Respiratory Effects of Simultaneous Exposure to Respirable Crystalline Silica Dust, Formaldehyde, and Triethylamine of a Group of Foundry Workers.

BACKGROUND: Foundry workers are occupationally exposed to hazardous substances such as silica dusts and toxic gases. The aim of this study was to examine the effects of simultaneous exposure to complex mixtures of silica dust, formaldehyde, and triethylamine on lung function parameters. STUDY DESIGN: A cross-sectional study. METHODS: This study was conducted on 55 male workers of core making unit of a foundry plant (the case group) and 55 workers in a food industry were enrolled as a control group in 2015. Workers were monitored for personal exposure to crystalline silica respirable dust, according the NIOSH method No.7602. The concentrations of formaldehyde and triethylamine were measured using a PID instrument. Lung function tests were performed according to the ERS/ATS standards. RESULTS: The mean concentrations of personal exposure to silica dust, formaldehyde, and triethylamine in the core making workers were 0.23 mg/m3, 2.85 ppm, and 5.55 ppm and respective exposures of control subjects were less than the LOD (limit of detection). There were significant associations between exposure to silica dust and decreases in FVC (Forced vital capacity) values (P<0.05). The findings showed a statistically significant synergistic effect of silica dust and triethylamine on FVC values (P<0.05). CONCLUSIONS: The mean exposure of all studied substances was higher than occupational exposure limits. Synergistic effects of exposure to silica dust and triethylamine on some lung function parameters were observed. Simultaneous exposure of foundry workers to silica dust and triethylamine could impair lung function.

Risk Evaluation of Construction Workers' Exposure to Silica Dust and the Possible Lung Function Impairments.

BACKGROUND: Aerosols generated during construction activities are an integral part of building operations. Considering the nature of materials used in construction activities, respirable dust contains crystalline silica and particulates not otherwise specified (PNOS). Due to lack of data regarding the occupational health status of Iranian construction workers, the objective of this study was to evaluate occupational exposure to silica and to examine their respiratory health status. MATERIALS AND METHODS: In this cross sectional study, 85 construction workers and 40 controls (without active exposure to construction dust) were studied. The workers' exposure to PNOS and silica aerosols was monitored by the NIOSH method No.0600 and a new Fourier transform infrared spectroscopy (FTIR)-based method, respectively. All subjects were also monitored for lung function parameters, such as forced expiratory volume/forced vital capacity (FEV1/FVC), peak expiratory flow rate (PEFR), forced expiratory flow (FEF25-75), FVC, and FEV1. RESULTS: The mean exposure of workers to respirable PNOS and silica was 9.8 (0.35) and 0.13 (0.019) mg/m3, respectively. The groups of construction workers showed significant differences in exposure to PNOS (P< 0.001) and silica (P= 0.007). The mean pulmonary function parameters, including FEV1% and FVC%, were significantly lower among construction workers, compared to the control group (P< 0.001 and P= 0.009, respectively). The pulmonary status of 51.8% of construction workers showed moderate restriction, while 4.70% exhibited obstruction. CONCLUSION: Considering the construction workers' excessive exposure to PNOS and silica, besides depressed lung function parameters, they can be classified as a high-risk group for respiratory diseases.

Air pollution: the knowledge and ideas of students in Tehran-Iran, and a comparison with other countries.

Study of students' knowledge about air pollution can help authorities to have better imagination of this critical environmental problem. This research examines guidance school and high school students' ideas about air pollution and the results may be useful for the respective authorities to improve cultural and educational aspects of next generation. In this cross-sectional study, a closed questionnaire was used to examine knowledge and ideas of 2140 randomly selected school students of Tehran-Iran about composition of unpolluted air, air pollution and its causes and consequences. Cognitive scores were also calculated. Outcomes were compared with results of similar researches in Australia, Hong Kong and the United Kingdom. While a student's 'cognitive score' could range from -16 to +16, Iranian students' mean cognitive score was equal to +2.97. There was not significant statistical difference between girls and boys (P=0.32). In response to question "most common gas in unpolluted air" nitrogen was mentioned by only 23.7%, While 45.1% of students mentioned oxygen. In general, student's knowledge was not acceptable and there were some misconceptions such as "supposing oxygen as the most prevalent gas in unpolluted air". The findings of this survey indicate that, this important stratum of society of Iran have been received no sufficient and efficient education and sensitization on this matter.

Knowledge and Practice of Asthmatic Children's Parents About Daily Air Quality.

BACKGROUND: Knowledge and practice about air pollution are essential subjects in special groups such as cardio-pulmonary patients. For children with air pollution-related diseases, knowledge and attitude of parents play a determining role in this respect. Since providing a coherent curriculum needs evidence-based information, this survey was conducted to assess the knowledge and practice of asthmatic children's parents about daily air quality since asthmatic children are among the most vulnerable at-risk groups when it comes to air pollution. MATERIALS AND METHODS: All parents of asthmatic children referred to the Pediatric Clinic of Masih Daneshvari Hospital during one year period (250 people) completed knowledge and practice questionnaire on air pollution. Knowledge questions consisted of familiarity with pollution standard index (PSI), ways to find out about it, respiratory effects of air pollution and etc. Practice questions consisted of reducing outdoor presence and activity of children and actions taken to reduce air pollution in polluted days. RESULTS: In general, 3.2% of parents were familiar with PSI, 12.5% were aware of ways to find out about daily air quality, 65.2% were aware of air pollution respiratory effects, 65.6% were aware of air pollution effects on asthmatic children and 4.4% were aware of ineffectiveness of surgical masks in prevention of air pollution health effects. The obtained practice score ranged from 4 to 16, and the participants' mean score was equal to 11.79. CONCLUSION: This study revealed that parents of asthmatic children were aware of air pollution hazards for their children and wanted to prevent them but they did not know how. Therefore, asthmatic children in Tehran are still exposed to risks of air pollution.

Global warming: knowledge and views of Iranian students.

Study of students' knowledge about global warming can help authorities to have better imagination of this critical environmental problem. This research examines high school students' ideas about greenhouse effect and the results may be useful for the respective authorities to improve cultural and educational aspects of next generation. In this cross-sectional study, a 42 question questionnaire with mix of open and closed questions was used to evaluate high school students' view about the mechanism, consequences, causes and cures of global warming. To assess students' knowledge, cognitive score was also calculated. 1035 students were randomly selected from 19 educational districts of Tehran. Sampling method was multi stage. Only 5.1% of the students could explain greenhouse effect correctly and completely. 88.8% and 71.2% respectively believed "if the greenhouse effect gets bigger the Earth will get hotter" and "incidence of more skin cancers is a consequence of global warming". 69.6% and 68.8% respectively thought "the greenhouse effect is made worse by too much carbon dioxide" and "presence of ozone holes is a cause of greenhouse effect". 68.4% believed "not using cars so much is a cure for global warming". While a student's 'cognitive score' could range from -36 to +36, Students' mean cognitive score was equal to +1.64. Mean cognitive score of male students and grade 2 & 3 students was respectively higher than female ones (P<0.01) and grade 1 students (P<0.001) but there was no statistically significant difference between students of different regions (P>0.05). In general, students' knowledge about global warming was not acceptable and there were some misconceptions in the students' mind, such as supposing ozone holes as a cause and more skin cancer as a consequence of global warming. The Findings of this survey indicate that, this important stratum of society have been received no sufficient and efficient education and sensitization on this matter.

Monitoring of occupational exposure of mild steel welders to ozone and nitrogen oxides.

BACKGROUND: Metal Inert Gas (MIG) welding and Tungsten Inert Gas (TIG) welding are widely used for mild steel segments in basic metal industries. Pulmonary problems such as asthma, pulmonary inflammation, hyper-responsiveness of airways and higher susceptibility to infections are reported as the result of occupational exposure of welders to ozone and nitrogen oxides. Potent oxidizing agents like ozone and nitrogen oxides are also reported to be a precursor for respiratory problems and cause lipid peroxidation of membranes. MATERIALS AND METHODS: A total of 43 nonsmoking MIG and TIG welders and 41 nonsmoking workers without appreciable exposure to any chemicals as the control population were chosen to participate in this study. Occupational exposure to ozone was monitored according to the validated methods. Malondialdehyde (MDA) of blood serum as a biomarker for lipid peroxidation was analyzed using Reverse Phase High Performance Liquid Chromatography. Data obtained from this study were analyzed using t-test, Pearson's correlation coefficient and multiple regression analysis. RESULTS: A total of 88.4% and 74.4% of welders had exposure to ozone and nitrogen dioxide higher than the permissible limit of occupational exposure, respectively. Generally, exposure of MIG welders to ozone was significantly higher than TIG welders (P = 0.006). However, exposure to nitrogen dioxide gas was comparable in both groups. Serum MDA of welders was significantly higher than that of the control group (P = 0.001). A significant correlation was detected between ozone exposure and level of serum malondialdehyde. Such correlation was not observed for nitrogen dioxide exposure. CONCLUSION: Considering the high exposure of welders to ozone and nitrogen dioxide, and higher level of serum malondialdehyde in them compared to controls, risk management is recommended for this group of workers.