There are several different reasons people are willing to pay more for organic produce, but many consumers do so believing that it is a way avoid pesticide residues. That widely held belief is unfounded. Here is why:
- There are definitely pesticides used in the growing of organic crops. There are residues of those materials on the harvested products.
- Residues of synthetic pesticides are also frequently found on organic produce, even though they are not materials that are approved for use on organic.
Residues of Organic-Approved Pesticides on Organic Produce
Anyone who has ever gardened realizes that there are plenty of pests out there that like to "share" the plants we grow for food. There is no magic feature of organic that gets around this biological reality, and so there is an extensive list of pesticides that can be used by organic farmers. That list is not based on safety, but rather on whether the material is considered "natural." "Natural" does not automatically mean "safe." Indeed, some of the most toxic chemicals known come from nature. The organic-approved pesticides still have to be registered with the EPA because it is that agency's job to insure that these materials can be used in ways that are safe for us and safe for the environment.
Some organic approved pesticides are very benign (low hazard) materials, but so are a great many of the synthetic pesticides used by conventional farmers. Some organic-approved pesticides are slightly to moderately toxic. This is also the case for synthetics. There are many pesticides that are used by both conventional and organic growers. Some of the pesticides commonly used on organic crops are applied at rather high rates (pounds per treated acre). Some are approved for use until almost immediately before harvest. In any case, organic-approved pesticides definitely leave residues on treated crops by the time they reach the consumer.
Synthetic Pesticide Residues on Organic Produce
Occasionally, government agencies intentionally conduct specific surveys of organic produce to check for residues of non-allowed, synthetic pesticides. The Canadian Health Authority did this in 2011/13 and they found synthetic pesticide residues on 46% of the organic produce samples. In 2010/11, a similar survey was conducted by the USDA, and they also found synthetics on 43% of organic produce samples. Both sample sets included produce grown in the US, Canada and Mexico. What both of these agencies found wasn't alarming, but it definitely doesn't fit the marketing claims about organic as a way to "avoid synthetic pesticide residues." The presence of these residues does not generally mean that organic growers are violating the organic rules. Some of produce may have been mislabeled. Also, the testing methods are simply so sensitive that they can detect materials that got there unintentionally through something like spray drift or from harvesting or storage equipment. In fact, the rules for organic have always allowed for the "unintentional" presence of such chemicals. Buying organic does not mean "no synthetic pesticides."
Should We Worry About These Residues?Since avoiding all pesticide residues is not an option, the remaining question is "Should we worry about them?" Are the residues on organic and conventional different enough matter? The short answer is, "No." Here is why.
When regulatory agencies such as the EPA approve a pesticide for use on a crop, they use all the information they have about that chemical to define an amount of it which can be present at the consumer level without any meaningful risk. In the US that is called a "tolerance" and in most countries it is called an MRL (maximum residue level). These thresholds are designed to be very conservative, so that as long as the residues are at these levels or lower, they are about 100 times less than an amount that would be of any concern. These values are based on an extensive risk assessment based on millions of dollars worth of required testing. The regulators also restrict how the pesticide can be used (e.g. how long between the spray and harvest) so that any residues left should be below the tolerance.
So whether we are talking about the residues on organic or on conventional, the meaningful questions are:
- What is the particular chemical that was detected?
- How does the amount of that chemical which was found compare to the crop/chemical-specific tolerance or MRL?
Study after study demonstrate the substantial health benefits of a diet with lots of fruits and vegetables. That beneficial and delicious produce will come with some trace levels of the pesticides that conventional or organic farmers used to be able to successfully produce the food for your family. You can enjoy it without guilt.
Just a few links about produce and health:
- Broccoli benefits
- Asparagus benefits
- Health benefits of eating berries
- Vegetable fat health benefits
- How eating whole fruit reduces diabetes risk
- Comparing produce benefits to risks
- Eating apples can reduce stroke risk