Risks of ultrafine particles in the outside air

Ultrafine particles in the air outdoors consist of a mixture of particles smaller than 0.1 micrometres that are released during various combustion processes. Because these particles are so small, they can penetrate deep into the lungs when inhaled, from where they can have effects elsewhere in the body through the bloodstream.
There is increasing evidence that long-term exposure to ultrafine particles has a negative health impact, especially on the respiratory tract, the cardiovascular system and foetal development and growth. This is on top of the effects of other air pollution components such as particulate matter (particles smaller than 10 micrometres in diameter) and nitrogen dioxide.
The Health Council of the Netherlands is therefore making various recommendations to reduce ultrafine particles emissions from e.g. road and air traffic and industry. The Health Council also recommends structural monitoring of ultrafine particles concentrations in the Netherlands.