International Journal of Occupational Hygiene
Volume:2 Issue: 1, Jan 2010

Welders may suffer from welding fumes generated during the process if the ventilation systems are improperly applied. The objective of the present work was to study the mitigation of air pollutants at welding stations, using different ventilation scenarios. Four air pollutants including iron oxide, respirable dust, ozone, and carbon monoxide were measured during four different ventilation scenarios using US OSHA and US NIOSH sampling and analysis methods. Meantime, face velocity, volumetric airflow rates, duct velocity, static, and velocity pressures at different locations of the ventilation systems were also measured using BS 1042 standard methods. The paired t-test revealed that with p<0.05 there was a significant difference between occupational exposure to air pollutants in 4 different ventilation scenarios. The results also showed that when local and general ventilation systems were both on, the occupational exposure to iron oxide and carbon monoxide were below than their TLVs, but the exposure to the respirable dust in two welding stations and ozone levels in three welding stations were higher than their respective TLVs. The duct air velocity in three welding stations is higher and in eight stations lower than 10.1 m/s recommended by ACGIH. The mean value of volumetric airflow rates in all 11 stations were 34.7% of the required volumetric airflow rates based on standard ventilation systems recommended value. The applied general exhaust ventilation was only 35.5% of standard required value. The local exhaust ventilation is expected to mitigate the air pollutants to acceptable levels at welding stations.

The school environment is an environment wherein a student spends one third of his life with teachers and other students. In the present study، the safety levels of governmental and non-governmental schools were studied and compared. In a descriptive cross-sectional study we assessed schools safety using Fire and Life Safety Inspection Checklist presented by the National Fire Prevention Agency (NFPA). After determining the sample size using simple random sampling، 35 high schools of Yazd of which 21 were governmental and 14 were non-governmental schools were selected. Evaluation of the data was done using SPSS V. 17. 0 software program. The results showed that the highest coefficient of safety in the schools of Yazd was related to air conditioning systems، while the lowest coefficients were related to the electrical and fire safety. Also، the mean electrical and fire safety scores were higher in thenon-governmental schools as compared to the governmental schools (p<0. 01). Safety coefficients of all departments were higher in the non-governmental schools as compared to the governmental schools. Considering the results of the study، it is both essential and critical to pay greater attention to the process of reconstruction، repair، maintenance and building of new schools according to international safety standards in order to have a safe school environment that requires the attention of all those responsible in the education department.

Cobalt is widely used in different industrial processes for production of various synthetic materials. For assessment of human exposure to toxic metal of Co (II)، environmental and biological monitoring are essential processes، in which، preparation of samples is one of the most time-consuming and error-prone aspects prior to instrumental analysis. The aim of this study was to achieve optimum factors necessary for development of a sample preparation technique for cobalt (II)، present in urine، hair، and nail samples followed by atomic absorption spectrometry. Solid phase extraction (SPE) using mini columns filled with Chromosorb 102 resin was optimized regarding sample pH، ligand concentration، loading flow rate، elution solvent، sample volume (up to 500 ml)، elution volume، amount of resins، and sample matrix interferences. Cobalt ion was retained on sorbent and was eluted with 2 M HNO3 followed by determination by flame atomic absorption spectrometry. Obtained recoveries of cobalt ion were more than 92%. To evaluate occupational exposure to Co (II)، successful applicability of the optimized method for human exposure was used by treatment real samples، including urine، hair، and nail. Suitable results were obtained for relative standard deviation (less than 10%). This optimized method can be considered successful in simplifying sample preparation for trace residue analysis of Co (II) in different matrices when an evaluation of occupational and environmental exposures is required.

Attentional demands and individuals’ cognitive failure are hypothesized to be determinant factors for workload assessment and job analysis, although previous researches have focused merely on one aspect of attentional demands. The objective of this study was to investigate the degree to which various attentional paradigms would be demanding to the participants with different levels of cognitive failure. A total of 24 participants within three groups of low, medium, and high cognitive failure questionnaire (CFQ) scorers completed two 15-min and one 60-min tasks representing three paradigms of “divided”, “selective”, and “sustained” attention. The participants were undergraduate male students from the University of UOEH, Japan. Outcomes were measured in subjective workload, stress-arousal and anxiety level, along with performance measures. Accordingly, MANOVA and Post Hoc Tukey-test analyses between variables showed that the divided attention task created a higher workload with a better arousal level, while an increased level of frustration with a decreased level of arousal was induced by the sustained attention task. Confirming the proposed model of cognitive failure in this study, greater workload with worse psychological functioning and performance breakdown was found among the high CFQ scorers. These findings have important implications for conducting workload analysis researches in real-world or laboratory settings; focusing on attentional demand and cognitive failure may be an effective way to alleviate stress.

Prevalence of chronic disease could be adversely having an effect on the capability of the driver. In addition, it must increase probability of accidents. The aim of this study was to examine the relationship between chronic medical conditions and contribution in crashes among drivers. In this cross-sectional study, the populations were professional truck drivers. The numbers of 323 people were selected to participate in the study. All of information for this survey was gathered by self-repot questionnaire. Analyses were performed by binary Logistic Regression, Cochran''s and Mantel-Haenszel statistics and chi-square test. There was not a significant relationship between drivers who reported that they had heart disease and involved in crashes with divers without cardiovascular disorders involved in accidents. Drivers involved in crashes were further possible to have diabetes mellitus and respiratory disorders compared with drivers not involved in crashes. There was a significant relationship between vision complaint and driving accidents (p<0.05). The present study indicates that, several medical conditions were associated with the risk of crashes.

The undesirable effects and consequences of occupational fatal accidents have placed a great emphasis on applying preventive measures. This study was aimed to analyze and specify the latent causes of occupational fatal accidents in Exir Chemical Plant, Urmia - Iran in 2008-2009. The analytical Tripod-BETA method was used. A geographic Information System (GIS) was then used to determine a list of the most significant preconditions and active failures contributing to occupational fatal accidents. The total number of recognized preconditions and latent failures were 572 and 852 respectively. The most frequent preconditions and latent failures were determined by overlaying the coded sheets on each other. Results of the study showed that Promoting and enhancement of the company''s safety culture, a carrot and stick motivation policy accompanied by comprehensive assessments to prioritize safety training programs, were among recommended preventive actions to control and reduce fatal accidents.

The aim of the study was to determine the prevalence of metabolic syndrome (MeS) in professional bus drivers, and its association with overtime working hours among those drivers in Urmia, Iran. In this cross sectional study the studies population was 626 professional bus drivers, aged 20-69 yr. The MeS (according to the National Cholesterol Education Program Adult Treatment Panel III), Waist circumference, Systolic blood pressure, Diastolic blood pressure, Fasting plasma glucose, Triglyceride, HDL-cholesterol, age, and working time per week. The overall prevalence of the metabolic syndrome was 32.4%. The prevalence of the MeS was higher than the general Iranian population. There was a statistically significant positive relationship between over time driving and MeS (P: 0.028). This represents an odds ratio of 1.46 (95%CI: 1.04 – 2.05). The metabolic syndrome is becoming a noteworthy health problem in bus drivers; therefore, early detection and appropriate intervention need to be established.

Gamma rays pose enough energy to remove electrons from atoms of absorbing material including human body and adversely affect human health. The external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined. Therefore, we monitored gamma dose rate in indoor environments and estimated corresponding annual effective dose in selected districts of Ardabil Province, Iran. Indoor environmental gamma dose rates were measured using an Ion Chamber Survey Meter, FLuke-451b, in 88 selected dwellings (One in city center and the remaining in cardinal and ordinal directions with an appropriate distance from each other) in Ardabil, Sar Ein, Germy and Kosar. The measurements of gamma radiation dose rate were performed at 20 and 100 cm above the ground for a period of one hour. Average absorbed dose rate (i.e. arithmetic average of dose rate at 20 and 100 cm above the ground) inside buildings for Ardabil, Sar-Ein, Germy, and Kosar were 238, 221, 402, and 361 nSvh-1, respectively. The respective corresponding values for annual affective absorbed dose rate due to indoor environments for the studied area were 1.17, 1.08, 1.97, and 1.77 mSv, respectively. Calculated annual effective doses for selected districts of Ardabil Province were appreciably higher than the population weighted average exposure to environmental gamma radiation worldwide as well as the average estimated value for Iran