Acrylamide in bread: a review on formation,health risk assessment,and determination by analytical techniques

Environmental Science and Pollution Research - Acrylamide is a water-soluble toxicant found in high-protein and carbohydrate-containing foods exposed to high temperature like bread as the staple...     

The effects of low frequency noise on mental performance and annoyance

Low frequency noise (LFN) as background noise in urban and work environments is emitted from many artificial sources such as road vehicles, aircraft, and air movement machinery including wind turbines, compressors, and ventilation or air conditioning units. In addition to objective effects, LFN could also cause noise annoyance and influence mental performance; however, there are no homogenous findings regarding this issue. The purpose of this research was to study the effects of LFN on mental performance and annoyance, as well as to consider the role of extraversion and neuroticism on the issue. This study was conducted on 90 students of Iran University of Medical Sciences (54 males and 36 females). The mean age of the students was 23.46 years (SD?=?1.97). Personality traits and noise annoyance were measured by using Eysenck Personality Inventory and a 12-scale self-reported questionnaire, respectively. Stroop and Cognitrone computerized tests measured mental performance of participants each exposed to 50 and 70 dBA of LFN and silence. LFNs were produced by Cool Edit Pro 2.1 software. There was no significant difference between mental performance parameters under 50 and 70 dBA of LFN, whereas there were significant differences between most mental performance parameters in quiet and under LFN (50 and 70 dBA). This research showed that LFN, compared to silence, increased the accuracy and the test performance speed (p?<?0.01). There was no association between LFN and noise annoyance (p?>?0.01). Introverts conducted the tests faster than extraverts (p?<?0.05). This research showed that neuroticism does not influence mental performance. It seems that LFN has increased arousal level of participants, and extraversion has a considerable impact on mental performance.     

Preparation and Characterization of Biodegradable Blend Membranes of PBS/CA

Asymmetric membranes of cellulose acetate/poly (butylene succinate) were prepared using immersion precipitation technique. The blended membranes were characterized by contact angle, scanning electron microscopy, thermogravimetric analysis, degradation test in compost and dynamic test of raisin wastewater treatment. Results demonstrated that hydrophilicity of cellulose acetate was enhanced by addition of poly (butylene succinate) up to 50 %. Furthermore, polymeric composition affects cross sectional structure of the membranes by controlling formation of macrovoids. Addition of poly (butylene succinate) improved the membranes thermal stability and obviously their degradation in compost. The prepared membranes were able to reject the wastewater pollutants properly.     

Simultaneous Removal of Nitrate and Natural Organic Matter from Drinking Water Using a Hybrid Heterotrophic/Autotrophic/Biological Activated Carbon Bioreactor

Simultaneous removal of nitrate ([Formula: see text]) and natural organic matter (NOM) from drinking water using a hybrid heterotrophic/autotrophic/BAC bioreactor (HHABB) was studied in continuous mode. The HHABB consisted of three compartments: ethanol heterotrophic part, sulfur autotrophic part, and biological activated carbon (BAC)-part (including anoxic and aerobic sections). Experiments were performed with [Formula: see text] concentration 30?mg N/L, [Formula: see text] loading rate 0.72?kg N/m(3)/d, C?:?N ratio 0.53, and three concentrations of NOM (0.6, 2.6, and 5.7?mg C/L). Overall denitrification rate and efficiency of the HHABB were not affected by NOM concentration and were in the suitable ranges of 0.69-0.70?kg N/m(3)/d and 96.0%-97.7%, respectively. NOM removal at concentration 0.6?mg C/L was not efficient because of organic carbon replacement as soluble microbial products. At higher NOM concentrations, total NOM removal efficiencies were 55%-65%, 55%-70%, and 55%-65% for dissolved organic carbon, trihalomethane formation potential, and UV absorbance at 254?nm (UV(254)), respectively. The more efficient compartments of the HHABB for the removal of NOM were the ethanol heterotrophic phase and aerobic BAC-phase. The efficiency of the HHABB in the removal of NOM was considerable, and the effluent dissolved organic carbon and trihalomethane formation potential concentrations were relatively low. This study indicated that the HHABB without the anoxic BAC-phase could be a feasible alternative for simultaneous removal of [Formula: see text] and NOM from drinking water at full scale.     

Direct and indirect costs of nonfatal road traffic injuries in Iran: A population-based study

Objectives: The objective of this study was to assess the incidence rate as well as direct and indirect costs of nonfatal road traffic injuries (RTIs) in Iran in 2011.

Methods: Data from the 2011 national household survey were used. In this survey, data on demographics, history, and costs of injury were obtained in 2 steps: first, direct face-to-face interview and second, telephone calls. We estimated the incidence rate of nonfatal RTIs in this year. The direct costs included medical care as well as nonmedical costs paid by the patient or insurance services. The indirect costs were estimated by considering the cost of absence from work or education. We also used logistic regression analyses to investigate risk factors of nonfatal RTIs.

Results: We found 76 nonfatal RTI cases (0.96%) out of 7,886 whole reference study cases. These 76 injured patients had a history of RTI in the preceding 3 months. The annual incidence of RTIs was estimated at 3.84%. The mean age of RTI cases was 28.5 ± 10.6 and 88.16% of them were male. Male gender was a major risk factor (odds ratio [OR] = 9.64, 95% confidence interval [CI], 4.79–19.41) and marriage was a protective factor (OR = 0.44, 95% CI, 0.28–0.70) for RTI. The medians of direct, indirect, and total costs were US$214, US$163, and US$387, respectively. The total cost of nonfatal RTIs in Iran was estimated at 1.29% of the gross domestic product (GDP) in 2011.

Conclusions: In Iran, nonfatal RTIs imposed a total cost of almost US$7 billion to the country for one year. Extension and more serious implementation of preventive measurements seem necessary to decrease this notable burden of RTIs.     

The detection of SARS-CoV-2 RNA in indoor air of dental clinics during the COVID-19 pandemic

Environmental Science and Pollution Research - In the indoor environment of dental clinics, dental personnel and patients are exposed to a risk of infection because of the transmission of...     

A multi-objective closed-loop supply chain network design problem under parameter uncertainty: comparison of exact methods

Environment, Development and Sustainability - Forward and reverse supply chains are one of the most important issues in supply chain management. These kinds of supply chain networks include a...     

Laboratory waste minimization by recovery of silver as nano-silver colloidal dispersion from waste silver chloride

The use of cyclic experiments, where the product of one reaction becomes the starting material for the next experiment, was proposed as an effective protocol for waste minimization in an educational lab. A simple, cheap and pollution-free method was developed for recovering silver as nano-silver colloidal dispersion from waste silver chloride in the laboratories of the Faculty of Health, Safety and Environment. Silver nanoparticles of the size 5–18 nm were recovered in the presence of sodium borohydride as a reducing agent and polyvinylpyrrolidone as a stabilizer agent. The nano-silver particles were studied for their formation, structure, stability and size using UV–Vis spectroscopy, transmission electron microscopy and dynamic light scattering techniques. The antibacterial assays of nanoparticles showed satisfactory results for Escherichia coli ATCC25922, Staphylococcus aureus ATCC 29213, and Acinetobacter baumanii (Clinical isolate). A laboratory experiment was designed in which students synthesize yellow colloidal silver solution from chemical waste silver chloride and estimate particle size using visible spectroscopy.