In a four-day series of tests at Lake Havasu, AZ, conducted by federal experts, dozens of lake visitors, boaters and police and fire officers on duty at the lake were given breath tests over the Memorial Day weekend. An alarming 53% of the police and fire personnel had abnormally elevated levels of carbon monoxide in their blood streams, up to 5-10% above normal and a level high enough to cause symptoms of poisoning such as headaches or dizziness.

The tests were performed at the request of the Arizona Dept. of Health as well as the Lake Havasu City Fire Department. The testing agency was the National Institute of Occupational Safety and Health (NIOSH), led by carbon monoxide expert Jane McCammon of the NIOSH Denver field office.

“If the preliminary results in the NIOSH report hold true, all of the city employees had (CO) levels that would not be acceptable in any industry,” said Dr. Robert Barron, medical director at Lake Powell (AZ) National Recreation Area who has spearheaded a considerable amount of research on boat defects and CO poisonings, especially on houseboats.

The test subjects were both on land and water over the holiday weekend along the channel of Lake Havasu that runs near and under the landmark London Bridge. Lake Havasu is a man-made lake in the desert formed by a dam in the Colorado River along the border of Arizona and California. Hundreds of boats motor through the channel all weekend and boats also raft up, anchor or are stopped along the shore at Rotary Beach, many with the engines running. The area tested is not near highways or roads that could generate such levels of engine exhaust, McCammon said.

In addition to monitoring city workers, Dept. of Health technicians took random breath samples from 62 people recreating around the area and also had them answer a questionnaire. The preliminary results show “significant carbon monoxide exposure occurred among participants during the investigation.

“Among non-smoking participants, (CO in their bloodstream) increased from and average of 1% between 10 a.m. and 2 p.m. to 11% between 6 p.m. and 8 p.m.,” said the preliminary report, provided to BoatUS Magazine. “The cumulative carbon monoxide exposure increased as the day progressed. The COHb levels observed late in the day posed a public health hazard.” COHb stands for carboxyhemoglobin, the measurement of carbon monoxide in the subject’s blood. The breathalyzer samples are converted to COHB levels.

The test subjects are separated in the findings between smokers and non-smokers because smokers already have 1-3% residual CO in their blood.

The preliminary test results of the emergency workers (EMS) are equally grim. These are both marine officers aboard patrol boats around the London Bridge channel as well as EMS workers based on shore or patrolling in golf carts or small vehicles.

Of the 36 city employees working over the weekend, six showed an increase of CO in their blood of 5-10% on Friday, 12 reached that level on Saturday and five had 5-10% levels on Sunday while four police officers hit 10-15% levels also on Sunday. On these same days, 40 other city workers had increased COHb levels of either 0-3.5% or 3.5-5%.

Barron is especially concerned about the buildup of CO in police and fire personnel over their long holiday work shifts. The CO test results reported are the percentage of change from the beginning of their day-long shift compared to CO levels at the end of their shift, eight or sometimes 10 hours later. “We don’t know what they might have peaked at. People were recreating in an area that, if the firemen had a union, it would not allow them to work, Barron said.”

In addition, 14 city employees wore fixed air monitors and 11 of the 14 measured CO levels that exceeded the NIOSH limit of 200 parts per million (ppm) in the ambient air. (OSHA sets 35 ppm as the allowable limit for indoor workers’ exposure over eight hours.)

A CO poisoning victim with 20% or more in their bloodstream can become nauseous and suffer impaired judgement, in addition to dizziness, headaches, drowsiness or fainting. For police and EMS workers to even have a risk of impaired judgement is alarming to Dr. Barron since they’re the frontline to assisting the public in an emergency.

“If it’s happening at Lake Havasu, it’s likely this is not the only place. You can bet every state has a place like this,” Barron said. “It’s now not just a problem for boat owners and their boats. It’s a public health issue.”

Since one boater, age 20, drowned in three feet of water in the same area at Lake Havasu on Memorial Day a year ago, Dr. Barron fears the death could have been CO related although it was never determined. “I’m surprised somebody didn’t die over the Fourth of July weekend,” he said.

While there have been no houseboat carbon monoxide deaths at Lake Powell this year, Barron said he believes boatbuilders are going to have to consider design changes in powerboats to move the engine exhaust from the stern to the side of the boat. Most runabouts and ski boats have swim platforms that invites people to linger there at the same time it hides the exhaust outlet. “Teak surfing” is a fad that has already killed a number of young people who hang onto the swim platform of a moving boat, with three deaths reported in the past year and a half just in California.

Carbon monoxide is an odorless, colorless and tasteless gas, a byproduct of the combustion process and present whenever an engine or generator is running. A rash of deaths on houseboats, where generator exhaust was routed to an area beneath a stern deck, brought about congressional hearings and a nationwide Coast Guard houseboat recall two years ago.

But while the focus has been mainly on onboard boating, the Lake Havasu report now extends the problem to the public at least those who are near a crowded waterway. Add to the mix, the use of alcohol that goes hand in hand with shoreline partying on weekends and holidays, the effects of CO poisoning could be mistaken for overindulgence and too easily dismissed, Barron fears.

Technical committees made up of the major boating organizations, inlcuding NIOSH, the U.S. Coast Guard, American Boat and Yacht Council and National Marine Manufacturers Association, are working on possible engineering solutions.

By Elaine Dickinson

©BoatUS Magazine, September 2003