BackgroundAt 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.MethodsThe 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.ResultsConsidering 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.ConclusionA 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.

This study investigated the accidents recorded at the Gonabad Hospital Management Center for Hospital Management from 2014 to 2016, and identified important causes or parameters that influenced the incidence of accidents using the Pareto chart. Materials and Methods: This descriptive and analytic study examined 25,414 incidents recorded at the Gonabad Hospital Management Center. The key variables such as the types of accident, age, time, types of lesion, and treatment, were collected for transport and nontransport accident. Data analysis was performed using Pareto chart as well as Minitabver v.16 and SPSS v.21 software. Results: Based on the results, the highest rate of the accidents (39.79%) were among people aged between 0-10 years. Transport accidents (17.61%) and heart attacks (10.92%) were the most common that occurred during the study. The spring had the highest rate of accidents, while the winter had the lowest. Conclusion: Transportation accidents had the highest rate of incidents and injuries; therefore, the safety of transportation and vehicles should be taken more seriously.

Black globe temperature (T g ) is one of the most common measurement variables used for assessing heat stress; however, it is usually not reported in meteorological data. This study developed a model to estimate T g based on meteorological measurements, in order to calculate the occupational heat stress index in outdoor workplaces. This descriptive and analytical study was conducted from May to September 2013 in Qom, Iran. Environmental variables such as natural wet-bulb temperature (T nw ), dry-bulb temperature (T a ), solar radiation (SR) and relative humidity (RH) were measured by meteorological instruments in weather stations and T g was measured by a globe thermometer in the same situations at different times. Data were analysed using IBM SPSS16. Independent variables including T nw , T a , SR and RH and the dependent variable T g were introduced to the software, and several regression models were obtained. Finally, a model that had the most appropriate correlation with a significance level of 0.05 was chosen as the best model. The correlation co-efficients between T g and T nw , T a , SR and RH were obtained as 0.84, 0.63, 0.75 and −0.75, respectively. The results showed that T a , SR and RH can justify about 90% of the variation in T g . There was a significant relationship between T g and T a , SR and RH (p < 0.05). The correlation co-efficient between actual and estimated data was 0.95 (p < 0.001). The model obtained can be trusted to estimate the black globe temperature in a hot and dry environment and can be useful in assessing occupational heat stress in outdoor workplaces.

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Background: The purpose of this study was to assess the contrast perception of obstacles in a tunnel entrance which was placed in Ilam Province, Iran.Methods: An obstacle with the reflection coefficient of 20% was mounted at the entrance of thetunnel and then, the car was placed near the tunnel entrance and the intrinsic luminance of the road (Lr,intrinsic) and obstacle (Lo,intrinsic) were measured inside the car using the luminance meter.Results: Intrinsic luminance of obstacle and road at the entrance of the tunnel were measured as 41 and 17 cd/m2, respectively. The contrast perception of obstacle in deriver’s eyes and in the safe stopping distance (SSD) from the tunnel entrance was determined as 2.79 cd/m2. At the entrance of the studied tunnel, the contrast perception of obstacles with the reflection coefficient of 20% was lower than the minimum contrast perception (28%) recommended by International Commission on Illumination.Conclusion: The main conclusion that can be drawn from it, is that this obstacle in the SSD from the tunnel entrance cannot be conceived by the drivers, which may lead to higher rate of road traffic crashes.