Journal of Health and Safety at Work

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Introduction: Construction industry plays a major role in the economic development of all countries and among the various occupations, this industry is one of the most dangerous industries, particularly respiratory contaminants, around the world. The aim of this study was to evaluate the respiratory capacity of construction workers, working in different workshops in Tehran city and developing a regression model to examine the relationship between pulmonary capacities with the type of occupation, work experience and tobacco smoking.
Material and Method: This study was a cross-sectional descriptive study conducted among 628 construction workers in Tehran city in 2017. After data collection, data analyses were performed using statistical independent t-test, one way ANOVA and correlation tests by SPSS software version 22. Also, multiple backward regression was used to check the effect of independent variables on lung function.  
Result: According to the results of this study, a significant relationship was found between age and work history with the pulmonary function indexes (FVC, FEV1, FEV1/FVC and FEF25-75%) (P-value<0.001). The average of FEV1/FVC% was significantly different among various occupational groups (p-value<0.001). In the analysis of the findings of the pulmonary function test in the exposed group a separate model was made using multiple linear regression for each of the pulmonary functions, and the independent variables including age, work experience, job type and cigarette addiction were entered into the model.
Conclusion: The present study showed a significant change in the pulmonary function parameters of the construction workers and the chance of pulmonary disorders might be high among these individuals.

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Introduction: Measurement of pesticides in biological matrices is become a serious challenge for researchers due to their very low concentration in different matrices. The aim of this study was to develop a new sample preparation method with high accuracy and validity and short retention time for determination of diazinon.
Material and Method: Dispersive liquid-liquid micro-extraction technique coupled with high performance liquid chromatography equipped with ultra violet detector was developed for trace extraction and determination of diazinon pesticide in human urine samples. One variable at a time method was used to optimize parameters affecting the diazinon extraction. Different parameters such as extraction solvent, disperser solvent, and volume of the extraction solvent, volume of the disperser solvent, centrifugation time and speed, salt addition, and sample pH were studied and optimized.
Result: Findings showed that optimal levels of these variables for diazinon pesticide were 150 μl of carbon tetrachloride as extraction solvent, 1.5 ml of methanol as dispersive solvent, pH of 6, 5 minutes centrifuge time at speed of 4000 rpm , 0% (w/v) salt addition. Correlation coefficient was 0.9965 indicating the linearity of a wide range of concentrations of the toxin. LOD and LOQ was calculated less than 0.7 and 5 µg L-1 respectively. The relative standard deviation for six replicate experiments in intra-day and inter-day at tree selected concentrations (50, 200 and 1000 µg L-1) was less than 4% that indicates the accuracy and precision of the optimized method. Enrichment factor and extraction recovery for diazinon were 245 and 99% respectively.
Conclusion: According to the results, dispersive liquid-liquid micro-extraction procedure was successfully developed for the extraction of diazinon from human urine samples. Compared to other extraction techniques, the proposed procedure had some advantages such as shorter extraction time, better reproducibility, and higher enrichment factor.

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Introduction: Many studies have been carried out on the effects of heat stress on cognitive functions, but the results are contradictory. Therefore, this study was conducted to review the effect of heat stress on cognitive functions.
Material and method:  In this study, all English articles conducted on effect of heat stress on cognitive, perceptual, and psychomotor functions from 1970 to 2018 were reviewed. For this, articles with keywords such as heat strain, heat stress, cognitive function, memory, comprehension, psychomotor, reaction time, mental performance, mood, mental response, error, task performance, fatigue, alertness, hyperthermia, and heat exhaustion in the  Scopus, Web of Science, Science Direct, Pub Med, Springer, Wiley Online Library and ProQuest databases were searched. Out of 157 retrieved articles, 39 articles were finally reviewed according to the inclusion criteria.
Results: Out of 157 retrieved articles related to the topic, according to the inclusion criteria, 39 articles were finally considered for review. Among this articles, 9 (%23) articles were published before 2000 and 30 (%77) after 2000. Two articles were in athletes, four articles (%10.2) in workers, four articles (%10.2) in students, four articles (%10.2) in military soldiers and twenty-five articles (%64.2) were conducted in ordinary people.Based on the results, heat stress was identified as a detrimental factor for decreased cognitive functions such as reading comprehension, memory, focus, mathematical processing, tracking test, reaction time, perception  and decoding text and numeric messages, visual alertness, mental computing, text reading , hidden figures test and verbal fluency.
Conclusion: Based on the results of these studies, heat stress has been introduced as a detrimental factor for disrupting cognitive functions, but conclusion based on the results of studies is a systematic method is difficult because many confounding variables such as type of work, exposure time, skill and adaptation plays a big role.

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Introduction: Errors are a byproduct of human information processing or cognitive functioning. Although everyone is disposed to an error while performing various activities, individual differences in cognitive abilities can lead to various types and rates of errors committed in similar situations. Human errors are one of the most important challenges in work environments, including health care systems, wherein such errors are abundantly occurring. Errors in the delivery of correct medications due to the resemblance in appearance and name are thus one of the cognitive errors that come about in health care systems. The main purpose of this systematic review was to evaluate evidence and approaches recently practiced to reduce medication errors caused by the use of look-alike-sound-alike (LASA) medications.
Material and Methods: The study was conducted on August 30, 2018, through searches in the databases of PubMed and Embase, all available years, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) instructions. The searches were done in the titles or abstracts of the articles using the intended terms and the Medical Subject Headings (MeSH) index in combination. These studies were selected based on the inclusion and exclusion criteria and then categorized based on the type of interventions and outputs. Finally, the data were analyzed descriptively.
Results: The research designs and methods varied widely among the studies. There were also discrepancies in the number of participants, number of tests, type of medications, and test conditions. The approaches examined in these studies were tall-man lettering, color-coding, label background variations, and use of signs and symbols. Accordingly, 11 studies had utilized tall-man lettering and the most important reported in all articles were “error rate” and “response times”. As well, a wide range of medication names had been tested. It should be noted that medication
Conclusion: errors have different dimensions, but the errors caused by the look-alike-sound-alike (LASA) medications and the effect of tall-man lettering of medication name were only investigated in the present study. Laboratory studies in this respect have shown that tall-man lettering contributes to mitigating the rate of errors, which might be due to the better legibility of labels, but evaluations in real work environments are needed to reinforce this conclusion. There is also insufficient evidence to support color-coding, as well as several other approaches such as use of signs and symbols. Because of the novelty of the studies in this field, no uniform mechanism has been so far introduced.