Cancer is among the leading causes of deaths worldwide. In 2018 alone, there were 9.5 million cancer-related deaths around the world.
There is no single cause for cancer. In fact, scientists believe that it is caused by a combination of many factors. These potential causes include genetic, lifestyle, and environmental factors.
Lately, more researchers are expanding on studies that link cancer to environmental factors, particularly heavy pesticide exposure.
A recent study by Claremont Graduate University found that exposure to agricultural pesticides may increase one’s risk of developing brain cancer by up to 20 percent.
How do pesticides affect the brain?
It’s no secret that pesticide exposure harms our nervous system. Aside from its effects on the central nervous system, exposure to chemical pesticides also puts you at risk of several neurological diseases, including Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis (ALS), among many others.
In fact, a certain pesticide has been the target of many lawsuits lately. Studies have linked exposure to the herbicide Paraquat to an increased risk of developing Parkinson’s disease.
With brain cancer, the most significant risk factors are family history and radiation exposure. However, geographical variance in brain cancer cases suggests that environmental chemicals like pesticides may contribute to the risk.
Several research has also noted the adverse effects of pesticide exposure on the brain. These negative effects may include the following:
- Learning disabilities
- Developmental disorders
Therefore, new studies that aim to explain the connection between chronic pesticide use and brain cancer calls for the need to reevaluate safety limits on pesticide exposure for those who closely work with and around these harmful chemicals to prevent chronic and potentially fatal diseases.
What the Study Found
The study researchers reviewed meta-analysis studies to evaluate findings published between January 1997 and August 2019. All in all, the researchers evaluated a total of 52 different studies.
Findings of the study demonstrated that 77% of the studies show a positive association between brain cancer and farming, with a heightened risk factor between 1.03 to 6.53 times.
Based on demographic information, white farmers have the highest rates of brain cancer. However, according to occupation, individuals managing livestock, where insecticides are also widely used, have higher rates of brain cancer cases compared to individuals managing crops.
Overall, the study found that farmers who experience pesticide exposure increases their risk for brain cancer by up to 20 percent. The study expanded on a 1998 study evaluating brain cancer risk among the population of farmers.
Therefore, the 20 years evaluated in this study, along with research in the previous 40 years that provided evidence on the same topic, provide evidence on the potential association between brain cancer and pesticide exposure from farming.
Years of Evidence
A growing body of evidence over the past several years shows that chronic exposure even to low levels negatively affects our central nervous system (CNS). Particularly, researchers identify chemical exposure in agricultural settings as the cause of most adverse CNS effects.
However, aside from its adverse impacts to our CNS, pesticide exposure can also cause a wide array of neurological diseases. For instance, farmworkers as well as their children experience higher rates of neurological disorders due to cancer-causing compounds present in conventional agriculture.
These neurological disorders include:
- Amyotrophic lateral sclerosis (ALS)
- Parkinson’s disease
- Alzheimer’s disease
- Other adverse effects on cognitive function
Even indirect exposure to pesticides pose several risks to human health. Children, for instance, are more susceptible to the adverse effects of pesticides as their bodies are still growing.
Studies have also shown that a pregnant mother’s exposure to environmental toxins may increase the possibility of developing brain malformations as most developmental conditions begin even before birth.
This explains the increasing number of children with neurodevelopmental disabilities born in the United States. But the ones that are mostly affected are children from rural areas, where pesticide use is prevalent.
Indoor Use of Pesticides
The indoors must be a family’s safe haven. However, research found that even indoor use of insecticides can cause harm to individuals.
For instance, in a 2015 Harvard University meta-analysis, study authors found that indoor use of insecticides was linked to a 47 percent increase in childhood leukemia and a 43 percent increase in childhood lymphoma.
Meanwhile, a 2008 study showed that women who reported using herbicides have more than doubled their risk for meningioma brain cancer compared to women who never use herbicides. The risk of brain cancer was found to increase as years of herbicide exposure also increases.
It’s also important to note that the majority of these exposures came from handling herbicide-contaminated produce in grocery stores, and not from direct pesticide application.
Why is this important?
The study by Claremont Graduate University adds to the growing body of research supporting an association between neurological diseases and chronic exposure to pesticides.
According to the journal Occupational and Environmental Medicine, farm workers and individuals frequently exposed to high levels of pesticides have an elevated risk of developing brain tumors.
The National Farm Worker Ministry also indicates that farmworkers have an average life span of 49 years. For a better perspective, that’s 29 years less than the life expectancy of the general U.S. population.
The researchers conclude “…that the synthesis of evidence from over 40 years of epidemiologic literature supports an increased risk of brain cancer from farming with its potential for exposure to chemical pesticides. Increasing organic farming practices is one means to reduce the exposure of farmers to chemical pesticides.”
It’s important to understand how pesticide exposure affects human health, especially in cases where pesticides increase the risk of developing chronic disease. Mounting evidence that links pesticide use to different cancers can also aid in understanding the underlying causes of cancer in the future.
As several studies have already found, farmers and agricultural workers are not the only people who should be concerned of the adverse effects of pesticide exposure.
Even indirect exposure to environmental toxins can potentially harm people who live near farms and even unborn babies.