FRIDAY, June 19, 2009 (HealthDay News) -- Perhaps it's time to rethink the "three-second rule" when it comes to eating food after it falls on the floor.
New U.S. research shows that most kitchen floors have some insecticide residue, including traces of organochlorine insecticides, such as chlordane, heptachlor and DDT, that were withdrawn from the market or banned in the 1970s and 1980s.
The study is in the June 15 issue of the journal Environmental Science & Technology.
Researchers swabbed the kitchen floors of a nationally representative sample of 500 randomly selected homes between June 2005 and June 2006.
The floor swipes were gathered as part of a survey by the U.S. Environmental Protection Agency and the U.S. Department of Housing and Urban Development that collected data on a range of household contaminants, including lead, allergens, mold, pesticides and arsenic.
The most commonly detected insecticide was permethrin, a carcinogen, which was present on 89 percent of the floors.
About 78 percent of the floors had measurable levels of chlorpyrifos, a broad-spectrum insecticide used to control pests in the house and garden.
About 64 percent had chlordane, one of the organochlorine insecticides that are no longer in use.
Other compounds that were found included piperonyl butoxide (52 percent), cypermethrin (46 percent) and fipronil (40 percent), a relatively new residential-use insecticide used to kill fleas and ticks on pets, termites and ants and cockroaches in bait traps, according to the study.
The insecticide concentration was mostly low, the study reported. Even so, the presence of insecticides on kitchen floors could be a source of exposure to the occupants.
About 78 million U.S. households, or 74 percent, use pesticides, according to the government survey, and Americans spend nearly $1.3 billion and apply 888 million pounds of active ingredients annually.
North Dakota State University has more on safe handling of pesticides.