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The Health Risks of Ocean Pesticides

Introduction

Pesticides have been used since the Green Revolution for better longevity of crops, to remove antagonistic forces in property and farmer lands and to overall benefit the public health of a community. However, in contrast to popular belief, pesticides have shown to degrade the overall health of the population. Despite its terrestrial usage, pesticides have shown to flow into bodies of water, like rivers, and find their way into the major oceans of the world. For example, DDT, a popular pesticide, was “banned for its toxicity and risk to humans [because of its] dump[ing] into the ocean just off the coast of Los Angeles” (The Marine Mammal Center, 2024). DDT is known as Persistent Organic Pollution, in which the chemical builds up in the body of mammals causing chronic poisoning. DDT builds up in aquatic organisms like fish due to exposure and where this pesticide, and others, finds its way back into humans through fish consumption. Pesticide exposure, like that of DDT, can cause neurological disruption, reproductive issues, and endocrine malfunctions in many humans, mainly in those of developing countries who lack the knowledge of harmful effects of pesticides.

Neurological Disruptions and Disorders

            Oceanic exposure of pesticides, mainly through consumption of intoxicated seafood, has shown to correlate with neurological disorders like those of Alzheimer's Disease (AD), Parkinson's Disease, dementia, and multiple types of sclerosis, with “many pesticides [targeting] the nervous system of insect pests, and similarly are neurotoxic to humans” (Yegambaram Manivannan, 2015). Pesticides attack the body of humans similarly to those of pests, affecting the vital organs severely and leading to long-term damage in the nervous system as a whole, not strictly just the brain. For example, from the AP Psychology curriculum, the spinal cord is harmed due to pesticides, which is a part of the Central Nervous System that connects the Brain to the Peripheral Nervous System. The attack of the foreign substance could cause a disruption in the transmission of sending chemical messages from the body to the brain and vice-versa. This disruption would cause changes in mobility and lead to potential losses in bodily functions.   

Furthermore, the course curriculum contained information that expressed how acetylcholine is a neurotransmitter that deals with memory functions and processes. When there is a clear exposure of pesticides to ACh (Acetylcholine) neurons, they start to deteriorate, which “can affect the formation of the neurological basis of learning and memory long-term potentiation and lead to signal transduction disorders in the brain and ultimately to cognitive impairment” (Lian-kui Wen, 2023). This deterioration of ACh is associated with Alzheimer's Disease leading to life-long memory damage to the brain. 

In addition, other neurotransmitters can malfunction due to the exposure of pesticides in the body. Another example would be GABA which is a neurotransmitter that acts as an inhibitor, slowing the nervous system actions down to a more moderate rhythm. However, if there is a malfunction in the production of GABA, specifically an undersupply of production, then it leads to heightened anxiety, seizures, tremors and insomnia. Most pesticides act as GABA antagonists, blocking normal GABA functions and processes and, in turn, leads to the inability to regulate/”calm” nerve activity. According to the article of ScienceDirect, it specifically highlights, “[Pesticides] have the ability to modify GABA receptor activity, which can change inhibitory neurotransmission. This disturbance of GABAergic signaling can cause increased lipid peroxidation and damage to DNA in brain tissue.” (MD Faruque Ahmad, 2024). Lipid peroxidation is a destructive process that damages the cell membrane, leads to oxidative stress, and is linked with diseases with Alzheimer's. Damage to the DNA in brain tissue also leads to Alzheimer's Disease and can damage genetic information in the brain causing defects.

Dopamine levels are also altered by exposure to pesticides, specifically that of paraquat which “has been shown to trigger [...] dopamine depletion” (Rodriguez Alexis, 2025). Pesticides injure the dopamine receptors in the basal ganglia specifically, which is a neural structure that curves around the limbic system, helping maintain smooth voluntary muscle activity and helps us form muscle memories (AP Psychology). Due to both the basal ganglia and dopamine playing roles influencing movement and attention, a malfunction and an undersupply secretion of dopamine being produced by the basal ganglia would lead to problems like tremors and mobility problems like Parkinson’s Disease; a neurological disorder that, over time, affects movement, balance, and coordination of its victims. Suppression of dopamine levels is not only linked to physical changes, but also changes in mood patterns. People who have been exposed to pesticides for a long period of time have shown patterns of being much more aggressive and aggravated which, consequently, can lead to higher rates of suicidal contemplation.  

Reproductive and Developmental Issues

Oceanic exposure to pesticides can also affect babies and women by causing reproductive issues and developmental issues. According to Reini W Bretvald of the National Library of Medicine it clarifies that “exposure to pesticides has been associated with menstrual cycle disturbances, reduced fertility, prolonged time-to-pregnancy, spontaneous abortion, [and] stillbirths.” Pesticide exposure alters estrogen and progesterone production, in both men and women, and can cause both an overly high production of the two or an overly low production. Low estrogen and progesterone levels in women can cause difficulty in concentrating, irregular periods, increased chance of miscarriage, and difficulty conceiving. On the other hand, high levels of estrogen and progesterone could lead to a heavy or prolonged period, worsening of symptoms of premenstrual syndrome, and suppresses ovulation. In men, suppression of both progesterone leads to infertility and erectile dysfunction, in which these symptoms are closely related to those of low testosterone levels. Similarly, high estrogen levels can also lead to infertility and erectile dysfunction. An imbalance of these 2 hormones can also be linked to certain cancers, displaying the deadly effects of pesticides.

Endocrine Malfunctions

Pesticide exposures via oceans can also lead to endocrine malfunctions in the body. They act as endocrine disruptors which “are chemicals that mimic, block, or disrupt the normal function of hormones” (US EPA, 2023). These pesticides mainly disrupt the thyroid gland, pituitary gland, and adrenal glands. According to my Health A&P class and AP Psychology class, the thyroid gland is responsible for metabolism, heart rate and body temperature and with the thyroid gland disrupted homeostasis would be lost. The thyroid would either be underactivated, with metabolism being slowed and a colder body temperature, or overactivated, where rapid heart rates and weight loss is common. Furthermore, the pituitary gland is known as the “master gland” as it produces and secretes hormones, and, if disrupted, there would be hormonal disbalances in the body which would affect several different bodily functions. Similarly, adrenal glands also play a crucial role in producing hormones with its disruption also leading to imbalances of functions. The pushback of hormones produced by the adrenal gland would lead to Addison’s disease where the body is unable to produce the sufficient amount of hormones needed.

Conclusion

Pesticides exposed to oceans via natural run-off make their way back into the human cycle. This has shown to negatively affect daily human bodily functions by causing disruptions in reproduction, the neurological system and in several different endocrines. However, possible resolutions and counteractions have been discussed to prevent further detriments of pesticide exposure. A huge resolution to pesticide is education, with The Institute of Functional Medicine exclaiming, “A large part of reducing a patient’s total toxic burden is through education—bringing the patient into a level of awareness regarding different sources of toxicants so they can avoid potential exposures.” The awareness of exposure to pesticides, including that in aquatic systems, will allow the chronic detriments to be lowered, especially in lower developed countries where farmers aren’t as educated as those in developed countries. 

Works Cited

Ahmad, Md Faruque , et al. “Pesticides Impacts on Human Health and the Environment with Their Mechanisms of Action and Possible Countermeasures.” Heliyon, vol. 10, no. 7, 1 Apr. 2024, www.sciencedirect.com/science/article/pii/S2405844024051594, https://doi.org/10.1016/j.heliyon.2024.e29128.

Bretveld, Reini W, et al. “Pesticide Exposure: The Hormonal Function of the Female Reproductive System Disrupted?” Reproductive Biology and Endocrinology, vol. 4, no. 30, 31 May 2006, p. 30, www.ncbi.nlm.nih.gov/pmc/articles/PMC1524969/, https://doi.org/10.1186/1477-7827-4-30.

Kori, Rajesh Kumar, et al. “Neurochemical and Behavioral Dysfunctions in Pesticide Exposed Farm Workers: A Clinical Outcome.” Indian Journal of Clinical Biochemistry, vol. 33, no. 4, 22 Sept. 2018, pp. 372–381, https://doi.org/10.1007/s12291-018-0791-5.

Lian-kui, Wen, et al. “Pesticides as a Risk Factor for Cognitive Impairment: Natural Substances Are Expected to Become Alternative Measures to Prevent and Improve Cognitive Impairment.” Frontiers in Nutrition, vol. 10, 24 Feb. 2023, https://doi.org/10.3389/fnut.2023.1113099.

OctoberCMS. “Newsweek: Toxic Contamination in Our Oceans Can Reach Our Kitchen Tables | Opinion | the Marine Mammal Center.” Marinemammalcenter.org, 2024, www.marinemammalcenter.org/news/newsweek-opinion-toxic-contamination-in-our-oceans-can-reach-our-kitchen-tables.

Rodríguez, Alexis, et al. “Pesticides: Environmental Stressors Implicated in the Development of Central Nervous System Disorders and Neurodegeneration.” Stresses, vol. 5, no. 2, 7 May 2025, p. 31, www.mdpi.com/2673-7140/5/2/31, https://doi.org/10.3390/stresses5020031.

The Institute for Functional Medicine. “| the Institute for Functional Medicine.” Ifm.org, 5 July 2024, www.ifm.org/articles/pesticides-and-human-health-effects.

US EPA, OA. “EPA Rebuilds Endocrine Disruptor Screening Program to Better Assess Human Endocrine Effects of Pesticides.” Www.epa.gov, 26 Oct. 2023, www.epa.gov/newsreleases/epa-rebuilds-endocrine-disruptor-screening-program-better-assess-human-endocrine.

Yegambaram, Manivannan, et al. “Role of Environmental Contaminants in the Etiology of Alzheimer’s Disease: A Review.” Current Alzheimer Research, vol. 12, no. 2, 24 Feb. 2015, pp. 116–146, https://doi.org/10.2174/1567205012666150204121719.