Scientific illustration

PM-10 pollutant. Computer artwork of a microscopic solid pollutant particle. This particle is less than 10 micrometres (a hundredth of a millimetre) in diameter, and particles of this size are known as PM-10 particles. These particles are small enough to penetrate deep into the lungs, where their sharp edges can damage the lung tissues. Road traffic, and particularly diesel vehicles, are a major source of airborne PM-10 particles.

Image available from Science Photo Library.