Lightning hazard
Md. Arafat Rahman :
The upper part of the atmosphere is cooler than the lower part. Because of this, it is often seen that clouds flow from the bottom to the top. Such clouds are called thunder clouds. Like other clouds, this cloud also contains small water droplets. When the water content exceeds 5 mm, the water molecules can no longer bond to each other. Then they separated. As a result, there created an electric charge. And the value is higher than the lower part. Such potential difference results in emission of electric charge from top to bottom. At this time we see flashes of light or lightning.
Lightning should not to be taken lightly. Extreme precautions should be taken to protect against lightning. The safest thing to do during a lightning strike is to take shelter under a building or covered structure. One should never go out of the house during frequent lightning. Never be outside or in the open during lightning. Lightning is most likely to occur in open and high places. Therefore, if such a situation occurs, move away from open or high places and take shelter in a safe place.
Always stay away from power lines and tall trees to be safe. The probability of lightning is highest in these places. Especially if there are trees in a large open area, there is a high chance of lightning. So you should not take shelter in these places at all. Do not get out of your car when a lightning storm starts. Because tires used on car wheels are non-conductors, i.e. they do not transport electricity. But if there is a concrete shelter nearby then it is better to take shelter there instead of in the car. Avoid being in a car during frequent thunderstorms. It is better to sit with your feet on the seat. Care must be taken that the body does not touch the body of the vehicle or any metal. Do not touch the glass of the car.
Keep windows well closed and stay far away from windows. Avoid touching any metal object anywhere. Avoid touching stair railings, metal faucets, metal pipes etc. during lightning and storms. TV cable, land line telephone etc. cannot be touched. Touching them during lightning is likely to cause injury.
Special precautions should be taken with electrical appliances. It is best to keep these appliances unplugged during lightning. If there is a threat of storm and lightning, these appliances should be unplugged. If various appliances including refrigerator, TV, computer are electrically connected, there is a high possibility of damage due to lightning and it is likely to cause a major accident. Again, even if the electrical equipment is turned off, it cannot be touched by hand.
Being in water during a lightning strike is extremely dangerous as water is a very good conductor of electricity. If you are swimming in a small pond or in a watery place during a thunderstorm, you should get out of it.
Thunderstorms are loud enough to damage hearing. So, while it may sound strange to many, it will protect you. If you are in the roof of the house, you should quickly get down from there. If you have to stay in an open place, you should sit down. Many people have mud houses in the village. While staying in such a room, one should sit up on the bed instead of directly on the ground. If for any reason you have to stand on the ground, then rubber shoes should be worn. There is a possibility of lightning if wearing leather shoes or bare feet. At this time, non-conductive rubber shoes are the safest. Home should be protected against lightning. Proper earthing connection should be done with the advice of engineer. Improper handling can increase the chance of lightning strikes.
Most people die from lightning strikes. But some are injured. If someone is injured, they should be treated as like as injured by electric shock. But it is best to call a doctor quickly and get treatment. If necessary, take to the hospital.
(The writer is Asst. Officer, Career & Professional Development Services Department, Southeast University).
