Secondhand cigarette smoke as a cause of chronic carbon monoxide poisoning

Symptoms of carbon monoxide poisoning in a nonsmoking patient continued for several years until her husband stopped smoking cigarettes near her. Carbon monoxide poisoning should be considered in non-smokers when characteristic toxic symptoms occur (ie, lethargy, irritability, headache, blurred vision, slowed reaction time, and decreased concentration). Toxicity may develop simply from breathing second-hand smoke.