But the blame extends beyond building materials. In addition, household products lurking under sinks in most American households release potentially harmful chemicals every time they are used. Personal care products, such as hair sprays, add to the indoor air pollution problem, as do solvents and paints used by hobbyists. Indoor pesticide use is a contributor, too. Ironically, even some air fresheners contain the same toxic chemicals found in moth balls.
Humidity can also be a problem, because it promotes the growth of mold and mildew.
Even the dander of a pet dog or cat can be troublesome. And naturally occurring radioactive radon gas can seep in from under the house. Clearly, the air inside our homes is polluted. Studies show that in many homes, indoor air is 5 to 10 times dirtier than outside air. Unfortunately, few people give indoor air quality a moment's thought when remodeling their homes, although simple measures taken during design and construction can avert much suffering.