I know that if lightning hits a phone pole while you are on the phone, you can get electrocuted, and that if lighting hits a water line while you are in the shower, you also can be electrocuted.
So, if you’re on the toilet during a thunderstorm, and lightning hits a sewer line, can it travel through the sewer and up your toilet and electrocute you?
No. Once the lightning has been conducted to ground it dissipates, and the sewer pipes are quite well grounded. The danger in a shower isn’t from the cold water pipes, which are grounded, but the hot water pipes in your house which are not.
Generally speaking, Q.E.D. is correct.
Two caveats though:
If you ever find yourself in a place between Location A, where the lightning is coming from, and Location B, where the lightning wants to go, yes you can be electrocuted. This could include sitting on a toilet.
Being electrocuted while sitting on a toilet is a distinct possibility, especially if you are in a port-a-potty, or someplace similar, outdoors out in the open.
I was strictly addressing the question in the OP. In fact, you can be struck by lightning almost anywhere. One of the safest places in a thunderstorm is in your car, but not because of the rubber tires. It’s because the metal body and frame of your car conducts the lighting around you, and it jumps to ground from a low point on the vehicle.
QED said that hot water pipes aren’t grounded. Why is this?
A couple of years ago a house not too far from where I live got hit by lightning with people inside it. No one was hurt, but a while later someone noticed a pool of yellowish liquid on the floor. Not having a dog or small children, they investigated further & found 4 or 5 beer cans in a case in a nearby cabinet had pinprick holes in them, from the lightning.
If you have any cite for these, I’d be interested. Phone lines are typically small gauge as they enter a house and there is often a fusible link, so electrocution should be unlikely. Fresh water is a poor conductor and pipes are usually grounded, which suggests that your risk while showering is minimal.
Strange. I just checked, and my hot water heater (made of metal) has a copper cold water pipe entering it and a copper hot water pipe leaving it. (Both hot & cold pipes change to plastic on their way to sinks & showers.)
And by the way, at lightning voltages, almost everything becomes at least partially conductive, even wood and yes, fresh water…
Yes, but normally the pipes are connected to the heater tank with threaded connections wrapped with either teflon tape (an excellent insulator) or a mineral-based pipe-joint compound as well as other internal components made from plastic, which effectively breaks the grounding.
From this article.
Thanks for the link, but it’s not very satisfying. It starts off by noting that annualy in the US, 1000 people are struck by lightning and 100 die. It then says "Lightning is a very dangerous force that, yes, can even reach you indoors if you’re in contact with the telephone or plumbing. "
Okay, but how many of those 100 were indoors? How many were in contact with phone or plumbing? No info given. We are left with an assertion that lightning is dangerous indoors, but no pertinent facts.
From CNN.com
It’s rare, but it happens.
I agree that teflon tape (my favorite) or liquid “pipe dope” is routinely used to make threaded connections waterproof. I disagree that this breaks the grounding – the sharp threads and high force pretty well guarantee some metal-to-metal contact. In any case, lightning voltages would make short work of the tiny distance between the two threaded fittings.
I agree that a hot water heater could be non-conducting (perhaps the tank is fiberglass), meaning that pipes that emerge might not be grounded. I remain skeptical that this adds up to a meaningful risk of being zapped while showering.
Depends on your definition of meaningful. Has it happened? Sure. Is the risk great enough to be overly concerned about. No. I’ve talked on the phone and taken showers during small thunderstorms with mostly cloud-to-cloud lightning, and I’ll likely continue to do so. I’d be more wary in strong storms with frequent cloud-to-ground strikes.
There’s certainly truth in this. After all, lightning comes through the air, which is not generally thought of as a good conductor.
But the OP seemed to clearly imply a particular electrocution danger from telephones and showers. This is what I’m a bit skeptical of. If you are saying that there is some danger anywhere in a house (though less than outside it), I’d say we’re in general agreement.
Yes, basically I’mn saying there’s a risk anywhere in your house. There may be a very slightly elevated risk in the shower than elsewhere, but probably not by a statistically significant amount.
I should note that I once was struck by lightning inside a building (well, sort of). I was working in a university computing center when a loud ZAP! was heard and a huge spark (say 8’ long) fried a bunch of equipment in the corner of the room. I got a shock to my right hand that left it slightly numb for a few minutes. No one else had anything other than a bad scare.
I would have to read this thread while there’s a thunderstorm outside.
Shocking.
Well, you knew someone was gonna say it.
I’ve no idea why Q.E.D. states that hot water pipes are not grounded unless he is referring to the relatively new practice of installing non-metallic pipes in homes (this is also the reason that you are no longer allowed by code to ground to water pipes). If that were the case, cold water pipes would also not be grounded. If the cold water pipes are grounded, then the hot water pipes will also be grounded as they are ‘electrically’ connected in many places in the home. Basically, any place where the hot and cold water pipes converge (i.e. the water heater or any faucet set) they will be electrically connected as each pipe will be connected to the same metallic body.
As to the the possibility of a lightning strike affecting you while you were on the toilet, i think that would fall into the category of ‘freak accident’; while not strictly impossible, certainly improbable. The majority of toilets are porcelain which is the same material that the majority of insulators on power lines are made of. The water level of the toilet is probably 6" or so below the lip so the electricity would either have to arc the six inches to your keister or track along the porcelain and you would probably need to be in contact with some sort of ground to pose any real threat.
The grounding of any ‘conductor’ can not guarantee that you will be protected. In a lightning strike to the earth, there will exist areas of different potential concentrically radiating from the strike point (referred to as ‘step potential’). If you happen to be relatively close to the strike point with your feet spread apart there could be enough of a difference in potential between your feet to cause severe shock. In a shower, it is possible to be in 2 different electrical potential ‘zones’; the drainage pipes may be at a different potential than the water pipes.
The reason that you are not electrocuted while in a vehicle is that there is no path through you to a different potential. This is referred to as being in an ‘equipotential zone’ and is the same reason that linemen sitting on helicopter platforms can work on energized transmission lines in excess of 750,000 volts.