ABSTRACT
BACKGROUND: At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. METHODS: The average luminance was measured using a luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent luminance was determined according to the Holliday polar diagram. RESULTS: Considering the average luminance at the tunnel entrance (116.7 cd/m²) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. CONCLUSION: A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers’ eyes to the change in luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.
Subject(s)
Iran , Reflex , SunlightABSTRACT
Background: Necessity of evaluating heat stress in the workplace, require validation of indices and selection optimal index
The present study aimed to assess the precision and validity of some heat stress indices and select the optimum index for using in heavy work activities in hot and dry climates
Methods: It carried out on 184 workers from 40 brick kilns workshops in the city of Qom, central Iran [as representative hot and dry climates]
After reviewing the working process and evaluation the activity of workers and the type of work, environmental and physiological parameters according to standards recommended by International Organization for Standardization [ISO] including ISO 7243 and ISO 9886 were measured and indices were calculated
Results: Workers engaged in indoor kiln experienced the highest values of natural wet temperature, dry temperature, globe temperature and relative humidity among studied sections [P<0.05]
Indoor workplaces had the higher levels of all environmental parameters than outdoors [P=0.0001], except for air velocity
The wet-bulb globe temperature [WBGT], predicted heat strain [PHS] and heat stress index [HSI] indices had the highest correlation with the physiological parameters. Relationship between WBGT index and carotid artery temperature [r=0.49], skin temperature [r=0.319], and oral temperature [r=0.203] was statistically significant [P=0.006]
Conclusions: Since WBGT index, as the most applicable index for evaluating heat stress in workplaces is approved by ISO, and due to the positive features of WBGT such as ease of measurement and calculation, and with respect to some limitation in application of HSI; WBGT can be introduced as the most valid empirical index of heat stress in the brick workshops
ABSTRACT
Night work can have a significant impact on health, well-being, performance and occupational safety of workers. Night workers often complain about the sleep disorder characterized by excessive sleepiness. The aim of the study was to determine the level of sleepiness among night workers and investigate its relationship with oral temperature in a hot industry. This cross-sectional study involved 80 night workers. Stanford Sleepiness Scale [SSS] has been used to measure the level of sleepiness. Oral temperature and SSS were recorded at different hours of night shift [23 pm to 4 am] for two consecutive nights. The analysis of results showed that there was a positive linear trend in the sleepiness scale [Pvalue<0.001] and an increasing trend in the oral temperature between 23pm and 1am. Then a decreasing trend has been observed after 1am for both of them [Pvalue <0.001]. Comparison of the results for two nights indicated that the mean sleepiness index in the second night is higher than the first [Pvalue <0.001], but the mean oral temperature in the second night was equal to that in the first night. Findings suggest a weak negative association between sleepiness and oral temperature. [r=-0.24, Pvalue =0.03]. A substantial proportion of subjects were working while sleepy, especially at late night and early morning hours. The combination of heat stress and sleepiness can lead to impaired performance. The growing amount of sleepiness index indicates the high risk of sleep disorders and the other possible problems related health among night shift workers
ABSTRACT
Flour dust has been introduced as one of the effective factors in the prevalence of respiratory disorders among the workers of the flour production factories. The purpose of the present study is to examine the effects of this pollutant on the pulmonary functions and survey the prevalence of respiratory symptoms among workers of flour production factories in Arak, Iran. Exposure to flour dust is used to classify subjects into exposed [38 male workers of production plant] or unexposed groups [37 male employee from administrative section]. Exposure level to flour dust, the prevalence of respiratory symptoms and pulmonary function in two group were studied using air sampling [based on method NIOSH 0600], a researcher made questionnaire on respiratory symptoms and Spirometer, respectively. The results indicated that workers of the production plant are exposed to high concentration of flour, which causes a decrease in the ratio of FEV1 / FVC compared to the unexposed ones. Among study respiratory symptoms, subjects had reported significantly more sputum secretion than that in control group. Furthermore intervening parameters, including age, work experience, body mass index and smoking didn't show a significant effect on the pulmonary function of the individuals. Exposure to flour dust concentration with higher than threshold level values causes a decrease in workers respiratory capacity. Therefore, it is recommended that the reduction of both exposure risk and the 8-hour time-weighted average concentration of flour dust should be considered