Indoor Air Quality Questions & Answers

Q: What health problems can be caused by VOCs and mold?

A: VOCs (Volatile Organic Compounds) are invisible gases that are emitted from solids and liquids found in the home, such as building materials, cooking sources, gasoline and fuel, air fresheners, paints/varnishes, dry-cleaning, laser printers, carpeting, adhesives, cleaning solutions, and many other sources. These chemicals can build up in houses, especially in the winter and summer months when homes are generally closed up. Repeated exposure to VOCs can cause blurred vision, headaches, nausea, dizziness, coughing, lethargy, burning eyes, respiratory irritation, skin rashes, reduced lung function, respiratory illness, concentration difficulties, depression, and, in extreme cases, loss of consciousness and suffocation. Higher exposure can lead to liver damage, kidney and central nervous system irregularities. Some VOCs, like formaldehyde, can cause cancer.

Actively growing mold also produces gases, or chemicals, called MVOCs (Mold Volatile Organic Compounds). When mold levels are elevated and there is chronic exposure in the home, some individuals can experience negative health effects, or worsening of existing illnesses, that could run the gamut from mild to serious. These health effects could include allergies, skin irritations, asthma, respiratory infection, and toxic poisoning. In addition, individuals with suppressed immune systems may be particularly vulnerable to illnesses caused by mold contamination.

Q: Do VOCs and MVOCs stay in my house?

A: Yes, these chemicals will stay in the house until they are removed. The house is full of VOC sources as mentioned in the above question, and the amount in the air will eventually reach a constant level within a few days to a week in a closed house, depending on the source. Gasoline cans and kerosene lamps kept in an attached garage or in the home can generate significant VOCs, since they are generally stored in larger containers. VOCs from these sources can only be reduced by removing them from the home. If the VOC source can not be removed from the home, replacing the home air with fresh air on a regular basis will keep the VOCs at their lowest levels and will reduce your exposure. If the VOCs are from furnishings like wood and plastic, they will be at their highest levels when they are new, but will continue to emit VOCs for many years. In addition, VOCs from water-based paints can be present for up to 18 months after application.

MVOCs, since they are generated by growing organisms, can increase in concentration if mold growth is expanding in the house. This can lead to unsafe levels. The only way to remove this source is to have the existing mold removed and then prevent building materials like wood and drywall from getting wet, either from excessive humidity, leaky plumbing, or water intrusion from rain or ground water.

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