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1.
J Environ Pathol Toxicol Oncol ; 39(3): 201-212, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32865912

RESUMO

Acute and chronic effects of ultraviolet radiation (UVR) on human health have long been a concern. It is well known that acute UVR causes epidermal hyperplasia, erythema, delayed tanning, pigment darkening, and free-radical formation. Apart from acute effects of UVR, its chronic effects involve immunosuppression, photoaging, exacerbation, photodermatoses, and photocarcinogenesis. To protect skin from harmful effects of UVR, UV filters were developed. But these may cause harmful effects in humans and on the environment; adverse effects of these chemicals have been evaluated for > 20 yr. Studies show that UV filters may lead to endocrine disruption, hepatotoxicity, mutagenicity, and systemic toxicity. Literature on environmental effects of UV filters suggests that they are bioaccumulative, pseudopersistent, and possibly toxic to aquatic ecosystems. The objective of this review is to summarize toxic effects and safety concerns of organic UV filters on human beings and the environment. We focus on UV filters' organic endocrine-disrupting effects by reviewing both in vivo and in vitro studies.


Assuntos
Disruptores Endócrinos/toxicidade , Compostos Orgânicos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Protetores Solares/toxicidade , Animais , Biotransformação , Disruptores Endócrinos/química , Disruptores Endócrinos/farmacocinética , Humanos , Estrutura Molecular , Compostos Orgânicos/química , Compostos Orgânicos/farmacocinética , Protetores Solares/química , Protetores Solares/farmacocinética
2.
Ecotoxicol Environ Saf ; 201: 110827, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32535366

RESUMO

Numerous experimental and epidemiological studies have demonstrated that exposure to PM2.5 may result in pathogenesis of several major cardiovascular diseases (CVDs), which can be attributed to the combined adverse effects induced by the complicated components of PM2.5. Organic materials, which are major components of PM2.5, contain thousands of chemicals, and most of them are environmental hazards. However, the contamination profile and contribution to overall toxicity of PM2.5-bound organic components (OCs) have not been thoroughly evaluated yet. Herein, we aim to provide an overview of the literature on PM2.5-bound hydrophobic OCs, with an emphasis on the chemical identity and reported impairments on the cardiovascular system, including the potential exposure routes and mechanisms. We first provide an update on the worldwide mass concentration and composition data of PM2.5, and then, review the contamination profile of PM2.5-bound hydrophobic OCs, including constitution, concentration, distribution, formation, source, and identification. In particular, the link between exposure to PM2.5-bound hydrophobic OCs and CVDs and its possible underlying mechanisms are discussed to evaluate the possible risks of PM2.5-bound hydrophobic OCs on the cardiovascular system and to provide suggestions for future studies.


Assuntos
Poluentes Atmosféricos/toxicidade , Doenças Cardiovasculares/induzido quimicamente , Sistema Cardiovascular/efeitos dos fármacos , Monitoramento Ambiental/métodos , Compostos Orgânicos/toxicidade , Material Particulado/toxicidade , Poluentes Atmosféricos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/química , Material Particulado/química
3.
Ecotoxicol Environ Saf ; 201: 110817, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32512417

RESUMO

Cellular exposure to xenobiotic human-made products will lead to oxidative stress that gives rise to DNA damage, as well as chemical or mechanical damage. Distinguishing the chemicals that will induce oxidative stress and predicting their toxicity is necessary. In the present study, 4270 compounds in the ARE-bla assay were investigated to predict active and inactive compounds by using simple algorithms, namely, recursive partitioning (RP) and binomial logistic regression, and to develop the quantitative structure-activity relationship (QSAR) models of chemicals that activate the ARE pathway to induce oxidative stress and exert toxic effects on cells. A decision tree based on scaffold-based fragments obtained through RP analysis showed the best identification accuracy. However, the overall identification accuracy of this model for active compounds was unsatisfactory due to limited fragments. Furthermore, a binomial logistic regression model was developed from 638 active compounds and 3632 inactive chemicals. The model with a cutoff of 0.15 could predict chemicals that were active or inactive with the prediction accuracy of 69.1%. Its area under the receiver operating characteristic (ROC) curve metric (AUROC) was 0.762, which indicated the acceptable predictive ability of this model. The parameters nBM (number of multiple bonds) and H% (percentage of H atom) played dominant roles in the prediction of the activity (inactive or active) of chemicals. A global QSAR model was developed to predict the toxicity of active chemicals. However, the model displayed an unsatisfactory result with R2 = 0.316 and R2ext = 0.090. Active chemicals were then classified on the basis of structure. A total of 79 compounds with carbon chains could be predicted with acceptable performance by using a QSAR model with six descriptors (R2 = 0.722, R2ext = 0.798, Q2Loo = 0.654, Q2Boot = 0.755, Q2ext = 0.721). The simple models established here contribute to efforts on identification compounds inducing oxidative stress and provide the scientific basis for risk assessment to organisms in the environment.


Assuntos
Compostos Orgânicos , Estresse Oxidativo/efeitos dos fármacos , Algoritmos , Elementos de Resposta Antioxidante/genética , Bioensaio , Bases de Dados Factuais , Genes Reporter , Humanos , Modelos Logísticos , Compostos Orgânicos/química , Compostos Orgânicos/toxicidade , Estresse Oxidativo/genética , Relação Quantitativa Estrutura-Atividade , beta-Lactamases/genética
4.
Proc Natl Acad Sci U S A ; 117(27): 15473-15481, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571948

RESUMO

The development of sustainable methods for the degradation of pollutants in water is an ongoing critical challenge. Anthropogenic organic micropollutants such as pharmaceuticals, present in our water supplies in trace quantities, are currently not remediated by conventional treatment processes. Here, we report an initial demonstration of the oxidative degradation of organic micropollutants using specially designed nanoparticles and visible-wavelength sunlight. Gold "Janus" nanorods (Au JNRs), partially coated with silica to enhance their colloidal stability in aqueous solutions while also maintaining a partially uncoated Au surface to facilitate photocatalysis, were synthesized. Au JNRs were dispersed in an aqueous solution containing peroxydisulfate (PDS), where oxidative degradation of both simulant and actual organic micropollutants was observed. Photothermal heating, light-induced hot electron-driven charge transfer, and direct electron shuttling under dark conditions all contribute to the observed oxidation chemistry. This work not only provides an ideal platform for studying plasmonic photochemistry in aqueous medium but also opens the door for nanoengineered, solar-based methods to remediate recalcitrant micropollutants in water supplies.


Assuntos
Nanopartículas Metálicas/efeitos da radiação , Fotólise/efeitos da radiação , Luz Solar , Poluentes Químicos da Água/química , Poluição Química da Água/prevenção & controle , Ouro/química , Ouro/efeitos da radiação , Nanopartículas Metálicas/química , Nanotecnologia/métodos , Nanotubos/química , Nanotubos/efeitos da radiação , Compostos Orgânicos/química , Compostos Orgânicos/toxicidade , Oxirredução/efeitos da radiação , Dióxido de Silício/química , Dióxido de Silício/efeitos da radiação , Água/química , Poluentes Químicos da Água/toxicidade
5.
Aquat Toxicol ; 224: 105496, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32408003

RESUMO

Predicting the toxicity of organic toxicants to aquatic life through chemometric approach is challenging area. In this paper, a six-descriptor quantitative structure-activity/toxicity relationship (QSAR/QSTR) model was successfully developed for the toxicity pEC10 of organic chemicals against Pseudokirchneriella subcapitata, by applying support vector machine (SVM) together with genetic algorithm. A sufficiently large data set consisting of 334 organic chemicals was randomly divided into a training set (167 compounds) and a test set (167 compounds) with a ratio of 1:1. The optimal SVM model possesses coefficient of determination R2 of 0.76 and mean absolute error (MAE) of 0.60 for the training set and R2 of 0.75 and MAE of 0.61 for the test set. Compared with other models reported in the literature, our SVM model for the toxicity pEC10 shows significant statistical quality and satisfactory predictive ability, although it has fewer molecular descriptors and more samples in the test set. A QSTR model for pEC50 of organic chemicals against Pseudokirchneriella subcapitata was also developed with the same subsets and molecular descriptors.


Assuntos
Clorofíceas/efeitos dos fármacos , Ecotoxicologia/métodos , Compostos Orgânicos , Poluentes Químicos da Água , Compostos Orgânicos/química , Compostos Orgânicos/toxicidade , Relação Quantitativa Estrutura-Atividade , Máquina de Vetores de Suporte , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
6.
Artigo em Inglês | MEDLINE | ID: mdl-32223371

RESUMO

Observations made for the analysis of the oil spill dispersant tracer dioctyl sulfosuccinate (DOSS) during LC50 toxicity testing, highlighted a stability issue for this tracer compound in seawater. A liquid chromatography high-resolution quadrupole time-of-flight mass spectrometry (LC/QToF) was used to confirm monooctyl sulfosuccinate (MOSS) as the only significant DOSS breakdown product, and not the related isomer, 4-(2-ethylhexyl) 2-sulfobutanedioate. Combined analysis of DOSS and MOSS was shown to be applicable to monitoring of spill dispersants Corexit® EC9500A, Finasol OSR52, Slickgone NS, and Slickgone EW. The unassisted conversion of DOSS to MOSS occurred in all four oil spill dispersants solubilized in seawater, although differences were noted in the rate of MOSS formation. A marine microcosm study of Corexit EC9500A, the formulation most rapid to form MOSS, provided further evidence of the stoichiometric conversion of DOSS to MOSS under conditions relevant to real world dilbit spill. Results supported combined DOSS and MOSS analysis for the monitoring of spill dispersant in a marine environment, with a significant extension of sample collection time by 10 days or longer in cooler conditions. Implications of the unassisted formation of MOSS and combined DOSS:MOSS analysis are discussed in relation to improving dispersant LC50 toxicity studies.


Assuntos
Ácido Dioctil Sulfossuccínico/toxicidade , Monitoramento Ambiental/métodos , Hidrocarbonetos/toxicidade , Lipídeos/toxicidade , Tensoativos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cromatografia Líquida , Ácido Dioctil Sulfossuccínico/análise , Hidrocarbonetos/análise , Dose Letal Mediana , Lipídeos/análise , Microbiota/efeitos dos fármacos , Compostos Orgânicos/análise , Compostos Orgânicos/toxicidade , Petróleo/análise , Poluição por Petróleo/análise , Salmão/crescimento & desenvolvimento , Água do Mar/química , Água do Mar/microbiologia , Succinatos/análise , Succinatos/toxicidade , Tensoativos/análise , Testes de Toxicidade , Poluentes Químicos da Água/análise
7.
Chemosphere ; 249: 126073, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32088464

RESUMO

Oil sands process-affected water (OSPW) is a byproduct of bitumen extraction in the surface-mining oil sands industry in Alberta, Canada. Organic compounds in OSPW can be acutely or chronically toxic to aquatic organisms, so part of a long-term strategy for remediation of OSPW is ageing of water in artificial lakes, termed end-pit lakes. BaseMine Lake (BML) is the first oil sands end-pit lake, commissioned in 2012. At the time of its establishment, an effects-directed analysis of BML-OSPW showed that naphthenic acids and polar organic chemical species containing sulfur or nitrogen contributed to its acute lethality. However, the chronic toxicity of these same chemical fractions has not yet been investigated. In this work, the short-term fathead minnow reproductive bioassay was used to assess endocrine-system effects of two fractions of BML-OSPW collected in 2015. One of the fractions (F1) contained predominantly naphthenic acids, while the other (F2) contained non-acidic polar organic chemical species. Exposure of minnows to F1 or F2 at concentrations equivalent to 25% (v/v) of the 2015 BML-OSPW sample (5-15% of the 2012 BML-OSPW sample) did not alter reproductive performance, fertilization success, or concentrations of sex steroids in female or male minnows. Additionally, there were no significant differences in fertility, hatching success, or incidence of morphological indices of embryos collected on day 7 or 14 from exposed breeding trios. However, exposure of male fathead minnow to 25% (v/v) intact 2015 BML-OSPW resulted in a significantly greater hepatosomatic index. Exposure of fathead minnow to refined fractions of dissolved organic chemicals in 2015 BML-OSPW, or a 25% (v/v) of the intact mixture did not affect fertility or fecundity as measured by use of the 21-day reproductive bioassay. These data will be useful in setting future threshold criteria for OSPW reclamation and treatment.


Assuntos
Cyprinidae/fisiologia , Lagos/química , Campos de Petróleo e Gás/química , Reprodução/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Alberta , Animais , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/fisiologia , Ácidos Carboxílicos , Feminino , Hidrocarbonetos , Masculino , Mineração , Compostos Orgânicos/toxicidade , Poluentes Químicos da Água/análise
8.
Chemosphere ; 243: 125440, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995888

RESUMO

To date no study has been able to clearly attribute the observed toxicological effects of atmospheric particles (PM) to a specific class of components. The toxicity of both the organic extractable matter (OEM2.5-0.3) and non-extractable matter (NEM2.5-0.3) of fine particles (PM2.5-0.3) was compared to that of PM2.5-0.3 in its entirety on normal human epithelial bronchial BEAS-2B cells in culture. The specific effect of the quasi-ultrafine fraction (PM0.3) was assessed, by comparing the responses of cells exposed to the PM2.5-0.3 and PM0.3 organic extractable matter, OEM2.5-0.3 and OEM0.3 respectively. Chemically, PAH, O-PAH, and N-PAH were respectively 43, 17, and 4 times more concentrated in PM0.3 than in PM2.5-0.3, suggesting thereby a predominant influence of anthropogenic activities and combustion sources. BEAS-2B cells exposed to PM2.5-0.3, NEM2.5-0.3, EOM2.5-0.3 and OEM0.3 lead to different profiles of expression of selected genes and proteins involved in the metabolic activation of PAH, O-PAH, and N-PAH, and in the genotoxicity pathways. Specifically, OEM0.3 was the most inducer for phase I and phase II enzymes implicated in the metabolic activation of PAH (AHR, AHRR, ARNT, CYP1A1, CYP1B1, EPHX-1, GSTA-4) thereby producing the highest DNA damage, felt by ATR and, thereafter, a cascade of protein phosphorylation (CHK1/CHK2/MDM2) closely related to the cell cycle arrest (P21 and P53 induction). This study underlined the crucial role played by the organic chemicals present in PM0.3. These results should be considered in any future study looking for the main chemical determinants responsible for the toxicity of ambient fine PM.


Assuntos
Poluentes Atmosféricos/toxicidade , Células Epiteliais/efeitos dos fármacos , Material Particulado/toxicidade , Poluentes Atmosféricos/análise , Brônquios/citologia , Linhagem Celular , Dano ao DNA , Humanos , Compostos Orgânicos/toxicidade , Tamanho da Partícula , Material Particulado/análise
9.
PLoS One ; 15(1): e0227567, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31968006

RESUMO

Prolific heterotrophic biofilm growth is a common occurrence in airport receiving streams containing deicers and anti-icers, which are composed of low-molecular weight organic compounds. This study investigated biofilm spatiotemporal patterns and responses to concurrent and antecedent (i.e., preceding biofilm sampling) environmental conditions at stream sites upstream and downstream from Milwaukee Mitchell International Airport in Milwaukee, Wisconsin, during two deicing seasons (2009-2010; 2010-2011). Biofilm abundance and community composition were investigated along spatial and temporal gradients using field surveys and microarray analyses, respectively. Given the recognized role of Sphaerotilus in organically enriched environments, additional analyses were pursued to specifically characterize its abundance: a consensus sthA sequence was determined via comparison of whole metagenome sequences with a previously identified sthA sequence, the primers developed for this gene were used to characterize relative Sphaerotilus abundance using quantitative real-time PCR, and a Sphaerotilus strain was isolated to validate the determined sthA sequence. Results indicated that biofilm abundance was stimulated by elevated antecedent chemical oxygen demand concentrations, a surrogate for deicer concentrations, with minimal biofilm volumes observed when antecedent chemical oxygen demand concentrations remained below 48 mg/L. Biofilms were composed of diverse communities (including sheathed bacterium Thiothrix) whose composition appeared to shift in relation to antecedent temperature and chemical oxygen demand. The relative abundance of sthA correlated most strongly with heterotrophic biofilm volume (positive) and dissolved oxygen (negative), indicating that Sphaerotilus was likely a consistent biofilm member and thrived under low oxygen conditions. Additional investigations identified the isolate as a new strain of Sphaerotilus montanus (strain KMKE) able to use deicer components as carbon sources and found that stream dissolved oxygen concentrations related inversely to biofilm volume as well as to antecedent temperature and chemical oxygen demand. The airport setting provides insight into potential consequences of widescale adoption of organic deicers for roadway deicing.


Assuntos
Biofilmes/efeitos dos fármacos , Gelo , Compostos Orgânicos/toxicidade , Rios/química , Poluentes Químicos da Água/toxicidade , Biofilmes/crescimento & desenvolvimento , Modelos Lineares , Metagenômica , Sphaerotilus/efeitos dos fármacos , Sphaerotilus/genética , Sphaerotilus/fisiologia
10.
Ecotoxicol Environ Saf ; 190: 110146, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31923753

RESUMO

A quantitative structure-toxicity relationship (QSTR) model based on four descriptors was successfully developed for 1163 chemical toxicants against Tetrahymena pyriformis by applying general regression neural network (GRNN). The training set consisting of 600 organic compounds was used to train GRNN models that were evaluated with the test set of 563 compounds. For the optimal GRNN model, the training set possesses the coefficient of determination R2 of 0.86 and root mean square (rms) error of 0.41, and the test set has R2 of 0.80 and rms of 0.41. Investigated results indicate that the optimal GRNN model is accurate, although the GRNN model has only four descriptor and more samples in the test set.


Assuntos
Compostos Orgânicos/toxicidade , Tetrahymena pyriformis/efeitos dos fármacos , Redes Neurais de Computação , Relação Quantitativa Estrutura-Atividade , Tetrahymena pyriformis/fisiologia , Testes de Toxicidade
11.
Aquat Toxicol ; 218: 105360, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31765943

RESUMO

Labile dissolved organic carbon (DOC) is a major pollutant in coastal marine environments affected by anthropogenic impacts, and may significantly contribute to coral bleaching and subsequent mortality on coastal reefs. DOC can cause bleaching indirectly through the rapid proliferation of copiotrophic and pathogenic bacteria. Here we demonstrate that labile DOC compounds can also impair the coral-dinoflagellate symbiosis by directly affecting coral physiology on both the host and algal symbiont level. In a controlled aquarium experiment, we monitored over several weeks key physiological parameters of the tropical coral Stylophora pistillata exposed to ambient and elevated labile DOC levels (0.1 and 1.0 mM) in combination with low and high nitrogen (i.e. ammonium) conditions (0.2 and 4.0 µM). At the symbiont level, DOC exposure under low ammonium availability decreased the photosynthetic efficiency accompanied by ∼75 % Chl a and ∼50 % symbiont cell reduction. The photosynthetic functioning of the symbionts recovered once the DOC enrichment ceased indicating a reversible shift between autotrophic and heterotrophic metabolism. At the host level, the assimilation of exogenous DOC sustained the tissue carbon reserves, but induced a depletion of the nitrogen reserves, indicated by ∼35 % decreased protein levels. This suggests an imbalanced exogenous carbon to nitrogen supply with nitrogen potentially limiting host metabolism on the long-term. We also demonstrate that increased ammonium availability delayed DOC-induced bleaching likely by keeping symbionts in a photosynthetically competent state, which is crucial for symbiosis maintenance and coral survival. Overall, the present study provides further insights into how coastal pollution can de-stabilize the coral-algal symbiosis and cause coral bleaching. Therefore, reducing coastal pollution and sustaining ecological integrity are critical to strengthen the resilience of coral reefs facing climate change.


Assuntos
Compostos de Amônio/farmacologia , Antozoários/efeitos dos fármacos , Dinoflagelados/efeitos dos fármacos , Compostos Orgânicos/toxicidade , Simbiose/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Antozoários/metabolismo , Processos Autotróficos , Mudança Climática , Recifes de Corais , Dinoflagelados/metabolismo , Processos Heterotróficos , Oceano Índico , Fotossíntese/efeitos dos fármacos
12.
Chemosphere ; 238: 124573, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31454741

RESUMO

This study investigated the nutrient content and reuse potential of wastewater generated during hydrothermal liquefaction of microalgal biomass. The hydrothermal liquefaction reaction was tested at 270, 300, 330, and 345 °C to determine the effect of temperature on the formation of non-biodegradable dissolved organic nitrogen (nbDON). Total nitrogen, ammonium, color, and toxicity were selected as key characteristics for the reuse of hydrothermal liquefaction wastewater. Results indicated that a higher concentration of nbDON5 (nbDON defined with a 5 day growth assay) and more diverse heterocyclic N-containing organic compounds were associated with greater toxicity as measured by a growth rate assay. For the tested temperature ranges, the total nitrogen content of the hydrothermal liquefaction wastewater slightly decreased from 5020 ±â€¯690 mg L-1 to 4160 ±â€¯120 mg L-1, but the % nbDON5 fraction increased from 57 ±â€¯3 %DON to 96 ±â€¯5 %DON. The temperature of hydrothermal liquefaction reactions can be optimized to maximize carbon conversion and nitrogen recovery.


Assuntos
Chlorella/crescimento & desenvolvimento , Microalgas/crescimento & desenvolvimento , Compostos de Nitrogênio/toxicidade , Compostos Orgânicos/toxicidade , Águas Residuárias/toxicidade , Biodegradação Ambiental , Biocombustíveis , Biomassa , Nitrogênio/análise , Compostos de Nitrogênio/metabolismo , Compostos Orgânicos/análise , Temperatura , Águas Residuárias/química
13.
Chemosphere ; 239: 124754, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726531

RESUMO

We conducted the ecological risk assessment in an urban stream by using multiple-level approaches ranging from community level, chemical analyses in water and sediments, physiological assays of DNA biomarkers, embryonic development tests, and gene-level marker analyses of cyp1a, c-Fos, CRH, transgenic fli1:GFP and HuC:eGFP in zebrafish (Danio rerio). In water, the chemical perturbations based on nutrients (N,P), organic matter, ionic contents and metals identified in downstream zone. Analogous corroborations verified in sediment samples having hazardous metals (Zn, Pb, Cu, Ni, As, Cd). The chemical contaminations reflected significant damages in fish DNA, based on tDNA, tail length (TL), and tail extent moment (TEM). Zebrafish embryonic development experiments significantly enlightened the chemical contaminants in downstream compared to those in control and reference conditions. Hatching and survival rates rigorously declined in downstream region. Embryonic development delayed and followed by death in the downstream substantiated by the above-mentioned findings. Similar were the findings on heart rate and pigmentation largely affected in the contaminated zone. Pollutants in urban stream reflected significantly at the gene level, and were corroborated through experiments using transgenic zebrafish strains that were influenced by pollutants during the process of occurrence. In conclusion, these studies illuminate the community to gene-level ecological health assessment that could be useful for ecological risk assessments of urban streams and rivers. Further, the gene-level biomarkers and transgenic zebrafish experiments combination propose the procedures could be effectively used as sensitive and efficient biomarkers of ecological health and risk assessment in urban streams from community to gene-level assessments.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Metais Pesados/toxicidade , Compostos Orgânicos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Animais , Biomarcadores/análise , Dano ao DNA/efeitos dos fármacos , Ecologia , Metais Pesados/análise , Compostos Orgânicos/análise , Medição de Risco , Rios/química , Poluentes Químicos da Água/análise
14.
J Toxicol Sci ; 44(12): 821-832, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31813901

RESUMO

The Amino acid Derivative Reactivity Assay (ADRA) is an in chemico alternative to animal testing for the prediction of skin sensitization potential. Although co-elution of test chemicals and nucleophilic reagents during HPLC analysis is sometimes problematic when using the Direct Peptide Reactivity Assay (DPRA), it rarely occurs when using ADRA. Nevertheless, the application of either of these tests to multi-constituent substances requires nucleophilic reagents capable of selective detection. With this issue in mind, the authors developed an ADRA fluorescence detection method (ADRA-FL), which utilizes the natural fluorescence of ADRA nucleophilic reagents. In this study, we demonstrate the efficacy of ADRA-FL by testing 82 test chemicals used in the development of both DPRA and the conventional ADRA (ADRA-UV) as well as establish a threshold value for distinguishing sensitizers and non-sensitizers. Our results show that not only are depletion values obtained using ADRA-FL virtually identical to those obtained using ADRA-UV, the threshold value for either test is 4.9%. Additionally, in order to demonstrate the applicability of ADRA-FL to multi-constituent substances, we prepared test samples that consisted of a set of 10 non-sensitizers combined with one of 10 different sensitizers and tested each using ADRA-FL. The test results were concordant with those obtained using ADRA-UV. Also, because ADRA-FL chromatograms showed a significant decrease in multiple peaks as well as extremely stable baselines, we conclude that ADRA-FL is a highly selective and highly accurate mans of quantifying nucleophilic reagents that is applicable to a wide variety of chemical substances.


Assuntos
Acetilcisteína/química , Alanina/análogos & derivados , Alternativas aos Testes com Animais/métodos , Dermatite de Contato/etiologia , Fluorometria/métodos , Naftalenos/química , Compostos Orgânicos , Alanina/química , Modelos Teóricos , Compostos Orgânicos/química , Compostos Orgânicos/classificação , Compostos Orgânicos/toxicidade , Valor Preditivo dos Testes , Relação Quantitativa Estrutura-Atividade , Sensibilidade e Especificidade
15.
PLoS One ; 14(12): e0226042, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31815965

RESUMO

Workers in the dry-cleaning industry are exposed to organic solvents that may cause eye irritation and tear film changes. Objective To quantify changes in the ocular surface and tear film in dry cleaners exposed to organic solvents and associate these changes with ocular irritation as reported in a symptom questionnaire for dry eye diagnosis. Methods This was a case and control study in which the characteristics and eye-irritation symptoms were compared between two groups of 62 participants that were either exposed or not exposed to organic solvents. A general optometric examination and the following test were performed: lipid interferometry, Lissamine Green Stain, tear breakup time, Schirmer I, conjunctival impression cytology and the Donate dry eye symptoms questionnaire. Results Sixty-five percent of exposed workers obtained a higher score than 13 on the Donate dry eye symptoms questionnaire which indicated the presence of more irritation symptoms than those in the non- exposed group. A Chi-square analysis indicated the exposed group reported significantly higher incidences (P <0.005) for eye irritation symptoms of sandy sensation; tearing eyes sensation; foreign body sensation; tearing; dry eye; dryness; eyestrain and heavy eyelids. A Mann Whitney-U indicated greater severity only for symptoms relating to dry eye; sandy sensation; foreign body sensation, tearing; tearing eyes and dryness. There was a statistically significant difference (P <0.05) for Schirmer I; tear break up time; and the ocular surface assessed with Lissamine green staining and conjunctival impression cytology between groups. A reduction in the thickness of the lipid layer in the exposed group compared to the non-exposed group was observed. Surprisingly, clinical test outcomes were not significantly correlated with dry eye symptoms nor years of exposure. Conclusion Workers in the dry-cleaning industry exposed to organic solvents are associated with changes in ocular surface and tear film generating irritation symptoms commonly present in evaporative dry eye.


Assuntos
Túnica Conjuntiva/efeitos dos fármacos , Síndromes do Olho Seco/diagnóstico , Compostos Orgânicos/toxicidade , Solventes/química , Lágrimas/efeitos dos fármacos , Adolescente , Adulto , Astenopia/etiologia , Estudos de Casos e Controles , Túnica Conjuntiva/patologia , Túnica Conjuntiva/fisiologia , Síndromes do Olho Seco/etiologia , Pálpebras/efeitos dos fármacos , Pálpebras/fisiopatologia , Feminino , Humanos , Lavanderia , Lipídeos/química , Masculino , Exposição Ocupacional , Compostos Orgânicos/química , Lágrimas/química , Lágrimas/fisiologia , Adulto Jovem
16.
Environ Monit Assess ; 191(11): 699, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667650

RESUMO

Effects of industrial and municipal wastewaters on the freshwater snail, Lanistes carinatus, were evaluated. Concentrations of some chemicals in some effluents were greater than permissible limits promulgated internationally by various jurisdictions. Pesticides and polychlorinated biphenyls (PCBs) observed in tissues of snails collected during summer were greater than those measured in snails collected during winter. Catalase activities observed during autumn were greater than those observed during other seasons. Activities of catalase were greater at all sites near sources of contamination than in snails from the reference site (S6). Lactate dehydrogenase activity was also greater at all sites relative to the location designated as the reference (S6), at which activities did not exceed 8.10 U/L. Patterns of genomic DNA in snails, as determined by use of OPA-02 primer, were significantly different among sites. Location S1 (Belshay village) exhibited 11 bands, followed by S2 (El-Demer zone) and S5 (Rosetta branch) which exhibited 6 bands. In contrast, all sites exhibited greater numbers of bands when the OPA-08 primer was used. Thus, DNA fingerprinting, lactate dehydrogenase, and catalase offer useful biomarkers in ecotoxicology and risk assessment programs.


Assuntos
Monitoramento Ambiental , Compostos Orgânicos/toxicidade , Caramujos/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Catalase , Ecotoxicologia , Egito , Água Doce , Compostos Orgânicos/análise , Praguicidas , Bifenilos Policlorados , Estações do Ano , Poluentes Químicos da Água/análise
17.
Ecotoxicol Environ Saf ; 186: 109810, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31629190

RESUMO

Little is known about how the chemical properties (molecular structure, such as the hydrophobic and hydrophilic end group for organic chemical, and particle size for nanomaterials (NMs)) quantitatively affect the toxicokinetics (TK) in organisms especially in short-term, single-species studies. A novel method based on a first-order one compartment TK model which described the monophasic uptake pattern and two-compartment TK model which adequately described the biphasic metabolism pattern was used to determine the bioconcentration and TK rate constants of organic compounds (n = 17) and nanomaterials (NMs, n = 7) in zebrafish. For both one and two compartment model, the uptake (kin) and elimination (kout) rate constants were fitted using a one- and two-compartment first-order kinetic model, and bioconcentration factors (BCF) and 95% depuration times (t95) for all tested chemicals were calculated, respectively. The results showed that there was significant difference in TK parameters kin, kout, and BCF between organic chemicals and nano metal oxides. For organic compounds, significant correlations were found between the kin and BCF and the octanol-water partition coefficient (Kow) and molecular mass. For nano metal oxides, there was a significant negative correlation between the kin or BCF and particle size, but a positive correlation between kin and Zeta potential of nanoparticles and also a significant positive correlation between kout and particle size or specific surface area. Those findings indicated that NMs particle size does matter in biological influx and efflux processes. Our results suggest that the TK process for organic compound and NMs are correlated by different chemical properties and highlight that the Kow, the absorption kin, metabolism k12 and k21, elimination rate kout, and all the parameters that enable the prediction and partitioning of chemicals need to be precisely determined in order to allow an effective TK modeling. It would therefore appear that the TK process of untested chemicals by a fish may be extrapolated from known chemical properties.


Assuntos
Nanoestruturas/química , Compostos Orgânicos/química , Compostos Orgânicos/toxicidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Modelos Teóricos , Nanoestruturas/toxicidade , Compostos Orgânicos/metabolismo , Toxicocinética , Poluentes Químicos da Água/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-31480482

RESUMO

Background: Existing evidence shows an urgent need to improve respiratory protective equipment (RPE) use, and more so among migrant workers in small and medium-sized enterprises (SMEs). The study aimed to assess the effectiveness of a behavioral intervention in promoting the appropriate use of RPE among internal migrant workers (IMWs) exposed to organic solvents in SMEs. Methods: A cluster randomized controlled trial was conducted among 1211 IMWs from 60 SMEs in Baiyun district in Guangzhou, China. SMEs were deemed eligible if organic solvents were constantly used in the production process and provided workers with RPE. There were 60 SMEs randomized to three interventions on a 1:1:1 ratio, namely a top-down intervention (TDI), a comprehensive intervention, and a control group which did not receive any intervention. IMWs in the comprehensive intervention received a module encompassing three intervention activities: An occupational health education and training component (lectures and leaflets/posters), an mHealth component in the form of messages illustrative pictures and short videos, and a peer education component. The TDI incorporated two intervention activities, namely the mHealth and occupational health education and training components. The primary outcome was the self-reported appropriate RPE use among IMWs, defined as using an appropriate RPE against organic solvents at all times during the last week before measurement. Secondary outcomes included IMWs' occupational health knowledge, attitude towards RPE use, and participation in occupational health check-ups. Data were collected and assessed at baseline, and three and six months of the intervention. Generalized linear mixed models were performed to evaluate the effectiveness of the trial. Results: Between 3 August 2015 and 29 January 2016, 20 SMEs with 368 IMWs, 20 SMEs with 390 IMWs, and 20 SMEs with 453 IMWs were assigned to the comprehensive intervention, the TDI, and the control group, respectively. At three months, there were no significant differences in the primary and secondary outcomes among the three groups. At six months, IMWs in both intervention groups were more likely to appropriately use RPE than the control group (comprehensive intervention: Adjusted odds ratio: 2.99, 95% CI: 1.75-5.10, p < 0.001; TDI: 1.91, 95% CI: 1.17-3.11, and p = 0.009). Additionally, compared with the control group, the comprehensive intervention also improved all three secondary outcomes. Conclusions: Both comprehensive and top-down interventions were effective in promoting the appropriate use of RPE among IMWs in SMEs. The comprehensive intervention also enhanced IMWs' occupational health knowledge, attitude, and practice. Trial registration: ChiCTR-IOR-15006929. Registered on 15 August 2015.


Assuntos
Indústrias , Exposição Ocupacional/prevenção & controle , Compostos Orgânicos/toxicidade , Dispositivos de Proteção Respiratória , Solventes/toxicidade , Migrantes , Adulto , Terapia Comportamental , China , Análise por Conglomerados , Feminino , Humanos , Masculino , Autorrelato , Adulto Jovem
19.
J Mol Model ; 25(10): 303, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31493097

RESUMO

A model for computing the atomic compressibility (ß) based on two periodic descriptors, namely, absolute radius (r) and atomic electrophilicity index (ω), is proposed as[Formula: see text]The ansatz is invoked to compute compressibilities of atoms of 57 elements of the periodic table. The computed atomic data exhibits all sine qua non of periodic properties. Further, the concept group compressibility (Gß) is also established invoking additivity property using some molecules with different functional groups and consequently utilized in correlating with molecular polarizability. Since toxicity prediction is an imperative need of the hour, chemical reactivity descriptors are of paramount importance in the study of toxicological behaviour along with a lot of other molecular reactivity studies within a Quantitative Structure-Activity Relationship (QSAR) context. Hence, this quantity is applied in the modelling of toxicological property through QSAR and a comprehensive study is performed in an effort to investigate and validate the application of compressibility in determining its toxicological power. Consequently, varied 209 organic molecules are selected for studying the toxic effect on Tetrahymena pyriformis. A QSAR model is constructed in terms of compressibility which offers a superior prediction of toxicity independently without adopting additional descriptors or properties as in some other QSAR studies. Graphical abstract.


Assuntos
Modelos Moleculares , Compostos Orgânicos/toxicidade , Relação Quantitativa Estrutura-Atividade , Análise de Regressão , Tetrahymena pyriformis/efeitos dos fármacos
20.
Environ Toxicol Chem ; 38(11): 2472-2479, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31386757

RESUMO

Thallium (Tl) is a trace element associated with base metal mining and processing, but little is known regarding how its toxicity is influenced by water chemistry. In the present study, the 48-h median lethal concentration (LC50) of Tl to Daphnia magna was determined in a standard laboratory water, and toxicity was reassessed under conditions of varying cation (Ca2+ , K+ , Na+ ), anion (Cl- , HCO- 3 ), and dissolved organic matter (DOM) concentrations. The calculated 48-h LC50 of 1.86 mg Tl/L was consistent with previous work on Tl toxicity to D. magna. At the 48-h LC50 concentration, changes in water chemistry had no statistically significant effect on mortality, although there was a trend toward lower Tl toxicity with elevated water K+ . Test waters containing 10 mM CaCl2 did not support control survival. The measurement of Tl complexation with DOM using asymmetric flow field flow fractionation confirmed the outcomes of biogeochemical speciation modeling: Tl speciation was relatively unaffected by water chemistry, and the majority of Tl remained in the ionic form across all treatments. These data indicate that Tl toxicity is largely independent of speciation, a property that will greatly simplify risk assessments for this metal in freshwaters. Environ Toxicol Chem 2019;38:2472-2479. © 2019 SETAC.


Assuntos
Daphnia/efeitos dos fármacos , Compostos Orgânicos/toxicidade , Tálio/toxicidade , Testes de Toxicidade Aguda , Animais , Fracionamento Químico , Cobre/toxicidade , Água Doce/química , Íons , Solubilidade , Poluentes Químicos da Água/toxicidade
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