Though he is small, PM10 can cause a lot of trouble. PM10 stands for particles of 'particulate matter' which is less than 10 microns in diameter - that is VERY small (there are 1000 microns in a millimetre!). These particles can be made up of dust, soil, sea salt, or other chemicals. In Scotland PM10 is mostly from road vehicles and industry.
PM10 is so small that it can get deep into our lungs and cause damage. If we are already ill with heart or lung diseases, it will make us worse. But our bodies can trap bigger particles before they get into our lungs.
Once you've read about all the suspects that cause pollution, take the quiz by clicking below: