Even though our air should be clean in order for us to enjoy all its benefits, unfortunately, its pollution is rapidly increasing, particularly in the cities. Often we can detect such dangerous compounds as carbon monoxide, sulfur oxides, nitrogen oxides, hydrocarbons, and particulate matter (PM). PM2.5 measurement is especially important when it comes to air quality. But what is it, and how do we measure it?
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What is PM2.5?
Before we learn how to measure PM2.5, we should learn more about this compound. PM2.5 describes particulate matter, which has a diameter of fewer than 2.5 microns. That means such particles are almost 30 times smaller than the thickness of human hair. Even though PM10 has a bigger particle size and is much more visible, PM2.5, because of its size, can enter human lungs and even the bloodstream and cause an array of adverse health conditions. On top of that, this chemical contains plenty of toxic substances and can be transported long distances. PM2.5 is produced mainly by combustion sources, such as vehicle exhaust, power plants, and wildfires.
How to measure PM2.5?
So how is PM2.5 measured? The amount of this compound is usually monitored with an aerosol sampler or a PM2.5 monitor. Both devices work similarly, as they draw in the air inside and then calculate the concentration of PM2.5 found on a filter. The results are conveyed as a microgram per cubic meter of air (μg/m3). The World Health Organization sets acceptable PM2.5 levels at 10 µg/m³ annually and at 25 µg/m³ in the 24-hour window.
But what does PM2.5 measure? The composition of this compound is quite complex, and it consists of both solid and liquid particles. However, the main ingredients often include organic matter, nitrate, sulfate, ammonium salt, carbon as well as some metal compounds. The majority of the chemicals on this list are dangerous to human health.
Of course, PM2.5 measurements can be done both indoors and outdoors, and you should match the type of device to your needs. Whenever the levels of 2.5PM get too high, make sure to stay home or at least wear a protective mask on your face. Indoors, you can also use air purifiers.
Read also how air pollution affects the eyes.