Problems associated with problems in handling:
(1) relative humidity consistently > 50%. Humidity ideally should be kept between 30 and 50%.
(2) humidifiers and air handling equipment cleaned and maintained according to manufacturer's instructions, with regular cleaning of filters
(3) adequate ventilation with sufficient air changes per hour
Air handling problems may increase the concentration of pollutants and may encourage growth of molds and mites.
Water damage and mold:
(1) history of water leaks or flooding
(2) carpet in damp or unventilated areas
(3) visible mold growth
(4) noticeable smells (musty, fishy or locker room)
Biological sources:
(1) pets or other animals
(2) rodents, cockroaches or other insects
(3) plants or organic materials (soil, mulch, hay, etc.)
Pollutants associated with biological sources include dander, excrement, and food.
