Proof is online: try googling “air pollution and health effects” and you will get several million hits in half a second. So the health impact of breathing bad air, especially in the most polluted cities of the world, is being well documented today. Air pollution is now estimated to be responsible for several million premature deaths each year. It is also considered to be one of the highest risk factors for death globally and a leading environmental risk factor for disease. Cast of particles The most typical particulates in the air are: • PM1 – particles