Occupational Exposure to Respirable Dust, Crystalline Silica and Its Pulmonary Effects among Workers of a Cement Factory in Kermanshah, Iran.

BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Risk Assessment of Occupational Exposure to Crystalline Silica in Small Foundries in Pakdasht, Iran.

BACKGROUND: 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. METHODS: 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. RESULTS: Geometric means of occupational exposure to crystalline silica in 4 different casting processes were studied within the range of 0.009-0.04 mg/m(3). 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. CONCLUSION: 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/m(3)). Several cases of silicosis and lung cancer are anticipated for this occupational group in near future.

Assessment of Occupational Exposure to Dust and Crystalline Silica in Foundries.

BACKGROUND: 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. MATERIALS AND METHODS: 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: Results showed that crystalline silica concentration was higher than NIOSH and the American Conference of Government Industrial Hygienist (ACGIH) allowed extent (0.025 mg/m(3)). Concentration of crystalline silica was 0.02-0.1 mg/m(3). Total dust concentration average was higher than the allowed extent by Permissible Exposure Limit (PEL) of the Occupational Safety and Health Administration (OSHA). CONCLUSION: 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.

Dust exposure and respiratory health effects in cement production.

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 SiO(2) contents of the bulk samples. The arithmetic means (AM) of personal respirable dust were 30.18 mg/m(3) in the crushing, 27 mg/m(3) in the packing, 5.4 mg/m(3) in the cement mill, 5.9 mg/m(3) in the kiln and 5.48 mg/m(3) in the maintenance that were higher than threshold limit value (TLV) of the American Conference of Governmental Industrial Hygienists (ACGIH) which is 5 mg/m(3). This value in the unexposed group was 0.93 mg/m(3). 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 (FEV(1)), Forced Vital Capacity (FVC), and Forced Expiratory Flow between 25% and 75% of the FVC (FEF(25-75%)) (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.

Musculoskeletal symptoms in workers.

Self-report measures of musculoskeletal discomfort are a widely used and generally accepted risk factor for musculoskeletal disorders in epidemiologic research. The aim of this study was to investigate the prevalence of musculoskeletal symptoms in packing workers. A cross-sectional study of 75 workers was carried out using a modified Nordic questionnaire. Prevalence was determined with the percentage of positive responses to questions on musculoskeletal symptoms. Odds ratios and 95% confidence intervals were the measures of association between prevalent musculoskeletal symptoms and demographic factors; they were determined with logistic regression. Most musculoskeletal symptoms in workers were from the low back (44.0%), shoulders (33.3%) and neck (32.0%). Years worked were strongly significantly associated with musculoskeletal symptoms and pain in the neck, shoulders and wrists/hands, P < .001-.050. Hazards related to repetitive movements and discomfort postures could be reduced with stretching exercises, rotation schedules and through new engineering solutions.

Prevalence of respiratory symptoms among workers in industries of south Tehran, Iran.

OBJECTIVE: The aim of the present study was to determine the prevalence of respiratory symptoms from occupational lung hazards among workers in industries of south Tehran, IRAN. METHODOLOGY: This was a cross-sectional study in which by multistage random sampling items on demographic characteristics, cigarette smoking, occupational history and respiratory symptoms were collected of workers. RESULTS: The mean age of the workers was 38.5 (SD = 10.2) yr: age ranged from 19 to 70 yr. Of 880 workers under study, 252 (28.7%) were smoking. Also, it has been observed that workers exposed in the workplace with occupational chemical exposures such as dust, gas and fume pollutants. The prevalence of respiratory symptoms was cough (20.7%), phlegm (41.6%), dyspnea (41.7%), feel tightness (27.4%) and nose irritation (23.5%). CONCLUSIONS: Occupational exposures among workers in industries of south Tehran may cause respiratory symptoms and respiratory disorders, engineering controls and industrial hygiene is recommended.

Formaldehyde exposure in some educational hospitals of Tehran.

This research was conducted to determine formaldehyde exposure of staffs in pathology laboratories, surgery rooms and endoscopy wards in eight large hospitals of Tehran University of Medical Sciences located at Tehran, Iran. Air sampling have been made by both long and short-term methods. Total numbers of samples were 160 for both methods. Nineteen samples of 160 samples were collected as blank in other non-exposed environments such as administrative sections. The mean (SD) levels of formaldehyde in long-term methods were 0.96 (0.74), 0.25 (0.21) and 0.13 (0.18) ppm, at pathology laboratories, surgery rooms and endoscopy wards, respectively. The results of measurements showed that mean (SD) concentration of formaldehyde in one hour sampling at short intervals were 0.83 (0.29), 0.23 (0.16) and 0.75 (0.25) ppm at pathology labs, surgery rooms and endoscopy wards, respectively. There were significant differences in the mean levels of formaldehyde (long-term) at surgery rooms (p < 0.02) and endoscopy wards (p < 0.005) in eight hospitals of this study. It is concluded that the concentration levels of formaldehyde at pathology laboratories exceeded recommended limit which established by the American Conference of Governmental and Industrial Hygienists ACGIH (TLV-C = 0.3 ppm). It is recommended that local exhaust ventilation should be installed to minimize the contact to formaldehyde in the staffs.