Tuesday, May 5, 2009

Lightning strikes

Thunderstorm in Phnom Penh
Lightning is a major concern in Cambodia. Already this year, 50 people have died as a result of being struck by lightning and we are only four months into the year. 10 people died this weekend alone. And with the monsoon rains coming early this season, Phnom Penh has been subjected to lightning on most days for the last couple of weeks. It's a real concern. Last year 95 people were killed by lightning in Cambodia. By comparison, 3 people die on average due to lightning strikes in Britain. Education is a key factor in reducing deaths in a country where lots of people work out in the open. Here are a few simple precautions to take during a thunderstorm:
  • Avoid wide, open spaces or exposed hilltops and don't shelter beneath tall or isolated trees. Seek shelter inside a large building or a motor vehicle. Check and take heed of weather forecasts of thunderstorms when planning a day outdoors.
  • If you are swimming or on a body of water, get to the shore as quickly as possible. Move away from wide, open beaches and seek shelter inside a large building or motor vehicle.
  • If caught out in the open during a thunderstorm, discontinue carrying umbrellas, fishing rods, golf clubs and other large metal objects. Keep away from metal objects such as motorcycles, tuk-tuks, bicycles, wire fences and rails.
  • If your hair stands on end or nearby objects begin to buzz, move quickly away as lightning may be about to strike. These effects happen because the positive electrical charges forming at the ground are streaming upwards to try to make contact with the advancing downward negatively-charged 'leader'. Lightning does not always follow, as not all of the upward discharges make contact with the leader, but it is best to move away as a precaution. Seek shelter in a large building or motor vehicle.
  • If caught out in the open with no shelter nearby, move to a place of lower elevation such as a hollow or dry ditch. Crouch down (to lower your height) with both feet close together. Do not place your feet wide apart or lie flat on the ground as this will increase the difference in voltage across your body, increasing the electrical charge you may receive from radial ground currents, if lightning strikes the ground nearby. Tuck your head in and place your hands on your knees.
  • If inside a motor vehicle stay there during the thunderstorm. It will protect you as long as you do not touch the metal of the car body. A lightning strike will normally be safely conducted over the metal bodywork of the vehicle before earthing to the ground over the wet tyres.
  • When indoors, keep away from windows, avoid touching metal pipes or radiators. If lightning strikes a television aerial, the cable may conduct the current into the building where it can jump to other wiring or metal piping circuits. Do not use a telephone except in an emergency.
  • Finally, give first-aid (and get professional medical attention immediately) to anyone struck by lightning to help them recover. You will not receive an electrical shock as they carry no electrical charge. Act promptly.

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9 Comments:

Anonymous Anonymous said...

Hi andy,
thanks for sharing this important news about thunderstorm killed many people. Did you talked to scientist about this problem? what is the main reason for this problem?

why in the past there are a little thunderstorm? Why last year and this year, it has alot of thunderstom?

What about mobile phone tower? There are alot of mobile phone operation company in cambodia, they installed thousand of mobile phone tower everywhere across country. Do you think mobile phone tower make thunderstorm?
Other problem, i heard from one of my friend in bangkok, he said, to construct building or apartment or mobile phone tower...etc we have to put some metal underground to prevent thunderstorm. Is there any technical team in cambodia to look this problem?

sorry, it sounds many question. Just share my idea with you.

regards,
Nimol

May 5, 2009 at 1:42 PM  
Blogger Andy Brouwer said...

Hi Nimol,
you make very valid points but I don't have any answers. I am just concerned at the frequency of deaths caused by these thunderstorms in Cambodia as I had never heard of so many people being killed before. I know that more people were killed by lightning last year in Cambodia than the whole of USA. And then try to imagine the size of Cambodia compared to the size of USA.
I appreciate some of the obvious reasons that more people work in the open, in farming, etc than in many other countries. But for the reasons why so many life-threatening thunderstorms are in Cambodia, I don't know the answer.
I also don't know the death rate compared yo our neighbours like Laos and Vietnam. I know Vietnam suffers every year from many storms and this causes large losses of life as well. Maybe it has always been the case but never before widely reported. I simply don't know.
But it is worthwhile reading the suggestions just in case you get caught in a thunderstorm, and so you will remember what to do.
Andy

May 5, 2009 at 4:34 PM  
Anonymous Anonymous said...

Mobile phone towers don't make thunder storm. The metal thing in underground you mentioned is a decoy for if lightning strikes, the unit won't be destroyed because the lightning energy would travel through the decoy instead of the unit.

Why thunder storms and lightning increase? My educated guess is that the world's climate has been changing and maybe why Cambodia saw so many natural disaster death is just a pure mother nature's work.

Also, remember! In Cambodia, people get outside to play in the rain or at least me when I was young but in the country like the US, where I am at, people run away from rain.

May 5, 2009 at 9:43 PM  
Anonymous Anonymous said...

Andy, thanks very much for the great advice on lightning safety. I agree with you that education about how to stay safe is priceless for everyone. A lot of Khmer people need this advice as well. That said, most Khmer people who grew up in Cambodia for all their lives are very cautious not to wander outside during a thunderstorm or any type of big tropical storm. In fact, most local people are overly cautious; however, a few are the adventurous types as well. Andy, in Great Britain, how did they prevent death from lightning strike? Is there a way i.e. installing lightning rod, etc., to prevent death from lightning strike in a tropical country like Cambodia? Maybe someone from the West can help educate or help Cambodia to reduce such death by installing some kind of modern equipment to absorb the electrical charges during the thunderstorm in Cambodia? God Bless.

May 6, 2009 at 1:20 AM  
Anonymous Cameron Macauley said...

Hi Andy,

Perhaps you can shed some light on this topic: Khmer customs forbid anyone to touch a person who has been struck by lightning, is it true? When I worked on the Thai border in 1984 I saw several cases of people who were struck and lay untended in the rain until they either died or recovered. Undoubtedly this contributes to increased mortality. Khmer beliefs regarding lightning are mysterious to me--I was never able to get a clear explanation of what they thought would happen if you touched a lightning victim. What do you know about this? Is there a religious belief behind this?

--Cameron Macauley cmacauley@aol.com

August 19, 2009 at 4:44 AM  
Blogger International Lightning Protection Association said...

Thanks Andy for your helpful post. As far as I know, lightning has killed 113 people in 2009 in Cambodia, making it the worst in recent years for deaths attributable to the natural phenomenon (93 in 2008, and 45 in 2007). It’s very good that Nimol brought up those questions because I find education about lightning and lightning protection is very important to decrease the number of deaths.
Here are my answers to his/her questions base on my knowledge about lightning:

1. Do you think mobile phone tower make thunderstorm?
Mobile phone tower does not create thunderstorm, and it is a totally natural phenomenon. There were some researches on possible “attraction” due to the radiations emitted by the mobile phone towers but it was clearly demonstrated that these radiation are unable to trigger any lightning discharge.
2. What makes thunderstorm?
Lightning is produced in thunderstorms when liquid and ice particles above the freezing level collide, and build up large electrical fields in the clouds. Once these electric fields become large enough, a giant "spark" occurs between them reducing the charge separation. The lightning spark can occur between clouds, between the cloud and air, or between the cloud and ground.
In Cloud to ground lightning, the discharge usually happens between the cloud and the highest spot from the ground surface. Mobile phone tower is most of the time higher than surrounding buildings; therefore, it is more likely to be struck by lightning.
3. We have to put some metal underground to prevent thunderstorm, is it true?
We cannot do anything to prevent thunderstorm/lightning strike but there are lightning protection systems to minimize damage to your assets/buildings. The more widely used in Cambodia is the Early Streamer Emission (ESE) lightning protection system. The ESE air-terminal will actively attract lightning strike on a specific capture point (the lightning rod) and safely conduct the current to the ground using copper conductors.
For more information and expert’s answers to any question, please visit International Lightning Protection Association’s website and Google group for lightning protection:
www.intlpa.org
http://groups.google.com/group/ilpa-international-lightning-protection-association?hl=en

May 25, 2010 at 3:16 PM  
Anonymous Ben said...

How to mitigate the lighting strike?

May 27, 2010 at 2:03 PM  
Anonymous ILPA said...

Dear Ben,

You can't decrease the intensity of the current but you can use lightning protection systems (LPS)to conduct it safely to the ground.
I know Cambodia is using an Early Streamer Emission air conductor to protect its world heritage the Angkor Wat and thousand of tourists everyday. This new technology allows large protection areas (buildings and surroundings, approx 100m protection radius)

If you have any more questions about lightning protection please post it on this Google Group, you will get answers from experts from the industry:

http://groups.google.com/group/ilpa-international-lightning-protection-association?hl=en

May 27, 2010 at 4:02 PM  
Anonymous vehicle check said...

We live in spain where there are some spectacular storms,good advice about staying in the car,must act like a faraday cage.these cages are often used to protect electrical equipment.

October 22, 2010 at 5:41 PM  

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