Thursday, August 30, 2018

CARBON MONOXIDE, THE SILENT KILLER: Traveling with a boat at slow speeds or idling in the water can cause carbon monoxide to build up in a boat’s cabin, cockpit, bridge, and aft deck, or in an open area






Workplace Medical Mystery Solved: Water Patrol Deputy Gets Sick Out on the Lake



Posted on August 30, 2018 by Stephanie Stevens, MA



Jim worked as a water patrol deputy for the county sheriff’s office. While working a 10-hour shift in the hot sun over a busy holiday weekend he began to feel sick. It started with a headache while he was working in a channel where hundreds of boaters congregate for a floating party. He then became dizzy and started to slur his speech. Jim’s patrol partner rushed him to the shore where medics took him to the hospital. Read more about his case here.

At first it seemed Jim may be suffering from heat exhaustion, however, his slurred speech indicated something more severe. While his symptoms were consistent with heat exhaustion, emergency department staff also tested a sample of Jim’s blood for carboxyhemoglobin (COHb), a marker of carbon monoxide exposure, after learning that he had been on a boat for most of the day. Test results indicated Jim was suffering from carbon monoxide poisoning with a COHb concentration of 20%.

Carboxyhemoglobin is a substance made in your blood when hemoglobin, a part of red blood cells, binds with carbon monoxide instead of oxygen. Concentrations of COHb greater than 15% can be potentially toxic. Smoking tobacco increases the amount of CO in the blood so smokers are at greater risk of CO poisoning when exposed to another source of CO, such as potentially elevated CO levels in the channel that day, which may have been caused by excessive boat traffic. 

Photo by NIOSH

Jim was given 100% oxygen through a facemask placed over his nose and mouth and will make a full recovery.

Carbon monoxide is a colorless and odorless gas that can poison or kill someone who breathes too much of it. It is produced any time a fossil fuel is burned. Gasoline-powered engines on boats, including onboard generators, produce CO. Traveling at slow speeds or idling in the water can cause CO to build up in a boat’s cabin, cockpit, bridge, and aft deck, or in an open area. The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. High levels of CO inhalation can cause death. If near water, such as on a boat, CO poisoning can also cause a person to pass out and fall into the water and drown.

Some steps that could be taken to reduce the health hazard for the water patrol unit employees in this fictional account include: 


  • Determine what actions could be taken to reduce overall CO concentrations within an area where concentrations are found to be high, thus reducing the potential for employee over-exposure. Measures might include limiting the number of boats in certain areas or enforcing a “no idle” policy when boats are stationary.
  • Employees assigned to duty on boats should receive training about the health effects of CO, how to recognize symptoms of CO poisoning in themselves and co-workers and work-practices that can reduce exposure to vehicle and boat exhaust.
  • In areas where CO concentrations are determined to be elevated, until the CO concentrations can be reduced, employee assignments should be rotated periodically to areas where CO exposure does not occur.
  • An employee exposure monitoring program can be developed to determine patterns of overexposure for employees (i.e., are they overexposed only on warm-weather holiday weekends, or at other times or during certain job tasks) and to ensure that control measures such as assignment rotation, or reduction of CO concentrations within an area with excessive CO concentrations, are effective.
  • Employees should be encouraged to report symptoms of CO poisoning to designated health and safety personnel and should be provided with appropriate medical evaluation of symptoms.

Visit the NIOSH website for more information on how to prevent CO poisoning on boats.

Stephanie Stevens, MA, is a Health Communication Specialist in the NIOSH Office of the Director.



Workplace Medical Mysteries are fictional, however, they are loosely based on Health Hazard Evaluations (HHE) conducted by NIOSH or other reports by NIOSH and other sources, and any recommendations made herein were for the specific facility evaluated and may not be universally applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved. HHEs are publicly available at https://www2a.cdc.gov/hhe/search.asp, but the names of individuals and facilities mentioned in this series have been changed to protect their identities. For more information on the NIOSH HHE program, visit www.cdc.gov/niosh/hhe/.


Sources:

McCleery, R.E., Tapp, L., McCammon, J., Dunn, K.L. (2004); Health Hazard Evaluation Report 2002-0393-2928. Retrieved from: www.cdc.gov/niosh/hhe/reports/pdfs/2002-0393-2928.pdf.

Centers for Disease Control and Prevention. (2004, April 23). Carbon Monoxide Poisonings Resulting from Open Air Exposures to Operating Motorboats — Lake Havasu City, Arizona, 2003. Morbidity and Mortality Weekly Report. Retrieved from: www.cdc.gov/mmwr/preview/mmwrhtml/mm5315a3.htm

Centers for Disease Control and Prevention. (2017). Prevent Carbon Monoxide Poisoning on Your Boat.

Centers for Disease Control and Prevention. (2017). Carbon Monoxide Poisoning.

Mayo Clinic. (2018). Carbon monoxide poisoning. Quest Diagnostics. Carboxyhemoglobin, Blood.
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Being on a motor boat on Long Island Sound or a Connecticut’s lake, it’s hard to imagine people being exposed to carbon monoxide poisoning. 

But it’s a real danger says the state Department of Energy and Environmental Protection.
In fact, in the last two years 14 boaters have died and hundreds sickened, according to the U.S. Coast Guard. CO poisoning has been called the ‘silent killer” because the invisible gas is odorless and early symptoms are similar to being seasick.


And the growing popularity of wake surfing and other towed water sports - that keep the participants close to the exhaust ports of a boats - exposes them to even more danger.
On DEEP’s Boating in Connecticut’s Facebook page, it posted a photo of a boat cruising on the water.


“What’s wrong in this picture? If you have taken our Safe Boating class hopefully you’ll remember, nothing is ‘wrong’ in this picture. If you haven’t taken our class or need a refresher, look at the flag. Which way is it blowing? We use this picture to raise your awareness of a silent killer - Carbon monoxide.”

More Information

How to prevent CO poisoning on boats

Install and maintain a working CO detector listed by Underwriters' Laboratories as appropriate for marine use inside the boat to alert people when dangerous levels of CO have built up inside the boat cabin.

Properly install and maintain all fuel-burning engines and appliances.

Educate all passengers about the signs and symptoms of CO poisoning.

Swim and play away from areas where engines vent their exhaust.

Watch children closely when they play on rear swim decks or water platforms.

Never block exhaust outlets. Blocking outlets can cause CO to build up in the cabin and cockpit areas-even when hatches, windows, portholes, and doors are closed.

Dock, beach, or anchor at least 20 feet away from the nearest boat that is running a generator or engine. Exhaust from a nearby vessel can send CO into the cabin and cockpit of a boat.

The flag was blowing in the opposite direction. The same direction that fumes from the boat’s exhaust were going.

“Many times the early symptoms resemble seasickness - headache, dizziness, nausea, and vomiting. Carbon monoxide is a colorless, odorless, and tasteless gas and in severe case of COP victims can die without any signs,” DEEP says, “so those affected may not receive the medical attention they need.”

According to the Centers for Disease Control and Prevention, larger boats, such as houseboats, sometimes have generators that vent toward the rear of the boat. This venting poses a danger of CO poisoning to people on the rear swim deck or water platform. On larger boats CO builds up above the water near the water platform. CO that builds up in the air space beneath the stern deck or on and near the swim deck can kill someone in seconds, the CDC says.

“Traveling at slow speeds or idling in the water can cause CO to build up in a boat’s cabin, cockpit, bridge, and aft deck, or in an open area,” the CDC says. “Wind from the aft section of the boat can increase this buildup of CO. Back drafting can cause CO to build up inside the cabin, cockpit, and bridge when a boat is operated at a high bow angle, is improperly or heavily loaded, or has an opening that draws in exhaust.”

The U.S. Coast Guard says sources on a boat may include engines, gas generators, cooking ranges, and space and water heaters.

While many new boats come already come with CO detectors, owners of older boats need to install them.

Only Minnesota has a state law requiring any motorcoat with an “enclosed accomodation area” to have CO detectors. It was named “Sofia’s Law” after the death of 7-year-old Sophia Baechler, who died in 2015 after carbon monoxcide leaked from a hole in a boat’s exhaust pipe.

The New York Assembly passed a similar bill in June, but needs a signature from Gov. Andrew Cuomo to become law