Stop Idling
They say that small changes in your lifestyle can lead to big, and sustainable, improvements in health. Small changes in lifestyle may also help to improve air quality and the amount of smog you are exposed to, which in turn may also improve your health. The small change I am thinking of here is to stop idling. Idling is the name given to the habit of keeping a vehicle's engine running when it is not in motion. The practice is rooted in the idea that it damages the engine, or drains the battery if you keep stopping and starting it. There is no doubt also an element of simple laziness involved, in that it's just easier to keep your car idling while you pick up or drop off a passenger, or collect a takeaway.

In fact, the idling habit is one that's well worth kicking, because it has a cumulative environmental impact on air quality. According to Transport for London (TfL), which launched a campaign to reduce idling in the capital, if all drivers in central London switched their engines off for just one minute a day, it would reduce harmful emissions, such as nitrogen oxides, ozone, particulate matter and Volatile Organic Compounds, by 90 kg per year. That is the equivalent (in emission terms) of a diesel car (known for their pollution potential) driving 62 times around the world.

The Transport for London campaign aims to persuade drivers that are waiting for more than a minute to stop idling and switch their engines off. A poster and radio campaign targets vehicles such as black cabs picking up and dropping off passengers and vans making deliveries. Drivers need to be more aware of the modern science behind idling, namely:

  • It is not more fuel efficient to leave our engine running. The opposite is true! Leaving the engine idling for even 10 seconds uses more fuel than switching off and restarting.
  • Modern ignition systems mean that switching on and off does not harm the engine or drain the battery. Test vehicles could tolerate having their engine being switched on and off more than 100 times per hour without damage. Overall, idling increases wear and tear on a vehicle, for the simple reason that it extends its lifetime unnecessarily.
  • There is no need to 'rev up' a vehicle's engine by idling. A modern engine will warm up straight away once it is driven.
  • Idling does not keep the car warm inside any better than simply driving it.
  • Most important, turning your engine on and off promptly, instead of idling, causes less pollution. Put simply, when the engine is not on, there can be no polluting emissions. To maximise the time the engine is off, and minimise the time it is on by reducing idling to a minimum.

Every little helps – because air pollution causes the premature deaths of over 4,000 London residents, particularly those with pre-existing heart and lung disease. Particulate matter, known as PM10 or PM2.5 (one is particles of 10 microns or less, the second particles of 2.5 microns or less), is known to be especially bad for health as the tiny particles are inhaled deep into the lungs. It's too early to know what impact the TfL campaign on idling will have on Londoners' health and on London's air pollution levels. But I hope it will quickly have an impact on people's awareness of how their actions, however small, can affect the quality of the air around them.