbons polluted groundwater in practical applications.

BACKGROUND: Drinking water at U.S. Marine Corps Base (MCB) Camp Lejeune, North Carolina was contaminated with trichloroethylene and other industrial solvents from 1953 to 1985.
METHODS: A cohort mortality study was conducted of Marines/Navy personnel who, between 1975 and 1985, began service and were stationed at Camp Lejeune (N = 159,128) or MCB Camp Pendleton, California (N = 168,406), and civilian workers employed at Camp Lejeune (N = 7,332) or Camp Pendleton (N = 6,677) between October 1972 and December 1985. Camp Pendleton\'s drinking water was not contaminated with industrial solvents. Mortality follow-up was between 1979 and 2018. Proportional hazards regression was used to calculate adjusted hazard ratios (aHRs) comparing mortality rates between Camp Lejeune and Camp Pendleton cohorts. The ratio of upper and lower 95% confidence interval (CI) limits, or CIR, was used to evaluate the precision of aHRs. The study focused on underlying causes of death with aHRs ≥ 1.20 and CIRs ≤ 3.
RESULTS: Deaths among Camp Lejeune and Camp Pendleton Marines/Navy personnel totaled 19,250 and 21,134, respectively. Deaths among Camp Lejeune and Camp Pendleton civilian workers totaled 3,055 and 3,280, respectively. Compared to Camp Pendleton Marines/Navy personnel, Camp Lejeune had aHRs ≥ 1.20 with CIRs ≤ 3 for cancers of the kidney (aHR = 1.21, 95% CI: 0.95, 1.54), esophagus (aHR = 1.24, 95% CI: 1.00, 1.54) and female breast (aHR = 1.20, 95% CI: 0.73, 1.98). Causes of death with aHRs ≥ 1.20 and CIR > 3, included Parkinson disease, myelodysplastic syndrome and cancers of the testes, cervix and ovary. Compared to Camp Pendleton civilian workers, Camp Lejeune had aHRs ≥ 1.20 with CIRs ≤ 3 for chronic kidney disease (aHR = 1.88, 95% CI: 1.13, 3.11) and Parkinson disease (aHR = 1.21, 95% CI: 0.72, 2.04). Female breast cancer had an aHR of 1.19 (95% CI: 0.76, 1.88), and aHRs ≥ 1.20 with CIRs > 3 were observed for kidney and pharyngeal cancers, melanoma, Hodgkin lymphoma, and chronic myeloid leukemia. Quantitative bias analyses indicated that confounding due to smoking and alcohol consumption would not appreciably impact the findings.
CONCLUSIONS: Marines/Navy personnel and civilian workers likely exposed to contaminated drinking water at Camp Lejeune had increased hazard ratios for several causes of death compared to Camp Pendleton.

Trichloroethylene (TCE) is a common environmental pollutant and industrial chemical that has been associated with adverse health effects, especially on organ systems. The purpose of this review is to summarize the current findings on organ system damage caused by TCE exposure and the underlying mechanisms involved. Numerous studies have shown that TCE exposure may cause damage to multiple organ systems, mainly the skin, liver, kidney, and circulatory system. The mechanisms leading to TCE-induced organ system damage are complex and diverse. TCE is metabolized in vivo to reactive intermediates, through which TCE can induce oxidative stress, interfere with cell signaling pathways, and promote inflammatory responses. In addition, studies have shown that TCE interferes with DNA repair mechanisms, leading to genotoxicity and potentially carcinogenic effects. This review highlights the importance of understanding the deleterious effects of TCE exposure on organ systems and provides insights into the underlying mechanisms involved. Further research is needed to elucidate the full range of organ system damage caused by TCE and to develop effective prevention and treatment strategies.

In specific pathological conditions, addressing liver injury may yield favorable effects on renal function through the phenomenon of liver-kidney crosstalk. Mitochondrial DNA (mtDNA) possesses the capability to trigger downstream pathways of inflammatory cytokines, ultimately leading to immune-mediated organ damage. Consequently, understanding the intricate molecular mechanisms governing mtDNA involvement in diseases characterized by liver-kidney crosstalk is of paramount significance. This study seeks to elucidate the role of mtDNA in conditions marked by liver-kidney crosstalk. In previous clinical cases, it has been observed that patients with Trichloroethylene Hypersensitivity Syndrome (TCE-HS) who experience severe liver injury often also exhibit renal injury. In this study, patients diagnosed with trichloroethylene hypersensitivity syndrome were recruited from Shenzhen Occupational Disease Control Center. And Balb/c mice were treated with trichloroethylene. The correlation between liver and kidney injuries in patients with TCE-HS was assessed using Enzyme-Linked Immunosorbent Assay (ELISA). Alterations in mtDNA levels were examined in mouse hepatocytes, red blood cells (RBCs), and renal tubular epithelial cells utilizing immunofluorescence and PCR techniques. TCE-sensitized mice exhibited a significant increase in reactive oxygen species (ROS) and the opening of the mitochondrial permeability transition pore in hepatocytes, resulting in the release of mtDNA. Furthermore, heightened levels of mtDNA and Toll-like Receptor 9 (TLR9) expression were observed in RBCs. Additional experiments demonstrated elevated expression of TLR9 and its downstream mediator MyD88 in renal tubule epithelial cells of TCE-sensitized mice. In vitro investigations confirmed that mtDNA activates the TLR9 pathway in TCMK-1 cells. Collectively, these results suggest that mtDNA released from mitochondrial damage in hepatocytes is carried by RBCs to renal tubular epithelial cells and mediates inflammatory injury in renal tubular epithelial cells through activation of the TLR9 receptor.

Atomic hydrogen (H*) is a powerful and versatile reductant and has tremendous potential in the degradation of oxidized pollutants (e.g., chlorinated solvents). However, its application for groundwater remediation is hindered by the scavenging side reaction of H2 evolution. Herein, we report that a composite material (Fe0@Fe-N4-C), consisting of zerovalent iron (Fe0) nanoparticles and nitrogen-coordinated single-atom Fe (Fe-N4), can effectively steer H* toward reductive dechlorination of trichloroethylene (TCE), a common groundwater contaminant and primary risk driver at many hazardous waste sites. The Fe-N4 structure strengthens the bond between surface Fe atoms and H*, inhibiting H2 evolution. Nonetheless, H* is available for dechlorination, as the adsorption of TCE weakens this bond. Interestingly, H* also enhances electron delocalization and transfer between adsorbed TCE and surface Fe atoms, increasing the reactivity of adsorbed TCE with H*. Consequently, Fe0@Fe-N4-C exhibits high electron selectivity (up to 86%) toward dechlorination, as well as a high TCE degradation kinetic constant. This material is resilient against water matrix interferences, achieving long-lasting performance for effective TCE removal. These findings shed light on the utilization of H* for the in situ remediation of groundwater contaminated with chlorinated solvents, by rational design of earth-abundant metal-based single-atom catalysts.

Mud volcanoes are dynamic geological features releasing methane (CH4), carbon dioxide (CO2), and hydrocarbons, harboring diverse methane and hydrocarbon-degrading microbes. However, the potential application of these microbial communities in chlorinated hydrocarbons bioremediation purposes such as trichloroethylene (TCE) has not yet been explored. Hence, this study investigated the mud volcano\'s microbial diversity functional potentiality in TCE degradation as well as their eco-physiological profiling using metabolic activity. Geochemical analysis of the mud volcano samples revealed variations in pH, temperature, and oxidation-reduction potential, indicating diverse environmental conditions. The Biolog Ecoplate™ carbon substrates utilization pattern showed that the Tween 80 was highly consumed by mud volcanic microbial community. Similarly, MicroResp® analysis results demonstrated that presence of additive C-substrates condition might enhanced the cellular respiration process within mud-volcanic microbial community. Full-length 16 S rRNA sequencing identified Proteobacteria as the dominant phylum, with genera like Pseudomonas and Hydrogenophaga associated with chloroalkane degradation, and methanotrophic bacteria such as Methylomicrobium and Methylophaga linked to methane oxidation. Functional analysis uncovered diverse metabolic functions, including sulfur and methane metabolism and hydrocarbon degradation, with specific genes involved in methane oxidation and sulfur metabolism. These findings provide insights into the microbial diversity and metabolic capabilities of mud volcano ecosystems, which could facilitate their effective application in the bioremediation of chlorinated compounds.

In response to environmental concerns at the global level, there is considerable momentum in the exploration of materials derived from waste that are both sustainable and eco-friendly. In this study, CS-Fe (carbon, silica, and iron) composite was synthesized from coal gasification slag (CGS) and innovatively applied as a catalyst to activate PS (persulfate) for the degradation of trichloroethylene (TCE) in water. Scanning electron microscope (SEM), fourier transmission infrared spectroscopy (FTIR), energy dispersive x-ray spectroscopy (EDS), brunauer, emmet, and teller (BET) technique, and x-ray diffractometer (XRD) spectra were employed to investigate the surface morphology and physicochemical composition of the CS-Fe composite. CS-Fe catalyst showed a dual nature by adsorption and degradation of TCE simultaneously, displaying 86.1% TCE removal in 3 h. The synthesized CS-Fe had better adsorption (62.1%) than base material CGS (36.4%) due to a larger BET surface area (770.8 m2 g-1), while 24.0% TCE degradation was recorded upon the activation of PS by CS-Fe. FTIR spectra confirmed the adsorption and degradation of TCE by investigating the used and fresh samples of CS-Fe catalyst. Scavengers and Electron paramagnetic resonance (EPR) analysis confirmed the availability of surface radicals and free radicals facilitated the degradation process. The acidic nature of the solution favored the degradation while the presence of bicarbonate ion (HCO3-) hindered this process. In conclusion, these results for real groundwater, surfactant-added solution, and degradation of other TCE-like pollutants propose that the CS-Fe composite offers an economically viable and favorable catalyst in the remediation of organic contaminants within aqueous solutions. Further investigation into the catalytic potential of coal gasification slag-based carbon materials and their application in Fenton reactions is warranted to effectively address a range of environmental challenges.