Cigarette smoking and exposure to carbon monoxide.
D000397:Air Pollution / Q000032:analysis*; D002248:Carbon Monoxide / Q000032:analysis* / Q000097:blood; D002249:Carbon Monoxide Poisoning / Q000209:etiology; D004781:Environmental Exposure; D006207:Half-Life; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008131:London; D008297:Male; D008722:Methods; D012119:Respiration; D012907:Smoking; D013997:Time Factors; D001335:Vehicle Emissions; D014887:Weather
D006454:Hemoglobins; D001335:Vehicle Emissions; D002248:Carbon Monoxide