Mold thrives most often in moist conditions. Moisture, combined with a nutrient source such as soil, dust and products containing cellulose or other dead organic matter provides the ideal environment for colonization. Concern about the potential health risks of certain kinds of mold has resulted in a number of highly publicized incidents and court cases in the last few years.
There have several high profile mold lawsuits in California and Texas involving millions of dollars being awarded for damages.
Indoor mold always has been a problem. The problem has been aggravated by changes in construction techniques brought on by the energy crisis of the 1970's. Efforts to create energy-efficient houses without accompanying efforts to regularly exchange the air inside have been linked to a dramatic increase in cases of asthma in the last three decades. There has been a heightened sensitivity to all environmental issues because of heightened air-quality concerns, especially mold issues.