Particulate Matter

In-depth explanation of Particulate Matter

Particulate matter is a mixture of small solid or liquid particles suspended in air. PM10 has diameters below 10 micrometres and PM2.5 below 2.5 micrometres, and the finer fraction can penetrate deep into the lungs and cross into the bloodstream. Particles arise from combustion in vehicles, power plants and fires, from dust, construction and industry, and from secondary formation of aerosols from gaseous precursors. Exposure is linked to cardiovascular disease, asthma and premature death. Air quality standards set limits on annual and daily particulate concentrations.

Going deeper: Particulate Matter

Key ideas: Tiny solid and liquid particles: PM10 under 10 micrometers (reaches the throat), PM2.5 under 2.5 micrometers (reaches the alveoli and blood), ultrafine below 0.1. Sources: combustion, dust, industry, secondary formation from SO2, NOx and ammonia. WHO annual guideline for PM2.5 is 5 micrograms per cubic meter (2021).

Common mistakes and connections: Students judge danger only by mass; smaller particles penetrate deeper. Visibility haze is often secondary sulfate and nitrate aerosols. Electrostatic precipitators and bag filters control industry emissions. Links to AQI, smog and respiratory health.

Visualization of Particulate Matter

Diameter of particles compared with PM10 and PM2.5. The finest fraction is small enough to reach deep into the lungs and the bloodstream. The interactive lesson shows this as a live animation or chart.

Worked example and use case

Smoke from wildfires can raise local PM2.5 concentrations to very hazardous levels within hours.

Where Particulate Matter fits in Biochemistry, Environment & Industry

Particulate Matter is topic 77 of 127 in Biochemistry, Environment & Industry.

Related topics

• Ozone Layer DepletionIntermediate
• CFCsIntermediate
• SmogBeginner
• Air Quality IndexBeginner
• Water PollutionBeginner
• EutrophicationIntermediate

Browse all 127 topics in Biochemistry, Environment & Industry