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1.
Environ Res ; 252(Pt 1): 118791, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38552826

RESUMO

Indoor air pollution (IAP) has been associated with various adverse health effects. However, the evidence regarding such an association with leukocyte telomere length (LTL) in cord blood samples is still scarce. Therefore, the present study aimed to assess the relationship between exposure to indicators of IAP and LTL in umbilical cord blood samples. This cross-sectional study was based on 188 mother-newborn pairs who participated in our study between 2020 and 2022 in Isfahan, Iran. Umbilical LTL was measured by quantitative real-time polymerase chain reaction (qRT-PCR) technique. Linear mixed-effect models were used to assess the relationship between IAP indicators and umbilical LTL, adjusted for relevant covariates. The median (interquartile range (IQR)) of umbilical LTL was 0.92 (0.47). In fully adjusted models, frequency of using degreasing spray during pregnancy (times per month) (ß = -0.047, 95% CI:0.09, -0.05, P-value = 0.02), using air freshener spray during pregnancy (ß = -0.26, 95% CI: -0.5, -0.02, P-value = 0.03) and frequency of using insecticides during pregnancy (times per month) (ß = -0.025, 95% CI: -0.047, -0.003, P-value = 0.02) were significantly associated with shorter umbilical LTL. There was a positive significant relationship between the frequency of using cleaning spray during pregnancy (times per month) with umbilical LTL (ß = 0.019, 95% CI: 0.005, 0.033, P-value = 0.01). Furthermore, the direct connection of the parking with home and the frequency of using barbecue (times per week) were marginally associated with shorter umbilical LTL. For other indicators of IAP, we did not observe any statistically significant associations. Overall, this study suggested a negative association between prenatal exposure to IAP during pregnancy and umbilical LTL.


Assuntos
Poluição do Ar em Ambientes Fechados , Sangue Fetal , Leucócitos , Exposição Materna , Humanos , Poluição do Ar em Ambientes Fechados/análise , Feminino , Sangue Fetal/química , Leucócitos/efeitos dos fármacos , Gravidez , Estudos Transversais , Adulto , Exposição Materna/efeitos adversos , Irã (Geográfico) , Telômero/efeitos dos fármacos , Masculino , Recém-Nascido , Poluentes Atmosféricos/análise , Adulto Jovem
2.
Pediatr Hematol Oncol ; 41(1): 54-64, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37477214

RESUMO

Vitamin D deficiency/insufficiency (VDD, VDI) is common in children yet limited experience exists on the association of VDD and hematologic malignancies amongst this population. Therefore, this study aimed to compare serum vitamin D levels in children with acute lymphoblastic leukemia (ALL) and controls. Moreover, vitamin D levels is compared in subjects with and without relapse and evaluated as a prognostic factor for relapse-free survival (RFS). Children with newly diagnosed ALL were recruited as case group. Data on demographic variables as well as the dietary habits were collected by interview. In addition, serum 25(OH)D3 was measured. The case group was followed up for 36 months to assess RFS. Overall, 358 subjects were included in the study (n = 169 cases, n = 189 controls). The mean levels of 25(OH)D3 were 28.05 ± 18.87 and 28.76 ± 12.99 in cases and controls, respectively (p = .68). VDD was found in 15.4% (n = 26) and 4.2% (n = 8) of the case and control groups, respectively (p < .001). Relapse was seen in 18.34% of patients and vitamin D levels of 20 ng/mL or above were associated with longer RFS (p = .044 by log-rank test). In this study, VDD and VDI amongst children with ALL were significantly higher than controls. In addition, lower levels of Vitamin D were associated with increased risk of relapse.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Deficiência de Vitamina D , Criança , Humanos , Vitamina D , Fatores de Risco , Recidiva , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações
3.
J Environ Manage ; 291: 112595, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33940359

RESUMO

Pulsed light (PL) technology, which is based on photonic technology involves the application of broadband emission of light with short and high-power pulses is beginning to emerge for the treatment of wastes via advanced oxidation processes (AOP). The present work investigates the efficiency of PL as a light source for persulfate (PS) activation (PL/PS) and 4-chlorophenol)4-CP) degradation, an organic model pollutant. The influencing parameters on 4-CP degradation such as solution pH, reaction time, initial concentration of 4-CP, PS dose, pulse intensity and frequency, and distance from PL source are systematically investigated. With increasing pH from 3 to 9, the 4-CP degradation decreased from 49.79 ± 2.49 to 33.12 ± 1.66%. The 4-CP degradation followed the first order kinetics that was improved with increasing reaction time, PS dose, pulse intensity, frequency of pulse, and decreasing pH, initial 4-CP concentration and distance from the PL source. The presence of sulfate, chloride, and carbonate anions in the solution has the inhibitory effects on 4-CP degradation, while nitrate anion improved the performance of PL/PS system. In addition, presence of humic acid had an inhibitory effect on the PL/PS system, which led to a decrease of reaction rate constant and 4-CP degradation was performed in PL/PS system with OH, SO4-, O2- and 1O2 radicals. The contributions of OH and SO4- radicals were 46% and 51%, respectively for the 4-CP degradation and synergistic effect of PL/PS system showed a significant influence on 4-CP degradation while using a combination of PL and PS, suggesting that PL is an effective activator of PS.


Assuntos
Clorofenóis , Poluentes Químicos da Água , Oxirredução , Sulfatos , Poluentes Químicos da Água/análise
4.
J Environ Manage ; 292: 112759, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33984638

RESUMO

The complex nature of wastewater treatment has led to search for alternative strategies such as different artificial intelligence (AI) techniques to model the various operational parameters. The present work is aimed at predicting the transmembrane pressure (TMP) as a key operational parameter in the case of anaerobic membrane bioreactor-sequencing batch reactor (AnMBR-SBR) during biohydrogen production using the adaptive neuro-fuzzy inference systems (ANFIS) and artificial neural network (ANN). In both the models, organic loading rates (OLR) ranging from 0.5 to 8.0 g COD/L/d, effluent pH (3.6-6.9), mixed liquor suspended solid (4.6-21.5 g/L) and mixed liquor volatile suspended solid (3.7-15.5 g/L) were used as the input parameters to test TMP as an output parameter. The ANFIS model was trained using the hybrid algorithms for TMP prediction. The higher prediction performance was obtained by using the Gauss membership function with four membership numbers. A back-propagation algorithm was also employed for the feed forward training of ANN model; the best structure was a Levenberg-Marquardt training algorithm with nine neurons in the hidden layer. By employing ANFIS and ANN models, relatively a good prediction of TMP was obtained with the R2 values of 0.93 and 0.88, respectively while the calculated mean square error for TMP in the ANFIS model (7.3 × 10-3) was lower than that of ANN model (8.02 × 10-3). The higher R2 and lower MSE values for the ANFIS model exhibited a better TMP prediction performance than the ANN model. Finally, it was observed that in the sensitivity analysis of ANN model, OLR was the most important input parameter on the variation of TMP.


Assuntos
Inteligência Artificial , Lógica Fuzzy , Anaerobiose , Reatores Biológicos , Redes Neurais de Computação
5.
J Environ Manage ; 297: 113349, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34314964

RESUMO

In the present work, effect of coexisting anions on the degradation performance of UV/chlorine (UV/Cl) processes as an advanced oxidation treatment for the dye containing wastewater was investigated. The results showed that by increasing pH of the solution from 3 to 11, degradation efficiency of UV/Cl process was reduced from 96.2 ± 1.4% to 62.9 ± 3.1%. In the case of 100 mg/L of DR83:1, the removal efficiency was improved from 30.2 ± 1.5% to 93.3 ± 4.7% when the chlorine dose was increased from 100 to 1000 µM. The HCO3- and Br- ions were the main inhibitor and promotor anions responsible for the degradation of DR83:1. The relative contribution of Cl• was higher than that for HO• and UV, which was about three-times higher than that for HO•. The lowest and highest amounts of trihalomethanes were generated at acidic and alkaline conditions as well as low disinfection by products at low pH due to the generation of more HO• radicals at acidic pH in comparison to higher pH such that less intermediates were remained to react with chlorine.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Ânions , Cloro , Desinfecção , Halogenação , Cinética , Oxirredução , Raios Ultravioleta , Águas Residuárias , Poluentes Químicos da Água/análise
6.
J Environ Manage ; 268: 110678, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32383648

RESUMO

The 4-chlorophenol (4-CP) is known to be a highly toxic compound having harmful effects on human health and the environment. Due to adverse effect of 4-CP, a new combination of persulfate (PS) and oxalic acid (OA) with heterogeneous Fenton like (HFL) system was developed and applied for 4-CP degradation as an emerging contaminant from synthetic wastewater. The individual (OA, PS, and HFL) and combined (HFL/OA, HFL/PS, and HFL/OA/PS) systems were investigated under various conditions to synergistic effects verification and determination of degradation mechanism of 4-CP. Compared to individual and combined systems, significant synergetic of 4-CP degradation efficiency was observed by HFL/OA/PS system. The highest 4-CP degradation efficiency by HFL/OA/PS system under optimal conditions (solution pH: 6, H2O2 dose: 275 mg/L, goethite dose: 125 mg/L, OA dose: 50 mg/L and PS dose: 100 mg/L) with an initial 4-CP concentration of 30 mg/L was 99.6 ± 4.9% after 35 min reaction time. 4-CP degradation by HFL/OA/PS system was followed with the first-order kinetic. The application of radical scavengers including ethanol (EtOH) and tert-butyl alcohol (TBA) revealed that the SO4•- radical was determined as primary produced radical species. The Cl- ions release was measured during degradation reaction at various 4-CP concentrations and indicating the complete 4-CP degradation. The developing of the adaptive neuro-fuzzy inference system (ANFIS) for 4-CP degradation efficiency prediction was revealed. These results show that prediction of 4-CP degradation efficiency using HFL/OA/PS system is possible by the ANFIS model with a high accuracy (R2: 0.98).


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Clorofenóis , Peróxido de Hidrogênio , Ácido Oxálico , Oxirredução
7.
J Environ Manage ; 271: 111005, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778290

RESUMO

The performance of a polyamide-based thin-film composite nanofiltration (NF) membrane (NF33) was investigated for the retention of atenolol, a pharmaceutical pollutant, from the single and binary aqueous solutions. The effect of pH, applied pressure, feed flux, initial atenolol (ATN) concentration, and different co-existing salts with varying concentrations were studied to test the performance of the membrane. The removal efficiency of ATN increased with increasing solution pH giving the highest retention (70.9 ± 3.1) at pH 9, which was slightly decreased with the increasing initial ATN concentration but increased with increasing applied pressure and feed flux. As per the uncharged solutes rejection concept, the average pore radius of NF membrane for slit-like and cylindrical pore geometries were, respectively 0.169 ± 0.003 and 0.264 ± 0.009 nm. The Spiegler-Kedem model could predict the performance of NF membrane by retaining ATN over the investigated range of feed flux. The calculated reflection coefficient (σ) was close to unity, demonstrating the convective transport. Addition of CaCl2 as a co-existing salt into the feed showed promoting effect on ATN retention, and its efficiency was lowered by the addition of NaCl and Na2SO4 salts. As per the cost analysis, the total annualized cost of treatment by the NF was found to be 0.53 $/m3.


Assuntos
Atenolol , Filtração , Membranas Artificiais , Rádio (Anatomia) , Água
8.
J Res Med Sci ; 25: 61, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33088298

RESUMO

BACKGROUND: Exposure to endocrine disrupting chemicals such as triclosan (TCS) leads to disrupting the endocrine system and consequently effect on the birth outcomes. The findings of studies in this field are controversial. MATERIALS AND METHODS: This systematic review and meta analysis was conducted based on the identified published papers in Scopus, Web of Science, and PubMed up to November 2019. All steps, including searching, screening, data extracting, and quality assessment, were done by two independent researchers. RESULTS: Finally 15 published papers selected. The number of participants in whom the association of TCS exposure was assessed with birth weight, birth length, birth head circumference, and gestational age were 9112, 4311, 2854, and 3181 mother infant pairs, respectively. The pooled analysis showed that TCS exposure during pregnancy leads to increasing the birth weight for boys with ß= 3.97 and 95% confidence interval (CI) (-3.98, 11.92), and girls with ß= 5.37, 95% CI (-6.00, 16.75), but the association was not statistically significant. In addition, according to fixed effects models, the TCS exposure was not significantly associated with birth length (-0.008, 95% CI [-0.049, 0.034]), birth head circumference (-0.01, 95% CI [-0.08, 0.06]), and gestational age (-0.005, 95% CI [-0.017, 0.006]). Likewise, analysis for data segregated by gender of infants revealed similar results. CONCLUSION: The obtained results depicted that the TCS exposure during pregnancy period was associated with higher birth weight for boys and girls. No significant association was observed for TCS exposure with variation of birth length, head circumference, and gestational age duration. In fact, the results showed the evidence of null associations between maternal TCS exposure and birth outcomes.

9.
J Environ Manage ; 250: 109461, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31499462

RESUMO

Mixed culture sludge has been widely used as a microbial consortium for biohydrogen production. Simple thermal treatment of sludge is usually required in order to eliminate any H2-consuming bacteria that would reduce H2 production. In this study, thermal treatment of sludge was carried out at various temperatures. Electron flow model was then applied in order to assess community structure in the sludge upon thermal treatment for biohydrogen production. Results show that the dominant electron sink was acetate (150-217 e- meq/mol glucose). The electron equivalent (e- eq) balances were within 0.8-18% for all experiments. Treatment at 100 °C attained the highest H2 yield of 3.44 mol H2/mol glucose from the stoichiometric reaction. As the treatment temperature increased from 80 to 100 °C, the computed acetyl-CoA and reduced form of ferredoxin (Fdred) concentrations increased from 13.01 to 17.34 e- eq (1.63-2.17 mol) and 1.34 to 4.18 e- eq (0.67-2.09 mol), respectively. The NADH2 balance error varied from 3 to 10% and the term e-(Fd↔NADH2) (m) in the NADH2 balance was NADH2 consumption (m = -1). The H2 production was mainly via the Fd:hydrogenase system and this is supported with a good NADH2 balance. Using the modified Gompertz model, the highest maximum H2 production potential was 1194 mL whereas the maximum rate of H2 production was 357 mL/h recorded at 100 °C of treatment.


Assuntos
Reatores Biológicos , Esgotos , Elétrons , Fermentação , Hidrogênio
10.
Int J Environ Health Res ; 29(1): 94-106, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30203985

RESUMO

In this study, the association of exposure to Bisphenol A (BPA) with obesity and cardiometabolic risk factors was investigated on 132 children and adolescents aged 6-18 years living in Isfahan, Iran. Potential contributors to BPA exposure were assessed by a questionnaire. Total BPA was detected in urine samples of all participants without significant difference in boys and girls. The mean body mass index (BMI) and waist circumference (WC) increased significantly across the BPA tertiles (p for trend = < 0.001). Similar trend was documented for systolic blood pressure (SBP) and diastolic blood pressure (DBP) as well as fasting blood sugar. The risk of obesity was 12.48 times higher in participants in the third tertile of BPA than in others (95% CI: 3.36-46.39, p < 0.001). The current study showed significant association between BPA exposure with obesity and some cardiometabolic risk factors in children and adolescents, however, further longitudinal studies are necessary to evaluate the clinical effects of this finding. Abbreviations: BMI: Body Mass Index; BPA: Bisphenol A; BSTFA: N, O-Bistrifluoroacetamide; CDC: Centers for Disease Control and Prevention; CI: Circumference Interval; DBP: Diastolic Blood Pressure; DLLME: Dispersive liquid-liquid microextraction method; FBS: Fasting Blood Glucose; HDL: high-density lipoprotein cholesterol were; LDL: low-density lipoprotein cholesterol; OR: Odd Ratio; PA: Physical Activity; SBP: Systolic Blood Pressure; TC: total cholesterol; TG: triglycerides; WC: Waist Circumference.


Assuntos
Compostos Benzidrílicos/urina , Doenças Cardiovasculares/epidemiologia , Poluentes Ambientais/urina , Obesidade/epidemiologia , Obesidade/urina , Fenóis/urina , Adolescente , Criança , Monitoramento Ambiental , Feminino , Humanos , Irã (Geográfico) , Masculino , Fatores de Risco
11.
Water Sci Technol ; 2017(3): 636-649, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30016281

RESUMO

The aim of study is removal of atenolol from aqueous solutions by multiwalled carbon nanotubes modified with ozone. The design of the experiment was adopted across four levels with the L16 matrix arrangement. The factors influencing atenolol adsorption include changes in the pH value, contact time, the dose of the modified multiwall carbon nanotube, and the initial concentration of atenolol in the solution; these factors were evaluated along with the extent of their influence on removal efficiency. Data analyses were performed by the Design Expert 6 software. The results indicated that the pH, contact time, adsorbent dose, and the initial concentration were 7, 20 min, 0.15 g/L and 1 mg/L, respectively. In this state, the removal efficiency was calculated to be 75.79%. The maximum adsorption capacity was obtained as 5.05 mg/g under optimal conditions. The data were analyzed using adsorption models obtained from the isotherm fitting tool software. The results suggested that the data had a greater congruence with the Freundlich model (corrected Akaike information criterion = 2.58). Furthermore, the kinetics of the reactions followed pseudo second order kinetics (R2 = 0.95). Based on this study, it can be concluded that modified multiwall carbon nanotubes enjoy high potential and efficiency as adsorbents for the removal of atenolol from aqueous solutions.


Assuntos
Atenolol/química , Nanotubos de Carbono , Ozônio , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Soluções , Eliminação de Resíduos Líquidos/métodos , Água
12.
J Sep Sci ; 40(22): 4403-4410, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28926682

RESUMO

A new method was developed for the trace determination of phthalic acid esters in plasma using dispersive liquid-liquid microextraction and gas chromatography with mass spectrometry analysis. Plasma proteins were efficiently precipitated by trichloroacetic acid and then a mixture of chlorobenzene (as extraction solvent) and acetonitrile (as dispersive solvent) rapidly injected to clear supernatant using a syringe. After centrifuging, chlorobenzene sedimented at the bottom of the test tube. 1 µL of this sedimented phase was injected into the gas chromatograph for phthalic acid esters analysis. Different factors affecting the extraction performance, such as the type of extraction and dispersive solvent, their volume, extraction time, and the effects of salt addition were investigated and optimized. Under the optimum conditions, the enrichment factors and extraction recoveries were satisfactory and ranged between 820-1020 and 91-97%, respectively. The linear range was wide (50-1000 ng/mL) and limit of detection was very low (1.5-2.5 ng/mL for all analytes). The relative standard deviations for analysis of 1 µg/mL of the analytes were between 3.2-6.1%. Salt addition showed no significant effect on extraction recovery. Finally, the proposed method was successfully utilized for the extraction and determination of the phthalic acid esters in human plasma samples and satisfactory results were obtained.


Assuntos
Ésteres/sangue , Cromatografia Gasosa-Espectrometria de Massas , Microextração em Fase Líquida , Ácidos Ftálicos/sangue , Humanos
13.
Environ Monit Assess ; 189(8): 387, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28695403

RESUMO

In this study, the reclamation of clean water from spent filter backwash water (SFBW) was investigated through pilot-scale experiments. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF). Two coagulants of PAFCl and FeCl3 were investigated with respect to their performance on treated SFBW quality and UF membrane fouling. At the optimum dose of PAFCl and FeCl3 turbidity removal of 99.6 and 99.4% was attained, respectively. PAFCl resulted in an optimum UV254, TOC, and DOC removal of 80, 83.6, and 72.7%, respectively, and FeCl3 caused the removal of those parameters by 76.7, 80.9, and 65.9%, respectively. PAFCl removed hydrophilic and transphilic constituent better than FeCl3, but FeCl3 had, to some extent, higher affinities to a hydrophobic fraction. It was concluded that PAFCl showed a better coagulation performance in most cases and caused a lower membrane fouling rate compared to FeCl3. Finally, the treated SFBW with both coagulant-UF systems met the drinking water standards.


Assuntos
Purificação da Água/métodos , Cloretos/química , Água Potável/química , Monitoramento Ambiental , Compostos Férricos/química , Floculação , Ultrafiltração , Água/química , Poluentes da Água/química
14.
Water Sci Technol ; 74(3): 606-15, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27508365

RESUMO

Electrical current in the hydrolytic phase of the biogas process might affect biogas yield. In this study, four 1,150 mL single membrane-less chamber electrochemical bioreactors, containing two parallel titanium plates were connected to the electrical source with voltages of 0, -0.5, -1 and -1.5 V, respectively. Reactor 1 with 0 V was considered as a control reactor. The trend of biogas production was precisely checked against pH, oxidation reduction potential and electrical power at a temperature of 37 ± 0.5°C amid cattle manure as substrate for 120 days. Biogas production increased by voltage applied to Reactors 2 and 3 when compared with the control reactor. In addition, the electricity in Reactors 2 and 3 caused more biogas production than Reactor 4. Acetogenic phase occurred more quickly in Reactor 3 than in the other reactors. The obtained results from Reactor 4 were indicative of acidogenic domination and its continuous behavior under electrical stimulation. The results of the present investigation clearly revealed that phasic electrical current could enhance the efficiency of biogas production.


Assuntos
Biocombustíveis/análise , Esterco/análise , Animais , Reatores Biológicos , Bovinos , Eletroquímica , Hidrólise , Temperatura
15.
Med J Islam Repub Iran ; 30: 424, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28210589

RESUMO

Background: Water, sanitation and hygiene have a very important role in public health. Poor sanitation is the cause of water contamination, which causes many types of diseases. The aim of this paper was to present the attributable death and disability adjusted life year (DALYs) of untreated water and insanitary environments from 1990 to 2010 in Iran. Methods: In the Global Burden of Disease 2010 study, using the comparative risk assessment, the proportion of death and DALYs attributable to untreated water source and insanitary environment has been calculated in 1990 to 2010. The certain outcomes were intestinal infectious diseases for both untreated water source and insanitary environments. Estimated attributable deaths and DALYs were reported with 95% uncertainty interval (UI). Results: DALY number for untreated water source and insanitary environments was 5838 (95% UI: 198- 14837) in 1990, which decreased to 326 (95% UI: 9-863) in 2010 and the percent of decrease was 94.42%. In addition, DALY rate was 5667 (95% UI: 192-14402) DALY per 100,000 in 1990, which decreased to 453 (95% UI: 13-1199) DALY per 100,000 in 2010 and the percent of the reduction was 92.01%. The greatest percentage of decrease in the attributed number of deaths was also found in the late neonatal age group (95.45%). Conclusion: A significant decrease has occurred in a number of DALYs and deaths between 1990 and 2010, which was attributed to the development of new water systems and environmental sanitations in Iran.

16.
Environ Monit Assess ; 187(5): 276, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25893751

RESUMO

Almost all bioassays have been designed only for pH levels around 7; however, some toxicant characteristics may be different at lower pH values. In this study, a modified resazurin reduction method was used to evaluate the toxicity of heavy metals and metal plating wastewater on acid-tolerant (AT) and conventional bacteria at the natural and acidic pH conditions. According to our optimized protocol, resazurin was rapidly reduced by both conventional and AT active microorganisms. Considering the 30-min median effective concentration (30 min EC50) values, conventional bacteria were comparatively more resistant than the acid-tolerant bacteria (ATB) in the case of exposure to Cd, Pb, Cr, and Zn, but the reverse case was found for Hg. After an exposure of 30 min, Cr and Hg showed the highest toxicity to ATB (30 min EC50 values were 0.34 and 17.02 µmol/L, respectively), while Zn and Pb had a considerably lower toxicity. The modified resazurin reduction method successfully assessed the impact of metal plating wastewaters on the activities of conventional and AT bacteria. According to the findings where the wastewaters contain heavy metals, wastewater treatment facilities, which are dependent on ATB activity, should use bioassays at acidic pH values for better understanding of the effects of toxicants.


Assuntos
Metais Pesados/toxicidade , Oxazinas/metabolismo , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Xantenos/metabolismo , Bactérias/efeitos dos fármacos , Monitoramento Ambiental/métodos , Metais Pesados/análise , Oxazinas/química , Águas Residuárias/química , Águas Residuárias/microbiologia , Poluentes Químicos da Água/análise , Xantenos/química
17.
Environ Monit Assess ; 187(5): 263, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25893755

RESUMO

One of the most important factors that affect the operation efficiency of sequencing batch reactor (SBR) technology is bacterial viability and biomass activity. The acute toxicity of three heavy metals to four dominant strains of sequencing batch reactor (Pseudomonas, Aeromonas, Enterobacter, and Bacillus) was investigated using a resazurin bioassay. After exposing the bacterial strains to soluble compound of Hg, Cd, and Pb, at more than five selected concentrations, the median effective concentration (EC50) and the mortality rate values were calculated. Large differences were observed in sensitivities of the four bacterial strains to the metals. Pseudomonas showed the highest sensitivity for Cd (EC50 = 0.06 µmol/L) and Hg (EC50 = 11.75 µmol/L), while Aeromonas showed the highest sensitivity for Pb (EC50 = 48.27 µmol/L). Considering the EC50 test results, it was concluded that Pseudomonas and Aeromonas are excellent and reliable bioindicators for assessing the toxicity of water and wastewaters polluted by Cd, Hg, and Pb. The rapidity (30 min) and simplicity of the resazurin bioassay procedure enable this enzymatic test to be used in toxicity assessment of small and decentralized wastewater treatment plants (WWTPs).


Assuntos
Reatores Biológicos/microbiologia , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Biomassa , Cádmio/toxicidade , Monitoramento Ambiental , Chumbo/toxicidade , Mercúrio/toxicidade , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Águas Residuárias/microbiologia
18.
Pak J Med Sci ; 31(2): 369-73, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26101493

RESUMO

OBJECTIVES: Air pollution is a hazardous environmental problem with several adverse health effects including its impact on the development of chronic diseases as diabetes mellitus. This study aimed to investigate the association of geographical distribution of air quality index (AQI) and type 2 diabetes mellitus in an air-polluted city by using geographic information system (GIS). METHODS: This cross-sectional study was conducted in Isfahan, Iran. The records that have been registered from 2009 to 2012 in major referral public diabetes clinics were gathered; they included data of 1467 diabetic patients. Their living area was represented with spots in the city map. AQI data were also interpolated from monitoring stations spreading around the city. The GIS maps of air pollutants and diabetes were developed and the associations were determined. RESULTS: The density of diabetic population was higher in highly polluted areas compared with areas with the lower levels of air pollution. No significant correlation was documented between the distribution of diabetic patients and air pollution level throughout the city. CONCLUSION: Although the density of diabetic patients was higher in areas with higher air pollution, but the lack of association between AQI and the prevalence of diabetes might be because the air of different parts of the city was highly polluted, and we could not compare the prevalence of diabetes in areas with clean and polluted air.

19.
ScientificWorldJournal ; 2014: 416752, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24587723

RESUMO

The integration of bioventing (BV) and soil vapor extraction (SVE) appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC) and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE) including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5%) of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing) after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.


Assuntos
Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/química , Solo/química , Tolueno/química
20.
MethodsX ; 11: 102369, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37719920

RESUMO

As the usage of pesticides for both agricultural and non-agricultural uses increases, it is more important than ever to employ probabilistic methods rather than deterministic ones to calculate the danger to human health. The current work demonstrates the application of deterministic and probabilistic approaches to assess the human health risk related to glyphosate during the consumption of surface and groundwater by different population groups. To that aim, the concentration of glyphosate pesticide in the surface and groundwater was measured and human health risk for three population groups including children, teens, and adults was evaluated. Overall, the probabilistic approach via Monte Carlo simulation showed a valid result for the estimation of human health risk and determination of dominant input parameters.•The health risk of glyphosate exposure during water consumption for various population groups were evaluated using deterministic and probabilistic methods.•The modeling is performed by Crystal Ball (11.1.2.4) software, as open access software, and requires a limited number of inputs.•The probabilistic method could reliably assess the risks of glyphosate by considering the variability and uncertainty in input variables.

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