Lightning: ‘cultured man’ harms environment

Miran PERERA

If we need to lead a normal and healthy life there are a few important subjects we need to focus on. First is our health and protection. A clean, natural environment is essential for human life because food production depends on it, and our health is directly connected to pollution. The future of Sri Lanka depends on the children, who ought to be brought up with morals, social ethics, and most importantly discipline.

Environmental reporting is still a relatively new concept not only in Sri Lanka but worldwide. There is little consensus as yet regarding what should be included in such accounts. When we talk about the environment we think of pollution and other matters related to it; but there is always lightning which creates changes in the environment as well as causes human death. During the past few months we heard and read reports of many deaths due to lightning. Lightning is a natural atmospheric phenomenon caused by the instability of charge distribution within a cloud. It also occurs due to charge separation in masses of ash and dust ejected in a volcanic eruption or a nuclear explosion. The impact of lighting on the environment is enormous as it could cause death to living beings.

Generally a lightning flash originates inside a cloud several kilometres above ground level. Except for ball lightning which is a very rare phenomenon, lightning is simply an electric spark between a cloud and the ground; between two clouds or two parts of a cloud. In the first stage of the lightning strike a channel of charge flows towards ground from the cloud. When this channel is about 50-100 metres above earthbound objects in the vicinity such as trees, buildings, human beings, animals etc. start sending upward channels of opposite charges to meet the downward channel from the cloud. When an upward channel succeeds in meeting the downward channel and subsequently large current flows through the object, the object is said to be lightning struck. The lightning current is a short term transient lasting about 100 m/s. However in a single lightning flash such electric current may flow several times into the ground.

Telecommunication towers

All Sri Lankans should thank the Environment and Natural Resources Ministry and the authorities concerned for introducing four new taxes on Telecommunication Towers, mobile phones, CFL bulbs and vehicles. This is a commendable and timely act. Usually taxes are a burden to the public but without the environment human life will not last. The people should demand to double the four taxes because all four taxes especially the tax on telecommunication towers will be a big relief for the poor masses. The taxes on telecommunication towers and mobile phones are very appropriate and timely. We cannot live without mobile phones and the telecommunication towers which enable to transmit signals. But we have to take stern action when people are affected. Action should be taken to prevent future disasters. There was the instance when many houses were destroyed and people injured due to lightning that struck a nearby poorly earthed telecommunication tower in the premises of a temple. There are several other similar incidents reported from all over the country, that go unnoticed. Therefore the Rs. 50,000 tax on telecommunication towers is necessary.

Non technical views on Telecom towers also are pointed out frequently. There is one group, the environment lovers who declare their objections to the erection of Telecom towers because the towers spoil the beauty of the environment. This is a valid argument, but too late an argument because man has been spoiling the environment since he began to change natural living practices.

Lightning could have a very vicious impact on the environment. The lightning inception and propagation, the self ionizing stepped leader initiated at cloud level propagates towards the earth at an average speed of about 100,000 m/s. When it is about 50m-100m above ground level earth bound objects send oppositely charged streamers to meet the stepped leader. One of them becomes successful in meeting the stepped leader before the others so that a large current will flow through the object that sent the successful oppositely charged streamer. Then that object, perhaps a coconut tree is said to be lightning struck.

When the lightning current flows along the tree a large potential develops along the tree so that in respect to the base of the tree the potential towards the top of the tree will be very large. Similarly, the potential decreases away from the point at which the current enters the ground base of the tree. When a person is standing in such a way that his feet are apart along the potential gradient, a potential difference develops between the two feet. As a result a current will flow through the body of the person which may injure or even kill the person.

The natural man never harmed the environment for his living. But the ‘cultured man’ has already done significant harm to the environment. Raping the environment has accelerated with the invention of technology in areas such as transport, construction, power generation, food production and agriculture. Man has extended his area of activity to all sorts of topography including mountains, forests and deserts. Buildings and other structures have come up even on top of hills. Millions of high tension transmission lines run over all parts of the island. Millions of high tension transmission towers have been erected spoiling the beautiful environment and prone to lightning. Big hotels, factories and buildings have already covered many hill tops which were at one time green caps.

Awareness of lightning hazards

Among the millions of structures which have raped the environment the harm done by a few hundreds of com.towers do not seem significant. A person struck by lightning does not carry any current or charge and should be attended to immediately and given first aid. Almost 90 percent of lightning related deaths could have been avoided if the deceased had been attended to promptly. The vast majority of lightning casualties can be easily, quickly and cheaply avoided if proper measures are followed. The general public needs increased awareness of lightning hazards and knowledge of lightning safety, including procedures of first aid.

Com.towers though serving the nation by relaying important messages, if poorly built and not up to proper specifications would be prone to lightning. What is the awareness of the environmentalist or environment lovers about the big hotels, factories, housing schemes etc. built on top of hills and other environments that would be otherwise beautiful? Once a tower is built it affects the visual beauty of the environment, but with time it will become part of the environment. With lightning there could be torrential rains, floods, cyclonic winds and devastation to the environment. To be injured or temporarily disabled one need not essentially be struck by lightning, even if one is close to the point of strike he may receive lethal injuries to which the victim may succumb.