Pests

Pests are living organisms that can cause damage to crops, to animals, and to humans, including insects, weeds, rodents, and fungi. In addition to damaging crops, pests can also leave behind dangerous chemical toxins, e.g., fungal produced mycotoxins. In order to safely feed the ever-growing population and to minimize the environmental impact of inefficient crop production, pesticides have been developed to prevent, deter, or destroy, detrimental pests.

The Nature of "Natural"

Pesticides

All non-mobile life forms, including plants, have evolved defense mechanisms to thwart those organisms that would consume them, including physical structures and chemical pesticides. When natural pesticides are ingested by larger animals, or a non-targeted species, their effects may be attenuated or found to be different. Many biologically active compounds have turned out to be of importance to human culture and health. One of the most notable is caffeine, produced by coffee plants and tea bushes, which paralyzes or kills any organism that feeds on the plant, but in humans serves as an enjoyable stimulant.

Pesticides are a large class of pest-targeting chemicals, including antibiotics, herbicides, fungicides, and insecticides, which are employed in agriculture to ensure high yields of quality crops.

EPA: About Pesticides

Advances in pesticide research and development has led to new synthetic and biological pesticides that are more specific for a target organism, less toxic to mammals and invertebrates, and more environmentally friendly. These reduced-risk pesticides may be applied at very low levels compared to older broad-spectrum synthetic and natural pesticides.

Pesticides: Probably Less Scary Than You Imagine

Do You Really Need to Buy Organic Foods To Avoid Pesticide Residues?

California Pesticide information Portal (CALPIP)

When Increased Pesticide Use Is A Good Thing


Black rot in apples caused by Botryosphaeia obtusa
For more examples, please navigate through the IPM images

Balancing the risks and benefits of pesticide use.

Agricultural pesticides offer significant advantages to consumer health, serving to reduce crop loss, increase land efficiency, and kill disease-causing organisms. While offering measurable benefits to human health, pesticides, as well as any synthetic or naturally produced chemical, can pose a risk to humans and the environment. In the United States, the Environmental Protection Agency (EPA) sets strict standards for pesticide application (frequency, quantity, timing before harvest), in order to safeguard consumer health.

What is the balance between the risks and benefits of pesticides?

The EPA assesses the potential risk of consuming pesticide residues from food and establishes safety limits to ensure “protection from unacceptable pesticide exposure.” The degree to which a specific pesticide is harmful depends on its chemical properties, target specificity, biodegradability, and water solubility. For consumer produce, the risk of pesticide exposure is dependent upon the identity and the quantity of pesticide residues present on produce.

Pesticides: Probably Less Scary Than You Imagine.

Pesticide Danger

A simple way of understanding the risk associated with a substance is to look at the quantity of that substance that is required to kill half the animals in a toxicity experiment. This quantity is known as the median lethal dose (LD50) and is a measure of oral acute toxicity. LD50s are determined for most chemicals that humans are exposed to, including caffeine, nicotine, salt, drugs, and pesticides, and are suitable for comparison analysis and risk assessment.

The following table and chart compare LD50 values for a variety of common chemicals as well as some of the widely used agricultural pesticides. The higher the LD50, the safer the chemical, i.e. the greater a dosage required for health effects.

EPA: Lethal Dosage (LD50) Values

Steve Savage did an analysis of the top pesticides used in California crops (California Pesticide information Portal (CALPIP)), and how they ranked with everyday chemicals that the population is exposed to (see graph below). Fifty-five percent (55%) of the pesticides used in California in 2010 were less toxic than Vitamin C. Sixty-four percents (64%) were less toxic than vitamin A. Seventy-one percent (71%) were less toxic than the vanillin in ice cream or lattes. Seventy-six percent (76%) of the pesticides were less toxic than prozac and 89% were less toxic than the ibuprofen in products like Advil. Ninety-seven percent (97%) of California pesticide use in 2010 was with products that are less toxic than the caffeine in our daily coffee, the aspirin many take regularly, or the capsaicin in hot sauces or curries. This is not the sort of image that most people visualize when they hear the word 'pesticides.' It is not that easy for most people to relate to these EPA category descriptions, so it is useful to make comparisons between pesticides and familiar chemicals in foods and pharmaceuticals (see graph below).

How dangerous are pesticides?

How dangerous are pesticides?

Pesticide Regulation

The Environmental Protection Agency reviews a variety of studies to ensure that new pesticides do not pose an “unreasonable risk to human health or the environment,” and to establish usage restrictions and regulations. Some of the types of information utilized in the approval process include toxicity analyses of the pesticide and its metabolites, application quantity and frequency, and the residues remaining in the food after harvest. The EPA updates regulations for pesticides as new data become available; this can include reducing application quantities, permitting usage on a new crop, or removing the pesticide from the market.

“EPA sets a tolerance, or maximum residue limit, which is the amount of pesticide residue allowed to remain in or on each treated food commodity. The tolerance is the residue level that triggers enforcement actions.” These tolerances ensure “reasonable certainty of no harm.“

EPA Factsheet

Minimizing Pesticide Risk with Tolerance Limits

The Environmental Protection Agency establishes tolerances limits for any pesticide that may be found on food by assessing the “potential risks to human health posed by that pesticide.” Conservative tolerances are determined based on worst-case-scenario risk assessments, which assume constant high level pesticide presence in food. This ensures strict tolerance limits that ensure human safety.

The EPA reassesses pesticide tolerance limits to ensure that they are concordant with current safety standards and scientific information.

EPA: Pesticide Tolerances

Read more about Process for Reviewing Tolerance Decisions Based on Anticipated or Actual Residue Data and also Status of Anticipated/Actual Tolerance Review Process Data.

USDA Pesticide Data Program

“In order to assure the safety of the US food supply, the United States Department of Agriculture’s Pesticide Data Program (USDA-PDP) has been monitoring pesticide residues in a wide range of domestic and imported commodities for over 20 years.”

USDA Pesticide Data Program

Every year the USDA-PDP selects a variety of crops for testing. The selected crops represent those of high consumption by the general public and by infants and children. Samples are collected at supermarkets and distribution centers, throughout the year, in order to “capture pesticide residues in the food supply as close as possible to the time of consumption.” This ensures “realistic estimates of dietary exposure to pesticides in the food supply”.

Thousands of samples are analyzed by cutting-edge analytical methods optimized for the detection of over 500 possible pesticides. Any samples with pesticide levels that exceed the safety tolerance limits set by the EPA are reported to the U.S. Food and Drug Administration (FDA).

Pesticide Use in Organic Farming

Prior to 2012, certified organic farms were not subject to periodic pesticide residue testing. Last year, a ruling was made to clarify a provision of the Organic Foods Production Act of 1990, which requires “periodic residue testing of organically produced agricultural products by accredited certifying agents.”

National Organic Program; Periodic Residue Testing

“Most consumers believe (erroneously) that organic crops are not sprayed with any pesticides at all. That is not true, and the criterion for what can be sprayed on organic has nothing to do with relative risk - it is simply based on whether the pesticide is deemed 'natural.'”

Pesticide Residues On Organic: What Do We Know? - Steve Savage

A variety of pesticides permitted in organic farming are much more toxic and less environmentally friendly than modern synthetic pesticides. A couple of examples:

More information

National Organic Program

Organic Regulations

The National List of Allowed and Prohibited Substances identifies substances that may and may not be used in organic crop and livestock production. It also lists the substances that may be used in or on processed organic products. In general, synthetic substances are prohibited unless specifically allowed and non-synthetic substances are allowed unless specifically prohibited.

Synthetic substances allowed for use in organic production

Organic crop production §205.601

Organic livestock production §205.603

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