May the dead rest in peace and the living be safe.

In the field of occupational medicine, there is a saying: "If there is no risk, where is the harm?". This is not a great truth that a celebrity has said, but it precisely explains the concept ofSafety. In the practical application of workplace safety, occupational medicine specialists usually follow the following steps:

Risk identification and assessment → risk reduction and control → check effectiveness

【Risk Identification and Evaluation】

This is a very important beginning.When everyone feels that there is no risk, it does not mean that there is no risk, but that no one knows how to identify the risk. We must understand thatEverything is at risk, and the pursuit of zero risk is unrealistic. The focus is on how to identify risks, assess risks, and control them within a reasonable range.

For example, during the COVID-19 epidemic, we identified what kind of virus the pathogen is, and used scientific data to quantitatively evaluate the spreading risk factors of COVID-19: confined space and close contact. Furthermore, we set the standard of safe social distance the selection criteria of respiratory protection equipment.

【Risk reduction and control】

Immediately after the results of risk identification and quantitative assessment, improvements are needed to reduce the risk and control it. In fact, in the field of occupational safety, there is a so-called risk reduction pyramid (as shown in the figure below):

The pyramid above illustrates one important thing:Risk reduction measures are prioritized. In order to achieve the best safety protection effect, improvement measures should be implemented in the order of 【elimination → replacement → engineering control → administration control→ personal protective equipment】.

Take a chemical plant as an example. Some cleaning agents in the process contain tetrachloroethylene (there is sufficient evidence to show that this substance has serious health hazards). In order of priority, if the process can be improvedby no use of this cleaning agent (eliminate), orby replacement of new cleaning agents that do not contain tetrachloroethylene (replacement), then there is no need to worry about the exposure risk of tetrachloroethylene, because there will be no more exposure at all!

Only when the previous top-two measures are difficult to carry out, we will proceed to the middle and lower sections of the pyramid. Engineering control, usually representsthe process hardware adjustment, such as: installing local exhaust equipment in the area where the cleaning agent is used, to reduce the local concentration of tetrachloroethylene, and then reduce the exposure of personnel. Administrative control, usually representsthe work flow adjustment, such as: reducing the frequency of operating the cleaning agent, to reduce the exposure of personnel. Personal protective equipment, refers tothe supply of appropriate protective gear corresponding to the source of the hazard, such as: providing breathing masks which can efficiently protect personnel from exposure.

It can be seen from the above that the priority of improvement measures actually depends on the efficiency of risk reduction.

【Check effectiveness】

After the improvement measures are implemented, the results need to be reviewed regularly to ensure that they are actually implemented, and the effects of risk reduction and control are well-achieved. If the results are not good, we should go back to the initial "risk identification and evaluation" for a complete re-evaluation and adjustment.

If the aforementioned methods are applied to this Taiwan Railways accident, we will know that there are much more for us to do, to improve the railway traffic safety.

From the point of view ofRisk identification and assessment, part of the safety risk of the railway will come from the surrounding rockfalls and foreign objects intrusion (such as the engineering vehicle this time). The rockfall may be caused by loose soil, and the cause of foreign body intrusion may be from rocks on the near slopes, or the surrounding engineering materials which are not stably stacked, etc.

Then according to the evaluation results,Risk reduction and controlshould be implemented in accordance with the order of priority. Forelimination, we can consider water and soil conservation or build a protective layer, in order to control soil looseness to avoid rockfall. if we want to avoid foreign matter intrusion, we can consider laying complete ramps or setting isolated storage areas in the surrounding work area. In addition, automated monitoring systems, standardized operating procedures, or railroad guardrails, are measures belonging to the middle and lower sections of the safety pyramid. After making improvements, the Taiwan Railways needs to launchRegular safety checkups and evaluation of the effectiveness of the safety system, and makes adjustments according to the results.

From the perspective of occupational medicine, if the control of risks depends on whether the individual complies with safety regulations, rather than the overall workplace safety system, it is the most unsafe risk control method.

Finally, we want to say that, risk assessment and control exist in our lives all the time. Even the decision of whether we should take the MRT or drive by ourselves, is an example of risk assessment and control. Only when most people have the mindset of risk assessment and control, the real safety we hope to have can be truly achieved.