Can you imagine wearing a gas mask as you walk the down the street trying to protect yourself from the increased air pollution? Although this is not a reasonable nor necessary measure to take, microscopic pollution is a real threat, one we should at least be aware of. Particulate matter (PM) is particle pollution in the air consisting of a mixture of extremely small solid and liquid particles, as defined by the US Environmental Protection Agency (EPA). Nitrate and sulfate acids, metal particles, organic chemicals, dirt and dust are among the various types of particle pollution.Dust and smoke are particles big enough to be seen by the naked eye. There are other particles, however, which are so small that they cannot be seen by the naked eye. These particles measure less than 10 micrometers in diameter. To put this into perspective, on average the diameter of human hair measures 70 micrometers.
The Dangers of Particulate Matter
The dangers of particulate matter are directly related to the size of the particles. Particles which are less than 10 micrometer in diameter cause the most serious health problems. Their size allows them to be inhaled into the lungs and bloodstream thereby affecting the lungs or heart.
The EPA has classified these particles of concern into two categories: “inhalable coarse particles” (PM10) and “fine particles” (PM2.5). Inhalable particles, 2.5 – 10 micrometers in diameter, may be found near dusty industrial plants and roadways. Fine particles, 2.5 micrometer or smaller in diameter, resulting from forest fires or automobile and production plant gases may be found in the smoke and haze. The most common PM10 and PM2.5 sources come from road dust, industrial processes, electricity generation, and fires.
Since particulate matter can be inhaled from the air, particle pollution exposure can create an array of health concerns. With relative exposure, PM can cause respiratory problems, lung damage, nonfatal heart attacks, and even premature death among those who already have a heart or lung condition.
Particulate Matter and the Environment
In addition to direct health issues, particulate matter in the air causes visibility reduction, otherwise known as haze. It also harms plant life and wildlife as it depletes nutrients in our soil and pollutes the ecosystem. In addition, PM can negatively impact our fresh water sources as well as our farm crops.
Government Regulations on Particulate Matter
The first set of standards for particulate matter was set in 1971. Since then, the Clean Air Act of 1970 has also created standards for environmental air pollutants, including particulate matter. This National Ambient Air Quality Standards (NAAQS) protects public health as well as public welfare including damage to animals and crops. The EPA continues to implement further regulations ensuring the decrease of PM concentrations and the increase of safety to humans and the environment.
