Why is understanding COHb levels important in fire investigations?

Understanding COHb (carboxyhemoglobin) levels is crucial in fire investigations primarily because it assesses exposure to carbon monoxide, a deadly byproduct of combustion. In a fire scenario, individuals may be exposed to various hazardous substances, but carbon monoxide is particularly dangerous as it can be present in higher concentrations in smoke.

By measuring COHb levels in the blood, investigators can determine the extent of carbon monoxide exposure a victim or individual may have experienced. Elevated levels of COHb indicate significant inhalation of carbon monoxide, which can help establish whether carbon monoxide poisoning was a contributing factor to a person's condition or death in a fire.

This understanding can provide key insights into the circumstances surrounding the event, such as confirming that a victim was present during the fire or assessing the effectiveness of smoke alarms or ventilation systems in mitigating exposure to smoke and gases. In contrast, the other options, while related to the broader aspects of fire investigations, do not directly measure the health impacts of exposure to smoke and gases in the same way COHb levels do.