Exhaled breath malondialdehyde, spirometric results and dust exposure assessment in ceramics production workers.

INTRODUCTION: The study aimed at measuring exhaled breath malondialdehyde (EBC-MDA) in workers exposed to dust containing silica and at its comparison with the non-exposed control group. MATERIAL AND METHODS: The cross sectional, case-control study (N = 50) was performed in a tile and ceramics production factory in Yazd, Iran. EBC-MDA was quantified in exhaled breath of the participants by a lab made breath sampler. Exposure intensity was measured according to the NIOSH 0600 method in selected homogeneous exposure groups. Additionally, spirometry test was conducted to investigate a correlation between EBC-MDA and spirometric findings in the exposed workers. RESULTS: There was no difference in the observed exposure intensities of silica containing dust in different units. However, "coating preparation" was the unit with the highest concentration of dust. Although, the level of EBC-MDA in the cases was slightly higher than in the controls, the difference was not statistically significant (U = 252, p = 0.464). A significant and positive correlation was found between dust exposure intensity in working units and the measured EBC-MDA of workers (r = 0.467, N = 25, p = 0.027). There were also no statistically significant differences among job categories in the exposed group for the values of FEV1% (F(3, 44) = 0.656, p = 0.584), FVC% (F(3, 44) = 1.417, p = 0.172), and FEV1/FVC% (F(3, 44) = 1.929, p = 0.139). CONCLUSIONS: The results showed a significant correlation between respirable dust exposure intensity and the level of EBC-MDA of the exposed subjects. However, our results did not show a significant correlation between lung function decreases and EBC-MDA.

Determinants of the accuracy of occupational hygiene expert judgment.

An experimental study was performed to determine the applicability and accuracy of occupational hygienist's expert judgment in occupational exposure assessment. The effect of tier 1 model application on improvement of expert judgments were also realized. Hygienists were asked to evaluate inhalation exposure intensity in seven operating units in a tile factory before and after an exposure training session. Participants' judgments were compared to air sampling data in the units; then after relative errors for judgments were calculated. Stepwise regressions were performed to investigate the defining variables. In all situations there were almost a perfect agreement (ICC >0.80) among raters. Correlations between estimated mean exposure and relative percentage error of participants before and after training were significant at 0.01 (correlation coefficients were -0.462 and -0.443, respectively). Results showed that actual concentration and experience resulted in 22.4% prediction variance for expert error as an independent variable. Exposure rating by hygienists was susceptible to error from several sources. Experienced subjects had a better ability to predict the exposures intensity. In lower concentrations, the rating error increased significantly. Leading causes of judgment error should be taken into account in epidemiological studies.

The comparison of the effect of Transactional Model-based Teaching and Ordinary Education Curriculum- based Teaching programs on stress management among teachers.

BACKGROUND & OBJECTIVES: Regarding the effect of teachers' stress on teaching and learning processes, the researchers decided to provide a stress management program based on Transactional Model to solve this teachers' problems. Thus, this study is going to investigate the effect of Transactional Model- based Teaching and the Ordinary Education Curriculum- based Teaching programs on Yazd teachers. METHODS: The study was a semi- experimental one. The sample population (200 people) was selected using categorized method. The data were collected via PSS Questionnaire and a questionnaire which its validity and reliability had been proved. Eight teaching sessions were hold for 60-90 min. Evaluation was performed in three steps. The data were described and analyzed using SPSS software version 15. Value of P<0.05 was considered as significant. RESULTS: The participants were 200 people of Yazd teachers of primary schools. Mean age of group 1 and 2 was 42.05±5.69 and 41.25±5.89 respectively. Independent T- Test indicated a significant mean score (p=0.000) due to perceived stress of interference groups in post interference step and follow-up one respectively. CONCLUSION: Results showed a decreasing effect of both programs, but the Transactional Model- based interference indicated to decrease stress more than the other.

Cancer Risk Assessment in Welder's Under Different Exposure Scenarios.

BACKGROUND: Welders exposure to nickel and hexavalent chromium in welding fumes is associated with increase of cancer risk in welders. In this study we calculated cancer risk due to exposure to these compounds in welders. METHODS: The role of exposure parameters in welders on derived incremental lifetime cancer risk were determined by stochastic modeling of cancer risk. Input parameters were determined by field investigation in Iranian welders in 2013 and literature review. RESULTS: The 90% upper band cancer risk due to hexavalent chromium and nickel exposure was in the range of 6.03E-03 to 2.12E-02 and 7.18E-03 to 2.61E-02 respectively. Scenario analysis showed that asthmatic and project welders are significantly at higher cancer risk in comparison with other welders (P<0.05). Shift duration was responsible for 37% and 33% of variances for hexavalent chromium and nickel respectively. CONCLUSIONS: Welders are at high and unacceptable risk of cancer. Control measures according to scenario analysis findings are advisable.

Risk Perception of Nonspecific Low Back Pain among Nurses: A Qualitative Approach.

BACKGROUND: Low back pain (LBP) is a common medical problem among nurses. A better understanding of nurses' experiences about LBP may help to develop preventative approaches. The study aimed to explore risk perceptions of nonspecific LBP among nurses in Bandar Abbas City, southern Iran. METHODS: This qualitative study conducted as directed content analysis in 2013. Private semi-structured interviews were conducted with a convenience sample of 30 nurses with minimum of 1-year working experience in hospital. The interview questions were based on perceived severity and vulnerability structures of Protection Motivation Theory. All interviews were transcribed and analyzed using thematic analysis. RESULTS: Perceived Severity had the following sub-themes: developing disorders in one's own life and profession, psychical and mental consequences, conflicts and problems in family life, and financial problems. Two sub-themes (problems and limitations in hospital's working system, nature of nursing profession) were identified in relation to perceived vulnerability. CONCLUSION: Nurses reflected their concerns about the impact of LBP on their job security and their considerations about how their back pain might be interpreted by their employers and co-workers. Importance of transparent medical diagnostic procedure and clinical evidence to justify degree of LBP and its burden on the nurses' performance was also addressed.

Application of mathematical models in combination with Monte Carlo simulation for prediction of isoflurane concentration in an operation room theater.

Applicability of two mathematical models in inhalation exposure prediction (well mixed room and near field-far field model) were validated against standard sampling method in one operation room for isoflurane. Ninety six air samples were collected from near and far field of the room and quantified by gas chromatography-flame ionization detector. Isoflurane concentration was also predicted by the models. Monte Carlo simulation was used to incorporate the role of parameters variability. The models relatively gave more conservative results than the measurements. There was no significant difference between the models and direct measurements results. There was no difference between the concentration prediction of well mixed room model and near field far field model. It suggests that the dispersion regime in room was close to well mixed situation. Direct sampling showed that the exposure in the same room for same type of operation could be up to 17 times variable which can be incorporated by Monte Carlo simulation. Mathematical models are valuable option for prediction of exposure in operation rooms. Our results also suggest that incorporating the role of parameters variability by conducting Monte Carlo simulation can enhance the strength of prediction in occupational hygiene decision making.

Changes in urinary catecholamines in response to noise exposure in workers at Sarcheshmeh Copper Complex, Kerman, Iran.

Noise is one of the most harmful agents in the workplace. In addition to the adverse effects of noise on the auditory system, as a stressor it may cause increased blood pressure, cardiovascular disease, anxiety, and impaired secretion of hormones. The purpose of this study was to evaluate changes in urinary catecholamines in workers exposed to industrial noise. This is an experimental study of the workers at the smelter section of Sarcheshmeh Copper Industries done on two separate days. During the first day, urine samples from 20 workers who did not use any hearing protection device, were collected during an 8-h work shift and on the second day the same was done but they were asked to use earplugs. Also 20 people were selected as a control group from people who were not exposed to noise at work. Urinary catecholamine levels were measured with ELISA kits. The mean urinary epinephrine and norepinephrine levels in the workers (without earplugs) was respectively 8.69 and 35.56 µg/8h on the first day and on the second day (with earplugs) dropped to 6.45 and 30.95 µg/8h. Noise reduction by earplugs led to almost significant reductions in urinary epinephrine (p = 0.05) and significant reductions in norepinephrine (p = 0.02). The results showed that with noise reduction the urinary excretion of stress hormones, especially norepinephrine significantly decreases and workers are probably less prone to stress-related disorders.

Effect of zinc oxide nanoparticles on viability of human spermatozoa.

BACKGROUND: The extensive use of different nanoparticles has raised great concerns about their occupational and biological safety. OBJECTIVE: The aim of this study was to evaluate the cytotoxic effect of zinc oxide nanoparticles (ZnO NPs) on viability of spermatozoa. MATERIALS AND METHODS: Semen samples were obtained from 15 healthy persons, and were analyzed using WHO guidelines. Each semen sample was separately incubated with different concentrations of ZnO NPs (10, 100, 500, and 1000 µg/mL) at 37(o)C for 45, 90, and 180 minutes. Then, the cell death percentage of spermatozoa was measured by MTT assay. Mann-Whitney test was used for comparison of different times and concentrations. RESULTS: The maximum cell death percentage was 20.8%, 21.2%, and 33.2% after 45, 90, and 180 minutes, respectively. In case of concentration, the highest concentration (1000 µg/mL) of ZnO NPs led to the highest toxicity for all incubation times. Statistically, there were significant differences in cell viability after 180 minutes vs. 45 and 90 minutes. CONCLUSION: This study indicated that cytotoxicity of ZnO NPs is dose and time dependent. This article extracted from M.Sc. thesis. (Marzieh Noorani).

Evaluation of Occupational Exposure of Glazers of a Ceramic Industry to Cobalt Blue Dye.

BACKGROUND: Cobalt is one of the most important constituent present in ceramic industries. Glazers are the relevant workers when they are producing blue colored ceramic, causing occupational exposure to such metal. Through this study, urinary cobalt was determined in glazers in a ceramic industry when they were producing blue-colored ceramic glazes. METHODS: In this case-control study, spot urine samples were collected from 49 glazers at the start and end of work shifts (totally 98 samples) in 2011. Control group were well matched for age, height, and weight. A solid phase extraction system was used for separation and preconcentration of samples followed by analysis by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). All participants filled out a self administered questionnaire comprises questions about duration of exposure, work shift, use of mask, skin dermatitis, kind of job, ventilation system, overtime work, age, weight, and height. The lung function tests were performed on each control and cobalt exposed subjects. Analysis of covariance (ANCOVA) was used to evaluate the obtained results. RESULTS: Urinary levels of cobalt were significantly higher in the glazers compared to the control group. There were significant differences at urinary concentration of cobalt at the start and end of the work shift in glazers. Spirometric parameters were significantly lower in the glazers compared to the control group. Among the variables used in questionnaire the significant variables were dermatitis skin, mask, ventilation, and overtime work. CONCLUSION: This study verified existence of cobalt in the urine glazers, showing lower amount than the ACGIH standard.

Evaluation and comparison of respiratory symptoms and lung capacities in tile and ceramic factory workers of Yazd.

Tile workers are exposed to dust particles and are susceptible to multiple pulmonary complications. Problems like asthma, chronic obstructive pulmonary symptoms, and silicosis are more common among them. As there are many tile factories in Yazd, we decided to evaluate the respiratory symptoms and lung capacities in these workers and compare them with controls. This study included 176 tile and ceramic factory workers occupationally exposed to dust and 115 unexposed workers as controls. We recorded the respiratory symptoms using the British Medical Research Council questionnaire and measured lung capacities of the two groups.All study subjects were male, and the two groups were comparable in age and smoking. The exposed group had frequent respiratory symptoms and a significant relationship between them and duration of employment. In addition, lung capacities in ceramic workers with symptoms were lower than in workers without the symptoms. Even though the respiratory symptoms were more frequent in the exposed group than in controls, lung capacities of the two groups were similar.

Lectin histochemistry of normal human lung.

This study aimed to identify and specify the glycotypes of cell populations in normal human lung including types I and II pneumocytes, alveolar macrophages and mast cells, and also in the larger tissue structures of lung, including blood vessels and bronchi/bronchioles, using lectin- and immuno-histochemistry on paraffin-embedded tissue from 11 normal cases. The alveolar macrophages were anti-CD68 positive whereas the cells lining the alveolar walls were positive for cytokeratins. The alveolar macrophages in normal lung tissues showed a broad spectrum of staining for different subsets of N-linked saccharides, N-acetylgalactosamine, N-acetylglucosamine, terminal beta-D-galactose and sialyl groups. This study showed that some lectins could be used as specific markers for some cell types i.e. Galanthus nivalis and Narcissus pseudonarcissus lectins for macrophages, Psophocarpus tetragonolobus lectin-II for capillary endothelium, Dolichos biflorus agglutinin for bronchial epithelial cells, Lycopersicon esculentum, Phytolacca americana or Triticum vulgaris (succinylated) for type I pneumocytes and Hippeastrum hybrid or Maclura pomifera lectins for type II pneumocytes. Patchy staining of type I pneumocytes by peanut agglutinin indicated the possibility of two distinct populations of these cells or a pattern of differentiation that is unapparent morphologically.