The public needs to be aware that showers, dishwashers and laundry machines are major sources of indoor air pollution, according to environmental engineers at the University of Texas at Austin. Tap water contains trace amounts of chemicals such as radon and chlorine. When the water is heated the chemicals are transferred from water to the air through vaporization. Breathing exposure to many of these chemicals may rival or exceed exposure from drinking the water, said Richard Corsi, a professor of civil engineering at the University of Texas who led the research funded by the Environmental Protection Agency. Americans who rely on well water are at even greater risk, he said, because well water may be contaminated by gasoline from leaking underground storage tanks, or industrial solvents previously spilled on soil.
Dishwashers are particularly effective at transferring the chemicals from water to indoor air.
All of the chemicals are released at once when the door is opened at the end of the cycle, said Corsi. He also said that laundry machines and dishwashers using chlorinated bleaches or detergents might increase exposure. Laundry machines using chlorinated bleaches or detergents might increase exposure to indoor air pollutants. Over the last 50 years, indoor air quality has gotten worse due to developments such as attached garages which can bring automobile exhaust and stored chemical vapors inside the house. As well, the energy crisis of the 1970s led to more airtight homes and buildings, allowing pollutants to build indoors, said Corsi.