Many modern cars are now fitted with cabin or 'pollen' filters in the heating and ventilation system.
With increasing traffic congestion and commuting distances adding up to more time being spent inside a car, cabin filters not only increase the comfort, but help to protect the health of the occupants by improving the quality of the air inside the vehicle.
Air contaminated by dust, soot, fumes and odours is not only unpleasant, but can present a serious hazard to health. In particular, filtering out many of the pollutants present in the roadside atmosphere can offer relief for asthma, allergy and hay fever sufferers.
Some filters even include a layer of activated carbon to further enhance their efficiency.
In common with all types of filter, a cabin filter will begin to lose it's effectiveness as it becomes dirty through use. Most car manufacturers recommend replacement at intervals of around 15000 miles or every 2 years.