N99 - NASK Smart Mask

What is particle pollution and what types of particles are a health concern?

Particle pollution, also known as particulate matter or PM, is a general term for a mixture of solid and liquid droplets suspended in the air. Particle pollution comes in many sizes and shapes and can be made up of a number of different

components, including acids (such as sulfuric acid), inorganic compounds (such as ammonium sulfate, ammonium nitrate, and sodium chloride), organic chemicals, soot, metals, soil or dust particles, and biological materials (such as pollen and mold spores).

Particles that are 10 micrometers (μm) in diameter or smaller pose the greatest problems. These smaller particles generally pass through the nose and throat and enter the lungs. Once inhaled, these particles can affect the lungs and heart and cause serious health effects in individuals at greatest risk, such as people with heart or lung disease, people with diabetes, older adults and children (up to 18 years of age)

Particles of concern can be grouped into two main categories:

  • Coarse particles (also known as PM10-2.5): particles with diameters generally larger than 2.5 μm and smaller than, or equal to, 10 μm in diameter. Note that the term large coarse particles in this course refers to particles greater than 10 μm in diameter.
  • Fine particles (also known as PM2.5): particles generally 2.5 μm in diameter or smaller. This group of particles also encompasses ultrafine and nanoparticles which are generally classified as having diameters less than 0.1 μm.