Participation of cars in pollution emission is significantly larger at the areas, where traffic is heavy. In Warsaw road transport accounts for 40 per cent of PM10* particulate matter, 20 per cent of PM2.5** particulate matter and 15 per cent of benzopyrene***.
the particles have diameters of 10 micrometers or less (human hair is 50-90 micrometers thick). They easily penetrate deep into the upper respiratory tract and lungs. They produce coughing, difficulty breathing and allergic reactions. If there are other toxic substances on the surface of a particle, inhaling them might entail serious health consequences.
its particles have diameters of 2.5 micrometers or less. Most of them are chemicals - particles of sand or plant pollen do not fit in this category. PM2.5 are frequently toxic substances - among others, heavy metal compounds or volatile organic compounds. PM2.5 are more dangerous to health than PM10 - smaller particles are transported to the lung alveoli, from where they might permeate to blood.