UPSC 2016 CDS II GK Paper

Carbon monoxide is the air pollutant that combines with the haemoglobin of human blood and reduces its oxygen-carrying capacity, leading to suffocation and may cause even death. It has strong affinity to combine/bind with haemoglobin in blood to form carboxyhaemoglobin, which reduces the oxygen-carrying capacity of blood to cause headache, nausea, asphyxiation or fainting.