Organic Foods

Organic.......Just be careful..
By Cobra01..

In the most places, farmers treat most crops with pesticides to increase yields and the foods' eye appeal.

Inevitably, studies have shown, traces of these pesticides remain on the food after harvest and are in the food we eat. People might be tempted to read that study's findings as suggesting that organically grown fruits and veggies are free of potentially toxic pesticides. In fact, the researchers tested only for a few pesticides—those currently approved for use on foods.

In contrast, an undergraduate chemistry student, in a separate small-scale study, recently screened veggies for a number of banned pesticides and made an interesting discovery: The chemicals showed up on both conventionally grown and organic veggies—in roughly comparable amounts. In fact, organic carrots had higher amounts of some chemicals than the conventional vegetables did. Even organic produce, especially root crops such as carrots, can carry trace residues of long-banned pesticides.

That pesticide-free period is supposed to permit rain to wash the soil of chemical residues. However, many long-used toxic—and now-banned—organochlorine pesticides can take decades to break down, Wolensky says. Moreover, many linger in soils for far longer than 3 years. Because root crops, such as carrots, make direct contact with soil, they have plenty of opportunity to contact lingering residues of formerly used pesticide.

Every carrot they tested harbored traces of p,p'-DDE, a breakdown product of the insecticide DDT. The leftover chemical is not only toxic itself but also functions inside the body as a weak hormone (SN: 7/15/95, p. 10). Many carrots carried residues of chlordane, a chemical widely used in treating homes threatened by termites. Some samples also contained small amounts of heptachlor, another once-popular termiticide.

In all the carrot samples, concentrations of these chemicals tended to be small, in the low–parts-per-trillion (ppt) range. Not surprisingly, the skin of the vegetables had accumulated higher concentrations of these chemicals than fleshy interiors had. For instance, in whole carrots, the mean concentration of p,p'-DDE was 40 ppt in the conventional vegetables, and 340 ppt in the organic ones. However, skin concentrations were 588 ppt for the conventional carrots and 3,050 ppt for the organic ones.

The same range of pesticides showed up in both conventionally and organically grown spuds, with the highest concentrations in the skins. For instance, among organic potatoes, mean p,p'-DDE concentrations were 40 ppb in skin but only 1.6 ppb in the flesh. Those values were roughly double the p,p'-DDE concentrations in conventionally labeled potatoes.

The variety of DDT breakdown products, termiticides, and other banned pesticides detected in both studies is consistent with that detected several years ago by an analytical chemist. Residues of chemicals inappropriate for crops turned up in 38 farm fields and two gardens sampled across four states.

At the concentrations detected, none of the chemicals in the carrots or spuds is dangerous alone. The veggies’ lingering residues wouldn't deter them from buying organic produce, because overall, they noted, organically grown crops should harbor far lower concentrations of pesticides and other agricultural chemicals currently applied to conventional crops. Still, they noted, the findings are a concern in that they add to the amount of pesticides entering our bodies from a host of sources—the air, water, household chemicals, and foods.

The residues that they found were what remained after they had washed each carrot, much as any cook might. They recommends that cook's further cut pesticides in families' diets by peeling all carrots, spuds, and other root vegetables before cooking or eating.