ABSTRACT
Contaminated indoor air began with soot from open fires on the ceilings of prehistoric caves, tepees, and hogans. Indoor air in the twenty-first century has developed its own distinctive pollution problems. Fifty percent of indoor air is generated from outside. Pollutants generated from indoor sources may be similar. They include carbon monoxide, carbon dioxide, nitrogen oxides, oxidants, hydrocarbons, biological aerosols, molds, pesticides, hydrocarbon products, terpenes, electromagnetic field, and radon and radon daughter products as well as respirable particulates. Sources of sulfur dioxide in the home include gas and coal stoves, sewer gas leaks, and some of the seepage from outdoor air when present. Nitrogen oxides pollute indoor air. Carbon monoxide is a pollutant commonly produced by combustion processes. Ozone is a secondary pollutant generated by photochemical reactions involving nitrogen oxides, hydrocarbons, and sunlight. The Environmental Exposures in Early Childhood Education Environments study examined air pollution and contaminant levels in dust in family-based childcare and preschool facilities in California.
