Iranian Journal of Ergonomics

Lack of attention to safety principles and sometimes unfamiliarity with mining equipment, methods and hazards leads to loss of health and life of thousands of people in surface and underground mines, loss of huge amounts of assets, irreparable damage to the environment and the credit of the mines (6).
The number of severe accidents reported in Iran's mines and mining industries in a 12-year period (2001-2002) was 10032 and the number of deaths was 197 (7). Although due to the lack of appropriate systems for recording and analyzing accidents, information about these accidents in many countries, especially in developing countries such as Iran, are not standardized, but the same amount of information provided can be used as a basis for safety activities in industrial environments (9). Lack of a comprehensive organizational system to create a safety culture among miners who are often illiterate and suffer from cultural poverty in safety behaviors, is one of the main causes of various occupational accidents in the mining sector and mining activities. These studies show that most accidents occur either directly as a result of unsafe workers 'behavior or due to environmental and organizational factors affecting workers' safety behaviors (13-10).
The aim of this study was to analyze occupational accidents in the mining sector based on the role of human factors and unsafe practices in the occurrence of these accidents and based on the Human Factors Analysis and Classification System.

 

This descriptive-analytical cross-sectional study was performed on occupational accident data over a 10-year period (2009-2018) in one of the major mines in Iran in 2019.
The statistical population of this study included 768 continuous accidents in the studied mine. Inclusion criteria for this study were presentation and availability of detailed incident reports. Accordingly, finally 664 eligible incidents were considered as a sample for this study.
Data collection tools in this study included a checklist and a detailed report of events during the ten years under study.
The technical analysis of the data in this study was based on the framework of the HFACS algorithm introduced by Wigman and Chapel (15). The study team consisted of 8 people (4 specialists in safety and 4 specialists in mining).
Safety performance in this study was evaluated using Accident Frequency Rate (14).

AFR= (Numbers of Registerd Accidents × 10⁵) / total Hrs of  Workers

Statistical analysis of the data of this study was performed based on the structural equation modeling approach and using SPSS 23 (SPSS Inc., Chicago, IL., USA). Goodness of fit in this study using general indices χ2 / df (2-3) and RMSEA (0.05-0.08) and adaptive indices CFI (0.95-0.1), NFI (0 / 1-95 / 0) and NNFI or TLI (0 / 1-95 / 0) were performed (16).
 

The results of 664 studied accidents that occurred over ten years showed that 712 people were injured during these accidents. The recurrence rate was 15.10 ± 3.34. The results related to the individual variables of the subjects are presented in Table 1.
The modeling results based on structural equation modeling showed that all layers of the HFACS model are known as causal layers and affect the frequency and recurrence of mine accidents (P<0.05). In addition, these results showed that the recurrence rate index is directly and indirectly affected by the causal layers of the HFACS model. The highest and lowest effects on the AFR index were related to the layer of unsafe actions (impact factor = 0.67) and organizational effects (impact factor = 0.32). The results of measuring the goodness-of-fit indices of structural equation modeling of the recurrence index also showed that the values ​​of χ2 / df, RMSEA, CFI and NNFI (TLI) indices were estimated to be 2.081, 0.034, 0.982 and 0.990, respectively. Therefore, based on these results and comparing it with the desired criteria, this model is an acceptable and good model.
 

Table 1. Descriptive results of the study of individual data section (712 people)                               

The results of the study showed that the recurrence rate index is directly and indirectly affected by causal layers in the HFACS model. In addition, these results showed that the greatest impact on the AFR index was related to the layer of unsafe actions due to its proximity and immediacy to the occurrence of accidents. According to the HFACS model, only the layer of unsafe actions has a direct effect on accidents and the other three layers have indirect effects. In this study, in addition to examining this specific hypothesis, another hypothesis that shows the direct effect of layers of organizational effects, the factor of supervision and monitoring, as well as the factor of unsafe preconditions was also tested. Therefore, the results showed that in addition to their indirect role in accidents, these crumbs also have direct effects on accidents. Also, the findings of this modeling indicated that the impact of indirect layers decreases as we move away from the layer of unsafe actions and leave their impact through indirect effects on events. This finding is in good agreement with the results of some studies (24). Unsafe practices are an important and integral component of occupational accidents that have been extensively studied by researchers. Unsafe acts with the highest share in occupational accidents and human error are one of the key causes of accidents in the mining sector (25). The results of some studies show that the worker or work team has a direct role in 70% of accidents due to various human errors and unsafe practices. Insecure individual behaviors can be influenced by other important factors such as causal layers of preconditions for unsafe practices, monitoring and supervision factors as well as organizational influences (18, 19, 26). When safe behavior is an important issue, more attention should be paid to the discussion of safety culture or atmosphere in any organization. In other words, issues such as safety attitudes, safety behaviors, atmosphere and safety culture are each, part of a complete chain that should be considered in a framework (28).

The findings of this study indicated that all four causal layers of human factors were effective in mine accidents. Since the HFACS model is highly effective for unsafe acts-based accidents analysis, it can be used for future planning to reduce accidents in the mining sector.
 

The authors are grateful to all those who assisted in the writing of this article.

 

The authors declared no conflict of interest.