If you've ever wondered about the air you breathe while cycling in London, or thought about wearing one of those anti-pollution masks, you might be interested in finding out about the pollution levels in your area.
Sign up for free to twitter messages and SMS alerts from AirTEXT, telling you the daily air quality index for the UK. The index represents air pollution using a 1-10 scale divided into four bands: LOW (1, 2, 3), MODERATE (4, 5, 6), HIGH (7, 8, 9), VERY HIGH (10).
Levels 1-6 are considered perfectly safe, but at higher levels those who suffer adverse effects should consider reducing their outdoor activity.
It's particularly important for the elderly, and those with heart and lung problems, as well as asthma sufferers.
The alerts also include temperature, UV ray and pollen information, to make sure you're prepared for your journey.
The site also links to longer-term studies on the effects of air pollution, which make sobering reading.
Air pollution is made up of numerous different pollutants, some of which have known harmful effects on the human body.
The pollution from diesel engines is of particular concern as the small particulates or ultra fine particles which tend to be emitted by diesel engines, can be inhaled further down into the lungs than the larger particles.
In people with existing respiratory disease this can cause significant airway irritation and breathing difficulties.
Some researchers believe that panting cyclists breathe deeper than other city inhabitants, drawing in more harmful pollutants into their lungs with every breath.
But knowledge, as they say, is power, and AirTEXT promises to be a tool that might influence your decision to choose a less congested route, or wear a mask on days when pollution is at its highest.
After an unpromising start, having to be bribed by her parents to learn to ride without stabilisers, Sarah became rather keener on cycling in her university years, and was eventually persuaded to upgrade to proper road cycling by the prospect of a shiny red Italian bike, which she promptly destroyed by trapping a pair of knickers in the rear derailleur. Sarah writes about about cycling every weekend on road.cc.