2,745 results match your criteria Toxicity Chlorine Gas

Boosting 5-ALA-based photodynamic therapy by a liposomal nanomedicine through intracellular iron ion regulation.

Acta Pharm Sin B 2021 May 29;11(5):1329-1340. Epub 2021 Apr 29.

Henan Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, China.

5-Aminolevulinic acid (5-ALA) has been approved for clinical photodynamic therapy (PDT) due to its negligible photosensitive toxicity. However, the curative effect of 5-ALA is restricted by intracellular biotransformation inactivation of 5-ALA and potential DNA repair of tumor cells. Inspired by the crucial function of iron ions in 5-ALA transformation and DNA repair, a liposomal nanomedicine ([email protected]/DFO) with intracellular iron ion regulation property was developed for boosting the PDT of 5-ALA, which was prepared by co-encapsulating 5-ALA and DFO (deferoxamine, a special iron chelator) into the membrane fusion liposomes (MFLs). Read More

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Evolving challenges and strategies for fungal control in the food supply chain.

Fungal Biol Rev 2021 Jun;36:15-26

School of Life Sciences, University of Nottingham, University Park Campus, Nottingham, United Kingdom.

Fungi that spoil foods or infect crops can have major socioeconomic impacts, posing threats to food security. The strategies needed to manage these fungi are evolving, given the growing incidence of fungicide resistance, tightening regulations of chemicals use and market trends imposing new food-preservation challenges. For example, alternative methods for crop protection such as RNA-based fungicides, biocontrol, or stimulation of natural plant defences may lessen concerns like environmental toxicity of chemical fungicides. Read More

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The Different Facets of Triclocarban: A Review.

Molecules 2021 May 10;26(9). Epub 2021 May 10.

Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Arcavacata di Rende, Italy.

In the late 1930s and early 1940s, it was discovered that the substitution on aromatic rings of hydrogen atoms with chlorine yielded a novel chemistry of antimicrobials. However, within a few years, many of these compounds and formulations showed adverse effects, including human toxicity, ecotoxicity, and unwanted environmental persistence and bioaccumulation, quickly leading to regulatory bans and phase-outs. Among these, the triclocarban, a polychlorinated aromatic antimicrobial agent, was employed as a major ingredient of toys, clothing, food packaging materials, food industry floors, medical supplies, and especially of personal care products, such as soaps, toothpaste, and shampoo. Read More

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Dimensionally Stable Anode Based Sensor for Urea Determination via Linear Sweep Voltammetry.

Sensors (Basel) 2021 May 15;21(10). Epub 2021 May 15.

Departamento de Química, Centro de Ciências Exatas, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória CEP 29075-910, ES, Brazil.

Urea is an added value chemical with wide applications in the industry and agriculture. The release of urea waste to the environment affects ecosystem health despite its low toxicity. Online monitoring of urea for industrial applications and environmental health is an unaddressed challenge. Read More

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The Pedosphere as a Sink, Source, and Record of Anthropogenic and Natural Arsenic Atmospheric Deposition.

Environ Sci Technol 2021 May 28. Epub 2021 May 28.

School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, Northern Ireland.

The Anthropocene has led to global-scale contamination of the biosphere through diffuse atmospheric dispersal of arsenic. This review considers the sources arsenic to soils and its subsequent fate, identifying key knowledge gaps. There is a particular focus on soil classification and stratigraphy, as this is central to the topic under consideration. Read More

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Unravelling molecular transformation of dissolved effluent organic matter in UV/HO, UV/persulfate, and UV/chlorine processes based on FT-ICR-MS analysis.

Water Res 2021 Jul 18;199:117158. Epub 2021 Apr 18.

State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China; Research Center for Environmental Nanotechnology (ReCENT), Nanjing University, Nanjing 210023, China. Electronic address:

Ultraviolet-based advanced oxidation processes (UV-AOPs) are very promising in advanced treatment of municipal secondary effluents. However, the transformation of dissolved effluent organic matter (dEfOM) in advanced treatment of real wastewater, particularly at molecular level, remains unclear. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) coupled with multiple statistical analysis were performed to better understand the transformation of dEfOM in UV/HO, UV/persulfate (UV/PS), and UV/chlorine treatments. Read More

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Development of chlorine-induced lung injury in the anesthetized, spontaneously breathing pig.

Toxicol Mech Methods 2021 May;31(4):257-271

CBR Division, Dstl Porton Down, Salisbury, UK.

Chlorine is a toxic industrial chemical produced in vast quantities globally, being used in a range of applications such as water purification, sanitation and industrial processes. Its use and transport cannot be restricted; exposure may occur following accidental or deliberate releases. The OPCW recently verified the use of chlorine gas against civilians in both Syria and Iraq. Read More

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Atmospheric Fate of a New Polyfluoroalkyl Building Block, CFOCHFCFSCHCHOH.

Environ Sci Technol 2021 Apr 22. Epub 2021 Apr 22.

Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.

Many per- and polyfluoroalkyl substances (PFAS) have been regulated or phased-out of usage due to concerns about persistence, bioaccumulation potential, and toxicity. We investigated the atmospheric fate of a new polyfluorinated alcohol 2-(1,1,2-trifluoro-2-heptafluoropropyloxy-ethylsulfanyl)-ethanol (CFOCHFCFSCHCHOH, abbreviated FESOH) by assessing the kinetics and products of the gas-phase reaction of FESOH with chlorine atoms and hydroxyl radicals. Experiments performed in a stainless-steel chamber interfaced to an FTIR were used to determine reaction kinetics and gas-phase products. Read More

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Photo-induced degradation and toxicity change of decabromobiphenyl ethers (BDE-209) in water: Effects of dissolved organic matter and halide ions.

J Hazard Mater 2021 Apr 8;416:125842. Epub 2021 Apr 8.

State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China. Electronic address:

BDE-209 is a widely used brominated flame retardant that is ubiquitous in the aquatic environment, especially in marine water. However, photodegradation of BDE-209 in seawater is still not fully understood. In this work, the photodegradation kinetics of BDE-209 in water was studied and the effects of seawater dissolved organic matter (S-DOM) and halide ions (Cl, Br) were evaluated. Read More

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Cytotoxicity evaluation of calcium hypochlorite and other commonly used root canal irrigants against human gingival fibroblast cells: An in vitro evaluation.

Dent Med Probl 2021 Jan-Mar;58(1):31-37

Department of Conservative Dentistry and Endodontics, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Chennai, India.

Background: The conventional endodontic therapy primarily focuses on biomechanical preparation, which is achieved by the application of various intracanal irrigants and intracanal medicaments. One of the most commonly used intracanal irrigants - sodium hypochlorite (NaOCl) - has already been proven to have an antimicrobial effect as well as the ability to dissolve tissues in the areas where files cannot reach. One of the recently used irrigants having a promising effect is calcium hypochlorite (Ca(OCl)2), which has been shown to be relatively more stable than NaOCl and has much more chlorine ions. Read More

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How Much of the Total Organic Halogen and Developmental Toxicity of Chlorinated Drinking Water Might Be Attributed to Aromatic Halogenated DBPs?

Environ Sci Technol 2021 05 8;55(9):5906-5916. Epub 2021 Apr 8.

Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Kowloon 999077, Hong Kong SAR, China.

Although >700 disinfection byproducts (DBPs) have been identified, >50% of the total organic halogen (TOX) in drinking water chlorination is unknown, and the DBPs responsible for the chlorination-associated health risks remain largely unclear. Recent studies have revealed numerous aromatic halo-DBPs, which generally present substantially higher developmental toxicity than aliphatic halo-DBPs. This raises a fascinating and important question: how much of the TOX and developmental toxicity of chlorinated drinking water can be attributed to aromatic halo-DBPs? In this study, an effective approach with ultraperformance liquid chromatography was developed to separate the DBP mixture (from chlorination of bromide-rich raw water) into aliphatic and aromatic fractions, which were then characterized for their TOX and developmental toxicity. Read More

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Occurrence, influencing factors, toxicity, regulations, and abatement approaches for disinfection by-products in chlorinated drinking water: A comprehensive review.

Environ Pollut 2021 Jul 17;281:116950. Epub 2021 Mar 17.

Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan. Electronic address:

Disinfection is considered as a vital step to ensure the supply of clean and safe drinking water. Various approaches are adopted for this purpose; however, chlorination is highly preferred all over the world. This method is opted owing to its several advantages. Read More

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Acidification inhibition, biodechlorination, and biotransformation of chlorinated acetaldehydes on acidogenic sludge and microbial community changes.

Chemosphere 2021 Aug 16;277:130231. Epub 2021 Mar 16.

School of Environment, Tsinghua University, Beijing, 100084, PR China.

Chlorinated acetaldehydes (CALs) are typical chlorinated organic compounds that posing a great threat to biological wastewater treatment plants. In this study, volatile batch acid (VFA) tests were employed to investigate the acidification inhibition, biodechlorination, and biotransformation of high-strength CALs on hydrolytic acidification. The results indicated that the optimum parameters were 4 g/L sludge, pH = 8, and glucose as an electron donor. Read More

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Integration of environmental and economic performance of Electro-Coagulation-Anodic Oxidation sequential process for the treatment of soluble coffee industrial effluent.

Sci Total Environ 2021 Apr 8;764:142818. Epub 2020 Oct 8.

Departamento de Ingeniería Química, Facultad de Ingeniería y Arquitectura, Universidad Nacional de Colombia, Sede Manizales, Campus La Nubia, km 9 vía al Aeropuerto la Nubia, Apartado Aéreo 127, Manizales, Caldas, Colombia.

This study examined a sequential Electro-Coagulation-Anodic Oxidation (EC-AO) process, using low-cost electrodes (EC: iron/stainless steel and AO: graphite/stainless steel), as an alternative for the treatment of soluble coffee industrial effluent (a complex mixture of organic macromolecules). Process operational parameters were optimized using experimental design, ANOVA, the response surface methodology, and a constrained nonlinear optimization algorithm. Experimental results allow discussing the role of graphite electrode, the mineralization via hydroxyl radicals and chlorine species (mainly as HClO and ClO as defined from pH conditions and equilibrium calculations). Read More

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Biotreatment potential of co-contaminants hexavalent chromium and polychlorinated biphenyls in industrial wastewater: Individual and simultaneous prospects.

Sci Total Environ 2021 Jul 12;779:146345. Epub 2021 Mar 12.

Department of Botany, University of Narowal, Pakistan.

Co-existence of polychlorinated biphenyls (PCBs) and hexavalent chromium (Cr(VI)) in the environment due to effluent from industries has aggravated the pollution problem. Both contaminants can alter chemical interactions, processes and impair enzymatic activities in the ecosystem that results in negative impacts on aquatic and terrestrial life. Previously, research has been performed for the fate and transfer of these contaminants individually, but simultaneous removal approaches have not received much attention. Read More

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Highly elevated levels, infant dietary exposure and health risks of medium-chain chlorinated paraffins in breast milk from China: Comparison with short-chain chlorinated paraffins.

Environ Pollut 2021 Jun 10;279:116922. Epub 2021 Mar 10.

State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.

Short-chain chlorinated paraffins (SCCPs) are persistent organic pollutants which are toxic to human. Median-chain chlorinated paraffins (MCCPs) have similar toxicity to SCCPs. The productions of chlorinated paraffins (CPs) in China were 1 million tons in 2013 and remained high after that, which may lead to high risks for human exposure to CPs. Read More

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Degradation kinetics of prometryn and formation of disinfection by-products during chlorination.

Chemosphere 2021 Aug 6;276:130089. Epub 2021 Mar 6.

College of Environmental and Chemical Engineering, Shanghai Engineering Research Center of Energy- Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai, 200090, PR China. Electronic address:

Prometryn is a herbicide that is widely used and frequently detected in aqueous environment and soil. Prometryn is chemically stable, biologically toxic, and easily to accumulate in living bodies, which can cause accumulate in the environment and acute and chronic toxicity to living creatures. In this study, factors affecting the degradation kinetics of prometryn chlorination were studied, including solution pH, bromide and ammonium concentrations, and temperature. Read More

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The roles of HO, ClO and BrO radicals in caffeine degradation: A theoretical study.

Sci Total Environ 2021 May 23;768:144733. Epub 2021 Jan 23.

Environment Research Institute, Shandong University, Qingdao 266237, PR China. Electronic address:

ClO and BrO are newly discovered reactive radicals that contribute to the degradation of micropollutants. However, the research on pollutant degradation by ClO and BrO is still lacking. Thus, the mechanism, kinetics, and toxicity of caffeine degradation by HO, ClO, and BrO were computationally studied and compared. Read More

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Heavy metal (PTE) ecotoxicology, data review: Traditional vs. a compositional approach.

Sci Total Environ 2021 May 20;769:145246. Epub 2021 Jan 20.

School of Natural and Built Environment, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom of Great Britain and Northern Ireland.

Potentially Toxic Elements (PTEs) otherwise known as heavy metals are ubiquitous in soils and can have a range of negative health and environmental impacts. In terrestrial systems understanding how PTEs move in the environment is made challenging by the complex interactions within soil and the wider environment and the compositional nature of PTEs. PTEs are compositional because data of individual PTEs within in a sample are ratios which may be under a sum constraint, where individual components sum up to a whole. Read More

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Cytotoxicity and Antibacterial Evaluation of O-Alkylated/Acylated Quinazolin-4-one Schiff Bases.

Chem Biodivers 2021 May 15;18(5):e2100096. Epub 2021 Apr 15.

School of Chemistry and Physics, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa.

A series of quinazolin-4-one Schiff bases were synthesized and tested in vitro for their cytotoxicity against two cancerous cell lines (MCF-7, Caco-2) and a human embryonic cell line (HEK-293) including their antibacterial evaluation against two Gram-positive and four Gram-negative bacterial strains. Most of the quinazoline-Schiff bases exhibited potent cytotoxicity against Caco-2. 3-[(Z)-({4-[(But-2-yn-1-yl)oxy]phenyl}methylidene)amino]-2-methylquinazolin-4(3H)-one (6f) with the O-butyne functional group displayed three-fold higher cytotoxic activity (IC =376. Read More

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Kinetics of the formation and destruction of PCDD/Fs in a laboratory tubular furnace.

Chemosphere 2021 Aug 4;276:130175. Epub 2021 Mar 4.

Chemical Engineering Department - Universitat d'Alacant, Carretera de San Vicente del Raspeig, s/n, Alicante, 03690, Spain.

A kinetic model has been developed for the formation of selected congeners of PCDD/Fs during the thermal decomposition of different wastes in a horizontal reactor. Previously published data on the decomposition of wastes have been correlated using a kinetic model that only considers process parameters, such as the presence of different amounts of oxygen in the atmosphere of reaction, chlorine and metals in the waste. The effect of both chlorine and metals is modelled through an equation assuming a "saturation effect", i. Read More

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Bioassay- and QSAR-based screening of toxic transformation products and their formation under chlorination treatment on levofloxacin.

J Hazard Mater 2021 07 24;414:125495. Epub 2021 Feb 24.

State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.

Levofloxacin (LEV) is a broad-spectrum quinolone antibiotic and widely used for human and veterinary treatment. Overuse of LEV leads to its frequent occurrence in the water environment. In this study, the transformation characteristics of LEV in water during the simulated chlorination disinfection treatment were explored. Read More

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Formation and control of C- and N-DBPs during disinfection of filter backwash and sedimentation sludge water in drinking water treatment.

Water Res 2021 Apr 23;194:116964. Epub 2021 Feb 23.

Department of Environmental Science & Engineering, Fudan University, Shanghai 200238, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China. Electronic address:

Drinking water treatment plants (DWTPs) produce filter backwash water (FBW) and sedimentation sludge water (SSW) that may be partially recycled to the head of DWTPs. The impacts of key disinfection conditions, water quality parameters (e.g. Read More

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Chloride-mediated co-formation of 3-monochloropropanediol esters and glycidyl esters in both model vegetable oils and chemical model systems.

Food Res Int 2021 02 10;140:109879. Epub 2020 Nov 10.

Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.

3-Monochloropropanediol esters (3-MCPDEs) and glycidyl esters (GEs) with high toxicity have drawn global concerns due to their widespread occurrence in refined oils and oil-based foods. The effect mechanisms of organic chlorine compound lindane, inorganic chlorine compounds tetra-n-butylammonium chloride (TBAC) and sodium chloride (NaCl) on the formation of 3-MCPDEs and GEs were investigated in model oils and chemical models at 240 °C. Results showed that 3-MCPDEs contents increased with the addition of lindane and TBAC, whereas, surprisingly, GEs presented the same tendency as the results of 3-MCPDEs. Read More

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February 2021

Chlorination decreases acute toxicity of iodophenols through the formation of iodate and chlorinated aliphatic disinfection byproducts.

Water Res 2021 Apr 18;194:116951. Epub 2021 Feb 18.

State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China. Electronic address:

Highly toxic iodinated phenolic by-products were frequently detected in the oxidative treatment and disinfection of iodine-containing water. Herein, it was found that three model iodinated phenolic disinfection byproducts (DBPs), 2-iodophenol, 4-iodophenol and 2,4,6-triiodophenol, were reactive with HOCl, and the reaction rate constants (at pH 7.0 and 25℃) were 1. Read More

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Formation of nitro(so) and chlorinated products and toxicity alteration during the UV/monochloramine treatment of phenol.

Water Res 2021 Apr 8;194:116914. Epub 2021 Feb 8.

Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510275, PR China. Electronic address:

The UV/monochloramine (UV/NHCl) process is an emerging advanced oxidation process (AOP) to remove organic contaminants in water treatment with radicals including hydroxyl radicals (HO), reactive chlorine species (RCS) and reactive nitrogen species (RNS). This study investigated the formation of nitro(so) and chlorinated products and toxicity alteration during the UV/NHCl treatment of phenol. RNS and/or RCS induced the formation of nitro(so), chlorinated and polymeric compounds during phenol transformation by UV/NHCl. Read More

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Kinetics and Mechanisms of Virus Inactivation by Chlorine Dioxide in Water Treatment: A Review.

Bull Environ Contam Toxicol 2021 Apr 25;106(4):560-567. Epub 2021 Feb 25.

School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou, 510275, China.

Chlorine dioxide (ClO), an alternative disinfectant to chlorine, has been widely applied in water and wastewater disinfection. This paper aims at presenting an overview of the inactivation kinetics and mechanisms of ClO with viruses. The inactivation efficiencies vary greatly among different virus species. Read More

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Identification and regulation of ecotoxicity of polychlorinated naphthalenes to aquatic food Chain (green algae-Daphnia magna-fish).

Aquat Toxicol 2021 Apr 13;233:105774. Epub 2021 Feb 13.

MOE Key Laboratory of Resources and Environmental Systems Optimization, North China Electric Power University, Beijing, 102206, China. Electronic address:

Polychlorinated naphthalenes (PCNs) are widely distributed in the aquatic environment and can be transmitted through the food chain, which can amplify their toxic effects on human. To inhibit their transmission in the trophic level, this study aimed to predict the joint toxicity mechanism of polychlorinated naphthalenes (PCNs) to the key organisms and control scheme of its toxicity in the aquatic food chain (green algae-Daphnia magna-fish). The toxic effect grade and mode of action (MoA) of PCNs on the food chain were first predicted to guide the establishment of toxic mechanism model. Read More

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Making Swimming Pools Safer: Does Copper-Silver Ionization with Chlorine Lower the Toxicity and Disinfection Byproduct Formation?

Environ Sci Technol 2021 03 17;55(5):2908-2918. Epub 2021 Feb 17.

Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States.

Swimming pools are commonly treated with chlorine, which reacts with the natural organic matter and organic matter introduced by swimmers and form disinfection byproducts (DBPs) that are associated with respiratory-related issues, including asthma, in avid swimmers. We investigated a complementary disinfectant to chlorine, copper-silver ionization (CSI), with the aim of lowering the amount of chlorine used in pools and limiting health risks from DBPs. We sampled an indoor and outdoor pool treated with CSI-chlorine during the swimming season in 2017-2018 and measured 71 DBPs, speciated total organic halogen, mammalian cell cytotoxicity, and -acetyl-l-cysteine (NAC) thiol reactivity as a cytotoxicity predictor. Read More

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