فهرست مطالب dr. mehdi ghasemkhani

Although the main hazard in cement processing is dust, and its effects on pulmonary function constitute the most important group of occupational diseases in this industry, evidence for association between exposure to cement dust and pulmonary function has not been conclusive. This study was performed with the aim to evaluate the impact of cement dust in the workplace on decreasing pulmonary function parameters among the workers.

In this cross-sectional study 283 workers were studied, of which 140 workers were considered as exposed group and 143 workers as non-exposed group. Fifty samples of respirable dust were collected from breathing zone of workers in different sections of cement factory. Visible absorption spectrophotometry was used according to the NIOSH Method 7601 to measure crystalline silica content of reparable dust samples. Spirometry test was also applied to assess workers’ pulmonary function parameters.

Respirable dust concentration was in the range of 1.77 to 6.12 mg/m3. The concentration of crystalline silica in all units was higher than the Threshold Limit Value (TLV) (0.025 mg / m3). There were a significant difference in the Peak Expiratory Flow (PEF) parameter among workers in the two exposed and non-exposed groups to respirable dust (P= 0.017). In other parameters of pulmonary function (FVC, FEV1, FEF 25-75, FEV1/FVC %), there were no significant differences between the two groups under study (P= 0.45, P= 0.14, P= 0.29 and P= 0.23, respectively).

The findings of this study have provided an evidence to confirm the hypothesis that exposure to cement dust can cause complication in PEF parameter of cement industry workers.

The term crystallized silica refers to the crystallized form of Sio2 and quartz, the most frequency composition in the earth’s crust that can cause silicosis and lung cancer through occupational exposure and inhalation of its large quantities. Occupational exposure of workers in Pakdasht, Iran, in 2011 was investigated in four different casting processes in small foundries with less than 10 workers. Sampling respirable dust was collected on MCE filter, using HD cyclone at a flow rate of 2.2 lit/min. The filters were analyzed for dust using NIOSH Method 7601. Gravimetric and visible absorption spectrophotometer was used to determine amounts of inhalable dust and free silica, respectively. Risk assessment techniques were also used to predict silicosis and lung cancer. Geometric means of occupational exposure to crystalline silica in 4 different casting processes were studied within the range of 0.009-0.04 mg/m3. Mortality rate due to silicosis was in the range of 1-13.7 per 1000 persons exposed. Risk of mortality due to lung cancer in exposed workers in small casting workshops in Pakdasht, Iran ranged 4-16 per 1000 persons exposed based on geometric mean and 45 years of exposure. According to risk assessment, mortality due to silicosis, cumulative exposure of 96% of population was at an acceptable level of 1/1000. Fifty percent of workers were exposed to crystalline silica dust in excess of Recommended Exposure Limit -NIOSH and Threshold Limit Value ACGIH (0.025 mg/m3). Several cases of silicosis and lung cancer are anticipated for this occupational group in near future.

The term "crystalline silica" refers to crystallized form of SiO2 and quartz, as the most abundant compound on the earth’s crust; it is capable of causing silicosis and lung cancer upon inhaling large doses in the course of occupational exposure. The aim of this study was to assess occupational exposure to dust and crystalline silica in foundries in Pakdasht, Iran. In this study, airborne dust samples were collected on PVC filters (37 mm diameter, 0.8 mm pore size), by using a sampling pump and open face cyclone at a flow rate of 2.2 l/min for a maximum volume of 800 liters. For determining crystalline silica spectrometry was used according to the National Institute of Occupational Safety and Health (NIOSH) method No. 7601 for analysis of samples. Results showed that crystalline silica concentration was higher than NIOSH and the American Conference of Government Industrial Hygienist (ACGIH) allowed extent (0.025 mg/m3). Concentration of crystalline silica was 0.02-0.1 mg/m3. Total dust concentration average was higher than the allowed extent by Permissible Exposure Limit (PEL) of the Occupational Safety and Health Administration (OSHA). It is essential to take necessary measures to control crystalline silica dust regarding the fact that 50% of workers are exposed to higher than the allowed extent.

Sleep is one of the most important day and night cycles and a complex biological pattern. It is necessary for humans physical and mental balance as sleep disturbance is often an early sign of mental illness. The purpose of this study is to survey and comparison of sleep disorders in shift workers of an automotive industry. This descriptive- analytical study has been conducted on 120 workers in an automobile manufacturing industry located in Tehran. Samples are selected using simple sampling. Data collection was included three questionnaires، demographic data، Insomnia Severity Index and Epworth Sleepiness Scale. The research data were analyzed using SPSS software. Insomnia Severity Index scores 16. 3 on the night shift with a standard deviation of 6 and 12. 55 in the morning with a standard deviation of 5. T-test results showed that the severity of insomnia is higher in unmarried than married individuals (P =. 004). Comparison scores on the night and morning shifts، using t- test، show that the average sleepiness scores in night shift is higher than morning shift، and is statistically significant (P =. 048). The results of this study indicated the high incidence of insomnia and sleepiness in workers in this vital industry. These results can be disturbing and may affect the quality of work and accident rates

Fatigue is indicated as a factor in occupational accidents and diseases and it can reduce individual efficiency. In shift workers who experience sleep disturbance، the occupational accidents and diseases occurring can be aggravated by fatigue. The present study aims to investigate the fatigue intensity and its relationship to insomnia severity among employees of Tehran rolling and steel production company. This descriptive analytical study had been done among 180 workers of the mentioned company. Data collection was done by face-to-face survey method and using the standard questionnaires. Results showed that the fatigue score among fixed-dayshift and rotating-shift workers was 6 and 7 respectively and fatigue level for both groups was 4. In all symptoms associated with fatigue average score of rotating-shift were higher than dayshift and there was a significant difference between them. Relationship between the symptoms of fatigue with Insomnia Severity Index was significant. Warehousing received the highest scores of fatigue and severity of insomnia between different tasks under study. Our findings indicate that level of fatigue and severity of insomnia among workers of industry is very high. Since this can lead to the occupational accident and reduction efficiency، it is necessary to provide facilities for personnel such as reducing working hours، doing regular rest and exercise during working time، paying sufficient attention to humanitarian needs and improving work system.

Cement dust is one of the workplace harmful chemicals. There is a disagreement about respiratory effects of cement. The main purpose of this study was to investigate the respiratory effects of exposure to cement dust.

The subjects consisted of 148 male workers (94 workers with current exposure to cement dust and 54 healthy unexposed employees as a referent group). Respiratory symptom questionnaires, as suggested by the American Thoracic Society, were administered to them. Determination of exposure was carried out by personal dust monitoring. Furthermore, the subjects underwent lung function tests by a spirometer. The data were analyzed applying t test and chi-square test.

The mean values of respirable and dust concentrations were estimated to be 7.70± 1.2 and 67.4± 5.4 mg/m3. Significant decrements in the parameters of pulmonary function were noted (p<0.05).

The findings of this study indicate that a strong association exists between exposure to cement dust and the prevalence of respiratory symptoms and functional impairments of the lungs.

Dust can be produced by almost all production processes in Portland cement factory. Dust exposure potentially can affect respiratory function. But evidence for respiratory effect of cement dust exposure has not been conclusive. In this study we assessed effect of cement dust exposure on respiratory function in a cement production factory. A respiratory symptoms questionnaire was completed and pulmonary function tests were carried out on 94 exposed and 54 non exposed workers at a cement factory in the east of Iran. Additionally, respirable dust level was determined by the gravimetric method. X-ray fluorescence (XRF) technique was performed to determine the silica phases and the SiO2 contents of the bulk samples. The arithmetic means (AM) of personal respirable dust were 30.18 mg/m3 in the crushing, 27 mg/m3 in the packing, 5.4 mg/m3 in the cement mill, 5.9 mg/m3 in the kiln and 5.48 mg/m3 in the maintenance that were higher than threshold limit value (TLV) of the American Conference of Governmental Industrial Hygienists (ACGIH) which is 5 mg/m3. This value in the unexposed group was 0.93 mg/m3. In this study cough, sputum, wheezing and dyspnea were more prevalent among exposed subjects. Exposed workers compared to the unexposed group showed significant reduction in Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC), and Forced Expiratory Flow between 25% and 75% of the FVC (FEF25-75%) (P<0.05). It can be concluded that in our study there was close and direct association between cement dust exposure and functional impairment among the cement factory workers.

Psychiatric distress and work related stress may have a profound effect on an individual''s well-being. The aim of this study was to estimate the prevalence rate of mental health problems and their distribution by age,educational level, marital status and years of employment in a chocolate manufacturing company in Iran. The General Health Questionnaire (a widely used screening instrument) which detects a wide range of psychological problems, mainly anxiety/depression spectrum, was used in this study.The study group consisted of 144 workers who were screened using the GHQ-28 in the Persian language version. Workers with a GHQ score of 6 or more were defined as having psychiatric distress. Multiple logistic regression was performed to assess the odds ratios (ORs) for mental health problems including age, years of employment, marital status and educational level of the GHQ.The prevalence of suspected mental health problems increased with age and years of employment (range 16.7%-41.2% and 15.2%-36.8%, respectively). The increased risks for mental health problems were observed for the range 11-20 (OR = 3.1; 95% CI 1.1-8.4) and >20 years employment (OR=3.7; 95%CI 1.2-11.3).The study results demonstrated a significant association between years of employment and suspected mental health problems.