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1.
Ecotoxicol Environ Saf ; 188: 109882, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31698175

RESUMO

Microplastics attract widespread attention, including for their potential to transport toxic chemicals in the form of plasticisers and associated hydrophobic organic chemicals, such as polybrominated diphenyl ethers (PBDEs). The aims of this study were to investigate how nylon (polyamide) microplastics may affect PBDE accumulation in snails, and the acute effects of nylon particles and PBDEs on survival, weight change and inherent microbiome diversity and community composition of the pond snail Lymnaea stagnalis. Snails were exposed for 96 h to BDEs-47, 99, 100 and 153 in the presence and absence of 1% w/w nylon microplastics in quartz sand sediment. No mortality was observed over the exposure period. Snails not exposed to microplastics lost significantly more weight compared to those exposed to microplastics. Increasing PBDE concentration in the sediment resulted in an increased PBDE body burden in the snails, however microplastics did not significantly influence total PBDE uptake. Based on individual congeners, uptake of BDE 47 by snails was significantly reduced in the presence of microplastics. The diversity and composition of the snail microbiome was not significantly altered by the presence of PBDEs nor by the microplastics, singly or combined. Significant effects on a few individual operational taxonomic units (OTUs) occurred when comparing the highest PBDE concentration with the control treatment, but in the absence of microplastics only. Overall within these acute experiments, only subtle effects on weight loss and slight microbiome alterations occurred. These results therefore highlight that L. stagnalis are resilient to acute exposures to microplastics and PBDEs, and that microplastics are unlikely to influence HOC accumulation or the microbiome of this species over short timescales.


Assuntos
Éteres Difenil Halogenados/metabolismo , Lymnaea/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Poluentes Químicos da Água/metabolismo , Animais , Carga Corporal (Radioterapia) , Exposição Ambiental/análise , Retardadores de Chama/análise , Retardadores de Chama/metabolismo , Retardadores de Chama/toxicidade , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/toxicidade , Lymnaea/metabolismo , Lymnaea/microbiologia , Nylons/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
3.
Sheng Wu Gong Cheng Xue Bao ; 35(11): 2050-2060, 2019 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-31814353

RESUMO

As flame retardants, organophosphate is recognized as a global environmental contaminant because of its wide application. This contaminant is hardly degradable by hydrolysis in the environment due to its special physicochemical properties. Therefore, it is of urgent needs to study the microbial degradation of organophosphate. Through continuous enrichment, we isolated one bacterial consortium, named YC-BJ1, from leachate of waste treatment plant in Beijing. The bacterial consortium YC-BJ1 could efficiently degrade 99.8% of triphenyl phosphate (TPhP) and 91.9% of tricresyl phosphate (TCrP) with the concentration of 100 mg/L within 4 days. Besides aryl phosphates, it could degrade chloro-phosphates, tris(1,3-dichloroisopropyl) phosphate (TDCPP) and tris(2-chloroethyl) phosphate (TCEP) by 16.5% and 22.0% respectively. The degradation of the consortium on TPhP was optimized through a broad range of temperature (15-40 ℃), pH (5.0-12.0) and salinity (0%-4%). 16S rRNA gene-based metagenomic analysis revealed that Hyphomicrobium (38.80%), Chryseobacterium (17.57%) and Sphingopyxis (17.46%) were the dominant genera of the consortium YC-BJ1. Compared with the reported organophosphorus flame retardants (OPFRs) degrading bacteria and microflora, the mixed microflora YC-BJ1 exhibited great advantages in degradation efficiency and environmental adaptability, demonstrating its wide application potential. The enrichment and isolation of highly efficient degrading flora can provide abundant microbial resources for the degradation of OPFRs and the bioremediation towards OPFRs-contaminated environments, and also lay a solid foundation for the exploration of its degradation mechanism.


Assuntos
Bactérias , Recuperação e Remediação Ambiental , Retardadores de Chama , Metagenoma , Compostos Organofosforados , RNA Ribossômico 16S , Bactérias/classificação , Bactérias/genética , Retardadores de Chama/metabolismo , Compostos Organofosforados/metabolismo , RNA Ribossômico 16S/genética
4.
Sheng Wu Gong Cheng Xue Bao ; 35(11): 2121-2132, 2019 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-31814359

RESUMO

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame-retardants in a variety of commercial products especially in the electronics and household industries. However, they are bioaccumulative, biotoxic and persistent, making them a globally distributed organic chemical toxin nowadays. Thus, it is extremely important to degrade PBDEs. This paper illustrates the research progress of metabolic pathways of PBDEs under both aerobic and anaerobic conditions, and also combines with in situ degradation studies to infer the degradation potential of archaea. The characteristics and comprehensive factors of various degradation pathways are analyzed. In addition, future researches on biodegradation mechanism of PBDEs, the design and application of PBDEs degradation system are discussed.


Assuntos
Archaea , Biodegradação Ambiental , Éteres Difenil Halogenados , Archaea/metabolismo , Retardadores de Chama/metabolismo , Éteres Difenil Halogenados/metabolismo , Pesquisa/tendências
5.
Environ Int ; 133(Pt B): 105240, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31654917

RESUMO

Water snake and small common carp samples collected from a Chinese pond polluted with electronic waste (e-waste) were analyzed for organophosphorus flame retardants (PFRs), PFR metabolites, and plasticizers to investigate their occurrence, biomagnification, and maternal transfer in ovoviviparous species. Mean concentrations of total PFRs, PFR metabolites, and plasticizers were 2.2-16, 1.3-2.8 and 151-1320 ng/g wet weight (ww), respectively in analyzed organisms. Metabolites of PFRs were found in the same order of magnitude as or even higher than their parent compounds, indicating the importance of monitoring metabolites to evaluate the internal exposure of PFRs in organisms. Biomagnification factors (BMFs) were below 1 for all targeted chemicals and negatively correlated with metabolite/parent ratios (MPRs), suggesting a biodilution driven by metabolism. The lipid normalized concentrations were lower in eggs than in muscle for most of targeted chemicals. The maternal transfer potential was significantly and positively correlated with log KOW (p < 0.05) when log KOW was below 6.


Assuntos
Bioacumulação/fisiologia , Resíduo Eletrônico , Retardadores de Chama/análise , Plastificantes/análise , Poluentes Químicos da Água/análise , Animais , Colubridae/metabolismo , Feminino , Retardadores de Chama/metabolismo , Exposição Materna , Músculo Esquelético/química , Óvulo/química , Plastificantes/metabolismo , Poluentes Químicos da Água/metabolismo
6.
Chemosphere ; 237: 124519, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549646

RESUMO

Tricresyl phosphate (TCP) is one of the organophosphorus flame retardants (OPFRs) used as plasticizer in consumer products and mixed as a lubricant in commercial jet engine oil, reportedly induce neurotoxicity and aerodynamic syndrome. No studies have been attempted so far on TCP to induce hepatotoxicity in human cells. This study for the first time confirms the hepatotoxic potential and activation of cancer pathways in TCP treated human hepatocellular cells (HepG2). MTT and NRU data showed 39.3% and 49.85% decline in HepG2 survival when exposed to the highest concentration of TCP (400 µM) for 3 days. Comet assay showed 27.1-fold greater DNA damage in cells treated with TCP (400 µM). Flow cytometric analysis revealed an upsurge in the intracellular reactive oxygen species (ROS) and nitric oxide (NO) production in cells, affirming oxidative stress. TCP (400 µM) exposure resulted in 27% reduction in Rh123 fluorescence, indicating dysfunction of mitochondrial membrane potential (ΔΨm). Cell cycle analysis exhibited 62.53% cells in the subG1 apoptotic phase after TCP (400 µM) treatment, also a massive increase in Ca2+ influx validate the on-set of apoptosis in cells. Immunofluorescence of TCP exposed cells showed activation of p53, caspase3, caspase9 reaffirming the involvement of mitochondrial-dependent intrinsic apoptotic signaling. qPCR array of 84 genes unravel the transcriptomic alterations in HepG2 cells after TCP treatment. mRNA transcripts of ATP5A1, GADD45A, IGFBP5, SOD1, STMN1 genes were prominently upregulated providing candid evidence on TCP mediated activation of human cancer pathways to orchestrate the apoptotic death of HepG2 cells, specifying hepatotoxic potential of TCP.


Assuntos
Retardadores de Chama/toxicidade , Compostos Organofosforados/toxicidade , Apoptose/fisiologia , Ensaio Cometa , Dano ao DNA , Retardadores de Chama/metabolismo , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Estatmina , Transcriptoma , Tritolil Fosfatos
7.
Ecotoxicol Environ Saf ; 185: 109690, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31563749

RESUMO

Hexabromocyclododecanes (HBCDs) are the third most highly produced brominated flame retardants (BFRs) all over the world. Based on the current research status of HBCDs, zebrafish were exposed to three dietary concentrations of HBCDs (0, 10, 100, 400 ng/g) for 56 days, and followed by clean food for 28 days. In order to investigate the enrichment and purification of HBCDs in zebrafish, HBCD enantiomers in zebrafish were determined using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). To investigate the effects of long-term exposure of HBCDs on thyroid dysfunction and oxidative stress in zebrafish, the concentrations of thyroid hormone (T3, T4, FT3 and FT4) and the activities of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) were measured. RT-PCR was used to reveal the molecular mechanism of HBCDs' influence on thyroid hormone in zebrafish. The result of UPLC-MS/MS showed that there were three main reasons for the existence of α-HBCD as the major isomer in the organism. HBCDs had significant inhibitory effect on T3 and T4 in liver of adult zebrafish after 56 days' exposure. Compared with the control group, the ratio of T3 and T4was significantly higher in the medium and high concentration group. The content of FT3 and FT4 in the liver tissue of zebrafish increased first and then decreased with the increase of exposure concentration. With the increase of exposure concentration, the content of MDA in zebrafish liver decreased firstly and then increased. The activity of SOD and CAT in zebrafish liver showed the opposite trend with MDA. And the concentration of GSH in liver decreased gradually, which showed a significant dose-effect relationship. HBCDs exposure has an inhibitory effect on thyroid hormone receptor gene (TRß) and adrenocorticotropin-releasing hormone gene (Crh) in zebrafish.


Assuntos
Retardadores de Chama/toxicidade , Hidrocarbonetos Bromados/toxicidade , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/metabolismo , Peixe-Zebra/metabolismo , Ração Animal , Animais , Cromatografia Líquida , Exposição Dietética/análise , Relação Dose-Resposta a Droga , Retardadores de Chama/metabolismo , Hidrocarbonetos Bromados/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estereoisomerismo , Espectrometria de Massas em Tandem , Glândula Tireoide/metabolismo
8.
Sci Total Environ ; 697: 134159, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31491624

RESUMO

Legacy wastewater contaminants from e-waste dismantling process such as 2,4,6-tribromophenol (TBP), one of the most widely used brominated flame retardants (BFRs), have raised concern owing to their toxicity and recalcitrance. Our previously isolated Bacillus sp. GZT from river sludge in e-waste dismantling area is a good candidate for bioremediation of BFRs contaminated sites considering its remarkable degradability of TBP and its intermediates. However, there exists a new challenge because bio-degrader cannot produce enough biomass or metabolic activity to cleanup TBP in practice complex environment. Here, we heterologously expressed and functionally characterized the genes and enzymes responsible for TBP degradation to examine the feasibility of enhancing the ability of this microorganism to detoxify TBP. Results demonstrated that five recombinant strains containing functional genes, designated tbpA, tbpB, tbpC, tbpD, and tbpE, become more tolerant toward a wide range of brominated compounds than the nontransgenic strain. Cytochrome P450 reductase encoded by tbpA gene could greatly increase efficiency to remove TBP (98.8%), as compared to wild-type strain GZT (93.2%). Its debromination intermediates 2,4-dibromophenol, 2,6-dibromo-4-methylphenol and 2-bromophenol were significantly metabolized by halophenol dehalogenases encoded by tbpB, tbpC, and tbpD, respectively. Finally, under the function of tbpE gene encoding enzyme, further debrominated product (phenol) was dramatically detoxified. To reduce the risk of these xenobiotics, the expression of these genes can be induced and significantly up-regulated during exposure to them. These results open broad scope for future study in developing genetic engineering technologies for more efficient remediation wastewater of e-waste recycling sites contaminated with TBP, which would certainly be important steps to lower TBP exposures and prevent potential health effects.


Assuntos
Bacillus/fisiologia , Biodegradação Ambiental , Resíduo Eletrônico , Retardadores de Chama/metabolismo , Fenóis/metabolismo
9.
Environ Sci Process Impacts ; 21(11): 1887-1898, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31552402

RESUMO

Major point sources of per- and polyfluoroalkyl substances (PFASs) cause ubiquitous spread of PFASs in the environment. In this study, surface water and aquatic invertebrates at three Swedish sites impacted by PFAS point sources were characterized, using homologue, isomer and extractable organofluorine (EOF) profiling as well as estimation of bioaccumulation factors (BAFs) and mass discharge. Two sites were impacted by fire training (sites A and R) and the third by industrial runoff (site K). Mean Σ25PFASs concentration in water was 1920 ng L-1 at site R (n = 3), which was more than 20- and 10-fold higher than those from sites A and K, respectively. PFOS was the most predominant PFAS in all waters samples, constituting 29-79% of Σ25PFAS concentrations. Several branched isomers were detected and they substantially contributed to concentrations in surface water (e.g. 49-78% of ΣPFOS) and aquatic invertebrates (e.g. 15-28% of ΣPFOS). BAFs in the aquatic invertebrates indicated higher bioaccumulation for long chain PFASs and lower bioaccumulation for branched PFOS isomers compared to linear PFOS. EOF mass balance showed that Σ25target PFASs in water could explain up to 55% of EOF at site R. However, larger proportions of EOF (>92%) remained unknown in water from sites A and K. Mass discharges were for the first time estimated for EOF and revealed that high amounts of EOF (e.g. 8.2 g F day-1 at site A) could be transported by water to recipient water bodies relative to Σ25PFASs (e.g. 0.15 g day-1 at site A). Overall, we showed that composition profiling, BAFs and EOF mass balance can improve the characterization of PFASs around point sources.


Assuntos
Organismos Aquáticos/química , Monitoramento Ambiental/métodos , Retardadores de Chama/análise , Fluorcarbonetos/análise , Água Doce/química , Invertebrados/química , Poluentes Químicos da Água/análise , Animais , Bioacumulação , Retardadores de Chama/metabolismo , Fluorcarbonetos/metabolismo , Suécia , Poluentes Químicos da Água/metabolismo
10.
Ecotoxicol Environ Saf ; 182: 109449, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398778

RESUMO

The flame retardant, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), is one of the most developmentally toxic organophosphate flame retardants (OPFRs). However, few mechanistic studies on phenotypic malformation caused by TDCIPP have been conducted. This study investigates the molecular mechanism underlying abnormal tail fin development consistently observed in zebrafish embryos exposed to TDCIPP. The results show that the defects in the tail fin (e.g., bent spine, defective caudal fin, and damaged tip) were associated with altered expression of transcription factors. The significant up-regulation of mmp9 and, among insulin-growth factor (IGF) families, igfbp-1a and igfbp1b was observed, whereas alterations in the expression of cdx4, igf1a, ifg1b, igf2b, and vegaa regulating tail development were dependent on time points. In accordance with changes in mRNA gene expression, TDCIPP impaired vessel formation and disorganized muscle in transgenic Tg(fli-GFP) zebrafish larvae. Furthermore, we found that the overexpression of mmp9 caused by TDCIPP was not linked to igfbp-1. Overall, these findings demonstrate that TDCIPP disrupts the progression of tail fin development, accompanied by defects in vessel and muscle formation in developing zebrafish embryos.


Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Retardadores de Chama/toxicidade , Compostos Organofosforados/toxicidade , Animais , Animais Geneticamente Modificados , Retardadores de Chama/metabolismo , Larva , Organofosfatos/metabolismo , Fosfatos/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
11.
Chemosphere ; 237: 124474, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31377596

RESUMO

The present study investigated the metabolism of the flame retardant and plasticizer chemical, triphenyl phosphate (TPHP), in a rat liver microsome-based in vitro assay with glutathione (GSH) in order to elucidate metabolic pathways leading to formation of conjugates. A highly sensitive and efficient method was developed for the detection and characterization of GSH reactive metabolites using LC-Q-TOF-MS/MS both in the negative and positive electrospray ionization modes. Seven GSH conjugates formed as a result of microsomal incubation, which were identified as S-conjugates based on MS/MS spectra, and confirmed by subsequent time-dependent incubation assays. With the exception of hydrolysis reactions leading to formation of a diester metabolite, diphenyl phosphate (DPHP), the results demonstrated that Phase I epoxidation on phenyl ring of TPHP leading to mono- and di-hydroxylated TPHP metabolites, which can further conjugate with GSH. Depending on hydroxylated TPHP formation, an o-hydroquinone intermediate formed in vitro via Phase I metabolism, and the o-benzoquinone form reacted with GSH and also formed GSH conjugates. The present study showed that via hydroxylated TPHP Phase I formation that GSH conjugates are important Phase II metabolites for TPHP metabolism in vitro. Some GSH conjugates may be valuable candidate biomarkers for monitoring TPHP exposure in biota.


Assuntos
Glutationa/metabolismo , Organofosfatos/metabolismo , Ativação Metabólica , Animais , Cromatografia Líquida , Retardadores de Chama/metabolismo , Hidroxilação , Masculino , Redes e Vias Metabólicas , Microssomos Hepáticos/metabolismo , Plastificantes/metabolismo , Ratos , Espectrometria de Massas em Tandem/métodos
12.
Sci Total Environ ; 689: 278-286, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31276995

RESUMO

The levels of eight polybrominated diphenyl ether (PBDE) congeners, and six novel brominated flame retardants (NBFRs) were determined in human milk collected from Beijing, China in 2014. The tested 111 samples were collected from 37 mothers, and each donor provided one milk sample per month for 3 months after childbirth. Levels of ∑PBDEs (total tri- to deca-BDEs) were in the range of 0.288 to 22.2 ng g-1 lw (lipid weight). BDE-209, with a median level of 2.2 ng g-1 lw, was the predominant congener. Decabromodiphenyl ethane (DBDPE), as an NBFR and a substitute for deca-BDE, was found to be the most abundant BFR in all tested human milk (median:5.96 ng g-1 lw). This result might suggest that the predominantly consumed BFRs in China have changed from PBDEs to PBDE substitutes. Additionally, a comparison to our previous studies conducted in 2005 and 2011 revealed that levels of tri- to hepta-BDEs showed significant reduction from 2005 to 2014, whereas levels of BDE-209 showed no significant variation from 2011 to 2014. Temporal trends of BFR levels over the three months of lactation were also investigated, and no significant changes were found in concentration with time over the three months lactation. For nursing infants up to 6 months old, the median lower bound of daily BFR intakes via human milk ingestion ranged from zero for 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) and 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE) to 18.7 ng kg-1 bodyweight day-1 for DBDPE. Although the daily dietary BFR intake for nursing infants was found to be much higher than that for adults, the risk assessment evaluated by the margin of exposure (MOE) approach revealed that dietary BFR intake for nursing infants was unlikely to pose significant health risks.


Assuntos
Exposição Ambiental , Retardadores de Chama/metabolismo , Éteres Difenil Halogenados/metabolismo , Leite Humano/química , Adulto , Pequim , Aleitamento Materno , Feminino , Halogenação , Humanos , Lactente , Recém-Nascido , Medição de Risco , Estações do Ano
13.
Environ Pollut ; 253: 899-908, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351298

RESUMO

Triphenyl phosphate (TPHP; CAS # 115-86-6), a commonly used plasticizer and flame retardant, has been reported in wild birds and identified as a potential high-risk chemical. We exposed Japanese quail (Coturnix japonica) by in ovo injection, and once hatched, orally each day for 5 days to safflower oil (controls) or TPHP dissolved in vehicle at low (5 ng TPHP/g), mid (50 ng TPHP/g), or high (100 ng TPHP/g) nominal TPHP doses. The low TPHP dose reflected concentrations in wild bird eggs, with mid and high doses 10x and 20x greater to reflect potential increases in environmental TPHP concentrations in the future. Despite no effects on mRNA expression in thyroid-related genes, TPHP exposure enhanced thyroid gland structure in high TPHP males, but in females, suppressed thyroid gland structure and activity (all TPHP females), and circulating free triiodothyronine (high TPHP females only). Consistent with thyroidal changes, and compared to controls, mid and high TPHP chicks experienced significantly reduced resting metabolic rate (≤13%) and growth (≤53%); mid TPHP males and high TPHP females were significantly smaller. The observed thyroidal effects and suppressed growth and metabolic rate of the quail chicks suggest that TPHP may adversely affect the health of wild birds.


Assuntos
Coturnix/fisiologia , Poluentes Ambientais/toxicidade , Organofosfatos/toxicidade , Glândula Tireoide/efeitos dos fármacos , Animais , Metabolismo Basal , Galinhas/metabolismo , Coturnix/crescimento & desenvolvimento , Feminino , Retardadores de Chama/metabolismo , Retardadores de Chama/toxicidade , Masculino , Plastificantes , Codorniz , Glândula Tireoide/metabolismo , Tri-Iodotironina
14.
Environ Pollut ; 253: 909-917, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351299

RESUMO

Tetrabromobisphenol A (TBBPA) is a nonregulated brominated flame retardant with a high production volume, and it is applied in a wide variety of consumer products. TBBPA is ubiquitous in abiotic matrices, wildlife and humans around the world. This paper critically reviews the published scientific data concerning the disposition, metabolism or kinetics and toxicity of TBBPA in animals and humans. TBBPA is rapidly absorbed and widely distributed among tissues, and is excreted primarily in the feces. In rats, TBBPA and its metabolites have limited systemic bioavailability. TBBPA has been detected in human milk in the general population. It is available to both the developing fetus and the nursing pups following maternal exposure. It has been suggested that TBBPA causes acute toxicity, endocrine disruptor activity, immunotoxicity, neurotoxicity, nephrotoxicity, and hepatotoxicity in animals. Cell-based assays have shown that TBBPA can induce reactive oxygen species in a concentration-dependent manner, and it promotes the production of inflammatory factors such as TNF α, IL-6, and IL-8. Cells exposed to high levels of TBBPA exhibit seriously injured mitochondria and a dilated smooth endoplasmic reticulum. This review will enhance the understanding of the potential risks of TBBPA exposure to ecological and human health.


Assuntos
Retardadores de Chama/toxicidade , Bifenil Polibromatos/toxicidade , Animais , Animais Selvagens , Disponibilidade Biológica , Fezes , Feminino , Retardadores de Chama/metabolismo , Halogenação , Humanos , Cinética , Masculino , Exposição Materna , Ratos
15.
Chemosphere ; 235: 481-491, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31272008

RESUMO

Chlorinated alkyl and non-chlorinated aryl organophosphate flame retardants (OPFRs) and some brominated flame retardants (FR) were introduced as replacements for polybrominated diphenyl ethers (PBDEs) after PBDEs phase-out in 2004 and 2013. Organophosphorous (OP) insecticides are mainly used in agricultural settings since the Food Quality Protection Act of 1996 phased-out most residential uses of OP insecticides in the United States. Urinary metabolites of FRs and OPs are known exposure biomarkers to FRs and OP insecticides, respectively. For large population-based studies, concurrent quantification of these metabolites using a small urine volume is desirable, but until now was not possible. We developed an analytical approach to quantify in 0.2 mL urine 10 FRs and six OP insecticide metabolites: diphenyl phosphate, bis(1,3-dichloro-2-propyl) phosphate, bis(1-chloro-2-propyl) phosphate, bis(2-chloroethyl) phosphate, dicresyl phosphates, dibutyl phosphate, dibenzyl phosphate, 2,3,4,5-tetrabromobenzoic acid, 2-((isopropyl)phenyl)phenyl phosphate, 4-((tert-butyl)phenyl)phenyl phosphate, dimethyl phosphate, diethyl phosphate, dimethyl thiophosphate, dimethyl dithiophosphate, diethyl thiophosphate, and diethyl dithiophosphate. The method relies on enzymatic deconjugation, automated off-line solid phase extraction, high-performance liquid chromatography, and isotope dilution tandem mass spectrometry. Detection limits ranged from 0.05 to 0.5 ng mL-1, accuracy from 89 to 118%, and imprecision was <10%. . This method is the first to quantify simultaneously trace levels of 16 biomarkers of FRs and OP insecticides in only four drops of urine. We confirmed the method suitability for use in large epidemiological studies to assess background and occupational exposures to these classes of environmental pollutants by analyzing 303 samples collected from the general population and a group of firefighters. FR metabolite and DAPs concentrations in the general population group were lower than in the firefighters group, and within the ranges reported in the U.S. general population and other non-occupationally exposed populations.


Assuntos
Biomarcadores/urina , Exposição Ambiental/análise , Monitoramento Ambiental , Poluentes Ambientais/urina , Retardadores de Chama/toxicidade , Inseticidas/toxicidade , Organofosfatos/toxicidade , Plastificantes/toxicidade , Cromatografia Líquida de Alta Pressão/métodos , Poluentes Ambientais/análise , Retardadores de Chama/análise , Retardadores de Chama/metabolismo , Éteres Difenil Halogenados/análise , Halogenação , Humanos , Inseticidas/análise , Inseticidas/urina , Limite de Detecção , Espectrometria de Massas , Exposição Ocupacional/análise , Organofosfatos/metabolismo , Organofosfatos/urina , Fosfatos , Plastificantes/análise , Plastificantes/metabolismo , Extração em Fase Sólida
16.
Chemosphere ; 234: 395-401, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31228842

RESUMO

In the present study, urine samples (n = 258) were collected from adults (n = 42) and children (n = 22) in an electronic waste (e-waste) recycling site. The concentrations and compositions of six di-esters, or the metabolites of phosphate flame retardants (PFRs), were measured at different time points on consecutive days. Bis(2-chloroethyl) phosphate (BCEP), dibutyl phosphate (DBP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP) were detected in more than 50% of urine samples. The median concentrations of BCEP, DBP, BDCIPP, and DPHP were 2.43-4.80, 0.09-2.65, 0.46-0.89, and 0.66-1.83 ng/mL in adult urine samples, respectively. For children, the median concentrations of BCEP, DBP, BDCIPP, and DPHP were 1.23, 0.08, 0.06, and 0.29 ng/mL in morning urine samples, and 1.86, 0.12, 0.14, and 0.27 ng/mL in nightfall urine samples, respectively. Nightfall urine had generally higher levels of di-esters than those in morning urine for both adults and children (p < 0.05). Children had significantly lower concentrations of di-esters than adults, indicating the occupational exposure risks of PFRs for adults. Significant correlations were observed in levels of BDCIPP (3 out of 6 groups of samples) and DPHP (2 out of 6 groups of samples) in couples (p<0.05). Significant correlations between parents and boys were only observed in BCEP levels in nightfall urine samples, and in DBP levels in morning urine samples (p<0.05). The results suggest that di-ester concentrations in e-waste recycling workers are highly variable depending on the time that samples are collected, which could further influence the estimation of human exposure to PFRs.


Assuntos
Resíduo Eletrônico/efeitos adversos , Retardadores de Chama/análise , Exposição Ocupacional , Fosfatos/urina , Reciclagem , Adulto , Criança , Ésteres/análise , Feminino , Retardadores de Chama/metabolismo , Humanos , Masculino , Fatores de Tempo
17.
Environ Sci Pollut Res Int ; 26(23): 23832-23841, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31209756

RESUMO

The coastal environments worldwide are subjected to increasing TBBPA contamination, but current knowledge on aerobic biodegradability of this compound by marine microbes is lacking. The aerobic removal of TBBPA using marine consortia under eight different cometabolic conditions was investigated here. Results showed that the composition and diversity of the TBBPA-degrading consortia had diverged after 120-day incubation. Pseudoalteromonas, Alteromonas, Glaciecola, Thalassomonas, and Limnobacter were the dominant genera in enrichment cultures. Furthermore, a combination of beef extract- and peptone-enriched marine consortia exhibited higher TBBPA removal efficiency (approximately 60%) than the other substrate amendments. Additionally, Alteromonas macleodii strain GCW was isolated from a culture of TBBPA-degrading consortium. This strain exhibited about 90% of degradation efficiency toward TBBPA (10 mg L-1) after 10 days of incubation under aerobic cometabolic conditions. The intermediates in the degradation of TBBPA by A. macleodii strain GCW were analyzed and the degradation pathways were proposed, involving ß-scission, debromination, and nitration routes.


Assuntos
Retardadores de Chama/metabolismo , Bifenil Polibromatos/química , Pseudoalteromonas/metabolismo , Aerobiose , Bactérias , Biodegradação Ambiental , Pseudoalteromonas/química
18.
Chemosphere ; 233: 590-596, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31200129

RESUMO

Several regulatory offices called for the phase-out of di (2-ethylhexyl) phthalate (DEHP) in medical devices if safer alternatives are available. In medical devices, the occurrence of alternative plasticizers (APs) is widely variable among types of devices. However, plasticizer use is constantly evolving, as there is no reference to guide manufacturers in the choice and amount to be integrated into their products. As intensive care unit (ICU) patients need numerous indwelling plastic devices during their treatment, we hypothesized that these patients are exposed to APs and phosphate flame retardants and plasticizers (PFRs). Urinary metabolites of APs and PFRs were analyzed in the urine of adult ICU patients (n = 24) over a time period of four days. Our results show that adult ICU patients are exposed to PFRs as well as to APs concentrations were much lower compared to the levels of DEHP metabolites in the same samples. However, significantly higher than in controls (n = 15) this exposure resulted in detectable urinary levels in almost every patient and at every studied time point. Increasing temporal trends were observed for several metabolites from admission until day 3 at ICU. The use of specific medical devices, such as continuous venovenous hemofiltration (CVVH) and extracorporeal membrane oxygenation (ECMO), was associated with an increase in urinary concentrations for several PFR metabolites, despite the lack of information on the presence of these plasticizer chemicals in such medical devices. Further research into the possibly toxic effects of these chemicals released from medical devices is urgently needed.


Assuntos
Poluentes Ambientais/urina , Retardadores de Chama/metabolismo , Plastificantes/metabolismo , Adulto , Aminas , Cuidados Críticos , Humanos , Masculino , Organofosfatos/urina , Fosfatos , Ácidos Ftálicos , Plásticos
19.
Chemosphere ; 233: 724-732, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31200132

RESUMO

Organophosphate flame retardants and plasticizers (OPFRs) are widely additives in consumer products and building materials. They are frequently detected in environmental media, including indoor air, water, soil, and dust. To provide a low-cost and multi-target tool for monitoring individual exposure to OPFRs, a high-throughput method for simultaneous detection of 15 urinary OFPR metabolites was established using solvent induced phase transition extraction (SIPTE) technique for sample pretreatment and ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) for target quantification. SIPTE is implemented by adding a hydrophobic solvent (methyl tert-butyl ether, used as the phase transition solution) to the homogeneous acetonitrile (ACN) aqueous solution for phase separation. Method performance was validated based on the evaluation indicators. The linear range of this present method was between 0.1 and 50 ng/mL for 15 urinary OPFR metabolites. The limits of detection (LODs) were from 0.012 to 0.25 ng/mL, and the spiked recoveries ranged of 71.3-117.6%, with corresponding relative standard deviations (RSDs) from 4.8 to 25.6%. Unlike most studies only focused on the determination of dialkyl and diaryl phosphate esters (DAPs), our analytical method also covered hydroxylated OPFRs metabolites (OH-OPFRs). Seven DAPs with detection frequencies (DF) more than 60% were detected in a small pilot study (n = 15). Besides, 4-hydroxy diphenyl phosphate (4-HO-DPHP) could be also detected in urine samples. Overall, this newly developed high-throughput analytical method could simultaneously determine 15 urinary OPFRs metabolites and screen these biomarkers of human exposure to OPFRs.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/urina , Retardadores de Chama/metabolismo , Organofosfatos/urina , Acetonitrilos , Biomarcadores , Cromatografia Líquida/métodos , Poeira/análise , Retardadores de Chama/análise , Humanos , Limite de Detecção , Organofosfatos/análise , Projetos Piloto , Plastificantes/análise , Projetos de Pesquisa , Solventes/análise , Espectrometria de Massas em Tandem/métodos
20.
Chemosphere ; 232: 195-203, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31154180

RESUMO

Tricresyl phosphates (TCPs), a typical sort of organophosphate flame retardants, has received extensive concerns due to its potential adverse effects. However, limited information is available on the efficient and safe removal methods of TCPs. In this regard, TCPs were tentatively biodegraded with Brevibacillus brevis. A probable degradation pathway was further proposed with the cellular reactions discussed in detail. Experiments showed that B. brevis at 2 g L-1 could degrade 1 mg L-1 tri-m-cresyl phosphate, tri-p-cresyl phosphate, and tri-o-cresyl phosphate by 82.91%, 93.91%, and 53.92%, respectively, within five days. In the process of biodegradation, B. brevis metabolism caused the release of Na+ and Cl- as well as the absorption of some nutrient ions including K+, PO43-, Mg2+, and SO42-; the presence of oxalic acid, citric acid, acetic acid, and malonic acid was also detected. Similar metabolic pathways were found among different TCPs isomers, but tri-o-cresyl phosphate induced more reactive oxygen species than the other two did. This work develops novel insights into the potential mechanisms of TCPs biodegradation by microorganisms.


Assuntos
Biodegradação Ambiental , Brevibacillus/metabolismo , Tritolil Fosfatos/metabolismo , Bacillus/metabolismo , Retardadores de Chama/metabolismo , Isomerismo , Redes e Vias Metabólicas , Organofosfatos/metabolismo
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