London’s air quality

Air quality is terribly important. There are various ways in which air can be polluted and various ways to test that the air quality is of a sufficiently high standard so as not to present a hazard to human health. One of the most important ways of measuring air quality is to measure pollution particles in the air that have an aerodynamic diameter of less than ten micrometres. If the particulate matter in the air at a given place is less than ten micrometres the measurement of this particulate matter is referred to as PM₁₀.