Particulate matter, sometimes called particle pollution or simply PM, is a term that refers to a mixture of solid particles and liquid droplets that can be found in the air. They are classified as pollutants and there are several different sizes of particulate matter. Some particulate matter, such as dust, dirt, soot, coal ash, and smoke are large enough to be seen with the naked eye. Particulate matter can also be extremely small, therefore, can only be seen with high-powered microscopes. As well as containing acids, particulate matter can contain hazardous elements such as arsenic, beryllium, cadmium, chromium, lead, manganese, and nickel..
Particulate matter can fall into several different categories depending on their size. These categories include inhalable coarse particles (PM10) that are between 2.5 and 10 micrometers in diameter and fine particles (PM2.5) with diameters of less than 2.5 micrometers. In addition, particulate matter can be separated into 2 categories:
The energy sector does a good job of preventing the emissions of particulate matter. Most particulate matter in Canada comes from open sources like driving on unpaved roads, or construction work.
The removal of particulate matter from flue gases is generally the first step in cleaning these gases before they are released through the smokestacks. There are several different ways to remove this particulate matter from the gases, but there are three main types of separation used.
Particulate matter can cause significant health problems in humans—specifically, particles that are smaller than 10 micrometers. These particles are harmful as they can penetrate past a lung'a barrier defences and lodge themselves deep in the lungs. Chronic exposure to these particles increases the risk of developing cardiovascular and respiratory diseases as well as increasing the risk of developing lung cancer. Exposure to particulate matter in high concentrations can even increase a persons risk of death as a result of some sort of respiratory failure. The elderly and young children are especially at risk for health problems, as well as anyone located in cities where smog is a problem. Figure 2 shows a map that indicates where PM2.5 particulate matter is an issue.
In addition to human health effects, particulate matter can harm the environment. The fact that particulate matter is a major component of smog means that it contributes to the blocking of natural sunlight that smog does. By limiting plants exposure to the Sun, their ability to take in carbon dioxide is limited, therefore, decreasing its photosynthetic capabilities. The chemical composition of the PM may also have an effect on the plants and their surrounding soil.
The following data visualization shows the sources emitting particulate matter in Canada. Note that the preset is for the larger PM10, but PM2.5 is also a selectable pollutant. It is important to note from the pie chart that a large amount of particulate matter doesn't arise from things related to energy production (much of it comes from driving on unpaved roads and construction, both of which use energy). Although coal ash makes up a portion of PM (and thus coal combustion is a source of PM), large sources include dust from construction and unpaved roads and mining operations.