Identifying and Removing Indoor Air Pollutants - Colorado Inspection Services

Carl Brahe
In most cases the air inside our homes is more polluted than the air outside. Pollution comes from many sources, mainly heating and cooking, sewer gasses, off gassing from furniture, building materials, carpets and drapes, dust and dander, scented candles, air fresheners, cleaners and moisture related sources like mold, bacteria, insects and rodents.
Pollutants fall into two categories: Particles and Volatile Organic Compounds (VOCs).

The EPA defines VOCS as:
Nov 6, 2017 - Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects. ... Organic chemicals are widely used as ingredients in household products.
‎Introduction · ‎Sources · ‎Health Effects

The EPA on indoor particulates:
Particulate matter (also referred to as PM or particle pollution) is a complex mixture of solid and/or liquid particles suspended in air. These particles can vary in size, shape and composition. EPA is especially concerned about particles that are 10 micrometers in diameter or smaller because these particles are inhalable. Once inhaled, particles can affect the heart and lungs and, in some cases, cause serious health effects. The human health effects of outdoor PM are well-established and are used to set health-based standards for outdoor air (National Ambient Air Quality Standards, NAAQS). PM is also found in all indoor environments. Indoor PM levels have the potential to exceed outdoor PM levels and the NAAQS. However, less is known about the specific impacts of indoor PM on health.

Some indoor pollution can be no more than an irritant, if even noticed by most people. People with sensitivities or those who are immune challenged may find these same pollutants deadly. Most can be removed from the air, although these air purifiers and filters do nothing for residues left on surfaces like tobacco or meth.

There are many sources of substances that can cause health problems both long-term and short-term. People often complain about smell like cigarette smoke and even meth fumes coming from neighbors. Most of these pollutants can be cleaned using various kinds of air purification technology.

It helps if you can identify the type of indoor pollutants in finding the source and eliminating it or at least taking the proper approach to cleaning the air. Indoor air quality monitors are available that connect with your smart phone and HVAC system to automatically act to keep your indoor air clean and healthy. They monitor fine particles, chemicals, CO2, humidity and temperature.

When you’ve identified the kinds of pollutants present the next step is to look for the sources. Health problems can be caused by a single pollutant or a combination. You may be able to eliminate the causes if they originate in your living space. Indoor pollution often comes from neighbors.

There are different kinds of air cleaners and filters that remove different pollutants in different ways. HEPA filters are the most common. These are not always true HEPA filters. True HEPA filters (class 14) remove 99.995% of all particles bigger than .3 microns. The lowest level of HEPA filters (class 10) clean only 85% of particles bigger than .3 microns.

HEPA filters are great for solids like dust and mold spores in the air but not so good for VOCs that are responsible for most of the smells and long-term health threats. Some symptoms from VOCs are headache, irritation of eyes, nose and throat, nausea and dizziness. VOCs can also make breathing related health problems worse. VOCs are off gassed from many sources like paint, varnish and stains, adhesives, solvents, cleaning chemicals and fuels, upholstery, drapes, carpets and furniture, cosmetics, moth balls and air fresheners, environmental smoke, and exhaust like vehicle emissions, radon and environmental smoking – tobacco, meth and marijuana, photocopiers and laser printers. Long-term exposure to some VOCs can cause cancer, nerve damage and organ damage. VOCs are cleaned from the air using activated charcoal. Activated charcoal is very porous with a large surface area that absorbs VOCs.

Activated charcoal filters remove VOCs from second-hand sources like smoking but do nothing to remove third-hand pollutants like residues from smoking cigarettes and meth that cling to all surfaces they touch and may find there way into your body through skin contact or through hand to mouth contact.

Some HVAC companies claim they can reduce radon to acceptable levels using a combination of methods even in high rise condos.

Ionization is another form of air cleaning technology that generates negative ions that attach to microscopic particles in the air making them heavier than the air causing them to drop to the floor or other surface where they can be swept, vacuumed or wiped away. Positive ions can help reduce radon. Some ionizers generate both positive and negative ions. Other air purifiers are hybrids that may include a HEPA filter to remove particles like dust, dander, spores, bacteria, etc. Others may include an activated charcoal filter to remove VOCs. Some offer all three technologies in a single unit.

Some air purifier manufacturers claim they can remove virtually every airborne contaminant down to a virus in size: pollen, dust, pet dander, mold spores, allergens and bacteria. The active carbon is also effective against smoke, odors, gases and VOCs. Some add magnesium dioxide and copper oxide to remove pollutants like carbon monoxide, ethylene oxide, and ozone.

There are other air cleaning technologies that may be harmful to health or ineffective like ozone generators or UV lights that kills microorganisms. UV light is mainly used as part of a system that may contain a HEPA filter. These filters can be fitted to and ion generators may be fitted to your forced air heating system.

You can make a quick, easy and in inexpensive air cleaner that can be placed near the source of the offending substance to filter it out at the site. A common 20” box fan that can be found in many homes and businesses is used to draw the polluted air through a filter and remove it. The only other materials needed are a roll of duct tape and 20 X 20-inch furnace filter. Tape the filter to the intake side of the fan with the arrow that indicates air flow direction on the filter pointing toward the fan.
These filters come in many kinds. The best type to use depends on the kind of pollutant. Filters with activated carbon absorb VOCs. Activated carbon is extremely porous giving it a large surface area for absorption. This is the filter you use for odors and gases you can’t smell.

For particles like spores, dust and dander use a HEPA rated filter. The higher the rating the better. Combination filters are also available. These filters can also be used in forced air furnaces to clean a larger volume of air. Most furnaces have a fan only setting that draws inside air through the filter without heating or cooling the air. A thicker than standard 1” filter may be desirable with increased fan use.

Air cleaners may decrease the results of indoor air pollution and reduce adverse health effects. There are many causes of sick building. Cleaning the air in your living space may remove all offending substances that originate within your living space, but it’s likely just one step in solving the problem.