In a manhole with low oxygen levels, a person falling in can lose brain function
If you fall into a manhole, there is a risk of suffocation due to oxygen deficiency. The manhole cover cannot block rainwater. Rainwater seeping through the edges of the cover pools at the bottom of the manhole, and microorganisms in the rainwater breathe, drawing in the oxygen inside the manhole. Additionally, metal structures such as the inner walls of the manhole, valves, and water pipes rust when in contact with water, absorbing oxygen from the air. In this state, if a person falls into the manhole and inhales the low-oxygen air, brain function is lost and muscle spasms occur. Oxygen binds with hemoglobin in the blood and is transported through capillaries to cells throughout the body. However, when oxygen levels are low, the body reduces the allocation of oxygen to muscle cells in order to send more oxygen to the brain and heart, which are vital for survival. Therefore, if you fall into a manhole, call 119 for help if you are in a place where you can use a phone, and if not, ask pedestrians for assistance. This is because manholes are deep and difficult to escape from on your own.
Walking to avoid manhole covers when it rains
Manhole covers are very heavy and strong, weighing about 40kg, but if rainwater backflows, the cover can be ejected, causing significant damage. In particular, when the manhole rattles, water is spilling around, or bubbles are rising, backflow has begun. Therefore, you should immediately avoid that area. During rain, the best course of action is to avoid walking near manholes. It is also advisable not to go out during heavy rain or typhoons. If you must go out, you must follow the proper safety procedures. Pedestrians should familiarize themselves with the locations of manholes on their usual routes in advance and avoid areas with manholes on rainy days. Although it varies depending on the design, manholes are usually located around sidewalks. Additionally, when the manhole is submerged and difficult to check, you should walk around the submerged area if possible. For vehicles, manholes are not usually located in the center of the road but are often on the shoulder, so it is best to avoid the shoulder when driving or parking.
Even if the rain stops, there is a risk of electric shock. Avoid manholes and streetlights.
Even after the rain has stopped, avoid walking over manholes. There is still moisture remaining, which poses a risk of electrocution or other dangers. It's not just about manholes. If you find utility poles or streetlights that have been neglected due to heavy rain, do not approach them and immediately report to 119. If an electrocution accident occurs on the scene, do not touch the victim directly with your hands.
