Why Ultrafine Particles Are Receiving More Attention
Air quality assessments have traditionally focused on particle mass metrics such as PM10 and PM2.5. However, there is increasing interest in ultrafine particles (UFPs), which are typically defined as particles smaller than 100 nm. Because of their small size, ultrafine particles contribute very little to overall particle mass but can exist in very high numbers.
Ultrafine particles are generated by a variety of sources, including vehicle exhaust, residential wood burning, industrial processes, power generation, aircraft emissions and atmospheric particle formation. In many urban environments, traffic is one of the most significant sources.
As a result, particle number concentration (PNC) is increasingly being used alongside traditional PM measurements to provide a more complete picture of airborne particles and exposure.
To support better understanding of the topic, we have published two new resources:
- Ultrafine Particles (UFPs): an introduction to ultrafine particles, particle number concentration and common emission sources.
- Measuring Ultrafine Particles: an overview of the most common measurement technologies, including condensation particle counters (CPCs) and diffusion chargers.
Read the articles:
Ultrafine Particles
Measuring Ultrafine Particles
We hope these resources provide a useful introduction to the topic for anyone working with air quality, emissions measurements, occupational exposure or aerosol research.