Can Pesticides and Health Live Together?

Previously in our Medium articles, we discussed the history of pesticides. Today we’re continuing the theme, looking at how pesticides impact our health.

#1 On the Origins of Pesticides 📜

#2 Can Pesticides and Health Live Together? 🚑

#3 Focus: Endocrine Disruptors


#Episode 2

Some people don’t think about it at all, some people figure it’ll all blow over, some people know someone who had problems…There are those who know the topic by heart and those who have heard a little something…And then there’s the majority of consumers, who just need transparency and clarity on how pesticides impact their health. So let’s do that.

Health That’s Feeling Kind of Down…

In 2013, a study analyzed the exposure of the French population to 3 types of pesticides: organochlorides (mostly banned, but still present in the environment), organophosphates and pyrethroids (mostly used as an insecticide). The results? Over 90% of the population is soaking in these pesticides, which means no less than 59 million people.

🚑 On a larger scale, according to the OMS, there are more than 1 million serious cases of pesticide poisoning and roughly 220,000 deaths across the world annually. That equals the entire population of a city about the size of Bordeaux or Lille…

These figures can make your head turn. But are they totally objective? When did people start to realize the potential impact of pesticides on our health, and who first spoke out?

Rachel Carson was one of the first people to study the impact of pesticides. Beginning in 1945, she particularly studied DDT, the most popular pesticide of the time (see our first article). In 1962, she published a work that made her famous, “Silent Spring,” listing the negative effects of pesticides on the environment and on birds. Specifically, DDT seemed to cause bird eggs to have thinner shells. According to her research, this caused a higher mortality rate and reproductive problems for the birds. The disturbing results quickly pulled down the full force of the chemical industry, and particularly Monsanto, onto Carson’s head. Monsanto even published a book meant to parody “Silent Spring”. Its title? “The Desolate Year”.

Ad published in Time Magazine in 1947

By publishing this work and her results, Carson truly awakened the public. If pesticides have an impact on the environment and on animals, why would humans be safe?

Many scientists began to investigate the subject. They wanted to analyze how pesticides could arrive in our bodies, as well as the potential consequences on our health.

One study analyzed the impact of DDT over 50 years after that first alert sounded by Rachel Carson. According to the results, American adults in their 50s who were exposed to DDT through their mothers while in utero were four times more likely to develop breast cancer than those who had been less directly exposed.

So even the early results led us to believe that pesticides had an impact on health. And that brings us to an essential question: how are we exposed to pesticides?

The Pesticide Pathways

The ways in which we are exposed to pesticides seems to be one of the key factors in their impact on our health. So let’s get into the details.

👉 Orally

Do you practice onycophagy in your free time? (Ok, it’s just a fancy word for biting your nails.) Do you, on occasion, eat? (Incredible question, right?) Do you ever bring your hands toward your mouth ( to yawn, to sneeze, or for whatever other reason that you’d prefer to keep to yourself)? Then you’ve likely been exposed to pesticides orally.

Here are two clear examples. In 2005, the DGCCRF in France (essentially, the government body in charge of fraud) found traces of pesticides in more than 75% of the strawberry that they tested. Even water isn’t totally guilt-free. According to a recent study by UFC Que Choisir, the water arriving from the tap of more than 2.8 million French people is polluted. And pesticides are “by far” the #1 cause of these results. They contaminate the water of almost 2million consumers, largely in rural areas where agriculture is a key activity.

👉 Inhalation

Pesticides, after being applied, can then travel more or less freely through the environment and the atmosphere. Somewhere between 25–75% of pesticides used:

  • move during the application process (part of the product doesn’t arrive at its target)
  • move following the application process (due to the nature of the pesticides and their additives, meteorological conditions…)
  • move due to erosion (the wind moving soil particles upon which pesticides have been applied).

Thus the products find themselves in the air around us, the air that we breathe. But the impact of pesticides due to inhalation is even more critical for professions, involving:

  • fumigation (using smoke or vapor to disinfect an area)
  • preparation or application of pesticides in closed spaces (greenhouses, silos, livestock pens…).

👉 Cutaneous

This pathway is mainly a concern for people who are in direct physical contact with pesticides. This may be due to domestic use (gardens, yards…), but it is clearly evident in the agricultural profession. There it is the principle exposure pathway: 80%.

How to avoid this? Throw on your most futuristic outfit when you’re about to use a product: gloves, safety goggles, cap, jumpsuit. Sure, you might look like a mummy, but you’ll avoid the risk of exposure.

Thus today, whether we use them professionally or not, it is almost impossible to avoid exposure to pesticides. So what are the consequences of this exposure?

Pesticides’ Impact on Health

Although there are many studies on the subject, it’s important to underline the fact that today there is no consensus. ⚠️ The results are oftentimes contradictory and influenced by outside factors (political, administrative, legal…). That’s why we’ve simply tried to put together an objective list of consequences that pesticides can have on our health.

👉 Cancer

In France, the frequency of cancer grew by 63% from 1978–2000. This rise was due to numerous factors. But we do want to note that certain types of cancer, those that are considered to be particularly linked to the environment, grew very rapidly. Breast cancer, for example, increased by 97% from 1978–2000, and prostate cancer by 271%.

Prostate cancer is the second most common cancer in men, following lung cancer. If its causes are still poorly understood, it is likely a combination of interactions between genetics, hormones and our environment. Advanced age, family history, and sub-Saharan origins are currently the established risk factors. A recent study suggests that pesticides could play a similarly essential role. In the United States, a group of farmers and others who work with pesticides was studied. The results showed a heightened risk of prostate cancer in farmers who worked with pesticides (an increase of roughly 19%) as well as in professionals who apply pesticides (an increase of roughly 28%).

The study also showed a direct link between exposure to pesticides and the appearance of various illnesses among children living near locations where pesticides were sprayed. These illnesses included leukemia, brain tumors, congenital malformations and developmental/neurobehavioral disorders. The risks are particularly pronounced in children whose mothers were exposed to pesticides during their pregnancies.

And as another signal that the phenomenon is real, France has recently recognized that one cancer of the immune system (non-Hodgkin’s lymphoma, to be specific) is an occupational hazard for farmers who have been exposed to pesticides during their work. What’s more, five pesticides including one of the most commonly utilized have been classified as carcinogenic by the International Agency for Research on Cancer.

👉 Congenital Disorders

These disorders begin during pregnancy and can be identified prior to the child’s birth, at birth or later in life. The embryonic, fetal and childhood phases are particularly affected by environmental pollution.

The health effects that can result from exposure are varied:

  • During pregnancy: miscarriage, congenital malformations, low birth weight, shortened gestational periods…
  • After birth: problems with the reproductive system, metabolism, growth, or intellectual or psychomotor development…

The INSERM has shown that in France the exposure of mothers to household pesticides during pregnancy doubles the risk that children develop acute lymphoblastic leukemia. Another study has shown a similarly sharp increase in the risk of males being born with genital malformations.

👉 Reproductive Issues

In males, fertility can be estimated through quantitative and qualitative examinations of sperm as well as testing the blood for reproductive hormones. In females, fertility is estimated by using ovulation and blood tests for reproductive hormones.

Almost all of the studies that have been completed regarding reproductive issues related to pesticides have concentrated on males. In 1992, one study showed that the average sperm levels in males in Denmark had diminished by roughly 50% from 1938 to 1990. Another study that included 1351 males in the Paris region confirmed these results. Between 1973 and 1992 sperm concentrations dropped an average of 2% each year. This decline seems to be linked in large part to pesticide exposure. But does it also equal a decline in our ability to reproduce? There are no studies that confirm that position.

Yet in 2012 the INSERM published a study showing that infertility affected one out of every ten couples, noting that certain pesticides play an important role in this. For the first time, some pesticides were classified as toxic in terms of reproduction.

👉 Neurological Issues

One of the first major studies in this area was the Phytoner study in 2001. This study looked at the cognitive effects of long-term exposure to the pesticides used in winemaking. The study population was divided into 3 groups:

  • Those who were directly exposed
  • Those who were exposed through contact with plants and/or the environment around vineyards
  • A control group who was not exposed

The results? Those who were directly exposed had much lower scores than the others. In other words, functions such as selective attention, verbal fluidity and abstract thought were highly affected.

If we zoom in on regular users of pesticides (farmers, gardeners, landscapers…), the results are even more alarming. One study has shown that farmers’ risk of developing Parkinson’s is multiplied by 5.6, and their risk of developing Alzheimer’s is multiplied by 2.4 when compared to non-exposed groups.

What’s more, multiple studies show that children exposed by living in agricultural zones with pesticides for neighbors can lead to lowered intellectual performance (slow development, lower IQs…). Exposure to pesticides also seems to increase the risks for autism. One study has shown that women who are highly exposed to pesticides during the first 3 months of pregnancy are 7–8 times more likely to have a child who lands on the autism spectrum when compared to women who were not exposed.

Epidemiologist Isabelle Baldi likewise studied a group of 221 adults living in the Bordeaux region who were afflicted with brain tumors, finding that the risk of developing brain cancer was 2.58 times higher in subjects who had been most highly exposed to pesticides.

And even if there are still questions within the scientific community and the studies cited above haven’t been enough to arrive at a consensus, the law seems to be choosing its side. In 2012, a decree in France (n. 2015–636) officially recognized the link between pesticides and Parkinson’s : “In the view of the state, given the knowledge at our disposal, there is a causal link between Parkinson’s disease and pesticides. Parkinson’s is furthermore recognized as an occupational hazard linked to pesticides.”

👉 Immune System Issues

A scientific report summarized the results of over 100 studies concerning the effects of different pesticides on the immune system. In the majority of studies, there is evidence of immunosuppressive effects. What does that mean? Pesticides have a negative impact on our immune system’s efficacy. Nonetheless, the results announced in these studies are still widely controversial. They thus cannot confirm with certainty the link between pesticides and this type of problem.

Taking a Breath

The choice to use pesticides was made in a complex historical context that didn’t offer many other options or opportunities to look for other solutions. Today we have a bit more distance, we’re able to see the impact of this choice, and we can opt for solutions that offer a brighter future. 🌟

What would happen if we cast aside all of those complicated chemical products? There are thousands of alternatives that let us produce food without using pesticides. From organic agriculture to agroecology to permaculture to urban agriculture, the choices are there. And every possibility should be encouraged.

Need a bit more inspiration? Take a look at Demain ❤️