What causes mold growth?
Mold is a ubiquitous part of the natural environment. Molds play a critical role in the decomposition of natural organic material. Individual mold spores are invisible to the human eye and are floating around outside in nature and indoors. However, when those spores and are exposed to wet/humid indoor areas they can begin to grow or colonize. It is impossible to eliminate mold and mold spores in the indoor environment due to daily human activity and the operation of building ventilation systems.
Mold is found almost everywhere and can grow on wood, paper, carpet, foods, insulation, ceiling tiles, clothing and painted walls as long as moisture and oxygen are present. Mold needs moisture to grow, therefore maintaining indoor moisture and humidity levels between 30-60 percent and fixing water leaks promptly will reduce the likelihood of indoor mold growth. Read more on mold from the CDC.
Given a source of moisture, mold can grow just about anywhere. Moisture control, air circulation and good housekeeping practices are necessary to control mold growth.
Are there state or national regulations regarding mold?
There are no federal or state regulations governing the presence of mold or mold spores in buildings. There are also no health standards from the Centers for Disease Control and Prevention (CDC) or public health departments for concentrations of mold spores in the indoor air. The presence of visible mold on indoor building materials should be remediated. Read more on mold testing from the EPA.
Why not conduct mold testing?
Mold testing is not recommended in many cases. Instead, careful detailed visual inspection and recognition of moldy odors should be used to find problems needing correction. Efforts should focus on areas where there are signs of moisture or water vapor (humidity) or where moisture problems are suspected. The survey goals should be to locate indoor mold growth to determine how to correct the moisture problem and remove contamination safely and effectively. If suspected mold or mold promoting conditions are found, UK EHS assumes a mold infestation and recommends the appropriate corrective action.
The CDC and EPA, do NOT recommend testing as there are no exposure-based standards to use for evaluation of the sampling results.
UK EHS does not recognize 'at home' purchased settling plate or 'do it yourself' mold sampling kits. These methods are non-volumetric, and not indicative of airborne concentrations. This method of sample collection does not follow the analytical methods recommended by the American Industrial Hygiene Association (AIHA) or other professional organizations. One will get similar results by leaving a piece of fruit on the counter - mold will grow where there is a food source and moisture.
How does mold spread?
Air circulation in a building varies throughout the day and depends on the level of activity in that space. Mold spores are always present in both the indoor and outdoor environment and can be carried in on clothing, backpacks, shoes, etc.
Should I purchase a portable air cleaner and dehumidifier?
If you would like to purchase a portable air cleaner for your residence, please refer to the Guide to Air Cleaners in the Home provided by the EPA.
What are the health effects of mold?
Some people are sensitive to mold and may experience short-term or acute reactions in the presence of mold growth. Symptoms associated with mold exposure are not unique and cannot be readily distinguished from symptoms caused by other medical conditions, such as the common cold or seasonal environmental allergies. We recommend that you see your health care provider if you experience any health concerns.