The Impact of Atrazine on Human Health

by Bashar Khiatah, MD

The Rise of Pesticides

The Environmental Protection Agency defines pesticides as any substance that is used to kill unwanted organisms. The general term ‘pesticides’ has many categories depending on the targeted organism: herbicides, fungicides, insecticides, etc. For centuries, humans have tried to utilize (or more recently invent) substances that will control weed growth and prevent insect, fungus, and parasite infections on their crops. As the agricultural industry grew, this issue became even more pressing, since pests on crops meant financial losses.  Then in 1939, Swiss chemist Paul Muller discovered DDT’s (Dichlorodiphenyltrichloroethane) potent insecticidal effect. DDT became the first synthetic organic pesticide commercially available to use in the US.

Although from the beginning, scientists expressed concern over potential safety hazards of DDT use, it took three decades to convince the government to ban its use, despite overwhelming data supporting its harmful impact on human health (1). The story of the DDT is perhaps the most well known story of the detrimental effect of toxins on health. Even today, we can identify DDT in our systems- the fact that it was banned 1972 didn’t get it out of our environment. You would hope that we would learn from toxin disasters like DDT that these pesticides are dangerous, but even today industry fights the research on the currently used pesticides.

After banning DDT, the agriculture industry moved on to other (equally problematic) pesticides, including glyphosate and atrazine. Although glyphosate gets more attention in the mainstream media, atrazine is the second most commonly used pesticide in the United States (2), used as an herbicide to control unwanted plant growth. Atrazine was banned from use in Europe in 2004,  yet the EPA only began to raise concern about the possibility of a harmful effect in 2016. Atrazine is fully absorbed in our gastrointestinal system, it is partially absorbed in our lungs, and almost 16% absorbed by our skin (3). Our body eliminates Atrazine within 24-48 hr after absorption through secreting it in urine. 90% of the US tested samples of water had a detectable levels of Atrazine. As reported by professor Tyrone Hayes from University of California Berkeley, Atrazine is the number one contaminant found in drinking water in the U.S. and probably globally probably in the world.

How Atrazine Impacts Human Health

So, exposure to atrazine is unavoidable, but what exactly does that mean in terms of our health? Well, in a study published in the International Journal of Molecular Science, investigating the effect of environmental detectable levels of atrazine on human cells, they found not only an increase in apoptotic signaling pathway (cell death), but also an increase in the DNA damage response pathway after 6 hours of exposure (4) . For the sake of comparison, the same level of DNA damage when cells are exposed to Gamma radiation takes a full 15 minutes. This shows the genotoxic (toxic to our genes) and carcinogenic effect of the environmental detectable levels of atrazine. In addition, research shows that the environmental levels of atrazine have a suppressive effect on the proliferation of human fibroblasts, which put simply, would significantly slow our body’s healing process from any trauma internally or externally (5).

Atrazine also has a direct impact on brain health. In our central nervous system, atrazine alters the levels of dopamine and norepinephrine levels. It also decreases the electrical activity of certain cells in the cerebellum, the area of the brain that controls motor movements (6). Finally, atrazine alters the level and metabolism of many hormones like prolactin, luteinizing hormone (7) and testosterone (8), which can grossly impact our overall physiology. The list of atrazine effects on the body goes on and on, with research showing the prominent impacts of many body systems: the immune system, the endocrine system, and the gastrointestinal system. What we can conclude is that no matter what pesticide we use, whether DDT, glyphosate, or atrazine, as long as it has a killing effect on some organism (which they all do), it will for sure have an effect on us. After all, these are low-dose poisons. Our current research methods make it nearly impossible to definitively identify the negative effects of these toxins right away. It takes years or decades to see the full impact of how these chemicals impact our health, and at that point, how many new incidents of metabolic disorders, cognitive impairment, cancers and autoimmune diseases have manifested?  

What’s the Takeaway?

At the Amos institute we are focused on preventing and reversing Alzheimer’s disease by looking at the body as whole. More research is always needed, but we shouldn’t wait to take action when we know that pesticide like atrazine are harmful. We can, to an extent, mitigate our exposure to these toxins by purchasing organic or pesticide free produce and by eating out at restaurants that follow the same standards. Set a new year’s resolution to do your best to purchase and consume more organic or pesticide free produce. Even if you don’t see the impact of this change now, you may be happy you did in the years to come.

References:

  1. DDT - A Brief History and Status. Retrieved from: https://www.epa.gov/
  2. Refind Ecological Risk Assessment For Atrazine. Retrieved from:  https://www.biologicaldiversity.org/
  3. Pathak, R.K. & Dikshit, A. (2011). Atrazine and Human Health. International Journal of Ecosystem, 1(1): 14-23.
  4. Huang, P., Yang, J., Ning, J., Wang, M., & Song, Q. (2015). Atrazine Triggers DNA Damage Response and Induces DNA Double-Strand Breaks in MCF-10A Cells. Int J Mol Sci. 16(7): 14353–14368.
  5. Manske MK1, Beltz LA, Dhanwada KR. (2004). Low-level atrazine exposure decreases cell proliferation in human fibroblasts. Arch Environ Contam Toxicol.May;46(4):438-44.
  6. Podda, M.V., 1997, Effect of atrazine administration on spontaneous and evoked cerebellar activity in the rat,” Pharmacol. Res, (36), 199-202
  7. Das, P.C., McElroy, W.K., and Cooper, R.L., 2000, Differential modulation of catecholamines by chlorotriazine herbicides in pheochromocytoma (PC12) cells in vitro, Toxicol. Sci, (56), 324-331
  8. Kniewald, J., 1987, Indirect influence of straizines on rat gonadotropic mechanism at early post natal period, J. Ster. Biochem, (27), 10095- 1100