Gas Detection in the Natural World
The tiny cpA neuron in a mosquito’s nose can detect an elevated level of carbon dioxide (CO2) in the air that results from human breathing from more than 20 metres away. Human beings, on the other hand, have no sensory perception for CO2 and the same can be said for other colourless, odourless gases such as methane and carbon monoxide.
If our noses were as sensitive at detecting CO2 as the mosquito is, we might have avoided many mining deaths over the last century. CO2 exists in mines for several reasons: it is an exhaust gas from internal combustion engines used to power trucks and machinery in the mine; it is produced as a by-product of explosives detonations and it can also be released, either alone or combined with methane, when a gas seam is cut through during excavation. Such outbursts of Illawara bottom gas have been relatively common when mining the Bulli coal seam in New South Wales, Australia. In 1991, on the 24th of July, one such outburst claimed the lives of three miners through CO2 asphyxiation in the South Bulli mine, which is one of nine mines that has operated on the Illawara Coal field in the past century.
Read more: Detecting danger – the role of gas detectors and high precision calibration gas mixtures in mining safety