 Carbon monoxide may be quantitated in blood using spectrophotometric methods or chromatographic techniques in order to confirm a diagnosis of poisoning in a person or to assist in the forensic investigation of a case of fatal exposure . Carboxyhemoglobin blood saturations may range up to 8 – 10 % in heavy smokers or persons extensively exposed to automotive exhaust gases . In symptomatic poisoned people they are often in the 10 – 30 % range , while persons who succumb may have postmortem blood levels of 30 – 90 % . 
