Learning to tackle lightning and thunderstorms
1. If you are caught outside and unable to reach a safe building or car:
* If your skin tingles or your hair stands on the end, a lightning strike may be about to happen. Crouch down on the balls of your feet with your feet close together. Keep your hands on your knees and lower your head. Get as low as possible without touching your hands or knees to the ground. DO NOT LIE DOWN!
* If you are in a boat and cannot get to shore, crouch down in the middle of the boat. Go below if possible.
* If you are on land, find a low spot away from trees, metal fences, pipes, tall or long objects.
* If you are in the woods, look for an area of shorter trees. Crouch down away from tree trunks.
2. Help victims
There is no danger to anyone helping a person who has been struck by lightning - no electric charge remains. So, lightning victims are safe to touch and need urgent medical attention. Get emergency medical help as soon as possible. Call 999. If more than one person is struck by lightning, treat persons who are unconscious first. They are at greatest risk of cardiac arrest.
* A person struck by lightning may appear dead, with no pulse or breath. Prompt, proper first aid could save their lives.
* If the person is unresponsive or not breathing, start cardiopulmonary resuscitation (CPR) immediately.
* Consider an Automatic External Defibrillator (AED), if one is available
Treat those who are injured but conscious next. Common injuries from being struck by lightning are burns, wounds and broken bones. Loss of hearing or eyesight and other nervous system damage may also occur.
b) Community or organisational level: In accordance with the weather forecast or any sign of approaching thunderstorms we have to make arrangements quickly to inform the people of that area about the imminent lightning. We should make our planning for any outside social gathering, meeting, festivals etc. keeping in mind the risks of lightning and thunderstorms.Children should be kept away from any kind of sports outside.Workers whose jobs involve working outdoors in open spaces, on or near tall objects, or near explosives or conductive materials (e.g. metal) have significant exposure to lightning risks. Worker activities at higher risk for lightning hazards include: Farming and field labour, Logging, Explosives handling or storage, Heavy equipment operation, Roofing, Construction works, Power utility field repair, Steel erection/telecommunications and Airport ground personnel operations. In USA the Occupational Safety and Health Administration (OSHA) and the National Oceanic and Atmospheric Administration (NOAA)provide safety guidelines for employers and workers at outdoor worksites. Bangladesh needs to develop lightning guidelines for outdoor events and lightning action plan for the potential striking period of March to June.
With the advancement of science and technologies many structural measures have been developed to save lives, properties and resources include the following:
a) Lightning detector sensor:It is a device that detects the presence of all forms of lightning including intra-cloud, cloud-to-cloud and cloud-to-ground. It can also warn of the risk of overhead lightning before the first discharge. It provides detection up to 300 miles away with directionality for tracking far off and close by storm movement.Lightning archive files are created automatically
and may be played back at a later date. Lightning strikes displayed within milliseconds
of detection. It is used for advanced storm tracking to determine path of storm. It provides customisable visual and audio alerts of heavy storm activity or nearby lightning strikes.
b) Lightning arrestor: A lightning arrestor is a device used on electric power systems and telecommunication systems to protect the insulation and conductors of the system from the damaging effects of lightning. When potentially dangerous lightning strikes, the arrester activates and diverts the lightning to the ground, where it will disperse harmlessly. The government has taken a step to install poles or lightning arresters in the fields across the country. Many electric poles can be turned into arresters easily. The government of Bangladesh is also focusing on ensuring the installation of lightning arresters in every house to reduce the risk of loss of life, damage and permanent failure of electrical/electronic equipment.
c) Surge arrester or surge absorber: It is used to protect the circuit or electrical equipment from high voltage transient or electrical surges. It protects the installation from inside while lightning arrester protects the equipment from outside. Surge arrester intercepts the surges and sends the extra unwanted energy to the ground, while lightning arrester diverts the energy flow to the ground wire. The surge absorber protects against the high voltage transient from lightning strikes as well as when the system voltage is high without lightning strike.
d) Lightning rod: It is used to capture the lightning charges and connect it with the ground.Lightning rods are installed on the highest point on the structure typically top floor on the building, top end of the transmission tower, top of the chimney etc. It protects the building, equipment etc. from direct lightning strikes. The lightning rods are made up of with the copperor conductor which laiddown from the top of the structure to bottom of the ground.
e) Concrete lightning shelters: The government is planning to build concrete lightning shelters in haors, baors, beels as farmers and fishermen are being the worst victims of the lightning strikes. Some shelters have already been built in Gangniupazila.
f) Plantation of Tall trees: Trees attract lightning because they provide a path for lightning to travel from the storm cloud to the earth.They do not prevent or reduce the risk of lightning striking a tree but they do control the path of the lightning after it hits.Electricity seeks the path of least resistance, and the moisture inside a tree is a much better conductor than air. Some studies have shown coconut trees attract lightning as the trees are tall and have moisture that acts as a conducting path for lightning.The govt. of Bangladesh has taken a plantation programme of millions of palm trees across the country (about 2.8 million palm kernels have already been planted).
g) Laser tractor beam technology: Recently it was developed by a team of researchers from Australian National University and University of New South Wales. It is capable of controlling the path and direction of lightning before it strikes. We need to intensify our research to improve the existing measures and devise appropriate technologies to harness and utilise the enormous power of this natural phenomenon for the benefit of mankind.
The writer is former editor, Journal of the Institution of Engineers, Bangladesh and writes from England