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Indoor Air Pollution
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PARTICULATES:
Particulates, particles or particulate matter are the general terms used for the mixture of solid particles and liquid droplets found in the air. |
- On average, every cubic foot of untreated indoor air has 20 million particles bouncing into each other.
- One way for a person to see some of these is when the sun is shinning through a window into the home.
- By count, less than 1% of particulate matter measures more than 10 microns and is visible to the naked eye. Some examples of large contaminants are pollen, mist, ash, dirt, and some dust.
- By count, over 98% of particulate matter measures less than 1 micron (sub micron) and can only be seen by powerful microscopes. Some examples of sub micron particulate matter include smoke, fumes, viruses, mold spores, and bacteria.
To put these sizes into perspective, you would have to line up more than 25,000 microns to equal one inch. The period at the end of this sentence is about 400 microns. And one strand of human hair measures from 40 to 120 microns across.
When we discuss airborne pollutants, the greatest concern is with particulate matter that is smaller than 2.5 microns because these can easily infiltrate your lungs. The small particles tend to stay airborne because their positive charge and minuscule weight keep them from settling onto surfaces.
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MICROBES:
Grouped by physical and behavioral characteristics, microbes include the following major categories: bacteria; protozoa; and, fungi/mold. Sizes range from 0.001 to 10 microns. Most of these biological contaminants rely on a humid and moist |
environment for their growth and survival. Some molds can produce certain chemicals, such as myco- toxins and Volatile Organic Compounds.
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GASES AND ODORS:
Indoor gases, such as benzene, formaldehyde, chloroform, and hydrogen sulfide, are released from furniture, cabinets, carpets, cleaning chemicals, copy machines, insulation, insect sprays, and hair sprays. Gases, ranging in size from 0.0001 to 0.001 microns, include volatile organic compounds (VOCs), |
which are chemicals containing carbon that evaporate or get into the air easily which make them easier to breathe in. Examples of common VOCs include benzene and trichlorethylene. Odors are typically made up of VOCs or other gases. To be effective, Air Purifiers should have a system that "ATTACKS" all three of these major components of indoor air pollution.
Indoor Air Pollution Sources
This chart lists the most common pollutants found in homes and buildings today.
| Category |
Pollutants |
Sources |
| Particulate |
Dust |
Humans, drapes, outdoor air |
| Particulate |
Pollen |
Clothing, outdoor air, pets |
| Particulate |
Tobacco Smoke, Hydrocarbons |
Smokers |
| Particulate |
Dander |
Humans, pets |
| Microbial |
Mold Spores |
HVAC ducts, carpets, outdoor air |
| Microbial |
Bacteria |
Waste containers, toilets, humans, A/C coils & ducts |
| Microbial |
Fungi |
Pets, foods, outdoor air, waste containers |
| Gas |
Methyl mercaptan |
Plastic, natural gas and propane additive |
| Gas |
Carbon disulfide |
Solvents |
| Gas |
Butyl acetate |
Lacquer, industrial chemicals |
| Gas |
Methyl mthacrylate |
Solvents |
| Gas |
MEK |
Solvents |
| Gas |
d-Limonene |
Solvents |
| Gas |
Toluene |
Solvents |
| Gas |
Hydrogen sulfide |
Toilet vents, water |
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