Difference Between Aerosol and Particulate Matter

The key difference between aerosol and particulate matter is that the term aerosol refers to a collection of suspended particles and the surrounding gases whereas the term particulate matter refers to the suspended solid or liquid matter in the air.

Both terms aerosol and particulate matter describe particles in the air. An aerosol is a collection of both particles and air while the particulate matter is only the particles suspended in the air. The particles in these two forms are called “particulates”, and they can be harmful when inhaled into the respiratory tract.

CONTENTS

1. Overview and Key Difference
2. What is Aerosol 
3. What is Particulate Matter
4. Side by Side Comparison – Acid Value vs Saponification Value in Tabular Form
5. Summary

What is Aerosol?

Aerosol is a suspension of solid particles or liquid droplets in air or another gas. Aerosols are either natural or man-made. Some natural aerosols include fog, mist, dust, forest exudates, and geyser steam, while some examples of man-made aerosols include articulate air pollutants and smoke. In an aerosol, the dimensions of liquid or solid particles are typically less than 1 micrometer. The suspension forms due to the presence of large particles with a significant settling speed. In common use, an aerosol is a spray that delivers a consumer product from a container.

Aerosols typically vary in their dispersity. There are monodispersed and polydispersed aerosols. A monodispersed aerosol can be easily produced in a laboratory, and it contains particles with a uniform size. A polydispersed aerosol, on the other hand, contains particles with a range of sizes. If the aerosol contains liquid droplets, we can observe that these droplets are almost always spherical.

There are many applications of aerosols such as test aerosols for calibrating instruments, performing research, delivering deodorants, paints, for agricultural purposes, for medical treatment in respiratory diseases, fuel injecting process, etc.

What is Particulate Matter?

Particulate matter or particulates are the solid particles or liquid droplets suspended in the air. These particles are microscopic; they can be either natural or anthropogenic. Some examples of atmospheric particles include thoracic and respirable particles, inhalable coarse particles, etc. These particles are not more than 10 micrometers in size.

The composition of particulates depends on the source from which the particles are made from. Some particulates come naturally to the atmosphere via volcanic eruptions, dust storms, forest fires, sea spray, etc. Generally, smaller and lighter particles stay a long time in the air. Large particles tend to settle down due to the action of gravity.

What is the Difference Between Aerosol and Particulate Matter?

Both terms aerosol and particulate matter describe the particles in the air. The key difference between aerosol and particulate matter is that aerosol refers to a collection of suspended particles and the surrounding gases, whereas particulate matter refers to the suspended solid or liquid matter in the air.

Below infographic shows more details of the difference between aerosol and particulate matter.

Summary – Aerosol vs Particulate Matter

Aerosol is a suspension of solid particles or liquid droplets in air or another gas. Particulate matter or particulates refers to the solid particles or liquid droplets suspended in the air. The key difference between aerosol and particulate matter is that aerosol is a collection of suspended particles and the surrounding gases, whereas particulate matter is the suspended solid or liquid matter in the air.

Reference:

1. “Aerosol.” ScienceDirect Topics, Available here.

Image Courtesy:

1. “Heavy mist” By fir0002flagstaffotos [at] gmail.comCanon 20D + Tamron 28-75mm f/2.8 – Own work, GFDL 1.2) via Commons Wikimedia

2. “Cloud 3” By Bm1996 – Own work (CC BY-SA 3.0) via Commons Wikimedia