10 Facts About Pesticides You Didn’t (Want to) Know

Pesticides have been widely used in the U.S. for decades to combat everything from weeds to insects to bacteria.  These compounds allow farmers to cultivate acres of successful crops and keep food on our dinner tables.  But every chemical poses a risk, so I always like to familiarize myself with the chemicals I’m being exposed to, in order to make informed decisions about the health and safety of me and my family.  Here are a few facts about pesticides I thought I’d share – just in case you’re on the same fact-finding journey I am.

  1. Every Pesticide is Classified Based on its Intended Target
Photo courtesy of USDA ARS
Photo courtesy of USDA ARS

With the hundreds of pesticide compounds available on the market today, it can be confusing to know which one is best for your pest issue.  It only gets more confusing when people incorrectly use the term “pesticide” interchangeably with “insecticide.”

The EPA understands this confusion and has put some effort into classifying pesticides (rather, the active ingredients in pesticides) into categories that describe the type of pest they target.  For example, fungicides are compounds that target fungi (mildews and molds and the like).  The list is quite comprehensive – there are even categories such as molluscicides (which target molluscs such as snails) and ovicides (which target the eggs of insects and mites).  If you want to read up on these categories, check out the EPA’s pesticide category page here.

This clarity is taken a step further with the registration process that’s required for all pesticide substances.  Each registered pesticide is given a unique registration number and is given its own page on the EPA’s website where you can find out more about it.  Information including its common brand name (or names), the active chemical it contains, what types of pests it targets, and when it was registered for use as a pesticide are all listed there.  For example, EPA registration number 538-192 refers to Roundup Garden Weed Preventer.  EPA registration number 239-2689 refers to Scotts EZ Weed, which targets crabgrass and lawn weeds.

  1. Billions of Pounds of Pesticides Are Being Applied to Crops in the U.S.                                                                                                                                              

Yes, you read that right – billions of pounds of pesticides are being used each year.  In 2012, the EPA evaluated pesticide usage around the globe and estimated that 1.1 billion pounds were being used in the U.S.  If you look at the number of people living in the U.S., that number equates to roughly 3 pounds of pesticides per person each year.

If you’re like me, you probably read that statistic and thought it looked quite high.  We’re really using 3 pounds of pesticides per person?  But you have to remember that we’re not just talking about pesticides that are being applied to acres of fields to protect our crops.  Individual households use them throughout the year to tackle pests that find their way onto their property.  When I looked at my own household’s use of pesticides over the year, I realized that I was no exception:  ant spray for red ants, ant traps for carpenter ants, hornet spray, weed killer, poison ivy killer and baited mouse traps in the basement.  After looking at my own pesticide usage, it was easier to see how that could scale to the number of pounds that get used globally.

  1. Pesticides Don’t Stay Put

Pesticides don’t always stay where we want them to.  Most pesticides are applied by spraying them onto their intended site – plant, crop, house, lawn, etc.  As you might expect, a pesticide that gets applied on a windy day could cause the aerosol to be carried downwind from where it was supposed to land.  Even on a day that’s not particularly windy, a gentle breeze or a light rain could be enough to cause the pesticide to drift.  From there, the runaway pesticide can end up – well, almost anywhere.  Nearby soil, groundwater, houses, playgrounds, people and animals could all be unintended targets.  Even with careful use and application of pesticides, it’s hard to prevent any and all drift from occurring.  The EPA estimates that roughly 70 million pounds of pesticides drift from their intended target every year.

In addition to the cost of losing that much pesticide product every year, the bigger issue stems from where the drifting pesticide goes.  What happens if the pesticide drifts onto a nearby crop or plant that wasn’t meant to handle that particular chemical?  What happens if the pesticide drifts onto a crop which already contains a pesticide coating and the chemicals mix together?  What happens if the pesticide drifts onto a nearby playground where children are playing?  What happens to the aquatic life in a nearby lake, river or stream that suffers from pesticide drift?  There are a surprising number of questions and unintended consequences that have resulted from pesticide drift.

  1. We Don’t Know What Happens When Pesticides Mix
Photo courtesy of USDA ARS

Pesticides are designed with a single target (or class of pests) in mind.  They weren’t designed as though consumers would make a pesticide stew – a spoonful of herbicide, a dash of fungicide, a pinch of insecticide.  But these are questions we now have to answer because pesticide drift is causing these chemicals to come into contact with one another, and those mixtures are landing on crops and lawns and animals.

Various state and federal agencies (including the EPA) provide mechanisms for reporting observations and incidents when a mixture of pesticides was involved.  The data is recorded to the best of their ability; however, it’s challenging in cases where the mixing was unintentional and the identity and concentration of each pesticide can’t be determined exactly.

  1. Pesticides and Bees Don’t Mix
Photo courtesy of USDA ARS

Many pesticides are designed to target insects (technically, these would be called “insecticides”), which means they’re probably toxic to insects we’re trying to get rid of as well as the ones we might want to keep around – like bees.

Pesticides aren’t typically applied in a carefully controlled “one plant at a time” manner which means nearby bees could get dosed unintentionally (remember the consequences of pesticide drift from the previous section?).  With enough exposure to these pesticides, bees get sick and die off.  This happens even faster if a bee returns to the hive with contaminated pollen and makes the entire hive sick.

For those who may have forgotten, bees play a vital role in helping flowering plants reproduce (the fancy word for that is “pollination”).  A lot of flowering plants are responsible for the production of vegetables, fruits, and nuts and they cannot reproduce without pollen being carried from one plant to the next.  In fact, the United States Department of Agriculture (USDA) estimates that 75% of the flowering plants around the world (which makes up about 35% of the global food supply) depend on these pollinators (like bees).

  1. Kids are More at Risk Than we Realize
Photo courtesy of USDA ARS

Most of us realize that kids are younger and smaller than adults (if you hadn’t realized this, perhaps you should consult the Wikipedia page for “child”).  Their bodies are smaller and are more vulnerable to contaminants of any kind – including pesticides.  Their brains are still developing, their organs and limbs are still growing, and their bodies are smaller, so the concentration of a toxin gets very high very quickly in a child as compared to an adult.

Kids are further at risk, based on their behavior.  Anyone who has been around young kids knows that they spend a lot of time near the ground, rolling around or throwing things, climbing on things, and just generally exploring.  Plus, they are constantly putting things near their faces and in their mouths.

  1. Pesticide Residues Aren’t Easy to Wash Off
Photo courtesy of USDA ARS

Like most people, I’m always careful to wash all the produce I get from the grocery store before, but washing and rinsing and scrubbing those fruits and veggies never gets rid of all the pesticide residues that might be there.  This is partly due to the fact that the skin on some produce is somewhat porous and can grab onto those pesticide residues quite strongly.  This is partly because pesticides are typically applied to the crop when the fruit or vegetable has just started to develop.  As it grows, the plant can incorporate the pesticide which then turns into a full-grown fruit or vegetable with a small amount of pesticide embedded into it.  No amount of scrubbing is going to counteract that.  Keep in mind that scrubbing the surface of your produce will remove most of the pesticide residues and you can always consult the USDA’s Pesticide Data Program database for more information on the chemical residues that might be on your produce.

  1. Pesticides Accumulate Over Time
Photo courtesy of USDA ARS

By the time we reach adulthood, we’ve all been exposed to some level of pesticides.  Whether we’ve inhaled, ingested or absorbed them, they’ve found their way into our bodies.  Many of the pesticides out there are compounds that our bodies can handle – either by passing it through or by breaking it down.  However, some pesticides are harder to break down, which allows them to hang around and build up in our waters, soils, plants and even our bodies.  Some of the most persistent pesticides have been classified by the EPA as persistent organic pollutants (POPs) and their use is restricted and carefully monitored.

  1. They’re Particularly Dangerous for Farmers
Photo courtesy of USDA ARS

While we may be exposed to pesticide residues from eating an unwashed tomato, or living near an apple orchard, our exposure risk is much less than that of the farmers who have to work with these chemicals in large quantities and at high concentrations.

In 1987, the National Institute for Occupational Safety and Health (NIOSH) established a program to monitor and report incidents where pesticide exposure lead to an illness, injury or death.  Both NIOSH and the EPA help provide funding for states to be able to monitor these incidents, but up to 20,000 pesticide poisonings are still reported in the U.S. each year.  These incidents include events such as an improper use of a bug bomb; however, most of the incidents involve agricultural workers being exposed to high concentrations of pesticide chemicals during occupational use.

  1. Not Just Anyone Can Apply Pesticides

Given the health risks of being exposed to high concentrations of pesticides, it would seem logical that a certain amount of training be required before someone can start spraying these chemicals across wide public areas.  In fact, the federal government requires people to be properly certified before handling and applying pesticides – the “restricted use” ones, anyway.

All 50 states have requirements related to training and certification for people who want to want to apply a restricted use pesticide.  Some states even require a certain number of supervised hours in the field as part of their certification process.

It’s important to continue monitoring our use of pesticides; however, it’s equally important to monitor the places where pesticide chemicals could travel to (particularly the persistent ones).  The EPA has published several methods to help laboratories extract pesticides from soils, plants and waters, in an effort to determine our exposure level.  EPA Method 508.1, for example, outlines the extraction and quantitation of a handful of pesticides in drinking water.  With this method, 29 pesticides, 3 herbicides and 4 organohalides can be extracted using solid-phase extraction (SPE) and quantified using gas chromatography with an electron capture detector (GC/ECD).  Here’s an app note that outlines the method.

If you have additional pesticide facts you’d like to share or to learn about, feel free to submit your thoughts in the comments!

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