Carbon Monoxide: An Unseen Danger of BoatingJun 17, 2014
Boats emit extremely high concentrations of carbon monoxide, which can lead to passing out and potentially drowning. Dr. Tom Martin, medical director at the Utah Poison Control Center, discusses the signs of carbon monoxide poisoning and what to do if you or someone else starts to exhibit those signs. He also talks about some of the most important things to remember to stay safe while boating.
Interviewer: We often thing of carbon monoxide poisoning as taking place mostly in the wintertime, but it happens in the summer, too. That's next on The Scope.
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Interviewer: I'm here with Dr. Tom Martin. He's the medical director at the Utah Poison and Control Center. Dr. Martin, when I think about carbon monoxide poison, I think of this happening in the wintertime.
And this year, we had a few fairly high profile cases. There was a family in Pocatello, Idaho, who died as a result of a water heater venting malfunction. There was a father and son camping at Flaming Gorge in their ice hut who died as a result of carbon monoxide from their propane heater, and early in May, there was a case where two stepbrothers in Richfield passed away from carbon monoxide when they had a generator running to heat the home that they were staying in.
But I understand that this also happens in the summertime, and it's often around boating. What can you tell me about that?
Dr. Tom Martin: That's true. Well, there are a number of scenarios or situations where people can get severely poisoned in their boats or on their boats, around their boats, or around their watercraft from high levels of carbon monoxide. It can be anywhere from just causing some headache, and weakness, and dizziness to passing out or having a seizure, and drowning.
Interviewer: Wow, so why is it that boats are so dangerous? I mow my lawn and I breathe in the exhaust from my lawn mower that I'm walking behind. Why boats?
Dr. Tom Martin: Well, one difference between a boat and your lawn mower is the amount of exhaust gas and carbon monoxide produced. So it's much larger for a boat or water craft than a lawn mower. Secondly, in many situations, the boat is not moving. That causes the biggest problems. But sometimes the boats can be moving, and you can still see a fatality occurring. And the one reason that we see so much more carbon monoxide poisoning around boats as opposed to cars is that boats don't have catalytic converter.
Interviewer: And the catalytic converter, tell me what that does to mitigate the carbon monoxide?
Dr. Tom Martin: So it turns carbon monoxide into carbon dioxide, and water, and water vapors and so it detoxifies the carbon monoxide before it releases it.
Interviewer: And when you boats don't have these, obviously, you've got a higher concentration monoxide, and so it's a lot easier to get poisoned by this. Especially if you're behind the boat, would you say that that's the most dangerous place to be?
Dr. Tom Martin: Well, there are a number of scenarios. So houseboats are notorious for having the exhaust from their gasoline electric generator vent under the dive platform behind the house. And so the most dangerous part of the houseboat that's built that way hasn't been properly modified or recalled is the dive platform.
And the most dangerous part around the dive platform is actually under the dive platform. So that if the houseboat has had some skiers, the ski rope gets caught up around the propeller or the outboard engine, and someone dives under the dive platform while the air conditioning is running and the electric generator is running, there can be extremely high concentrations of carbon monoxide and low concentrations of oxygen and some other asphyxiant gases in that dive compartment, that air compartment under the dive platform, so that there have been cases where people have surfaced in taking about two or three breaths and passed out and drowned, because it was such a very dangerous or nauseous environment under there.
Interviewer: Under the dive platform?
Dr. Tom Martin: Under the dive platform.
Dr. Tom Martin: And even sitting on a dive platform where the electric generator has been running for a while, and the gasoline powered generator has been running for a while, the whole area under the dive platform but around the dive platform gets permeated with carbon dioxide, and people have been reported later to have passed out and drowned from carbon monoxide poisoning while they were just sitting on the dive platform. And certainly children playing or swimming around a dive platform has also drowned, and there's even one report of three women swimming around the back of a houseboat and two of them drowning from carbon monoxide poisoning.
Interviewer: Wow. I mean you're outside in a boat and so they might be some wind, the boat is kind of bobbing up and down, and if you're stationery, why is it that carbon monoxide is staying right around there?
Dr. Tom Martin: Well, under the dive platform, that's sort of a confined space and the wind would not affect that. But above the dive platform, if it was a windy day, that would be safer and that's one reason why we don't see this as often as we might expect, because if there is a good wind, it's going to blow it away from the surface areas.
You know one thing that is interesting about houseboats is that many a houseboat owner has taken the battery out of their carbon monoxide detector because they thought it was malfunctioning, because it kept going off. It wasn't malfunctioning; it was working perfectly correctly and appropriately.
Interviewer: It was alerting them to the danger of carbon monoxide.
Dr. Tom Martin: It was alerting them but they didn't realize. Well, they thought that their engine was not running, how can I have any carbon monoxide here? And it was actually the gasoline powered generator that was producing the carbon monoxide and causing the detector to go off. So they thought it was malfunctioning, they would inactivate them.
Interviewer: So do not remove the battery from your carbon monoxide detector on your boat in other words.
Dr. Tom Martin: That's exactly right.
Interviewer: Wow. What are some other scenarios that people might get into where they're putting themselves in danger of carbon monoxide poisoning around boats?
Dr. Tom Martin: So one common phenomena or behavior is to tie boats together sometimes with the engine running so you can keep your stereos going and that's very dangerous, especially if it's not very windy, because the carbon monoxide fumes from multiple boats can just sort of accumulate around the boats and become poisoned from this.
Body surfing of the back of a boat, so what that is is some individuals will grab onto a railing at the very back of the boat, and while the boat goes at a relatively slow pace, they'll body surf on the water, but unfortunately the exhaust port from the engine of the boat comes out very close to where they're holding on so they're almost inhaling pure exhaust fumes without realizing it, and it doesn't take long for them to pass out sometimes, seize, and drown from those scenarios.
Interviewer: So what about jet skis and small water craft?
Dr. Tom Martin: Yeah, so water craft vehicles have the same risk. If they don't have the catalytic converter, they produce a lot of carbon monoxide and so swimming around and idling in a water craft like that is very dangerous. If it's moving, it's not so dangerous to the person there, but if you were, say, tied to a raft behind one, and then you would be sucking in their exhaust or breathing in their exhaust the whole time you were being pulled, and you could be poisoned.
And what's subtle about this is sometimes they'll just pass out, or they may feel like they have nausea and maybe they feel like they have a stomach virus and not realize that they've been poisoned by carbon monoxide.
Interviewer: What should a person do that gets to feeling light headed and they've been swimming behind the boat? What do you do?
Dr. Tom Martin: Well, first of all, you want to get away from the source of carbon monoxide. And secondly, if the symptoms go away within minutes from being away from it, then probably you're going to be okay, but if the symptoms persist or if they're more severe, then you should seek an evaluation, usually in the emergency department where we can do carbon monoxide blood levels, they're called carboxyhemoglobin levels and that gives us some idea of how severe the exposure has been, and we can check them for other effects of the poisoning.
Interviewer: Well, it seems like it's not that severe of an exposure. Is it enough to just shut the engine of the boat off and breathe some fresh air for a while?
Dr. Tom Martin: Certainly if it's very mild systems. If it's a little bit of light headedness or headache, I would say yes, turn off the engine. Turn off all sources of carbon monoxide, rest, give yourself about five minutes and see how you do.
Interviewer: Is carbon monoxide does it build up in your body? So if you are feeling a little light headed, so you stop the motor, you get some fresh air for a while, but then you go about your boating day. Does the carbon monoxide that enters your blood stream during that first exposure, does it remain there and become cumulative throughout the day?
Dr. Tom Martin: Well, it can if you continue to be exposure to that. So generally once the exposure stops, the levels in your body stops rising, but they fall off very slowly. The time for the levels to drop by 50 percent is about 4 hours of just breathing regular air. We can make that much shorter by putting people on oxygen. And even shorter yet, sometimes we have to use hyperbaric oxygen and that gets it out of the body much more quicker.
Interviewer: Now we hear a lot of reports about this every year. It seems like at Bear Lake and at Lake Powell especially, is it something about those two locations that makes it particularly dangerous, or is it people not being safe around their boats, and we just happen to hear about it because we're in Utah?
Dr. Tom Martin: Well, I think boats, where there might not be that much wind and there's a lot of heat where there is a high need for air conditioning, I think that the air conditioning need is really a particular important cause of monoxide poisoning, and that's probably the main factor is that the high ambient temperature, I'm not sure what the wind levels out there are like, but the high temperature requiring make me want to use your air conditioning is very dangerous.
Interviewer: It sounds like that'd be particularly at Lake Powell, especially if you get back up into one of those side canyons or something where the air might not be quite moving as much.
Dr. Tom Martin: That's right but still very hot. Let me just add that houseboats, so this has now been recognized since about 2000, and it's been recommended that some houseboats be recalled and so a number of houseboats that weren't built properly were recalled, and they were expected to put in the modification where the exhaust was taken up a vertical stack and released much higher above the boat and that made the dive platform area much safer. But not everybody has had that modification done to their houseboat, so we're seeing less than we used to but that's just the houseboat risk.
Then the other risk of a regular inboard outboard engine or a watercraft that has a vertical exhaust don't apply to them so much.
Interviewer: Now some people might not know that Utah actually has a state rule. It's called a state rule although it has the same effect as law about boating and it's geared towards preventing carbon monoxide poisoning. What can you tell us about that state rule?
Dr. Tom Martin: So that is state rule 65224 and it specifically prohibits a person from operating a boat or running the engine while idle while someone is either standing on the swim platform, or around the swim platform, or using a ladder on the motorboat, and also it prohibits people from being towed by boats in a non-standing position within 20 feet of the back of the boat.
Interviewer: So that sounds like that body surfing that you were telling me about.
Dr. Tom Martin: Exactly, or being pulled on an inner tube with a short rope. That would put you also very close to the exhaust of the boat.
Interviewer: You want to have a nice long rope.
Dr. Tom Martin: A nice long rope.
Interviewer: Okay, and final thoughts on this Dr. Martin?
Dr. Tom Martin: Any time you might think you might be exposed to carbon monoxide, feel free to call the poison center. We'll be glad to go over your symptoms with you and how you think you were exposed and give you some advice as to whether you can stay put and just continue to have no exposure or whether you should be evaluated.
Carbon monoxide primarily affects the heart and the brain and so it can make you feel dizzy or weak and pass out. And in fact in older people it can cause some heart damage. It actually binds to the heart tissue and perhaps decreases blood flow and can cause heart damage.
So it does have some very serious consequences, and our poison information specialists are trained to look for those signs and symptoms and treat accordingly.
Interviewer: Now if you're out boating on a lake and you might not have access to a phone, you might not be able to call a control center. Can you just go back to shore?
Dr. Tom Martin: Generally, I think what people do when they think they're having symptoms, and many times they don't realize it's carbon monoxide, but they're just not feeling well. So they'll come into the doc, because they're not feeling well, and they think it's motion sickness, a headache and nausea, but it doesn't get any better. So at that point, especially if they're looking pale, or they've past out, or they've had a seizure, or they're really confused, they'll call 9-1-1 and have a medic unit respond to them. And many times the medics can be tuned into this.
Interviewer: So we'll just remind everyone that carbon monoxide poisonings are almost always preventable. So just take precautions when you're out there on your boats this summer. Don't run your boat in idle. Be careful around the back of the boat and keep yourselves safe this summer.
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