Indoor Air Quality Assessments
"We have several employees in our office who complain of allergies, congestion, headaches, and trouble concentrating. Most say that they feel better at home and worse after they’ve been in the office for a few hours. We had the office tested for mold but nothing was found."
While exposure to mold can certainly result in some or all of the symptoms listed above, mold is not the only cause. Although mold is the number one indoor air quality issue, the complaints could arise from an allergic response to pollen, dust, construction debris, or other indoor air contaminants. They could be caused by animal dander that passed through an open window or through the HVAC system filters. There could also be chemical causes, such as cleaning products. Your employees could be responding to carbon monoxide levels resulting from a heat exchanger leak in your gas furnace or truck exhaust finding its way into the HVAC duct system. The symptoms could also result from excessive carbon dioxide or lack of oxygen due to insufficient fresh air entering the building.
How can real cause be identified?On-site, measurements of oxygen, carbon monoxide and carbon dioxide levels will quickly reveal if these are the culprits. The collection of samples of the indoor air and examining for animal dander, fibers, pollens and chemicals will determine if any of these agents are at the source of the issue. There are several class of contaminants that can cause similar symptoms.
Types of indoor air contaminants:
Bacteria, molds, mildew, viruses, animal dander, cat saliva, house dust mites, cockroaches, and pollen can aggravate allergies and asthma. Mold and dust mites require specific moisture and temperature conditions to flourish and can be controlled using proper waterproofing techniques and climate control. Dander and excretion from indoor pets can be difficult to control.
Common chemicals such as paint, cleaning supplies and pesticides can directly cause health problems. Air fresheners and cosmetics can also contribute to indoor air pollution.
Volatile Organic Compounds (VOCs) are the largest component of indoor air pollution. The most common one is formaldehyde, which off-gases from glues used in engineered-wood products such as plywood, OSB, or particle board. Synthetic carpet, oil-based paint and oil-based polyurethane are other sources of VOCs.
Smoke from candles, tobacco, fireplaces, poorly drafting heating systems, and food frying contains soot, ash, VOCs, carbon monoxide, and other contaminants that can cause health problems.
Older buildings may have asbestos steam pipe insulation, which, when flaking, can become airborne and has been linked to health problems. Radon is an invisible gas that occurs naturally in rocky soil. It can rise into house through cracks in the slab floor on the lowest level. Long term exposure to radon and airborne asbestos is believed to cause cancer.
Although moisture itself is not an indoor air pollutant, excessive moisture can cause condensation on cellulose materials such as paper or wood which eventually will lead to mold growth as well as provide favorable conditions for insects and other vermin.
Health symptoms from poor air qualityTo give you an idea, here are common symptoms associated with the various classes of contaminants.
Eye, nose, and throat irritation, shortness of breath, dizziness, lethargy, fever, digestive problems. Can cause or exacerbate asthma; humidifier fever; influenza and other infectious diseases.
Eye, nose, throat irritation, wheezing and coughing, fatigue, skin rash, severe allergic reactions. Long-term exposure may cause cancer. May also cause other effects listed under "VOCs"
Eye, nose, throat irritation, headaches, loss of coordination, nausea, damage to liver, kidney, and central nervous system. Some organics can cause cancer in laboratory animals, some are suspected or known to cause cancer in humans.
No immediate symptoms, but long-term risk of chest and abdominal cancers and lung diseases. Smokers are at higher risk of developing asbestos-induced lung cancer.
No immediate symptoms. Estimated to contribute to between 7,000 and 30,000 lung cancer deaths each year. Smokers are at higher risk of developing radon-induced lung cancer.
At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination, headaches, dizziness, confusion, nausea. Can cause flu-like symptoms that clear up after leaving the affected building. Fatal at very high concentrations.
Eye, nose, throat irritation, respiratory infections, bronchitis, lung cancer from severe and prolonged exposure.
Irritation to eye, nose, and throat; damage to central nervous system and kidney; increased risk of cancer.