Risk assessment of occupational exposure to BTEX in the National Oil Distribution Company in Iran

BACKGROUND: This study evaluated the quantitative, carcinogenic and non-carcinogenic risk of exposure to BTEX using lifetime cancer risk (LCR) and hazard quotient (HQ) in the National Company for Distribution of Petroleum Products in Iran.METHODS: In this risk assessment method, the data were collected in different parts of the company. In order to determine the concentration of BTEX, sampling was carried out in different parts using activated carbon. A Gas Chromatography–Flame Ionization Detector (GC-FID) was used for analysis. Analysis and sampling was conducted according to the NIOSH 1500 method. For carcinogenic risk assessment, LCR was calculated. For non-carcinogenic risk assessment, HQ was calculated.RESULTS: The carcinogenetic risk of benzene was definite for loading and deep handling units, and safety officer, and was probable rank for sealing, inspection gate, security, loading 1, and deep handling units. The carcinogenic risk of ethylbenzene was definite for quality control and loading 1 units, was probable for deep handling and loading 2 units, and safety officer, and was possible for sealing, inspection gates, security units. The non-carcinogenic risk of toluene was acceptable for deep handling, clothing, inspection gates, and sealing units, but was unacceptable for officer safety, quality control, loading 1, and loading 2 units. The non-carcinogenic risk of xylene was acceptable for the inspection gate unit, but was unacceptable for security, sealing, officer safety, quality control, deep handling, loading 1, loading 2 units.CONCLUSIONS: This risk assessment method used was a comprehensive and quantitative method, so it determined risk accurately. Commensurate with the risk level of each part of the company, the appropriate corrective actions must be carried out

Development of a novel setup for direct colorimetric visualization of elemental mercury vapor adsorption on colloidal gold nanoparticles

ABSTRACT Mercury is a toxic, persistent, and bio-accumulative pollutant that has adverse effects on environmental and human health. Various studies have been conducted to monitor different forms of mercury. The objective of this study was to develop a novel setup for assessing gas phase elemental mercury vapor adsorption using colloidal gold nanoparticles solutions that display a characteristic surface plasmon resonance absorption peak in the visible spectrum. The UV-VIS-NIR spectrographs of gold nanoparticles blue shifts after exposure to mercury vapor. The surface plasmon resonances (SPR) of ∼4 and ∼30 nm gold nanoparticles were appeared with the sharp peaks at 515 and 528 nm respectively. The mercury vapor adsorbed in gold nanoparticles was related to the size. The amounts of mercury vapor adsorbed per grams of ∼4 and ∼30 nm gold nanoparticles solutions were obtained 1100 µg•g-1 and 1300 µg•g-1 respectively. A proposed novel setup based on UV-Vis spectroscopic undertaken to provide simplicity, use facilitating, potentially inexpensive, and sensitive enough is a suitable system for mercury vapor capture in many fields. It was demonstrated that the amount mercury adsorbed has been related to the sizes of gold nanoparticles. The color change was observed, when elemental mercury vapor adsorbed on the gold nanoparticles

Risk assessment of occupational exposure to BTEX in the National Oil Distribution Company in Iran

BACKGROUND: This study evaluated the quantitative, carcinogenic and non-carcinogenic risk of exposure to BTEX using lifetime cancer risk (LCR) and hazard quotient (HQ) in the National Company for Distribution of Petroleum Products in Iran. METHODS: In this risk assessment method, the data were collected in different parts of the company. In order to determine the concentration of BTEX, sampling was carried out in different parts using activated carbon. A Gas Chromatography–Flame Ionization Detector (GC-FID) was used for analysis. Analysis and sampling was conducted according to the NIOSH 1500 method. For carcinogenic risk assessment, LCR was calculated. For non-carcinogenic risk assessment, HQ was calculated. RESULTS: The carcinogenetic risk of benzene was definite for loading and deep handling units, and safety officer, and was probable rank for sealing, inspection gate, security, loading 1, and deep handling units. The carcinogenic risk of ethylbenzene was definite for quality control and loading 1 units, was probable for deep handling and loading 2 units, and safety officer, and was possible for sealing, inspection gates, security units. The non-carcinogenic risk of toluene was acceptable for deep handling, clothing, inspection gates, and sealing units, but was unacceptable for officer safety, quality control, loading 1, and loading 2 units. The non-carcinogenic risk of xylene was acceptable for the inspection gate unit, but was unacceptable for security, sealing, officer safety, quality control, deep handling, loading 1, loading 2 units. CONCLUSIONS: This risk assessment method used was a comprehensive and quantitative method, so it determined risk accurately. Commensurate with the risk level of each part of the company, the appropriate corrective actions must be carried out

An overview of methods and instruments for the assessment of occupational exposure to nanoparticles

Background & objective:: In recent years, there has been a dramatic increase in the application of nanotechnology in industries and the number of workers occupied in different processes of research on and construction, production and residue disposal of products containing nanoparticles. Despite this growth, however, there is still a dearth of information on the risk of occupational exposure to these materials. Due to the growing application of nanoparticles in the workplace, selecting suitable sampling and characterization techniques and instruments as well as investigating their efficiency for the evaluation of occupational exposure is very important. Methods: The present review study was conducted to introduce the methods and instruments used for evaluating occupational exposure to nanoparticles with an emphasis on the results of the existing literature on methods and instruments of evaluating occupational exposure to nanoparticles and the different contributing factors and conditions through library resources. Results: The results of this study demonstrate that, in spite of the wide application of nanotechnology in the workplace, a reliable, international and standard method for evaluating occupational exposure to nanoparticles is still lacking. This study also shows that occupational exposure to nanoparticles can be evaluated through modern instruments that identify and characterize nanoparticles in terms of their number, mass concentration and surface area. The Scanning Mobility Particle Sizer (SMPS) was the most widely-used instrument for measuring the number and size distribution of particles. Conclusion: The accuracy and precision of the methods and instruments used for evaluating the exposure to nanoparticles can be investigated in future research as a way of establishing a suitable and reliable evaluative standard

The investigation of relationship between ambient concentrations and personal exposure levels of formaldehyde in the pathological departments at teaching hospitals in Hamada university of Medical Sciences

Background: Formaldehyde used in the pathology and histology laboratories as a tissue fixation. Formaldehyde classified in group A1 (human carcinogen) by the International Agency for Research on Cancer (IARC). The aim of this study was the evaluation of relationship between ambient concentrations and time-weighted average or ceiling exposures of formaldehyde the pathology departments. Methods: This descriptive analytical study was performed in the second half of year 1395 at four teaching hospitals in Hamadan university of Medical Sciences. For those purpose 28 TWA samples (by a census method), 17 environmental and, 5 ceiling samples in the peak of pollution were collected simultaneously. The NIOSH 3500 method was used to sampling and analysis of air samples. Result: The mean ambient concentration of formaldehyde was 1.67±1.81 ppm. The mean personal exposure levels in both TWA and ceiling were obtained 0.31±0.40 ppm and 2.36±2.34 ppm respectively. TWA and ceiling levels were more than from NIOSH recommended exposure limits (REL) and Iran's national occupational exposure limit (OEL) respectively. In this study, there were a significant correlation between the personal concentrations with TWA (r= 0.82 , P=0.0001) and ceiling exposure levels (r=0.47 , P=0.01). Conclusion: According to the exist challenges in the risk assessment of formaldehyde, this study in addition to measuring the ceiling exposure levels in the contaminant peak emphasized the simultaneously measure ambient concentrations and TWA exposure levels in order to informed of the staffs exposure levels to assurance effectiveness of control measures at the teaching hospitals. &nbsp

Knowledge and Attitudes of Environmental and Occupational Health Engineering Students towards the Benefits and Risks of Nanotechnology

Introduction: Nanotechnology as a key technology in the 21st century refers to the science of manipulating molecules and atoms in size range of 1 to 100 nanometers. Given the importance of investment in research and development, promoting knowledge and attitude of students can have a positive effect on expanding the scope and use of these emerging technologies. Methods: In this descriptive analytical study, the knowledge and attitudes of 130 students towards the benefits and risks of nanotechnology were investigated through a questionnaire. The participants were studying occupational and environmental health engineering in Hamadan, Ilam, and Semnan Universities of Medical Sciences. Results: The mean score of students' knowledge was 16.08 ± 1.61. A significant difference was observed between the mean scores of knowledge in undergraduate and graduate students (P= 0.001). However, no significant deference was observed in the mean score of knowledge between women and men, different age groups, and the year of entrance to university. Using linear regression equation and by considering knowledge level as a dependent variable, it was indicated that age and educational level were significantly related to the state of knowledge. Conclusion: The results showed that most students did not have an acceptable level of knowledge about nanotechnology. Considering the benefits and risks of this technology, students have a positive attitude to develop use of nanotechnology in Iran. &nbsp

Potential in the diagnosis of oxidative stress biomarkers in noninvasive samples of urine and saliva and comparison with serum of persons exposed to crystalline silica

Background: Prolonged exposure to crystalline silica (CS) (SiO2) dust enhances the production of reactive oxygen species. In many studies, oxidative stress has been measured in the serum of workers exposed to SiO2dust. Aims: We investigated the body fluids such as urine, saliva, and serum, which can provide very good results for assessing the health status of workers' exposures to SiO2dust. Materials and Methods: The oxidative stress biomarkers were evaluated in serum, urine, and saliva of 21 workers who were exposed to SiO2silica crushing factories in the Hamadan city at the west of Iran as a case group and 28 controls. Results: The level of malondialdehyde in serum, urine, and saliva was significantly higher than that in case group compared to controls (22.19 ± 8.70, 9.86 ± 5.43, and 9.41 ± 7.31 nmol/L vs. 7.30 ± 2.22, 6.79 ± 3.21, and 3.93 ± 3.73 nmol/L, respectively). In addition, the total antioxidant capacity in urine (0.23 ± 0.06 vs. 0.29 ± 0.08 mmol/L), as well as catalase in the serum and saliva of case group was lower than that compared to control group (5.46 ± 1.56 and 1.32 ± 0.55 IU/L vs. 12.55 ± 5.72 and 2.32 ± 1.53 IU/L, respectively). Conclusions: The current study indicated that chronic exposure to SiO2affects significantly on the oxidative stress biomarker levels in serum, urine, and saliva in persons exposed. Furthermore, SiO2leads to the induction of oxidative stress and decreases the activity of the antioxidant enzyme

Consequence modeling of fire on Methane storage tanks in a gas refinery

Introduction: using fossil fuels, some hazards such as explosion and fire are probable. This study was aimed to consequence modeling of fire on Methane storage tanks in a gas refinery using analyzing the risk, and modeling and evaluating the related consequences. Method: Hazard analysis by PHA was used to choosing the worst-case scenario. Then, causes of the scenario were determined by FTA. After that, consequence modeling by the PHAST software was applied for the consequence analysis. Results: Based on some criteria, the fire of methane gas tank (V-100) was selected as the worst-case scenario at the refinery. The qualitative fault tree showed three factors including mechanical, process, and human failures contribute in gas leakage. The leakage size and weather conditions were effective on the distance of radiation. Using consequence modeling, thermal radiation was considered as the major outcome of the incident. Finally, for outcome evaluating, probit equations were used to quantify losses and the percentage of fatalities due to the methane gas leakage and fire occurrence. The maximum number of fatalities caused by fire was obtained 23 persons. Conclusions: In conclusion, the methane gas vessel in the refinery can be considered as the main center of hazard, therefore the implementation of the safety rules, eliminating mechanical failures, personal protection and education, and Effective measures to prevent and fighting of fire are proposed for decreasing the probable losses and fatalities

Improving the Dictation in Attention Deficit Hyperactivity Disorder by Using Computer Based Interventions: A Clinical Trial

Objective: The aim of the current study was to assess the impact of computer games and computer-assisted type instruction on dictation scores of elementary school children with attention deficit – hyperactivity disorder (ADHD). Method: In this single-blind clinical trial, 37 elementary school children with ADHD, selected by convenience sampling and divided into group I (n=17) and group II (n=20), underwent eight one-hour sessions (3 sessions per week) of intervention by computer games versus computer-assisted type instruction, respectively. 12 school dictation scores were considered: 4 scores preintervention, 4 scores during interventions, and 4 scores post-intervention. Dictation test was taken during each session. Data was analyzed using repeated measure ANOVA. Results: Two groups were matched for age, gender, school grade, medication, IQ, parent’s and teacher’s Conners’ scale scores, having computer at home, history of working with computer, and mean dictation scores. There was no significant difference in dictation scores before and after interventions and also between the study groups. The improvement in school dictation scores had no significant correlation with age, gender, Ritalin use, owning a computer at home and past history of computer work, baseline dictation scores, Ritalin dose, educational status, IQ, and the total score of parent’s and teacher’s Conners’ rating scale. Conclusion: Absence of significant improvement in dictation scores in study groups may be due to the confounding effect of other variables with known impact on dictation scores. Further studies in this field should also assess the change of attention and memory