Respiratory Disease: Gases

Carbon monoxide
Carbon monoxide (CO) causes lethal exposures in indoor environments.  Rapid build-up of lethal 
levels of CO occurs if there is not adequate active mechanical ventilation.  Sources of CO include 
any internal combustion engine or heater burning gasoline products and include mechanical 
equipment running in barns, power washers in animal confinement buildings, and kerosene 
heaters.  Passive ventilation is not adequate.  CO is colorless and odorless and there is no 
method to detect it without air monitoring.  Symptoms can range from headache and fatigue in 
prolonged exposure to mildly elevated levels or coma, pulmonary edema, permanent neurologic 
sequellae, and even death in short term exposure to high levels.  Diagnosis involves a 
carboxyhemoglobin level.  100% oxygen is the mainstay of treatment and hyperbaric oxygen in a 
diving chamber may be used in severe CO poisoning.