These days, the air inside many homes is more polluted than the air outside. That's because everything from pets to gas appliances to paint and cleaning products contributes to indoor air pollution. Most homes contain an alarming number of chemicals, and modern homes are built so tightly that they tend to trap the bad air inside. In a two-part series, NPR's Jon Hamilton looks at what's in household air, and what researchers and builders are doing to reduce indoor air pollution.
Part 1: Diagnosing Sick Walls
The walls of a home are supposed to protect those living inside. But when it comes to air, walls -- which can emit toxic chemicals -- are often part of the problem. Inside Jianshun Zhang's lab at Syracuse University are life-size walls that replicate those found in many modern walls. They're made up of layers of interior paint, primer, gypsum wall board, a vapor barrier, insulation materials and vinyl siding. Most of these layers release irritating chemicals into the air, from formaldehyde, which can irritate the eyes and lungs, to the vinyl chloride produced by siding, which can damage the liver.
Zhang's team is trying to figure out what chemicals each layer is releasing and how it affects the quality of indoor air. NPR's Jon Hamilton spends a day with Zhang at his lab and reports on what's known about indoor air pollution, and how scientists are helping architects design healthier houses.
Part 2: Building Healthier Houses
Kevin Stack runs Northeast Natural Homes, a company in upstate New York that specializes in houses built to have a minimal impact on the environment and very clean indoor air. Stack is putting the finishing touches on a home that's a showcase for products and building techniques that improve air quality. The floor coverings and kitchen counters are natural products. There's no wall-to-wall carpeting to release chemicals and trap dander. The foam insulation is made from soybeans instead of urethane. The furnace and hot water heater have sealed burners so emissions can't get inside. And air filters are installed throughout the house -- one of the easiest steps consumers can take to clean up a home's air.
John Vasselli of the New York Indoor Environmental Quality Center says houses like this one represent the future. "We will look back 10 years from now on this and say, my goodness, when we used to talk about the phrase air conditioning, that meant temperature and humidity. How foolish. Because there are things we are breathing that are potentially going to kill you, and we don't even understand them today." Hamilton talks with Stack and Vasselli about what consumers can do to clean it up.
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