We will focus primarily on microbial contamination (mold and bacteria) caused by excessive moisture levels within the home from a variety of possibilities or by the mismanagement of the home environment by the occupant(s).

Biological contaminations are very common. Approximately 30 to 50% of homes in the northern USA and Canada have moisture content at a level conducive to the growth and buildup of microbial agents (mold and bacteria) that potentially could impact upon the health of the occupants. The majority of the population of the USA and many Western countries spend more than 90% of their time indoors. Several epidemiological studies in the USA, Canada, Taiwan, and Northern Europe have shown correlation between moisture in the home and increased respiratory tract complaints.