Application of Fe3O4@TbBd nanobeads in microextraction by packed sorbent (MEPS) for determination of BTEXs biomarkers by HPLC-UV in urine samples.

A relatively new adsorbent based on covalent organic frameworks (COFs) was employed for the first time to extract and determine Trans, trans-muconic acid (tt-MA), Mandelic acid (MA), Hippuric acid (HA), and 3-Methylhippuric acid (m-MHA) in urine. For this purpose, microextraction was performed using the packed sorbent (MEPS) method. Following the extraction process, the prepared samples were specified via the high-performance liquid chromatography-ultraviolet detector system. The precipitation polymerization was applied to synthesize the Fe3O4@TbBd nanobeads, and the morphological and dimensional structures of the products were specified with FE-SEM images. Some key variables affecting the extraction efficiency (i.e., sample volume, elution volume, condition and washing solvents, type and volume of elution solvent, extraction cycles, temperature, and pH of the sample solution) were investigated. In ideal conditions, the limit of detection (LOD) was obtained from 0.02 µg/ml for tt-MA to 0.5 µg/ml for MA. Calibration curves (at five-point) were plotted in the range 0.05-5 µg/ml for tt-MA to 1-300 µg/ml for MA (R2 > 0.98). Moreover, intra- and inter-day precision values were 3.1-5.5 and 4.6-9.8%, respectively. The developed method was successfully employed to determine four analytes in three concentrations (low, medium, and high QCs). The results showed a satisfactory recovery (70-87%). COF-MEPS technique is a rapid, easy, user-friendly, and environment-friendly method for separating the minimum values of all BTEXs chief biomarkers from urine samples without using complicated processes and only with one adsorbent. Also, it can be a good alternative for biomonitoring the workers exposed to BTEX compounds in occupational and environmental access.

Effects of Light on Attention and Reaction Time: A Systematic Review.

BACKGROUND: Accuracy, speed, efficiency, and applicability of activities in the workplace are among the most important effective factors on people's productivity, which is in turn affected by environmental factors, such as light. Therefore, the present research aimed to review the studies performed about the effects of light on attention and reaction time. METHODS: This review study systematically searched articles from 2000-2019 in databases of Google Scholar, ISC, SID, Magiran, Web of Science, Science Direct, PubMed, and Scopus using keywords of light, lighting, attention, and reaction time. The titles and abstracts of articles containing relevant results over the past 20 years were extracted. Thereafter, they were categorized and analyzed according to the title, author name, publication year, study method, study type, and evaluation results. RESULTS: Based on the results, the light with shorter wavelengths, higher intensity, and higher color temperature led to suppressed melatonin, higher consciousness, less somnolence, increased attention, and faster reaction time. Simultaneous exposure to harmful levels of environmental factors affects cognitive and physiological parameters, acting independently with a separate mechanism or synergistically with a similar mechanism. The best light in the regulation of psychological, biological, and cognitive processes is bright daylight in the morning with a short wavelength, high intensity, and more lasting effects. CONCLUSION: As evidenced by the obtained results,  light is a powerful modulator of non-visual performance in cognitive tasks. The wavelength, color temperature, and light intensity modulate brain responses to cognitive tasks, including attention and reaction time. Therefore, these parameters, along with personal and environmental factors, should be considered in designing and using light.

The Influence of Internal Wall and Floor Covering Materials and Ventilation Type on Indoor Radon and Thoron Levels in Hospitals of Kermanshah, Iran.

BACKGROUND: Building materials and the ventilation rate of a building are two main factors influencing indoor radon and thoron levels (two radioactive gases which have the most important role in human natural radiation exposure within dwellings). OBJECTIVES: This analytical descriptive study was intended to determine the relationship between indoor radon and thoron concentrations and the building materials used in interior surfaces, as well as between those concentrations and the type of ventilation system (natural or artificial). MATERIALS AND METHODS: 102 measurements of radon and thoron levels were taken from different parts of three hospital buildings in the city of Kermanshah in the west of Iran, using an RTM-1688-2 radon meter. Information on the type of building material and ventilation system in the measurement location was collected and then analyzed using Stata 8 software and multivariate linear regression. RESULTS: In terms of radon and thoron emissions, travertine and plaster were found to be the most appropriate and inappropriate covering for walls, respectively. Furthermore, granite and travertine were discovered to be inappropriate materials for flooring, while plastic floor covering was found suitable. Natural ventilation performed better for radon, while artificial ventilation worked better for thoron. CONCLUSIONS: Internal building materials and ventilation type affect indoor radon and thoron concentrations. Therefore, the use of proper materials and adequate ventilation can reduce the potential human exposure to radon and thoron. This is of utmost importance, particularly in buildings with a high density of residents, including hospitals.

Epidemiology of work-related injuries among construction workers of ilam (Western iran) during 2006 - 2009.

BACKGROUND: Work-related injuries are the most important cause of work absence, disability, retirement, mutilation, and even mortality. In Iran a great number of work-related injuries are occurred in construction industry. However, less than 12% of total workers are active in the construction sector. OBJECTIVES: This study aimed to determine the incidence rate of work-related injuries, the type of injuries, and its other determinants among the construction workers of Ilam (Iran). PATIENTS AND METHODS: The participants were the workers and staffs working in the construction activities of Ilam in Western Iran. All the recorded injuries and deaths related to the construction workers of Ilam from 2006-2009 were collected from the Bureau of Labor and Social Affairs and then analyzed by the statistical package of SPSS (version 19, for Windows). RESULTS: During 2006 - 2009 in Ilam, 387workers encountered the building accidents. Their mean age was 34.3 years (SD = 12.4). The average annual incidence of work-related injuries among the workers was 8.2 per 1000 workers. Fracture with 275 cases (71%) was the most common outcome of injuries, and slipping and falling with 77 cases (36%) were the most important events and exposures. The most important factor related to injuries was the lack of surveillance by employers which was also related with the severity of accident-induced injuries (P < 0.004). CONCLUSIONS: Considering the effectiveness of the relevant preventive measures activities such as training the workers as well as using safety tools and more surveillance by employers can decrease the number of work-related injuries among constructive workers.