Magnetic layered double hydroxides for the sensitive dispersive solid phase microextraction of hippuric acid in urine samples prior to HPLC-UV analysis.

The core- shell structural layered double hydroxide (Fe3O4-SiO2-EN@Zn-Al-LDH) was successfully synthesized and applied as a solid sorbent in the magnetic dispersive micro solid-phase-extraction (M-DµSPE) method. It was combined with high-performance liquid chromatography for the trace analysis of hippuric acid (HA) from urine samples. The obtained magnetic layered double hydroxides (LDHs) were characterized by XRD, FT-IR, VSM, FE-SEM, and BET techniques. The characterization analysis indicated that Fe3O4- SiO2- EN@ Zn-Al-LDH has a sufficient surface area and good saturation magnetism. The affecting variables on the extraction of HA by the proposed method were optimized. Excellent adsorption capacity (127.8 mg g-1), wide linearity dynamic range (0.015-500 µg mL-1), and satisfactory limits of detection and quantification (0.055 and 0.014 µg mL-1, respectively) could be obtained under optimum conditions. The good repeatability and low relative standard deviation (7.2 %), low carry-over (2.7%), good matrix effect (93.6%), high reusability (up to 19 times), and an acceptable percent recovery value (97.2%) proved the selectivity and applicability of the proposed method for the extraction of the trace levels of HA in real urine samples.

Sensitive and selective magnetic dispersive microextraction of diazinon from urine samples by molecularly imprinted polymer based on core-shell metal-organic frameworks.

A core-shell magnetic metal-organic framework (Fe3O4 SiO2/ PAEDTC@ MIL- 101 (Fe)) was synthesized as the substrate and then covered with a surface molecularly imprinted polymer (MIP) layer. Next, Fe3O4 SiO2/ PAEDTC@ MIL- 101 (Fe) @ MIP was characterized by XRD, FT-IR, BET, VSM, TEM, and FE-SEM techniques and applied for selective, fast, and sensitive magnetic dispersive solid-phase microextraction (M-DµSPE) of diazinon from urine samples by the GC- FID detection method. The key experimental variables affecting M-DµSPE were studied and optimized by central composite design (CCD). Under optimum conditions (5 mL; sample at pH: 7.0, the mass of solid sorbent; 6 mg, extraction time; 4 min, acetonitrile as an eluent solvent; 1.5 mL, and desorption time; 3 min, and then reconstituted with 100 µL of methanol), the proposed method exhibits high sensitivity with limits of detection and quantification of 0.005 and 0.017 ng mL-1, respectively. Excellent extraction recovery (98.5 %), wide linearity range (0.02-200000 ng mL-1, R2 > 0.992), high enrichment factors (47-53), and satisfactory precision (<6.3 % RSD) were achieved. The MIP- MOF@ M-DµSPE -GC-FID method can be used with high precision and wide linearity to extract and analyze trace levels of diazinon in real urine samples.

Effect of occupational exposure to lead on serum levels of lipid profile and liver enzymes: An occupational cohort study.

The present study was performed to know the effects of chronic lead exposure on serum lipids, lipoproteins, and liver enzymes in a cohort study among of lead mine workers. We followed of 200 Iranian workers for 3- years (2018-2020), 100 of them with known occupational exposure to lead thorough their work in lead mine while the others 100 were with no such exposure. Blood lead level (BLL), serum lipids, lipoproteins, and liver enzymes of the exposure group for 3- years were measured and compared with those attained in the non-exposed workers. The BLL levels of the lead-mine workers were higher than with recommended level and the non-exposed group (24.15 and 6.35 µg/dL, respectively). The findings indicated a positive and significant relationship between BLL and lactate dehydrogenase, aspartate transaminase, alkaline phosphatase, alanine transaminase, and bilirubin levels (P < 0.01). Also while we found a negative and significant correlation between BLL and triglyceride, total protein, albumin, and globulin levels (P < 0.01). This report depicted that chronic lead exposure is a risk factor for hematological, liver, and cardiovascular diseases. Despite the fact that the level of liver function parameters was in the normal range, the results of 3- years follow-up show a significant relationship between BLL and alteration of biochemical parameters levels.

Poly (4,4'-methylenedianiline)-graphene oxide nanocomposite: synthesize and application in removal of benzothiophene from model liquid fuel.

The adsorption of sulfur-containing compounds from fuels on polymer nanocomposite adsorbents modified with carbon-based materials was investigated. This work reports the removal of benzothiophene from the model liquid fuel using a novel adsorbent prepared by nanopoly (4,4'-methylenedianiline)-graphene oxide (NPMDA/GO) composite. The adsorbent was successfully synthesized with the in situ electrochemical method and characterized using thermal gravimetric analysis (TGA), field-scattering scanning electron microscopy (FE-SEM), transient electron microscopy (TEM), X-ray diffraction analysis (XRD), and Fourier transform infrared (FTIR). The results showed that the presence of graphene oxide (GO) nanosheets in NPMDA/GO composite adsorbent due to its high tendency to sulfur would increase the adsorption of benzothiophene compared to unmodified nanopoly (4,4'-methylenedianiline) (NPMDA). The π_complexation, oxygenated organic functional groups, and layered sheets of graphene oxide improve adsorption capacity for desulfurization. The NPMDA/GO composite presented maximum efficiency (63.33%) at 30 mg/L initial concentration, 120 mg adsorbent dose, and 120 min contact time at 25 °C. Furthermore, the adsorbent shows an almost good reusability after four cycles (67.12 mg/g sulfur absorption capacity). Pseudo-second-order model (R2 = 0.9975) and the Freundlich isotherm (R2 = 0.8813) were used to describe the adsorption process. Findings confirm that NPMDA/GO composite can be applicable for removal of benzothiophene from liquid fuels.

Toxic effects of subacute inhalation exposure to trichloroethylene on serum lipid profile, glucose and biochemical parameters in Sprague-Dawley rats.

The current study evaluated the inhalation toxicity of trichloroethylene (TCE) at 0, 10, 100, 250 and 400 ppm in Sprague-Dawley rats for 10 day period, because the subacute inhalation toxicity of TCE on serum lipid profile, glucose and some biochemical parameters has not been previously reported. TCE vapors were generated using the dynamic generation system based on evaporation method in the exposure chamber. On the basis of the results, mean serum low-density lipoprotein (LDL) and albumin (ALB) decreased significantly in all the groups exposed to TCE compared with the control group (p < .005), but there was a significant increase for parameters: fasting blood glucose (FBG) and alkaline phosphatase (ALP) (p < .005). Rats exposed to 400 ppm TCE showed a significant decrease in serum cholesterol (CHOL) and protein (Pr) compared with the control group (p < .005). A negative relationship was found between triglycerides (TG), very low density lipoprotein (VLDL), CHOL, LDL, Pr, ALB and urea levels and the subacute exposure to concentrations of TCE (R2 = -0.26, p < .05), but there was a direct correlation for parameters FBG, ALP and alanine aminotransferase (ALT) (R2 = 0.42, p < .05). In conclusion, studies with Sprague-Dawley rats demonstrated that subacute inhalation exposure to TCE (≥ 100 PPM) is associated with biochemical and lipotoxicity in the form of decreased serum ALB and LDL and raised ALP and glucose levels. The present study also provides additional evidence relating to decreased serum CHOL and Pr after subacute inhalation exposure to 400 ppm TCE.

Assessment of the effect of welding fumes on welders' cognitive failure and health-related quality of life.

INTRODUCTION: This study examined whether cognitive symptoms and health-related quality of life can be affected by welding fume exposure. METHOD: Participants consisted of welders (n = 40) and welder assistants (n = 25) from welding units as the exposed group, and office workers (n = 44) as the non-exposed group. All participants were studied using ambient air monitoring and two types of questionnaires: the Cognitive Failures Questionnaire (CFQ) and the 36-item Short Form Health Survey (SF-36). RESULTS: Welders and welder assistants were exposed to higher concentrations of all airborne metals than office employees, except for aluminum and chromium (p < 0.05). Mean (95% confidence interval) CFQ score was higher in welders (26.42 (12.74)) compared with welder assistants (22.68 (14.37)) and the non-exposed group (21.38 (8.75)), although these differences were not statistically significant. Mean total score of the SF-36 significantly differed among the three groups (p < 0.05) and welders had the lowest score (M (SD) = 54.84 (17.88)). The relationships between total CFQ score and the measured concentration of nickel at peak work rate was significant for welders. CONCLUSION: Cognitive symptoms and health-related quality of life were not related to the measures of welding fume exposure and further research should be performed to find other influencing factors.

Heavy metals determination in honey samples using inductively coupled plasma-optical emission spectrometry.

BACKGROUND: Honey contains a complex mixture of carbohydrates and other minor substances. Elements are minor constituents of honey that may threaten the human health in excess concentrations. So, determining the metals in honey helps its quality control as a food product. The aim of this study was to determine the concentrations of some metals in Iranian honey. METHODS: This study was performed in four regions of Ardabil, a province of Iran. Honey samples (n = 25) were digested in microwave oven by nitric acid and hydrogen peroxide, then analyzed using inductively coupled plasma- optic emission spectrophotometry (ICP-OES). RESULTS: No significant differences were observed in cadmium, zinc, nickel, and chromium levels between regions (P > 0.05). Zinc was the most abundant metal in honey samples (1481.64 µg/kg). Some metals had higher concentrations in the East region because of existence more industries there. The highest mean of lead level was 935.48 µg/kg in the East and the lowest was 205.4 µg/kg in the South region. The concentrations of metals were compared with recommended limits for foods. Some of them were higher than standard levels (lead) and some were lower than those (cadmium). CONCLUSIONS: Metals are released into the environment through their use in industrial processes and enter the food chain from uptake by plants from contaminated soil or water. Metals concentration in various places depends on many variables, leading to their different concentrations in honey. Some control measures like the quality control of food products, monitoring the soil in agricultural regions and limiting the use of fertilizers are recommended.

Survey of accidents in suburban Tehran and the prediction of future events based on a time-series model.

BACKGROUND: Car accidents are currently a social issue globally because they result in the deaths of many people. The aim of this study was to examine traffic accidents in suburban Tehran and forecast the number of future accidents using a time-series model. METHODS: The sample population of this cross-sectional study was all traffic accidents that caused death and physical injuries in suburban Tehran in 2010 and 2011, as registered by the Tehran Emergency Section. In the present study, Minitab 15 software was used to provide a description of traffic accidents in suburban Tehran for the specified time period as well as those that occurred during April 2012. RESULTS: The results indicated that the average number of traffic accidents in suburban Tehran per day in 2010 was 7.91 with a standard deviation of 7.70. This figure for 2011 was 6 daily traffic accidents with a standard deviation of 5.30. A one-way analysis of variance indicated that the average of traffic accidents in suburban Tehran was different for different months of the year (P = 0.000). The study results showed that different seasons in 2010 and 2011 had significantly different numbers of traffic accidents (P < 0.05). Through an auto-regressive moving average (ARMA), it was predicted that there would be 166 traffic accidents in April 2012 with a mean of 5.53 and maximum of 6 traffic accidents/day. CONCLUSION: There has been a decreasing trend in the average number of traffic accidents per day.

Descriptive Study of Occupational Accidents and their Causes among Electricity Distribution Company Workers at an Eight-year Period in Iran.

BACKGROUND: Occupational accidents are unplanned events that cause damage. The socio-economic impacts and human costs of accidents are tremendous around the world. Many fatalities happen every year in workplaces such as electricity distribution companies. Some electrical injuries are electrocution, electric shock, and burns. This study was conducted in an electricity distribution company (with rotational 12-hour shift work) in Iran during an 8-year period to survey descriptive factors of injuries. METHODS: Variables collected included accident time, age of injured worker, employment type, work experience, injury cause, educational background, and other information about accidents. RESULTS: Results indicated that most of the accidents occurred in summer, and 51.3% were during shift work. Worker negligence (malpractice) was the cause of 75% of deaths. Type of employment had a significant relationship with type of injuries (p < 0.05). Most injuries were electrical burns. CONCLUSION: High rate of accidents in summer may be due to the warm weather or insufficient professional skills in seasonal workers. Shift workers are at risk of sleep complaints leading to a high rate of work injuries. Acquiring knowledge about safety was related to job experiences. Temporary workers have no chance to work all year like permanent workers, therefore impressive experiences may be less in them. Because the lack of protective equipment and negligence are main causes of accidents, periodical inspections in workshops are necessary.

Determination of Job Stresses and Their Consequences in Drivers in Ilam.

BACKGROUND: Human factors cause 60-70 percent of automobile accidents. Everything related to people that is involved in and interacting with a system is considered to be a human factor. These factors can be psychological, biological, or social, and all of them can affect drivers' behaviors. Therefore, one of the negative and unfavorable effects of these factors is that they cause accidents. According to previous research, increases in the job stresses result in increases in the incidence of car accidents. Drivers who feel stressed often do not to observe the rules, and they may not even notice the warning signs. By measuring the job stress among drivers and its adverse effects, this research aimed to provide an appropriate managerial solution to reduce these problems. METHODS: The sample in this descriptive-analytical study consisted of 250 drivers who were selected and investigated. A job stress questionnaire was used as a means for collecting data. Health conditions were assessed by referring to clinical documents provided for the drivers. Accident data were included in the study using accident-related documentation. Two hundred and fifty drivers from Ilam, Iran participated and were analyzed in this study. This research is a cross-sectional study that was performed by dossiers and personal memoirs. Data were analyzed by SPSS16 and the chi-squared test. RESULTS: The study showed that the main factors that cause medium- to high-level stress are the physical environment, workload and ambiguity of duties. It also showed that the incidence and severity of accidents increased as stress levels increased. CONCLUSION: This study shows high prevalence of job stress amongst drivers in Ilam. The main causes of the prevalence of stress among drivers in Ilam City are physical environment, workload and ambiguity of duties, responsibility.

Assessment of the prevalence of occupational accidents and their influential actors in an electricity distribution company during a five-year period.

BACKGROUND: Occupational accidents have been considered as one of the most important crippling factors contributing to disabilities and life-threatening situations in many countries. This study was conducted to survey the prevalence of occupational accidents and the factors of that lead to injuries in an Electricity Distribution Company during a five-year period. METHODS: In this descriptive study, the accident report form included items asking about the season of the year when the accident occurred, the ages and the average age of those injured, the type of employment, work experience, nature of the injuries that occurred, parts of the body affected, treatments that were applied, average number of days lost per accident, the levels of education of those involved, and their marital status. Data was analyzed using SPSS. RESULTS: A total of 66 Electricity Distribution Company workers were determined to be suffering from injuries due to accidents. The accidents mostly occurred in the summer (33%). Most of the injured workers (16.7%) belonged to the age groups of 25 to 29 and 40 to 44; there were no accidents reported for workers who were less than 20. About 48% of the accident victims had to be hospitalized. Furthermore, 35% of the accident victims were treated in outpatient clinics, and 7.4% of the accident victims died. We demonstrated that there were significant relationships between: 1) marital status and accidental injuries (P<0.001); 2) the average age of those injured among both permanent and temporary workers (P<0.001), 3) the level of education and the consequences of the accidents (P<0.001), and 4) the average of days lost per accident in both the permanent and temporary workers (P<0.001). In this study, no significant relationships were found between the accident occurrence and age (P>0.05) or work experience and the distribution of the accidents (P>0.05). CONCLUSION: This study indicated that most of the injuries in these accidents were related to the nature of employment, marital status, and level of education. The results showed the necessity for providing appropriate safety training for the workers.

Survey and comparison of sleep quality among fixed and changing shift staff in a steel factory in Tehran, Iran.

BACKGROUND: Given the hazardous nature of the work in steel factories and that the staff has to deal with hazardous equipment and machines, improper sleep quality and drowsiness among the works tackles performance and boosts rate of job accidents. This study is aimed to survey the quality of sleep and sleepiness status and the pertinent factors among the workers in a rolling mill and a steel production company in Tehran, Iran. METHODS: In a Cross-Sectional study 2011, 180 workers were selected randomly from a rolling mill and a steel production company in Tehran. A questionnaire was designed to collect demographic data and variables of work condition. Pitersborg's sleep quality questionnaire was used to survey quality and problems of Participants' sleep. Epworth Sleepiness questionnaire was used to deals with sleepiness during work, studying, watching TV, or during time spent in public. RESULTS: Average score of sleep quality for the fixed shift staff and changing shift staff were 7.5±2.82 and 8.49±2.95 respectively. Surveys of sleep quality for the two groups of the participants based on T-test showed a significant difference between the two groups so that the changing shift staff group suffered poorer sleep quality (p=0.03). Comparison of average drowsiness scores between the two groups of participants based on Mann-Whitney test showed no significant difference (p>0.005). Chi square test showed a significant difference between severity of drowsiness and type of working shift (p =0.028 and 0.009). CONCLUSION: Staff in revolving shifts suffers poor sleep quality comparing with staff with fixed working shift. Moreover, type of working shift greatly affects severity of drowsiness as staff at different work shift experienced different level of sleepiness. It is essential to survey sleep disorder of the staff in the industry and pay more emphasis on sleep disorder epidemic in other fields of industry.

Investigation of Occupational Stress and its Relationship with the Demographic Characteristics of Workers in Ilam, Iran.

BACKGROUND: Workers are more susceptible to stress disorder for several reasons. The aim of this study was to investigate occupational stress among workers and other personnel at the ZardjinBaft Workshop in Ilam, Iran, and to examine the relationship between occupational stress and several parameters, such as age, gender, marital status, educational level, work experience, tobacco use, body mass index (BMI), and the type of work. METHOD: This was a descriptive, cross-sectional study that was performed in June 2010. The sample population that was studied consisted of all of the workers and other personnel (130 people) at ZardjinBaft Workshop in Ilam, Iran. They were studied using Cooper's standard questionnaire for stress in the work environment, and we examined the relationship between stress, as the dependent variable, and the eight independent variables mentioned in the Abstract. RESULTS: In the sample population that was studied, severe stress was not observed in most of the sections of the workshop. In addition, using the analysis of variance test (ANOVA), no significant relationship was observed between the average degree of stress and the average demographic characteristics. However, the average stress level had significant relationships with the level of education, work experience, and the type of work, suggesting that stress increases as the level of education increases. In addition, in the beginning and early years of employment, medium levels of stress were observed, and the prevalence of stress decreased after the first 10 years of employment. In addition, workers in the ventilation section of the factory had the highest stress levels. The fear of losing their jobs was the main factor that caused stress among the workers at ZardjinBaft Workshop in Ilam. CONCLUSION: We suggest that managers consider the high importance of stress in the work environment. They should be able to recognize when workers are stressed and offer them assistance and training. They also can eliminate the factors that cause stress in the work environment by taking preventive action. In parallel, workers should try to interact well with their managers and talk to her or him about the conditions of their jobs.