Science News –January 11, 2006
Organic vegetables not pesticide-free
When it comes to banned pesticides like DDT, organic root vegetables may harbor pesticide residues as high or higher than conventional vegetables.
As a nearly $8 billion business in the U.S. alone, according to 2000 data [244KB PDF] from the U.S. Department of Agriculture, organic fruits and vegetables have moved rapidly from a fringe business at the local food co-op to a mainstream supermarket staple. A key reason consumers buy organic is to avoid pesticide residues, but a small study suggests that organic produce may not be quite as clean as shoppers expect. Banned pesticides like DDT were found in organic carrots and potatoes at levels as high as or higher than conventionally grown produce, according to a screening study conducted by a college undergraduate and presented at the Society of Toxicology and Chemistry annual meeting in November.
In all the carrot samples, concentrations of these chemicals were very low, in the low parts-per-trillion (ppt) range. The chemicals concentrated in the skin of the vegetables