The Centre for Innovation in Science and Social Action (CISSA) in Thiruvananthapuram has called for an immediate need to create awareness among the public on lightning and on the casualties that occur owing to the natural hazard. The recent spate of lightning has resulted in the death of at least 22 people across the state, it added.
The organisation pointed out that recently-reported lightning incidents in the state bring to focus the depth of lack in awareness as well as ignorance about lightning and protection. “Though many agencies are operating in the state to support affected people against natural calamities, none of the programmes of these agencies are effective in reducing the depth of the incident. In this context lightning needs to be classified as a natural calamity and offering financial support to the affected families should be considered,” said Dr C Suresh Kumar, general secretary, CISSA.
The state looks up to the government to take immediate steps to create mass awareness among the public. Most of the casualties could have been avoided if the public had been given proper education in lightning protection, he added.
The organisation said step voltage (touch voltage) has been found as a major reason for the rise in casualties. During a lightning strike (either on a nearby tree or on a building) the current of the lightning reaches ground and it flows to several hundreds of metres through the ground depending upon the strength of lightning current as well as soil conductivity. This current flow creates voltage gradient and can give rise to a high voltage difference between the legs of a person standing or walking on ground. A current flow through the body owing to step voltage can injure human beings.
Safety rules listed down by CISSA to minimise the effects of lightning:
The first is the 30-30 rule, which says that if the time gap between lightning and its thunder is less than 30 seconds, then one should immediately seek shelter inside a building. Less than 30-second gap means the thunderstorm occurred somewhere very nearby and hence it is dangerous to remain outside.
Taking shelter inside rooms of buildings is the best way to escape the lightning. Once inside, stay away from any conducting path to the outside. Avoid using electronic appliances, lighting and electric sockets. Telephone use should also be avoided completely, as it has turned out to be the leading cause of indoor lightning injuries. Do not forget to disconnect televisions and radios from the external antennas.
If one finds oneself standing outside, never seek shelter under large trees. This is one of the major causes of lightning casualties. Along with tall trees, elevated locations, mountains and partially-enclosed buildings should also be avoided.
In case someone is struck by lightning, appropriate medical attention should be ensured immediately. Deaths can be prevented if the victims are properly attended to. First of all, check the pulse and breathing of the victim. Administer cardio-pulmonary resuscitation (CPR) measures, if necessary. Monitor the victim closely till professional help arrives.
Suitable Surge Protection Devices (SPDs) installed on power and signal lines can safeguard the electronic equipment from damage and failures. The traditional protective devices like fuse and circuit breakers in electrical distribution of the building do not prevent surges from entering the equipment as their response time is far slower than the fast transient surges.
The external lightning protection installed in buildings properly will protect the structure from a direct lightning strike as well as flow of lightning current over the structure. External lightning protection system will not protect electrical/electronic equipments inside a building during a lightning strike.