Carbon monoxide (CO) is a very dangerous pollutant gas
causing death in very high concentrations.
It is colourless, tasteless and has no smell.
Carbon monoxide is produced in the process of combustion. Complete
combustion in the presence of oxygen produces carbon dioxide (CO2),
but if there is a deficiency of oxygen carbon monoxide is
produced.
Almost all combustion produces some carbon monoxide, the amount
depending on the efficiency of the process and the
availability of oxygen.
The main sources of carbon monoxide are vehicle emissions
(approximately 75% of UK total) and fossil fuel burning.
The emission of carbon monoxide from vehicles is at its highest at
low speeds, therefore the peak values are recorded during the
morning and evening rush hour periods.
Carbon monoxide is gradually oxidised to carbon dioxide in the
air.
It is dangerous because it interferes with the red bloods
cells ability to transport oxygen around the body, at high
concentrations the effect on the body is severe resulting in loss
of consciousness and even death.
Low levels can increase the risk of heart problems for those with
cardiovascular diseases. Other effects from low levels of carbon
monoxide include reduced mental activity and the retardation of
growth in foetuses.
