Fine particles and pollutants

Fine particles and pollutants – their origin and their impact
Several studies have been conducted and published in Germany identifying fine particles as a source of asthma and respiratory diseases. This is due to the very small size of the particles which go into the pulmonary alveoli and can thus also be responsible for cardiovascular diseases.

Fine particles are produced by dusts from households, traffic and the industry. Particularly high rates are registered on intersections in big agglomerations. The reason for this are especially the diesel dusts and particles emitted by combustion motors.
Furthermore, fine particles are produced by energy supply systems and industrial processes, by metal and steel production or also by the work-and-turn of bulk materials.
There are also natural sources for the production of fine particles. Those can be particles coming from the Sahara Desert, microorganisms, pollen, rocks erosion, forest brands, volcano eruptions and see salts.

How do fine particles arise?
Fine particles arise from natural and anthropogenic (human) manners. Human fin particles producers are: industry, private households and little small consumers, traffic, rail transport, electric and district heating plant, transportation, bulk handling and industrial brands. 

What are fine particles?
Fine particles are nothing else but fine dusts, which means solid particles in the air smaller than 15 µm. For the definition of its reduction goal for air pollution, the European Union relied on the Nation Air Quality standards for Particulate Matter (PM) of the US environmental agency EPA (Environmental Protection Agency).

The Standard PM10 has been defined in the first version of the American directive, which also has to be observed since 2005 in the EU. In opposition to the common definition, PM10 do not have a size of 10 micrometers (10 µm) stricto sensu. This value reflects the separation capacity of the respiratory system. Indeed, fine particles with an aerodynamic diameter up to 1 µm are entirely absorbed. By fine particles with a bigger size, the bigger the particles are, the lower is the percentage of chances that they will be absorbed. The percentage reach almost 0% by fine particles of 15 µm. Technically, this reflects the use of a quantifier function (separating function) of the emissions (in practice, this will be realized through a size-based selection in measures instruments). The denomination PM10 is also distinguished from this separation process, since almost the half of the fine particles are absorbed by a size of 10 µm.

Why are fine particles so dangerous?
There is no concentration of fine particles that is not dangerous. For the people from all the European Union, the life expectancy can be reduced of one year in average because of the entire fine particles pollution. The rates fixed by the EU are more or less arbitrarily established and remain rather to political decision than to scientific information.

The risks incurred because of fine particles include increase of allergic symptoms, asthma, airways disturbances and lung cancer, as well as a big risk of inflammation of the middle hear for children and cardiovascular diseases. The risks incurred depend also on the toxicity of the particles but also on their size (for example by plumb, vanadium, beryllium, mercury). The smaller is the particle, the deeper it goas inside the lungs.