Stay up to date

Stay up to date

Air Pollution Science

What is Particulate Matter?

Picture of Dr. Yvonne Boose
By Dr. Yvonne Boose on September, 30 2020

In the world of air pollution and air quality, there is a lot of discussion about particulate matter and its impact on our health...but what exactly is it?

Particulate Matter is not 'One' Pollutant

When people refer to ‘Particulate Matter’ (or 'PM') it often sounds like they’re referring to just one pollutant, however, particulate matter is not a unified pollutant at all. We use this term to refer to a family of particles suspended in the air and characterized by their size. 


shutterstock_1824153368 (1)-min

Unlike some of the other major air pollutants that affect our health, such as ground-level ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide, PM is the only example that isn’t a gas - rather, it’s a solid or liquid-state pollutant. 

Particulate Matter can be composed of a number of different materials and compounds. It could be entirely mineral, but it could also include dissolved gases or black carbon.

PM10 and PM2.5 are categorized according to their size and relative impact on our health: PM10 is any particle that has a diameter of 10 microns or less, while PM2.5 particles have a diameter of 2.5 microns or less. As a result, PM2.5 also comprises a part of PM10.

New call-to-action

Particulate Matter has been Linked to Many Diseases

PM10 is inhalable and can get into our lungs, causing local and systemic inflammation in the respiratory system. In turn, this can cause respiratory diseases such as asthma and bronchitis. 

PM2.5, similarly, is inhalable, and because of its even smaller size, it can get even farther into our bodies. PM2.5 particles can enter and deposit into the last corners of our lungs, the alveoli and some of them can also pass into the bloodstream. Once it enters the bloodstream, they may affect the heart, causing cardiovascular diseases or be carried to organs beyond the respiratory and cardiovascular systems, posing a range of long and short-term health threats. 

Long-term exposure to PM2.5 has been linked to a number of forms of cancer. Studies have also found that long-term exposure to Fine Particulate Matter (PM2.5) can  increase our likelihood of developing severe Coronavirus symptoms.

Where does Particulate Matter Come From?

Particulate Matter can get into the atmosphere by being emitted from sources directly (‘primary particles’), or they can form in the atmosphere via chemical reactions of gases (‘secondary particles’). The sources of these gases and particles can be natural or man-made.

PM10 is generated primarily from sources such as natural (mineral) and road dust, sea spray, and pollen, while PM2.5 comes from fuel burning, smoke, industrial processes, transportation, and indoor heating.

Secondary particles formed in the air for example from nitrogen oxides emitted by traffic or industrial processes are also a part of PM2.5.

Sand Storms & My Dusty Cabinets - It's all the Same?

In a way, yes, it’s all Particulate Matter --‘Dust’ is often used as an interchangeable term for ‘respirable particles’. 


julian-hochgesang-4DqsMC4-QQc-unsplash (1)


However, when we talk about dust in terms of our households, this is usually a mixture of inorganic and organic material which people can also be allergic to thanks to the presence of dust mites. For example, your household dust could consist of hair, dead skin, pollen, pet dander and more.

When we talk about ‘dust’ in atmospheric science, we’re usually referring to mineral dust, which is material that gets transported through the air from deserts or soil. Dust can also carry bacteria on its surface or become coated with other materials. 

This reality is another reason why people get sick during extreme dust storm events - of course, this dust can also penetrate our lungs which is extremely unhealthy.

What about Pollen? Is this Particulate Matter too?

Pollen particles can sometimes rupture or burst into smaller fragments - at these times, the smaller fragments could then become small enough to fall into the category of PM10 or PM2.5, with further potential health implications. 

The Big Question: How Do I Reduce My Exposure?

First of all, it's very difficult to combat a problem we aren’t aware of. The best available method for managing exposure to harmful particulate matter is by knowing what’s in the air you breathe!

Check the Air Quality

For individuals, this means using reliable sources of air quality information to avoid unhealthy air - whether by app, website, connected device and more. However, you should check that whatever source you're using reports on all the important pollutants, and provides hourly and location-specific information.

Choose a Smart Air Purifier

There is a very strong correlation between indoor and outdoor air quality, which means on a dusty, hazy, or highly polluted day, there’s no guarantee the PM will stay outside. 

For this reason, we recommend using an air purification system which integrates live outdoor and indoor air quality information. This will help to understand the environmental conditions both inside and outside of your home, and when you need to take action.

What Can Companies Do?

We're excited to see more and more industry leaders from a range of sectors take on the air pollution problem! In the below webinar we discuss a number of companies that have empowered their customers to reduce exposure to air pollution. You may also be interested in our latest project collaborations with Siemens and Bosch

Click me

Submit a Comment