"Particulate matter" is a term used when discussing indoor air quality or an air purifier. Particulate matter (PM) is particle pollution in the form of dust, airborne metals, dirt, acids such as nitrates, and a whole host of other organic or inorganic materials. They can be large or small, liquid or solid, and be found in light or heavy concentrations.
As particles become smaller, they increase the potential for causing health problems. The smaller matter can more easily be inhaled and ingested into the lungs. If very small, they can even bypass the immune defense system, enter the body past the lungs and cause serious problems to the body's organs. The EPA defines two particulate matter groups: inhalable coarse particles and fine particles. The inhalable coarse particles can be from roadways, dusty industries, and other sources and are larger than 2.5 micrometers, but smaller than 10 micrometers in diameter. The fine particles can be smoke, gases and other sources where the particles are 2.5 micrometers in diameter and smaller.
More Information on Particulate Matter
Inhalable coarse particles can be seen by the naked eye without magnification, while the fine particles can only be seen with an electron microscope. To give prospective, the human hair is roughly 70 micrometers and the large, inhalable coarse particles are up to 10 micrometers. In other words, human hair is 7x larger than the inhalable coarse particles. That's small.
Particles can be emitted directly into the air from unpaved road or maybe dirt from construction sites. These forms of matter are known as primary particles. Then there are particles that can be chemically based and interact with air from such sources as power plants. They are considered secondary particles and often are the fine particles. It is these fine contaminations which are more difficult to understand and harder to predict environmental consequences. They are the major component in the haze surrounding our cities and reducing visibility.
Health Impact
Particle pollution is a health concern particularly for children, the ill, and those with preexisting health conditions. As intensity and exposure levels increase, so do the health risks. These risks could be in the form of simply sneezing, can evolve to conditions requiring hospitalization, or even worse, cause cancer.
The gamut of particulate matter health issues can be:
- Asthma
- Bronchitis
- Irritation to the respiratory system, causing coughing or difficulty breathing
- Reduced lung function
- Irregular heartbeat
- Heart attacks and
- Premature deaths for those with preexisting heart or lung disease
