Carbon monoxide (CO) is a colorless, odorless,
tasteless, deadly gas. You can't see, smell or taste it. Carbon monoxide
is slightly lighter than air and quickly spreads throughout an entire
house.
Carbon monoxide gas is produced when fossil
fuel burns incompletely because of insufficient oxygen. During incomplete
combustion, the carbon and hydrogen combine to form carbon dioxide,
water, beat, and deadly carbon monoxide. In properly installed and maintained
appliances gas burns clean and produces only small amounts of carbon
monoxide. Anything which disrupts the burning process or results in
a shortage of oxygen can increase carbon monoxide production. Wood,
coal, and charcoal fires always produce carbon monoxide, as do gasoline
engines.
Carbon monoxide symptoms mimic the flu: headaches,
fatigue, nausea, dizziness, confusion, and irritability. Continued exposure
can lead to vomiting, loss of consciousness, brain damage, heart irregularity,
breathing difficulties, muscle weakness, abortions and even death. Because
the symptoms mimic so many illnesses, it is often misdiagnosed.
When CO is inhaled, it bonds with hemoglobin,
displacing oxygen and forming carboxyhemoglobin (COHb) resulting in
a lack of oxygen to the body cells. The attraction of CO and hemoglobin
is approximately 250 times greater than the attraction between oxygen
and hemoglobin. The brain and heart require large amounts of oxygen
and quickly suffer from any oxygen shortage. This makes even small amounts
of carbon monoxide dangerous. Physical, non-reversible damage can occur.
High concentrations of carbon monoxide kill
in less than five minutes. At low concentrations it will require a longer
period of time to affect the body. Exceeding the EPA concentration of
9 ppm for more than 8 hours is suspected to produce adverse health affects
in persons at risk. The U.S. Occupational Health and Safety limit for
healthy workers is 50 ppm. Carbon monoxide detectors, which are designed
to protect against high concentration of carbon monoxide are required
to sound an alarm when concentrations are greater than 100 ppm. Continued
exposure to carbon monoxide can cause permanent brain, nerve, or heart
damage. Some people require years to recover while others might never
fully recover.
The time of exposure, the concentration of
CO. the activity level of the person breathing the CO, and the person's
age, sex, and general health all affect the danger level. For instance,
a concentration of 400 ppm. will cause headaches in 1 to 2 hours. In
3 to 5 hours the same concentration can lead to unconsciousness and
death. Physical exertion, with an accompanying increase in respiration
rate, shortens the time to critical levels by 2 or 3 fold.
No. Respiratory capacity decreases and the
risk of heart attack increases at levels well below 50 ppm. The EPA
level of 9 ppm appears to be a reasonable limit in homes.
Some clues for a family include:
·Entire family is sick at the same time.
·Flu-like symptoms decrease while away from the house. OlIlness is present
when gas appliances are in use.
·Excess moisture on the interior of windows.
They should immediately be moved into fresh
air and medical authorities consulted. Treatment depends on the amount
of carbon monoxide in the bloodstream and assessment of the patient.
Often oxygen is administered. In severe cases, patients are treated
in a hyperbaric chamber. This is a pressurized oxygen chamber. The combination
of oxygen and elevated pressure quickly and thoroughly forces carbon
monoxide from the body. Following are the locations of hyperbaric chambers
in Iowa.
Iowa Methodist Medical Center, Des Moines, Phone: (515) 241-5093
Mercy Hospital Medical Center, Des Moines, Phone; (515) 247-3290
University of Iowa Hospitals & Clinics, Iowa City, Phone: (319) 356-7706
Clarkson Hospital, Omaha, Nebraska, Phone: (402) 552-2000
US Air Force 55th Medical Group, Omaha, Nebraska, Phone (402) 294-4400
The half-life of carboxyhemoglobin in fresh
air is approximately 4 hours. To completely flush the carbon monoxide
from the body requires several hours, valuable time when additional
damage can occur. Medical treatment, using oxygen or hyperbaric chambers,
can reduce CO damage, speed recovery, and reduce medical problems.
When people lose consciousness due to carbon
monoxide poisoning, they will typically have relapses for several weeks.
They will suffer from headache, fatigue, loss of memory, difficulty
in thinking clearly, irrational behavior, and irritability. Recover
can be slow and frustrating. Some individuals suffer permanent brain
and organ damage. Victims may be highly sensitive to CO for the rest
of their lives.
Yes. If you have recently been exposed, a breath
test can determine carbon monoxide levels. Medical laboratories can
measure carboxyhemoglobin levels in the blood. Carboxyhemoglogin levels
in the blood drop after the victim is removed from the carbon monoxide
source. For this reason, carboxyhemoglobin tests should not be used
as the only indicator of the danger of exposure or the possible adverse
health effects. Neurological assessment tests, which ask the patient
to perform a variety of physical and mental skills, can be used to deterniine
the effects of CO exposure. Because the effects of carbon monoxide may
last for months, lack of elevated carboxyhemoglobin levels in the blood
does not insure that carbon monoxide is not the cause of health problems.
Consult hyperbaric chamber medical staff who are experienced in carbon
monoxide poisoning diagnosis for interpretation of results.
First, purchase a carbon monoxide detector(s).
Second, have all heating appliances checked every year by a qualified
heating contractor. And third, replace heating units with direct-vent
sealed combustion units.
For more information request other notes in the Carbon Monoxide series.
Agricultural Engineering Notes (AEN's) are informally published information
releases on topics of current concern to Iowans.
Prepared by:
Thomas H. Greiner, Ph.D., P.E.
Extension Agricultural Engineer
The Iowa Cooperative Extension Service's programs and policies are
consistent with pertinent federal and state laws and regulations on
nondiscrimination regarding race, color, national origin, religion,
sex, age and disability.
Jannary 1996 File:a\Jan96\AEN-166
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