Particulate Matter: The Hidden Killer

By Kelsey Miyashita

Particulate matter may be tiny, but it can be deadly. In fact, its size is partly what makes it so dangerous. But what is particulate matter? According to the EPA, particulate matter “is made up of a number of components, including acids, organic chemicals, metals, and soil or dust particles.” There are many different sources but the Air Quality Management Division of the Hamilton County Environmental Services gives examples such as exhaust pipes on vehicles, smoke stacks at factories or volcanoes to name a few; basically “any activity which involves burning of materials or…dust gathering.” The American Heart Association states that the particles are able to avoid detection and enter the lungs and once they are in the system they begin to cause irritation to both the lungs and the blood. According to the National Ambient Air Quality Standards for Particle Pollution, some of the effects of particulate matter are “premature death and harmful effects on the cardiovascular system…[and particulate matter is] also is linked to a variety of other public health problems, including respiratory diseases.” The American Heart Association also states that while anyone who encounters particulate matter can be affected by it, it is most likely to have more severe effects on children, elderly people or people who already suffer from things like asthma or heart disease. It may be impossible to avoid particulate matter but not just any amount of it is hazardous, Figure 2 shows how much of a threat different amounts of PM2.5 are.

Particulate matter, or PM2.5, is a tiny killer and what makes it even more frightening is that we are all exposed to it; however, some of us more than others. One of the factors that can determine how much exposure an area gets to PM2.5 is the weather. PM2.5 can be created and then simply carried away by wind, but it can also instead be trapped in one area when the surface air temperature is cold and the air above that is warm preventing the air near the surface from dispersing, also knows as a cold air inversion. The inversion and lack of wind keeps the PM2.5 together causing the air to become more and more polluted. An example of this happening can be found in Beijing, China where James Crugnale wrote about nearly two months ago. Figure 1 shows that Beijing reached unhealthy levels of smog, potentially dangerous for anyone inhaling it, which can be attributed to the mountainous surrounding geography, cars and industrial pollution combined with the cold air inversion. These aspects spell out trouble for Beijing because the inversion and the geography cause the polluted air to remain trapped in the area, the pollution the cars emit will continue to add to the trapped pollution. As a result, residents have been attempting to get medical aid in the crowded hospitals. It is safe to say Beijing’s cold air has them in hot water.

While Beijing may be far away, that doesn’t mean that those of us in the United States, specifically the Pacific Northwest, are not at risk. The PNW is known partly for its mountains, fast growing population and thriving industry. More industry and more people means more cars and more pollutants being released, and much how Beijing’s geography combined with an inversion can trap the pollution, so can the PNW’s mountains. So even though Beijing is not nearby, the problem of particulate matter is.

Just like how the climate can affect particulate matter, particulate matter can actually affect the climate as well. Aerosol particles can prevent the sunlight from reaching the earth, therefore causing a cooling of the climate. When many aerosols interact with clouds they cause the clouds to be a brighter white which reflects the sunlight. However particulate matter can also have the opposite effect on the earth’s climate. Dirt or soot can cover surfaces, like ice or snow, that would normally have an reflective effect and cause it to instead absorb the sunlight. Climate affects particulate matter by exacerbating its concentrations and impacts; particulate matter affects climate by actually causing the climate to heat or cool.

According to the EPA, the effects of climate change on particulate matter are not very certain; though they are working on gaining a better understanding. There is a much higher level of understanding for how particulate matter affects the climate and contributes to the change. An idea of how climate change might impact particulate matter is if the climate change leads to more stagnation (still, windless, rainless) days there might be less opportunities for the pollution to be removed from the area. But for an idea of how climate change could affect particulate matter, Lara Whitley Binder who is an outreach and adaptation support specialist at the University of Washington Climate Impacts Group stated that “impacts on air quality are most likely to occur from higher summer temperatures, including more extreme heat events…the increased risk of forest fires could increase the amount of particulates in communities affected by smoke.” So the climate change would cause higher summer temperatures which would in turn lead to more forest fires which would release more particulate matter.

Particulate matter may not be something that we can see but it is clear that these tiny particles are a big problem. PM2.5 has the potential to damage our health and our environment, and as the climate continues to change so will the impact of PM2.5. The problem is bigger than particulate matter, the problem is humans causing the climate to change and problems like PM2.5 are dangerous side effects. 


Kelsey MiyashitaKelsey Miyashita is a sophomore at UW Bothell majoring in Media and Communication Studies. She was born and raised in Kirkland, WA. “I care about the air we breathe because without clean air, human life will cease to exist …we are ruining one of the core things we need to survive.”