He suggests that long periods of exposure to carbon monoxide, even at low levels, can result in
long-
term effects. He calls this chronic carbon monoxide poisoning. This can cause effects in an individual for days, weeks, months, or even years. Results vary depending on the age and health of an individual.
For the purposes of Dr. Penney’s study, the term “chronic” is used to describe how long the carbon monoxide exposure lasts, not how long the resulting effects are.