Are Frozen Blueberries Pesticide Free?

The Dirty Dozen

• Blueberries, along with lettuce, collards, nectarines, spinach, grapes and peaches, comprise what the Environmental Working Group dubs "The Dirty Dozen" of fruits and vegetables most vulnerable to retaining pesticide residue. Thin-skinned or virtually unpeelable, the Dirty Dozen also contain high nutrient levels while being susceptible to a wide range of insect- or bacteria-borne diseases. The dilemma of the Dirty Dozen might best be described as being delicious to all possible eaters, human or otherwise.

Fresh vs. Processed

• In some cases, pesticide levels passed on to human consumers can be drastically reduced by the stringent cleaning, coring and peeling required for processing. Two frequently-cited examples are 80 to 90 percent reductions in benomyl levels in apples processed into applesauce and tomatoes processed into juice.

USDA Monitoring

• Since 1991 the U.S. Department of Agriculture's Pesticide Data Program has monitored pesticide levels in domestic and imported fresh and processed produce. Commodities chosen for monitoring are tested for 2 years, then rotated off the list for 5 years to make room for other items. The most recent information on fresh and frozen blueberries is from 2008. Two issues need to be factored into pesticide ratings for blueberries. While pesticide levels are classified as low, between 0 and 3.3 percent total residue levels in samples for fresh blueberries and between 0 and 2.2 percent for frozen blueberries, all blueberries cannot be classified as residue-free. Accumulations are lower in both number and levels when frozen blueberry totals are compared to fresh totals for 2008, but some frozen blueberries both show residues of more than a dozen pesticides. Second, all residue levels are set against the background of Maximum Residue Limits.

Residue-Free Frozen Blueberries

• Steady USDA sampling and stringent measurements assure that pesticide levels in frozen blueberries remain low to nonexistent, depending on regional, local or even individual grower practices. This does not, however, assure that frozen blueberries are pesticide free. Finding pesticide-free berries, along with other pesticide-free produce, requires searching out private or organic growers and processors not using pesticides.