Ultrafine particles (UFP) pass the blood-brain barrier

As if Particulate Matter (PM) wasn’t nocive enough, evidence is growing that the smallest subgroup of PM2.5—the ultrafine particles (UFP), also known as nanoparticles—pose a particularly high health risk.

Not only do they enter the lungs with each breath of polluted air that we take, they also get inhaled through the nose, entering the brain and central nervous system via the olfactory nerve, bypassing the protective blood-brain barrier.

Measurability of ultrafine particles

The technology for monitoring PM2.5 levels outdoors is very advanced and has been available for a long time. But PM2.5 particles can be as small as 0.3µm and can also contain 0.1µm particles. And these are much harder to measure due to their tiny size and erratic behaviour.

Highly sensitive and accurate equipment is therefore essential to ensure the precise measurements required to monitor local air pollution and make decisions to protect health.

Official air quality readings are often based on the mass of particles captured by the filters of measuring devices. As ultrafine particles with the same PM2.5 mass have a much larger number and surface area, the measurements usually do not reflect the full extent of the health risk posed by air pollution.