Julia Darnton from MSU Extension answers your questions about food and pesticides.
October 12, 2017Julia Darnton is a Community Food Systems educator with MSU Extension.
If you are concerned about the level of pesticide residues on your food, I advise that you educate yourself about food production and get to know a farmer. Ask about his or her growing practices and pest management techniques. A farmer should be able to tell you the kinds of controls used. This takes some time, and it also requires that you know what to ask. One of the first things I would recommend is to tell the farmer a little bit about why you are asking and what you are looking for. This helps the farmer to understand the motivation behind your search and helps you to begin to establish rapport and trust.
In addition, there are a few things you should know, including what a ‘pesticide’ is, why farmers use pesticides, and how pesticides and food safety are regulated in the United States. Pesticides are any a substance used for mitigating the negative effects of a pest (disease, insect, weed). Pesticides include everything from the biological caterpillar control Bacillus thuringiensis (“Bt”) to the somewhat infamous glyphosate (Roundup). Not surprisingly, people may feel differently about the presences or absence of a pesticide based on its characteristics, most importantly it’s toxicity to non-target organism (e.g. you and me). It is critical when talking about pesticide residues to discuss the idea of toxicity and exposure or dose. Toxicity is the ability of a substance to cause injury to a living organism and in the case of pesticides, toxicity levels to mammals, fish, birds, and plants are all of concern. But toxicity is not a characteristic unique to pesticides, in fact most substances can become toxic to people with a high enough exposure level, even those we commonly view as benign or beneficial including water or salt. Substances cannot simply be sorted into toxic or non-toxic categories. This concept of toxicity and exposure is how we assure a safe food supply, by limiting the dose and exposure of the public to pesticides based on rigorous residue and toxicity testing for each individual material and intended use or crop.
Most farmers use Integrated Pest Management (IPM) techniques, which involve scouting for pests, understanding their life cycles and choosing an intervention based on that information. IPM also emphasizes using the least toxic and most effective intervention necessary to control pests and in the least harmful way, to reduce potential impacts on humans, animals and the environment. Many controls don’t involve spraying pesticides including preventative measures, companion plants that repel insects, trapping, soil cultivation, knocking bugs off plants and even using other insects to control the pest. For example, ladybugs will eat destructive aphids.
If you are looking for food that has not been treated with pesticides, be clear about that when asking farmers. Food labeled “organic” is not necessarily free of pesticides. Instead, the National Organic Program (NOP) regulates what chemicals can and cannot be used in an organic system. The NOP encourages farmers to use IPM techniques. Organic farming is regulated through an audit process that requires farmers to maintain records about their production and follow organic standards of production.
Consumers looking for pesticide-free food should also ask about pest control techniques used in organic production. It’s important to understand that due to a reduced effectiveness on the part of organic pesticides, a greater amount of pesticides are applied to organic products than to conventional products. This actually may increase the potential pesticide residue on some organic products.
Washing with water reduces dirt, germs and pesticide residues remaining on fruit and vegetable surfaces. No washing method is 100% effective for removing all pesticide residues but according to the National Pesticide Information Center, holding the fruit or vegetable under flowing water is the best option for removing pesticide residues. Be aware that a farmer must wait a required length of time depending on the pesticide used before harvesting produce. During this time, the residues are degraded to below toxic levels. Many commercial crops go through several washing steps before they are sent to the store or a warehouse. Each wash after harvest reduces pesticide residues, too.
Also, are there any laws requiring food producers to disclose that pesticides are used on their products?
There are not any laws in Michigan or on the federal level that require food producers to disclose pesticides on their products either on the label or through any disclosure form; however, the use of pesticides in fresh produce is highly regulated.
All pesticides are specifically labeled for use against certain pests on certain crops. This labeling is considered federal law. If a pesticide is used in a way not specifically stated on the label (either through overapplication, or application against a pest or crop not stated on the label), the crop it is used on is considered adulterated and the farmer can face crop seizure, a fine or jail time.
Scientists, both with chemical companies and at universities, have spent years studying labeled chemicals used for food crops. They have determined the degradation times, human toxicity, nontarget organisms (such as bees, frogs and fish) toxicity and potential environmental impacts of these chemicals BEFORE they were approved by the Environmental Protection Agency (EPA) – the regulatory body for pesticides – for release. The EPA reviews this data and considers the totality of a person’s pesticide exposure when granting companies label uses. It considers the average exposure, through diet and in the environment, for an adult, a senior and a child when figuring out how many types of things it will allow a pesticide to be labeled on. If a particular use would increase the risk of exposure of any one group over a certain threshold, it is denied.
Many private companies go further in monitoring the pesticides used on the food they purchase from fruit and vegetable farmers. In several cases, companies hire their own IPM scouts to scout fields of farmers they will be buying from, specify the types of pesticides that can and cannot be used as well as the rates of application on their crops. All these specifications are more rigid than the law. Other produce buyers require all pest management records be audited annually for proper use. In general, the larger a fruit and vegetable grower is, the greater the number of controls in place.
Both federally and in Michigan, a class of pesticides and herbicides are marked as “restricted use.” This means that the sale and application of these chemicals is limited to licensed dealers who may sell that product to a certified applicator only. Each of these groups is required to take and pass examinations that demonstrate that they understand how to reduce the potential risks associated with the application of pesticides. Applicators must pass a standard or CORE exam and a more specific exam that relates to the subcategory of pesticides they will apply. Michigan State University Extension provides education for safe pesticide application through our IPM team.
There is an increasing effort to improve the traceability of food to address any potential foodborne illness. Traceability is a form of documentation that follows the food product from the farm to the retailer. Traceability standards are becoming more common to allow products to be linked back to the source to investigate potential vectors of contamination or infection. This can also add to the understanding of how food is grown on a particular farm or even a specific area of a field on that farm. This form of tracking requires that records be kept of the farming practices, and harvest and handling of foods on farms.
Ensuring that our food supply is safe and wholesome is a priority for federal, state and local governments, for farmers and food producers, and for Michigan State University Extension. Laws and regulations are in place and enforced to make sure chemical pest controls are used in accordance with labels, to reduce incidents of foodborne illness and to improve on-farm food safety.