The Hows and Whys of Pesticides

Consumers are often concerned about the amount of pesticides that can end up on produce after harvesting and worry if fruits and veggies are safe to eat. Carl Winter, PhD, a food toxicologist and the director of the FoodSafe Program at the University of California, Davis explains why we need pesticides and the regulation and safety behind them in this video. Winter explains that in toxicology, “it's the dose makes the poison.” The amount of a chemical, not its presence or its absence, determines the potential for harm. And with pesticides in food, whether it’s conventional food or organic foods, the levels of pesticide residues on those foods are very low and not considered to be of any health concern.

Why Are Pesticides Used?
Pesticides are one of the top tools that can control food waste by making it easier for producers to grow food. A lot of food is wasted because of damage from insects, plant diseases and weeds. By controlling those variables with the use of pesticides, it makes food more available and more affordable for consumers.

Are Pesticides Safe?
The risks from pesticide residues in foods like produce and grains are miniscule, and are typically at very small fractions of the levels that would be required for long-term health consequences. The benefits from consuming these foods are immense; and there is a tremendous amount of data showing that consuming a lot of these foods can decrease one's risk of heart disease and certain types of cancers. As a result, the benefits from the use of pesticides tend to significantly outweigh any theoretical risks to consumers from pesticide residues.

Who Regulates the Use of Pesticides?
There are many agencies involved in regulation. The U.S. Environmental Protection Agency is responsible for determining that pesticides pose a reasonable certainty of no harm in foods. They follow the best toxicological and risk assessment practices that are available to them to allow them to make those conclusions. The major federal agency that approves pesticides for use is the Food & Drug Administration (FDA). The FDA analyzes produce from all over the world for pesticide residues, and generally find that the typical levels encountered are much lower than the allowable levels. There is pretty high bar that any pesticide manufacturer has to get over before they can have their pesticides approved for use.

What about Produce from Other Countries?
The US does not allow residues of pesticides that are not registered here in this country for use on particular commodities. So anything coming in from other countries still has to meet our residue standards.

Does Washing Help Reduce Pesticides?
Washing produce is very important. The major benefit is that washing can minimize the risk of microbes like bacteria causing foodborne illness. At the same time, washing might reduce pesticide residues to even lower levels, even though they are already safe for consumption.

What about Pesticide Resistance?
Producers have seen over many decades that the pests that we're trying to control with pesticides can develop resistance. As a result, sophisticated resistance management programs are put in place like crop rotation to increase the fertility in the soil and pesticide rotation to minimize the chance of any resistance occurring for the weeds, the insects, or the plant diseases that we can control with pesticides.

Are Pesticides Used on Organic Foods?
Pesticides can be used on organic produce provided that they're approved for use by the national organic standards board. About a quarter of organic foods, do test positive for pesticide residues. Traditionally, the pesticides approved for use in organic production tend to be more biologically derived, such as naturally occurring chemicals. They still follow the same principles of toxicology as synthetic chemicals, but they do normally have a natural origin.