Journal of Occupational

Introduction
The occupational safety literature provides different theories about the recurrence of occupational accidents, which result in significant costs for companies, workers, and the society. Past research shows that there are more individuals with repetitive injuries associated with stress and gender than expected by chance alone. Research reports indicate that the majority of accidents occur at the workplace (1,2). Safety management decisions must be made for selecting and prioritizing problem areas as well as safety system weaknesses based on the recognition of hazards encountered in each activity of the process so as to reduce occupational accidents. Research reports 337 million occupational accidents per year (3,4).
Occupational accidents are among the major public health problems, which annually threaten the lives of many people in developing and developed countries and are also responsible for a high rate of inabilities and absenteeism; thus, occupational incidents play a critical role in the global financial burden of diseases (5). Both occupational accidents and injuries are caused by the risk factors that can be removed by performing measurements and following procedures. It should be noted that most industrialized countries possess a comprehensive occupational safety and health management system, which causes a significant reduction in occupational accidents (6).
Recent psychological studies in the field of incidents and their causes are associated with the factors of age, level of experience, and occupational characteristics of employees, from management’s point of view (7). Hayes believes that in the occurrence of accidents, insecure behaviors (88%), unsafe conditions (10%), and unforeseen factors (2%) are involved. By identifying the role of individuals’ unsafe acts from the second half of the 20thcentury in developed countries, incident control programs were focused on people’s unsafe behaviors (8). Studies on unsafe behaviors have shown that occupational stressors contribute greatly to insecure acts by employers through reduced focus, mental distraction, memory impairment, job delays, and reduced decision-making power (9). Job stressors along with adverse psychological effects can lead to the occurrence of occupational incidents, because of injuries to people and damage to equipment at the workplace (10). The role of communication with the safety department has also been studied. According to past research, the relationship between managers and the workforce has an important role in increasing employee safety and health, based on which the quality of the working relationships affects the incidence of unsafe behaviors and occupational accidents (11).
Incident surveys in most countries show that the incident dispersion rate is not uniform in people at risk, and that 75% of incidents occur to 25% of people at risk under equal conditions; thus, human factor can be considered as the most effective factor in the occurrence of occupational incidents (12,13). Although mortalities from occupational accidents have dropped significantly, the annual US Occupational Accident Report issues a record of 12,500 deaths and 2,200,000 disabling injuries per year (7). It is predicted that about 120 million job incidents and more than 200,000 deaths will occur annually due to job-related activities in the world (14,15).
In fact, data are very valuable for making decision on risks, thereby improving the environment, facilities, and hazardous conditions, planning for emergencies, determining the level of acceptable risks, relevant policies, inspection, and the maintenance of industrial installations, as well as other items (16). There are several methods, such as ET & BA, FTA, and SSHAfor identifying and assessing workplace hazards, among which Failure Modes and Effects Analysis (FMEA) is one of the valid techniques for identifying and assessing risks.
NASA first applied Failure Modes and Effects Analysis (FMEA) in 1963. This approach ultimately led to the automotive industry, which serves to identify and quantify potential defects in the design phase of products (17). FMEA has recently been used as a tool by automotive, aerospace, and electronics industries to identify, prioritize, and eliminate failure states, potential system problems, and pitfalls in the design phase and before releasing products to the market (18). Many industry-specific FMEA standards, such as those developed by the Association of Automobile Engineers, the Department of Defense, and the Automotive Industries Group, use the RPN number to measure the risk and severity of failures (19). FMEA usually examines the state-of-failure effects on a system’s reliability, and this limits the use of FMEA significantly. Pickard et al proposed a method for integrating multiple failure modes into a single unit, which allowed for the system to be analyzed under multiple failure scenarios at one time (20).
Road construction projects are among the major and strategic projects, and a lot of them are implemented in Iran. This research is conducted aimed at investigating risks, risk assessment methods, as well as the importance of financial costs and personnel damage caused by work-related accidents at a highway construction site in the southeast Iran using FMEA and by drawing safety contour maps by ArcGIS. Many studies have been done using FMEA, but no study has so far shown the range of safe points on the site map; however, this study considered the mentioned issue. Using the results of this research and through employing appropriate programs based on the root causes of accidents, the costs of accidents imposed directly or indirectly on the industries of Iran could be minimized.
 
Materials and Methods
This study was conducted to identify hazards and risk assessment methods at a highway construction site in the southeastern Iran using FMEA and by drawing safety contour maps with the help of ArcGIS in 2019. The mentioned site has an area of 10,000 square meters with 100 employees. This cross-sectional analytical study was conducted in 9 general steps, including 1. Reviewing demographic data, 2. Identifying human risks, 3. Identifying risk causes, 4. Identifying risk effects, 5. Determining the severity and occurrence of risks, 6. Rating risks, 7. Controlling risks, 8. Entering the coordinates and RPNs of occupations for each location in ArcGIS, and 9. Drawing safety contour maps using ArcGIS 10.2 (21,22).
Employees included in this study were working in the capacity and in the fields of sales, administrative-financial affairs, safety and health, water supply plants, asphalting, kitchens, flagging, logistics, facilities, repairs, welding, cutting, guarding, the technical department, crushing, asphalt rollers, soil rollers, finishers, asphalt plants, dumpers, water tankers, controllers, graders, loaders, light car drivers, implementers, managers, surveyors, and labs. Table 1 illustrates the overall worksheet of FMEA.

To identify the risks, causes, and effects of the jobs, we first started analyzing job tasks using the HTA method. This method was introduced by Annett (1971) and developed by other researchers. In this method, the studied occupation was considered as the ultimate goal, and to achieve the goal, the task was divided into the details necessary for doing the activity. In the next step, the occurrence of human errors was determined using the mentioned technique (23).

The higher RPNs need to be prioritized for a more comprehensive analysis and resource allocation. At this stage, the team suggests actions reducing the RPN. The RPN is calculated based on the three factors of severity, occurrence, and detection (Equation 1). These three factors are scored from 1 (best) to 10 (worst). in the end, the calculated risks are rated using the RPN.

Equation 1      RPN= S  O  D
S= Severity
O= Occurrence
D= Detection
 
Color and contour maps are the same as conventional graphical methods for the expression and assessment of work environments. These maps are utilized to identify various areas of the site based on the safety defined. To draw the maps, the site was first divided into chess areas of equal dimensions (5 5 m2). The center of each area was considered as the measurement station. After carrying out the measurements, the results were entered into the plant station and then into the file format (input data) into ArcGIS 10.2. In the next step, according to the three common areas already mentioned, the safety contour maps were drawn. In these maps, isolinesare aligned to each other. These lines, like topographic maps, show safety ranges (22). The risk of each project is different and depends on the management policies as well as theseverity of the failure; hence, we would have:
The safety area is of a (Low Risk) with RPN≤ 35 (in green), and the caution area is of a (Medium Risk) with 35 also of a (High Risk) with RPN>70 (in red). The results of this task were a colored and isoline map of the site. Next, the areas of safety, caution, and danger were identified. The most important area for controlling actions is related to the danger area.The fulfillment of the code of ethics for this study was approved by the Ethics Committee of Kerman University of Medical Sciences (IR.KMU.REC.1397.302). In addition, a written informed consent from was obtained from all participants.The mean, standard deviation, and percentage of information were also computed using SPSS Statistics V22.0. Furthermore, the safety contour maps were drawn using ArcGIS V10.2.
 
Results
Table 5 presents results from the statistical analysis of demographic data. The highest average age is 39 for the management, and the lowest average age is 26 for the health and safety unit. The highest work experience is for the asphalting unit with an average of 18 years, and the minimum work experience is for flaggers and the Health and Safety Department with an average of one year.

The average RPN for each unit is presented in Table 6. As demonstrated, the highest and lowest RPNs have been obtained for the light machinery and the laboratory unit, respectively.

The percentages of risk severity for the site units are shown in Figure 1. As demonstrated, 62.97% of the units are of medium risks, and the rest (37.03%) are of low risks.
 

Figure 1: Percentages of risk severity for the site units
 

Figure 2 shows safety and caution areas on the color map of the site. As one can see, although the number of safe units is low, most of the points on the map are green and only few of them are yellow, because the software considers the space between the units to be safe as well.

 

Figure 2: Safety Contour Map of the site