Groundbreaking Studies on Carbon Monoxide Reveal Exposure May Be More Dangerous Than Previously Thought

December 5 , 2000

Exposure to CO is Like Playing Russian Roulette with Your Life Say Researchers

CHICAGO, Dec. 5 /PRNewswire[from First Alert]/ -- An ongoing series of studies on carbon monoxide, under the direction of Brigham Young University neuroscientist Dr. Ramona Hopkins, has found that the nation's leading cause of accidental poisoning fatalities may pose greater risk to American families than previously thought. According to Dr. Hopkins' ongoing research, more than 250 patients exposed to acute levels of CO were followed for more than one year. The result? "Some individuals, regardless of age, may be more sensitive to this poison, and therefore, more susceptible to its debilitating effects," notes Hopkins. She stated that currently there is no test that can determine if a family member might be among this more sensitive "at-risk" population.

"Additionally, based on our initial analysis of our research, we find that a significant percentage (25 percent) of study participants suffered varying degrees of permanent brain damage," noted Hopkins. Neuropsychological testing was conducted on a group of 100 CO patients and compared to 85 normal control subjects. While the neuropsychological test scores were significantly lower initially in the CO patients and did improve somewhat over time, the CO patients never returned to a normal level of brain function. "As this ongoing research shows," noted Hopkins, "the current treatment for CO poisoning (oxygen or hyperbaric oxygen) did not prevent some individuals from having cognitive problems following the CO exposure. These problems included slow mental processing speed, memory loss, nerve damage, depression and anxiety, and personality changes."

"We now know that carbon monoxide will impact people differently and that some percentage of the population can be more severely affected than others," Hopkins noted. "And while traditional treatment with oxygen or oxygen in a hyperbaric (pure oxygen under pressure) chamber is essential and prevents some of the brain damage, once you get cognitive impairments, the person may not 'get better' despite continued treatment," she added. "CO exposure, therefore, can be like playing Russian roulette with your life. For a number of our study subjects, the impact of their CO exposure in the home has changed their lives permanently," she said.

Researchers conclude that prevention is more important than ever and should be at the top of any family's list of essential home safety practices. Installing a UL listed carbon monoxide alarm on each level of the residence, say fire service and safety organizations, can help warn of a carbon monoxide leak before exposure causes injury to the brain or worse.

Studies that were part of Dr. Hopkins' ongoing research were published recently in the journals Brain Injury, Chest, and the Archives of Clinical Neuropsychology . Taken together, the current and ongoing research represent some of the first studies to systematically track and assess the after-effects of carbon monoxide exposure in a large group of subjects over a one-year period of time, according to Dr. Hopkins.

"Basically, what we typically see after CO exposure is cell loss in the hippocampus of the brain, a structure that is involved in memory and new learning-and we see generalized cell loss throughout the brain," explained Dr. Hopkins. In the study published in Brain Injury , imaging scans of 21 patients showed that 81 percent of these CO patients had abnormal brain imaging scans that showed cell death and specific brain lesions.

"As a result," Hopkins noted, "in this select group of severely CO poisoned individuals, the subjects exhibited brain atrophy and decreased blood flow to the brain. In addition, 76% of the subjects had significant memory impairments, 75% had impaired executive function (ability to make decisions), 57% had slowed mental processing speed and 45% experienced impaired attention.

"One of my subjects," for example, noted Hopkins, "a father of two, had such severe memory impairments following his CO exposure that he had difficulties in his job due to short-term memory loss. He was unable to learn and retain new information. He elected to return to a position held previously, because he already knew the work and didn't have to learn new tasks that required short-term memory."

The Brain Injury study also reported that 95 percent of the CO poisoned patients experienced mood disorders that persisted to one year after exposure. In Hopkins' latest, ongoing research, a large percentage (45 percent) of the CO-poisoned patients also exhibited clinically significant mood disorders, especially depression and anxiety, even one year after their initial exposure to CO. The cognitive impairments and the changes in mood and personality due to CO persisted in many patients for months following exposure, according to Hopkins.

"Saddest of all is that, as with all damage to the brain, the damage from CO is permanent; but with CO poisoning, we can prevent the poisoning and therefore the brain damage," Dr. Hopkins noted. "These people suffer permanent damage that can literally change their lives forever," she continued.

"A simple and comparatively inexpensive device-a CO alarm-may mean the difference between life and death, brain damage or surviving unharmed. Hopefully, through the experience of others who have been exposed, we can raise awareness with the public to this household danger that can lead to these disastrous consequences," she said.

According to industry statistics, nearly 75 percent of homes currently do not have a CO alarm. And yet, according to a 1999 article published in Clinical Toxicology , a New Mexico study found that the use of CO alarms in homes could potentially reduce the numbers of deaths (over 2,100 per year according to the Journal of the American Medical Association and the Centers for Disease Control) by at least half.

New technology that helps make CO alarms even more affordable has been pioneered by First Alert, a leading manufacturer of home safety devices that also introduced the first UL listed battery operated CO alarm in 1993.

First Alert has introduced a combination smoke and carbon monoxide alarm that includes in one unit separate sensors to provide a warning of either fire or CO dangers. The alarm eliminates the need to install two separate devices, and provides distinctive horn patterns so residents can tell immediately what kind of problem has occurred. The First Alert combination ionization smoke and CO alarm is available at hardware, home center and mass merchandise outlets for about $40.

For more information about the CO hazard and how to protect the home, log on to www.firstalert.com or call 1-(800) 323-9005.

For additional information on carbon monixide alarms, try AIM at www.aimsafeair.com or 1-(800) ASK-4AIM (275-4246) or Kidde Safety at www.kiddesafety.com or 1-(800) 880-6788.

For information on training, consulting, and testing services available at Advanced Energy to help identify, remediate, or prevent indoor air quality problems, please contact Keith Aldridge at (919) 857-9034 or kaldridge@advancedenergy.org .