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1.
Environ Pollut ; 292(Pt B): 118400, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34688725

RESUMO

Silver nanoparticles (AgNPs) are used in many industries for multiple applications that inevitably release AgNPs into surface water sources. The formation kinetics of disinfection by-products (DBPs) in the presence of AgNPs was investigated during chlorination. Experiments were carried out with raw water from a canal in Songkhla, Thailand, which analyzed the formation potential (FP) of trihalomethanes FP (THMFP), iodo-trihalomethanes FP (I-THMFP), haloacetonitriles FP (HANFP), and trichloronitromethane FP. Increased AgNP concentrations by 10-20 mg/L led to a higher specific formation rate of chloroform which is described by zero- and first-order kinetics. The increase in the specific formation of chloroform as increasing chlorine contact time could enhance both the THMFP rates and the maximum THMFP concentrations in all tested AgNPs. The AgNP content did not have a significant influence on I-THMFP and HANFP concentrations or speciation. The I-THMFP and HANFP increased in a short-chlorination time as mostly complete formation <12 h, and then the rate decreased as the reaction proceeded. The levels of THMs and many emerging DBPs are related to the presence of AgNPs in chlorinated water and chlorine reaction time. THMFP had a higher impact on integrated toxic risk value (ITRV) than I-THMFP and HANFP because of the chlorination of water with AgNPs. The chlorine reaction time was more effective for increasing the ITRV of THMFP than the level of AgNPs. Water treatment plants should control the DBPs that cause possible health risks from water consumption by optimizing water distribution time.


Assuntos
Desinfetantes , Nanopartículas Metálicas , Poluentes Químicos da Água , Purificação da Água , Cloro , Desinfetantes/toxicidade , Desinfecção , Halogenação , Nanopartículas Metálicas/toxicidade , Tempo de Reação , Prata/toxicidade , Tailândia , Trialometanos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
2.
Environ Res ; 203: 111883, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34391733

RESUMO

This cross-sectional study aimed to examine the concentration of the by-products of chlorination in the swimming pool and estimate human health risk for the swimmers of Shiraz University of Medical Sciences. In this study, the chloroform concentrations of 16 samples were measured using Gas Chromatography (GC). All the measured concentrations were less than the allowed amount announced by the World Health Organization (WHO). The results of the cancer risk (CR) and hazard index (HI) showed that the major exposure routes were found to be dermal during swimming and the 95 percentile of estimated CR and HI for the male group were 1.38 × 10-10 and 1.82 × 10-5 respectively, which is higher than the values of 5.48 × 10-10 and 2.25 × 10-5 respectively, for the women group. Sensitivity analyses indicated that the swimming exposure time (ET), and chloroform concentration were the most relevant variables in the health risk model. Therefore, knowledge about the sources of micro-pollutants in swimming pools might help promote the health methods of the pool environment.


Assuntos
Desinfetantes , Piscinas , Clorofórmio/análise , Estudos Transversais , Desinfetantes/toxicidade , Desinfecção , Feminino , Humanos , Masculino , Natação , Trialometanos
3.
Environ Pollut ; 294: 118660, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34896221

RESUMO

One possible way to reduce the environmental impacts of pesticides is by nanostructuring biocides in nanocarriers because this promotes high and localized biocidal activity and can avoid toxicity to non-target organisms. Neem oil (NO) is a natural pesticide with toxicity concerns to plants, fish, and other organisms. Thus, loading NO in a safe nanocarrier can contribute to minimizing its toxicity. For this study, we have characterized the integrity of a nanosilica-neem oil-based biocide delivery system (SiO2NP#NO BDS) and evaluated its effectiveness in reducing NO toxicity by the Allium cepa test. NO, mainly consisted of unsaturated fatty acids, was well binded to the SiO2NP with BTCA crosslinker. Overall, this material presented all of its pores filled with the NO with fatty acid groups at both the surface and bulk level of the nanoparticle. The thermal stability of NO was enhanced after synthesis, and the NO was released as zero-order model with a total of 20 days without burst release. The SiO2NP#NO BDS was effective in reducing the individual toxicity of NO to the plant system. NO in single form inhibited the seed germination of A. cepa (EC50 of 0.38 g L-1), and the effect was no longer observed at the BDS condition. Contrarily to the literature, the tested NO did not present cyto- and geno-toxic effects in A. cepa, which may relate to the concentration level and composition.


Assuntos
Desinfetantes , Glicerídeos , Cebolas/toxicidade , Terpenos , Animais , Desinfetantes/toxicidade , Glicerídeos/toxicidade , Nanopartículas , Cebolas/efeitos dos fármacos , Dióxido de Silício
4.
Chemosphere ; 287(Pt 1): 131794, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34438205

RESUMO

Halogenated disinfection byproducts (halo-DBPs) are drinking water contaminants of great public health concern. Nine haloaliphatic DBPs have been regulated by the U.S. Environmental Protection Agency and various halophenolic compounds have been identified as emerging DBPs. In this study, we evaluated the cytotoxic interactions of the regulated bromoacetic acid and three emerging bromophenolic DBPs, i.e., 2,4,6-tribromophenol, 3,5-dibromo-4-hydroxybenzoic acid, and 3,5-dibromo-4-hydroxybenzaldehyde. Cytotoxicity was measured for each DBP individually as well as each of their mixtures using in vitro human epithelial colorectal adenocarcinoma (Caco-2) and neuroblastoma (SH-SY5Y) cells. Concentration addition (CA) model and isobolographic analysis were employed to characterize the interactions among the DBPs. Our results show that the cytotoxicity of four bromo-DBPs against both cell-types followed the descending rank order of bromoacetic acid > 2,4,6-tribromophenol > 3,5-dibromo-4-hydroxybenzaldehyde > 3,5-dibromo-4-hydroxybenzoic acid. Compared with the toxicity data in literature, our finding that bromoacetic acid showed higher cytotoxicity than bromophenolic DBPs was consistent with the results from Chinese hamster ovary cells (a commonly used in vitro model of DBP toxicological studies); but different from the results obtained from in vivo biological models. Significantly, with CA model prediction, we found that mixtures of four bromo-DBPs exhibited synergistic cytotoxic effects on both human cell types. Isobolographic analysis of binary DBP mixtures revealed that, for Caco-2 cells, bromoacetic acid, 2,4,6-tribromophenol, and 3,5-dibromo-4-hydroxybenzoic acid induced synergism; for SH-SY5Y cells, bromoacetic acid induced synergism with all three bromophenolic DBPs. The production of reactive oxidative species (ROS) induced by DBP mixtures could be an important reason for the synergistic cytotoxicity.


Assuntos
Desinfetantes , Água Potável , Poluentes Químicos da Água , Purificação da Água , Acetatos , Animais , Células CHO , Células CACO-2 , Cricetinae , Cricetulus , Desinfetantes/toxicidade , Desinfecção , Halogenação , Humanos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
5.
J Hazard Mater ; 421: 126679, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34332491

RESUMO

Intensive disinfection of wastewater during the COVID-19 pandemic might elevate the generation of toxic disinfection byproducts (DBPs), which has triggered global concerns about their ecological risks to natural aquatic ecosystems. In this study, the toxicity of 17 DBPs typically present in wastewater effluents on three representative microalgae, including Scenedesmus sp. (Chlorophyta), Microcystis aeruginosa (Cyanophyta), and Cyclotella sp. (Bacillariophyta) was investigated. The sensitivities of the three microalgae to DBPs varied greatly from species to species, indicating that DBPs may change the structure of phytoplankton communities. Later, co-cultures of these phytoplankton groups as a proxy of ecological freshwater scenario were conducted to explore the impacts of DBPs on phytoplankton community succession. M. aeruginosa became surprisingly dominant in co-cultures, representing over 50% after dosing with monochloroacetic acid (MCAA, 0.1-10 mg/L). The highest proportion of M. aeruginosa was 70.3% when exposed to 2 mg/L MCAA. Although Scenedesmus sp. dominated in monochloroacetonitrile (MCAN) exposure, M. aeruginosa accounted for no less than 30% even at 40 mg/L MCAN. In this study, DBPs disrupted the original inter-algal relationship in favor of M. aeruginosa, suggesting that DBPs may contribute to the outbreak of cyanobacterial blooms in aquatic ecosystems.


Assuntos
Desinfetantes/toxicidade , Fitoplâncton/efeitos dos fármacos , Scenedesmus , Técnicas de Cocultura , Desinfecção , Ecossistema , Água Doce , Scenedesmus/efeitos dos fármacos
6.
Chemosphere ; 286(Pt 2): 131636, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34358894

RESUMO

Inhalation exposure to polyhexamethylene guanidine phosphate (PHMG-P), one of the primary biocides used in humidifier disinfectants, caused a fatal pulmonary disease in Korea. Pregnant women were also exposed to PHMG-P, and subsequent studies showed that PHMG-P inhalation during pregnancy adversely affects their health and embryo-fetal development. However, the postnatal developmental effects after birth on prenatally PHMG-P-exposed offspring have not yet been investigated. Therefore, in this study, we aimed to examine the postnatal development of prenatally PHMG-P-exposed offspring. Pregnant rats (22 or 24 females per group) were exposed to PHMG-P during pregnancy in a whole-body inhalation chamber at the target concentrations of 0, 0.14, 1.60, and 3.20 mg/m3. After parturition, the prenatally exposed offspring were transferred to non-exposed surrogate mothers to minimize the secondary effects of severe maternal toxicities. Postnatal development of offspring was then examined with a modified extended one-generation reproductive toxicity study design. At 3.20 mg/m3 PHMG-P, increased perinatal death rates and decreased viability index (postnatal survival of offspring between birth and postnatal day 4) were observed. In addition, F1 offspring had lower body weight at birth that persisted throughout the study. PHMG-P-exposed pregnant rats also had severe systemic toxicities and increased gestation period. At 1.60 mg/m3 PHMG-P, a decreased viability index was also observed with systemic toxicities of PHMG-P-exposed pregnant rats. These results indicate that prenatal PHMG-P exposure adversely affects the offspring's future health and could be used for human risk assessment.


Assuntos
Desinfetantes , Umidificadores , Animais , Desinfetantes/análise , Desinfetantes/toxicidade , Feminino , Guanidinas , Humanos , Exposição por Inalação/análise , Pulmão/química , Gravidez , Ratos , Reprodução
7.
Sci Total Environ ; 811: 152355, 2022 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-34921876

RESUMO

The understanding of microbial susceptibility to disinfectants is an important step to provide drinking water (DW) of adequate microbiological quality. In drinking water distribution systems (DWDS) the application of disinfectants is the main approach to control microorganisms. Although chlorine has been commonly used for DW treatment, the increase of microbial resistance and the production of harmful disinfection by-products promote the necessity to seek new alternatives. This study evaluated the antimicrobial activity of sodium dichloroisocyanurate (NaDCC), trichloroisocyanuric acid (TCCA), and pentapotassium bis(peroxymonosulphate) bis(sulphate) (OXONE) against two emerging pathogens isolated from DW, Acinetobacter calcoaceticus and Stenotrophomonas maltophilia. Free chlorine from calcium hypochlorite was used for comparison. The dose and time-responses against planktonic bacteria were performed as well as the assessment of the effects on membrane integrity. Moreover, the effects against 48 h-old biofilms formed on polyvinyl chloride and stainless steel were evaluated in terms of biofilm culturability and removal. Minimum bactericidal concentrations of 2.1 and 3.1 mg/L for NaDCC, 2.5 and 3.8 mg/L for TCCA, 340 and 690 mg/L for OXONE, and 0.80 and 1.0 mg/L for free chlorine alone were obtained against S. maltophilia and A. calcoaceticus, respectively. The kinetic modeling revealed that NaDCC and TCCA caused similar inactivation rates and the time for first log reduction by OXONE was less than 10 min, for both bacteria. All the disinfectants triggered significant bacterial cytoplasmic membrane destabilization, even at sub-lethal concentrations. A 30 min treatment with the disinfectants allowed a reduction in the biofilm culturability up to 5 log. OXONE was the disinfectant with the best efficiency against both bacterial biofilms. However, none of the disinfectants caused significant biofilm removal (reduction < 1 log cells/cm2). This study highlights NaDCC, TCCA, and OXONE as promising alternatives to free chlorine for DW disinfection, particularly for planktonic growth control and biofilm culturability reduction.


Assuntos
Desinfetantes , Água Potável , Biofilmes , Desinfetantes/toxicidade , Desinfecção , Peróxidos , Potássio
8.
Epidemiol Health ; 43: e2021091, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34727493

RESUMO

OBJECTIVES: We aimed to determine the characteristics of the deceased victims of deaths caused by exposure to humidifier disinfectants, and present the distribution of the victims' data submitted for damage application, demographic characteristics, imaging findings, characteristics of humidifier disinfectant exposure, and distribution of the causes of death. METHODS: An integrated database of victims was established using the medical records data of 1,413 victims submitted during the application for death damage caused by exposure to humidifier disinfectants, and the demographic characteristics, medical records, imaging findings, exposure characteristics, and cause of death were examined. RESULTS: The average numbers of data submissions of each applicant for death damage were 3.0 medical use records. A total of 608 (43.0%) victims had more than one finding of acute, subacute, or chronic interstitial lung diseases. The average daily and cumulative use times of the victims were 14.40 and 24,645.81 hours, respectively, indicating greater exposure in this group than in the survivors. The humidifier disinfectants' components comprised polyhexamethylene guanidine (72.8%), chloromethylisothiazolinone/methylisothiazolinone (10.5%), other components (15.0%), and oligo-[2-(2-ethoxy)-ethoxyethyl] guanidine chloride (1.5%). The components' distribution was 67.8% for single-component use, which was higher than that in the survivors (59.8%). The distribution of the causes of death were: respiratory diseases (54.4%), neoplasms (16.8%), and circulatory diseases (6.3%). Other interstitial lung diseases (65.5%) were the most common cause of death among those who died due to respiratory diseases. CONCLUSIONS: Careful discussions of appropriate remedies should be conducted based on a comprehensive understanding of the characteristics of the deceased victims, considering their specificities and limitations.


Assuntos
Desinfetantes , Lesão Pulmonar , Causas de Morte , Desinfetantes/toxicidade , Humanos , Umidificadores , Registros Médicos , República da Coreia/epidemiologia
9.
J Vet Med Sci ; 83(11): 1800-1804, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34645734

RESUMO

Efficacy of African swine fever virus (ASFV) inactivation using five commercially supply compound disinfectants was evaluated under various condition. Virucidal efficacy demonstrated that products A and E could inactivate at 1:800 within 1 min for both temperatures, while products B, C and D inactivated at 1:400. However, product D could inactivate at 1:800 when the exposure time was extended to 30 min and effected only 20°C. In addition, the cytotoxicity demonstrated that products A, B, C, D and E did not significantly affect to cell at 1:51,200, 1:12,800, 1:12,800, 1:25,600 and 1:12,800 dilution, respectively. In conclusion, these disinfectants could inactivate ASFV, however, the application of these products should be performed under safety precautions to prevent cytotoxicity in humans and animals.


Assuntos
Vírus da Febre Suína Africana , Desinfetantes , Animais , Desinfetantes/toxicidade , Macrófagos Alveolares , Suínos , Temperatura
10.
BMC Pediatr ; 21(1): 340, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34384371

RESUMO

BACKGROUND: The purpose was to determine the association between infant exposure to humidifier disinfectant (HD) with neuropsychiatric problems in pre-school children. METHODS: A total of 2,150 children (age 4-11 months) were enrolled in the Panel Study of Korean Children (PSKC) study. The Korean version of the Child Behavior Checklist (CBCL) was used for assessments of neuropsychiatric problems. 1,113 children who participated in all the first to third PSKC studies and answered a question about HD exposure were finally enrolled. RESULTS: There were 717 (64.5%) children in non-HD group who were not exposed to HD and 396 (35.5%) in HD group with former exposure to HD. Exposure to HD was associated with total neuropsychiatric problems (adjusted odds ratio, aOR = 1.54, 95% CI = 1.15-2.06), being emotionally reactive (aOR = 1.55, 95% CI = 1.00-2.39), having attention problems (aOR = 1.96, 95% CI = 1.10-3.47), having oppositional defiant problems (aOR = 1.70, 95% CI = 1.07-2.71), and having attention deficit/hyperactivity problems (aOR = 11.57, 95% CI = 1.03-2.38). The risks for neuropsychiatric problems were clearly increased in boy, firstborn, and secondary smoker. CONCLUSIONS: Exposure to HD during early childhood had a potential association with subsequent behavioral abnormalities.


Assuntos
Desinfetantes , Umidificadores , Criança , Pré-Escolar , Estudos Transversais , Desinfetantes/toxicidade , Humanos , Lactente , Masculino
11.
Langmuir ; 37(33): 10020-10028, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34375117

RESUMO

Most marine antifouling coatings rely on the release of toxic biocides to prevent fouling organisms from attaching, causing environmental pollution. This work proposes a biocide-free environmentally friendly marine antifouling strategy. Slippery-liquid-infused electrostatic flocking surfaces (S-EFSs) were prepared by combining electrostatic flocking and slippery liquid infusion. They exhibited complete mussel resistance after comparing adhesion to the surface of different materials in the laboratory. In addition, the unique surface morphology including lubricant was found to be crucial to their antifouling performance. Real-time polymerase chain reaction showed that different surfaces significantly affected the gene-expression levels of the mussels' foot proteins, where higher levels on S-EFSs meant that the mussels tried to secrete more proteins but they failed to adhere. Moreover, a 148-day field test showed that S-EFSs can resist not only mussels but also tubeworms, tunicates, and barnacles, and the total fouling area decreased by more than 50% compared to control samples. Notably, the maturity of electrostatic flocking technology and the simplicity of the modification steps used endow this strategy with the potential to significantly reduce the economic loss caused by marine biofouling in practical applications.


Assuntos
Incrustação Biológica , Desinfetantes , Thoracica , Animais , Incrustação Biológica/prevenção & controle , Desinfetantes/toxicidade , Eletricidade Estática , Propriedades de Superfície
12.
Sci Total Environ ; 799: 149324, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34371395

RESUMO

Biofouling prevention is one of the biggest challenges faced by the maritime industry, but antifouling agents commonly impact marine ecosystems. Advances in antifouling technology include the use of nanomaterials. Herein we test an antifouling nano-additive based on the encapsulation of the biocide 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT) in engineered silica nanocontainers (SiNC). The work aims to assess the biochemical and physiological effects on the symbiotic coral Sarcophyton cf. glaucum caused by (1) thermal stress and (2) DCOIT exposure (free or nanoencapsulated forms), in a climate change scenario. Accordingly, the following hypotheses were addressed: (H1) ocean warming can cause toxicity on S. cf. glaucum; (H2) the nanoencapsulation process decreases DCOIT toxicity towards this species; (H3) the biocide toxicity, free or encapsulated forms, can be affected by ocean warming. Coral fragments were exposed for seven days to DCOIT in both free and encapsulated forms, SiNC and negative controls, under two water temperature regimes (26 °C and 30.5 °C). Coral polyp behavior and photosynthetic efficiency were determined in the holobiont, while biochemical markers were assessed individually in the endosymbiont and coral host. Results showed transient coral polyp retraction and diminished photosynthetic efficiency in the presence of heat stress or free DCOIT, with effects being magnified in the presence of both stressors. The activity of catalase and glutathione-S-transferase were modulated by temperature in each partner of the symbiosis. The shifts in enzymatic activity were more pronounced in the presence of free DCOIT, but to a lower extent for encapsulated DCOIT. Increased levels of oxidative damage were detected under heat conditions. The findings highlight the physiological constrains elicited by the increase of seawater temperature to symbiotic corals and demonstrate that DCOIT toxicity can be minimized through encapsulation in SiNC. The presence of both stressors magnifies toxicity and confirm that ocean warming enhances the vulnerability of tropical photosynthetic corals to local stressors.


Assuntos
Antozoários , Incrustação Biológica , Desinfetantes , Nanoestruturas , Animais , Incrustação Biológica/prevenção & controle , Recifes de Corais , Desinfetantes/toxicidade , Ecossistema , Nanoestruturas/toxicidade , Tiazóis
13.
Dis Aquat Organ ; 146: 9-21, 2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34435597

RESUMO

Several biocides are widely used in rainbow trout aquaculture against various ectoparasites and ectobionts, but the inflammation induced in treated fish is less well described. Dose-response studies were conducted to elucidate the effects on rainbow trout (gills and fins) induced by a series of biocides including formalin, hydrogen peroxide (H2O2), peracetic acid (PAA) and the surfactant SPH6, which was isolated from the bacterium Pseudomonas H6. The compounds have documented antiparasitic effects, but the specific effects on fish needs further documentation. This study was performed over 24 h, and inflammatory reactions were evaluated in gills and fins. A dose-dependent effect was noted for expression of immune genes encoding for IL-1ß, TNFα, IFNγ, IL-10, IL-8, lysozyme, serum amyloid A (SAA), hepcidin, precerebellin and complement factor C3. PAA induced the strongest upregulation of cytokine and acute phase reactant genes followed by H2O2 and formalin. SPH6 showed a lower effect, and in several cases the compound induced downregulation of several genes. Gills showed a stronger response compared to fins. The mucous cell density in fins showed a range of changes which varied by compound. PAA, and to a lesser degree H2O2 and formalin, initially induced mucous cell hyperplasia, whereas SPH6 immediately decreased the number of cells containing mucus.


Assuntos
Desinfetantes , Doenças dos Peixes , Oncorhynchus mykiss , Animais , Desinfetantes/toxicidade , Brânquias , Peróxido de Hidrogênio , Inflamação/veterinária
14.
Chemosphere ; 284: 131255, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34214929

RESUMO

Our study goal was to investigate the impact of biocides and nanoparticles (NPs) on the microbial diversity in a hydraulic fracturing impacted stream. Biocides and NPs are known for their antimicrobial properties and controlling microbial growth. Previous work has shown that biocides can alter the microbial community composition of stream water and may select for biocide-resistant bacteria. Additional studies have shown that nanoparticles can also alter microbial community composition. However, previous work has often focused on the response to a single compound. Here we provide a more thorough analysis of the microbial community response to three different biocides and three different nanoparticles. A microcosm-based study was undertaken that exposed stream microbial communities to either biocides or NPs. Our results showed a decrease in bacterial abundance with different types of nanoparticles, but an increase in microbial abundance in biocide-amended treatments. The microbial community composition (MCC) was distinct from the controls in all biocide and NP treatments, which resulted in differentially enriched taxa in the treatments compared to the controls. Our results indicate that NPs slightly altered the MCC compared to the biocide-treated microcosms. After 14 days, the MCC in the nanoparticle-treated conditions was similar to the MCC in the control. Conversely, the MCC in the biocide-treated microcosms was distinct from the controls at day 14 and distinct from all conditions at day 0. This finding may point to the use of NPs as an alternative to biocides in some settings.


Assuntos
Desinfetantes , Fraturamento Hidráulico , Microbiota , Nanopartículas , Desinfetantes/toxicidade , Nanopartículas/toxicidade , Óxidos/toxicidade , Rios
15.
J Hazard Mater ; 418: 126364, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34329020

RESUMO

Benzalkonium chloride (BAC) is a common ingredient of disinfectants used for industrial, medical, food safety and domestic applications. It is a common pollutant detected in surface and wastewaters to induce adverse effects on Human health as well as aquatic and terrestrial life forms. Since disinfectant use is essential in combatting against microorganisms, the best approach to reduce ecotoxicity level is to restrict BAC use. We report here that encapsulation of BAC in mesoporous silica nanoparticles can provide an efficient strategy for inhibition of microbial activity with lower than usual concentrations of disinfectants. As a proof-of-concept, Listeria monocytogenes was evaluated for minimum inhibitory concentration (MIC) of nanomaterial encapsulated BAC. Aptamer molecular gate structures provided a specific targeting of the disinfectant to Listeria cells, leading to high BAC concentrations around bacterial cells, but significantly reduced amounts in total. This strategy allowed to inhibition of BAC resistant Listeria strains with 8 times less the usual disinfectant dose. BAC encapsulated and aptamer functionalized silica nanoparticles (AptBACNP) effectively killed only target bacteria L. monocytogenes, but not the non-target cells, Staphylococcus aureus or Escherichia coli. AptBACNP was not cytotoxic to Human cells as determined by in vitro viability assays.


Assuntos
Desinfetantes , Listeria monocytogenes , Nanopartículas , Compostos de Benzalcônio , Desinfetantes/toxicidade , Poluição Ambiental , Humanos , Testes de Sensibilidade Microbiana , Nanopartículas/toxicidade , Dióxido de Silício/toxicidade
16.
J Toxicol Environ Health A ; 84(22): 932-943, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34315345

RESUMO

Isothiazolinone (IT) biocides are potent antibacterial substances used as preservatives and disinfectants. These biocides exert differing biocidal effects and display environmental stability based upon chemical structure. In agreement with our recent study reporting that 2-n-octyl-4-isothiazolin-3-one (OIT) induced dysfunction of the blood-brain barrier (BBB), the potential adverse health effects of two IT biocides 1,2-benzisothiazolin-3-one (BIT) and 4,5-dichloro-2-n-octyl-isothiazolin-3-one (DCOIT) were compared using brain endothelial cells (ECs) derived from murine brain endothelial cell line (bEND.3). BIT possesses an unchlorinated IT ring structure and used as a preservative in cleaning products. DCOIT contains a chlorinated IT ring structure and employed as an antifouling agent in paints. Data demonstrated that DCOIT altered cellular metabolism at a lower concentration than BIT. Both BIT and DCOIT increased reactive oxygen species (ROS) generation at the mitochondrial and cellular levels. However, the effect of DCOIT on glutathione (GSH) levels appeared to be greater than BIT. While mitochondrial membrane potential (MMP) was decreased in both BIT- and DCOIT-exposed cells, direct disturbance in mitochondrial bioenergetic flux was only observed in BIT-treated ECs. Taken together, IT biocides produced toxicity in brain EC and barrier dysfunction, but at different concentration ranges suggesting distinct differing mechanisms related to chemical structure.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Desinfetantes/toxicidade , Mitocôndrias/efeitos dos fármacos , Tiazóis/toxicidade , Animais , Barreira Hematoencefálica/metabolismo , Linhagem Celular , Desinfetantes/química , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Metabolismo Energético/efeitos dos fármacos , Glutationa/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Tiazóis/química
17.
BMC Public Health ; 21(1): 1458, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315451

RESUMO

BACKGROUND: Lung disease caused by exposure to chemical substances such as polyhexamethylene guanidine (PHMG) used in humidifier disinfectants (HDs) has been identified in Korea. Several researchers reported that exposure classification using a questionnaire might not correlate with the clinical severity classes determined through clinical diagnosis. It was asserted that the lack of correlation was due to misclassification in the exposure assessment due to recall bias. We identified the cause of uncertainty to recognize the limitations of differences between exposure assessment and clinical outcomes assumed to be true value. Therefore, it was intended to check the availability of survey using questionnaires and required to reduce misclassification error/bias in exposure assessment. METHODS: HDs exposure assessment was conducted as a face-to-face interview, using a questionnaire. A total of 5245 applicants participated in the exposure assessment survey. The questionnaire included information on sociodemographic and exposure characteristics such as the period, frequency, and daily usage amount of HDs. Based on clinical diagnosis, a 4 × 4 cross-tabulation of exposure and clinical classification was constructed. When the values of the exposure rating minus the clinical class were ≥ 2 and ≤ - 2, we assigned the cases to the overestimation and underestimation groups, respectively. RESULTS: The sex ratio was similar in the overestimation and underestimation groups. In terms of age, in the overestimation group, 90 subjects (24.7%) were under the age of 10, followed by 52 subjects (14.2%) in their 50s. In the underestimation group, 195 subjects (56.7%) were under the age of 10, followed by 80 subjects (23.3%) in their 30s. The overestimation group may have already recovered and responded excessively due to psychological anxiety or to receive compensation. However, relatively high mortality rates and surrogate responses observed among those under 10 years of age may have resulted in inaccurate exposure in the underestimation group. CONCLUSIONS: HDs exposure assessment using a questionnaire might not correlate with adverse health effects due to recall bias and various other causes such as recovery of injury and psychological anxiety. This study revealed exposure misclassification and characteristics affected by HDs and proposed a questionnaire-based exposure assessment methodology to overcome the limitations of past exposure assessment.


Assuntos
Desinfetantes , Pneumopatias , Desinfetantes/toxicidade , Humanos , Umidificadores , República da Coreia , Inquéritos e Questionários
18.
Sci Total Environ ; 795: 148772, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34247079

RESUMO

Due to the negative impact of climate change and anthropogenic activities, bromide intrusion into algae-impacted freshwater becomes a new challenge for safe drinking water supply worldwide, as bromide and algal organic matter are important disinfection byproduct (DBP) precursors. However, the influences of this phenomenon on algal precursor dynamic and their derived DBPs have to date received little attention. This study examined the effects of bromide intrusion on algal intra- (IOM) and extra-cellular (EOM) precursors during the growth of two freshwater algae Chlorella sp. and Microcystis aeruginosa. Both algae were well-adapted to Br-intrusion, and no significant effect on their growth and their IOM and EOM precursor characteristics was statistically found (p > 0.05). Notwithstanding, this phenomenon apparently added bromide ions into the algal-EOM solution, which resulted in a linear uptake of bromide by IOM. Under Br-intrusion from 0-4 mg/L (Br0-Br4), 15-60% (on average) of the initial bromide additions remained in the algal EOM. By contrast, only an average of ~1.5-2.4% of the additional bromide was taken up by the IOM, resulting in an elevation of brominated DBPs (Br-DBPs) upon chlorination, especially for those samples collected in the late exponential and declined growth phases. When Br0 shifted to Br4, the %Br-DBP yields from both IOM and EOM increased by more than 75%, with a corresponding increasing the total DBP yield of ~30%. The toxic potencies of all chlorinated Br-containing IOM/EOM were thus magnified, by over one order magnitude greater than the non-Br IOM/EOM at Br0. These results are highly significant for understanding the potential risks of Br-intrusion and algal blooming in raw water quality prior to chlorination.


Assuntos
Chlorella , Desinfetantes , Microcystis , Poluentes Químicos da Água , Purificação da Água , Brometos , Desinfetantes/toxicidade , Desinfecção , Halogenação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
19.
Environ Sci Technol ; 55(15): 10534-10541, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34132094

RESUMO

Intensified disinfection of wastewater during the COVID-19 pandemic increased the release of toxic disinfection by-products (DBPs). However, studies relating to the ecological impacts of DBPs on the aquatic environment remain insufficient. In this study, we comparatively investigated the toxicities and ecological risks of 17 typical, halogenated DBPs to three trophic levels of organisms in the freshwater ecosystem, including phytoplankton (Scenedesmus sp.), zooplankton (Daphnia magna), and fish (Danio rerio). Toxicity of DBPs was found to be species-specific: Scenedesmus sp. was the most sensitive to haloacetic acids, while D. magna was the most sensitive to haloacetonitriles and trihalomethanes. Specific to each DBP, toxicities were also related to their classes and substituted halogen atoms. Damage to photosystems and oxidative stress served as the potential mechanisms for DBPs toxicity to microalgae. The different sensitivities to DBPs indicate that a battery of bioassays with organisms at different trophic levels is necessary to determine the ecotoxicity of DBPs. Furthermore, the ecological risks of DBPs were assessed by calculating the risk quotients (RQs) based on toxicity data from multiple bioassays. The cumulative RQs of DBPs to all the organisms were greater than 1.0, indicating high ecological risks of DBPs in wastewater effluents.


Assuntos
COVID-19 , Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Animais , Organismos Aquáticos , Desinfetantes/toxicidade , Desinfecção , Ecossistema , Halogenação , Humanos , Pandemias , SARS-CoV-2 , Trialometanos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
20.
J Occup Environ Hyg ; 18(8): 361-368, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34185621

RESUMO

Pharmacy technicians are exposed to volatile organic compounds, like the disinfectant isopropyl alcohol (IPA), during the process of aseptic compounding of parenteral cytotoxic drugs. The occupational exposure to nebulized IPA during aseptic compounding has not been investigated. The aim of this study was to investigate the exposure to IPA during aseptic compounding of parenteral cytotoxic drugs and to assess compliance with legal and regulatory limits. As a secondary endpoint, the difference between two disinfection methods was compared regarding the exposure to IPA. The exposure to IPA was measured during five working shifts of 8 hr and one shift of 4 hr. The concentration IPA was measured by using a six-gas monitor. Total daily exposure was calculated as 8-hr Time Weighted Average (TWA) air concentration in mg/m3 and compared with an Occupational Exposure Limit (OEL) value of 500 mg/m3 and incidental peak exposure of 5,000 mg/m3. To assess whether the 8-hr TWA air concentration meets the legal and regulatory limits the Similar Exposure Groups (SEG) compliance test was used. A paired sample t-test was conducted to assess difference in exposure between two disinfection methods. The average 8-hr TWA exposure to IPA during the six measurements varied from 2.6 mg/m3 to 43.9 mg/m3 and the highest momentary concentration measured was 860 mg/m3. The result of the SEG compliance test was 3.392 (Ur value) and was greater than the Ut value of 2.187 which means the exposure to IPA is in compliance with the OEL value. No significant difference in exposure was shown between two disinfection methods (p = 0.49). In conclusion, exposure to IPA during aseptic compounding of parenteral cytotoxic drugs showed compliance to the OEL values with no significant difference in exposure between two disinfection methods.


Assuntos
Desinfetantes , Exposição Ocupacional , Preparações Farmacêuticas , 2-Propanol , Desinfetantes/toxicidade , Desinfecção , Exposição Ocupacional/análise
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