At the supermarket, there are usually two sections in the produce aisle. In one, all the fruits and vegetables, from apples to zucchini, are labeled “organic.” Often these products cost more than ones that look the same but don’t have the organic label.
The big price tag can lead people to assume organic food is better than conventionally grown food. But, in the United States, the label simply means that the food has met guidelines set out by the U.S. Department of Agriculture.
For instance, organic fruits, vegetables and other crops must not have been treated with synthetic fertilizers, certain pesticides or sewage sludge. Meat, eggs and milk must come from animals that have been raised according to specific health and welfare standards. Also, farmers may not treat these animals with antibiotics or growth hormones and must raise them on organic feed. Products with multiple ingredients must contain 95 percent or more organic content.
What benefits the organic label might signify, though, has not always been clear.
For years, scientists have been trying to tease out whether organic foods are themselves different than those grown conventionally. Research is beginning to show organic foods can be better — and not only for the people who eat it. Growing foods organically also can help the environment, new data show.
Pesticides are good travelers
On a farm, pests and weeds can destroy a crop. So most U.S. farmers apply chemicals called pesticConventional farmers can apply any pesticide approved for use in the United States. Organic farmers cannot use all of those same chemicals. That doesn’t mean organic farmers allow insect pests and weeds to live peacefully among their crops. They too can use pesticides and weed killers. They just have a smaller list from which to choose.
But none of these chemicals will necessarily stay put. Some share of them will tend to move off through the soil, air or water. Eventually, these pesticides end up in streams where they can mix, creating a mystery soup.
Scientists have been studying how far and how fast pesticides can move through the environment. These data may then point out which animals are at risk of being exposed to the pollutants.
For instance, researchers recently looked at pesticides commonly used on California farms. They found the pesticides in Pacific chorus frogs living in national parks, forests and other locations high in the Sierra Nevada mountains. In some cases, the frogs lived more than 100 kilometers (62 miles) from the nearest farms that had used the chemicals.ides to limit the damage.