I bet no one would believe me if I told them there were unidentified flying objects in their homes. So I am here to tell you that there are, millions of tiny unseen microscopic particles (so if you cannot see them you cannot identify them!!!) that we breathe into our lungs daily and contribute to indoor air pollution.
How we behave in our homes, the materials we put in them and the ability for outdoor air to infiltrate, all contribute particles into the air and contribute to indoor air pollution. The particles vary in size, shape and color and originate from many different places.
The particles we are most interested in and concerned about are particles in the size range of 0.3 microns to 10 microns. To give you an idea of how small a micron is, it is 25,000 times smaller than an inch or 50 times smaller than the width of a human hair.
Their shape and color vary, some particles looking like something from a horror movie while others have rugged or smooth edges (to see what some of them look like visit http://www.airmd.com/evaluations).
Some of the particles that can contribute to indoor air pollution include mineral particles, soot, pet dander, insect parts and waste, fiberglass, combustion particles, mold, bacteria.
The problem with small particles is their ability to enter deep into the respiratory system and deposit in the lungs. The particles can accumulate in important areas like the alveoli (where oxygen and carbon dioxide are exchanged that allows us to breathe) and cause problems like decreased lung function, COPD and asthma. Additionally, the particles can be absorbed into the bloodstream and deposit in and around the heart causing increases in blood pressure, heart rate and cause heart disease.
Although I make light of the topic title, fine particles in our home and work environments can cause serious problems and like any UFO, until you identify what they are (the specific particles in your home or work environment) you cannot be sure they will not harm you. It is for this reason everyone should periodically have their home and work environments evaluated for indoor air pollution.