A notable percentage of vinyl flooring and wallpaper contain substances linked to cancer, learning disabilities, reproductive problems, asthma, and birth defects, a Michigan-based research group announced today.

The Ecology Center of Ann Arbor said roughly 5% of the 1,016 flooring samples it tested contained lead; those 52 products comprised vinyl sheet flooring and vinyl tile. In tests of wallpaper containing PVC coatings—representing 96% of the total research sample—more than half contained such hazardous chemicals as lead, cadmium, chromium, tin, and mercury.

The Ecology Center posted its findings on its www.HealthyStuff.org website. That same site also contains reports on past research it has done regarding toxic chemicals in toys, pet products, cars, handbags, back-to-school products, and children’s car seats.

Some of the center’s findings involve products that are suspected of causing health problems but haven’t definitively been banned. One example is phthalates, which in the case of building products may be used to soften PVC products. The center said its tests of flooring samples “contained numerous phthalates, at up to 12.9% by weight. Limited testing for phthalate plasticizers indicates most vinyl flooring contains four phthalate plasticizers recently banned in children’s products.”

Most PVC wallpaper also contains phthalate plasticizers.

Linoleum, cork, bamboo, and hardwood all tested free of lead, cadmium, mercury, and other hazardous metals, the center said.

Craig L. Webb is Editor of ProSales. This article originally appeared on ProSales Online.