FOUL smells in air-conditioned cars have been traced to organisms which may carry potential health threats, warns the AA. The source of the problem is improper or irregular servicing of the air-conditioning units.

An initial study by American scientists has identified micro-organisms growing on insulation material and evaporators inside the air-conditioning units. Although not likely to cause human infections, according to the AA they may, in the worst cases, aggravate allergic reactions such as runny noses and asthma-like symptoms.