17
Nov
Co-Exposure to Organophosphate Insecticides and Covid-19 Elevates Threat of Cardiovascular Disease
(Beyond Pesticides, November 17, 2022) A report published in Toxicology and Applied Pharmacology finds organophosphate (OP) insecticides and the coronavirus (SARS-CoV-2/Covid-19) illicit similar damage to the heart and co-occurring exposure to both can escalate cardiac (heart) injury. Previous research suggests OPs may increase the ability of SARS-CoV-2 to cause COVID-19, especially among vulnerable individuals with underlying medical conditions. OPs have a wide range of biological uses—from insecticides to flame retardants—that make these chemicals ubiquitous, significantly contributing to ecosystem contamination. These compounds have a global distribution, with evaporation and precipitation facilitating long-range atmospheric transport, deposition, and bioaccumulation of hazardous chemicals in the environment. OPs are highly toxic, originating from the same compounds as World War II nerve agents, and residues are consistently present in human and animal blood, urine, tissues, and milk. Moreover, OPs are one of the leading causes of poisoning globally. Therefore, it is vital to understand how OP exposure will impact human health in conjunction with other immunologically compromising diseases like COVID-19.
Cardiovascular diseases are among the leading causes of death globally. Additionally, heart conditions are one leading cause of disability in the U.S., as research demonstrates environmental pollutant exposure can increase the risk of developing cardiovascular disease, including stroke, heart attack, heart failure, atrial fibrillation, and cardiac arrest. Therefore, it is essential to mitigate harmful chemical exposure to safeguard human health, especially during serious health crises. Considering COVID-19 and OP exposure act similarly on the cardiovascular system, exacerbating adverse inflammatory responses, reviews like these highlight the significance of evaluating synergism between diseases and toxic chemicals to safeguard human health. The report notes, “[T]he co-exposure and synergistic action of both agents may increase the possibility of severe cardiac injuries. Hence, indiscriminate use of these OP pesticides might escalate the severity of cardiac damage in the patients exposed to the SARS-CoV-2 infection. Proper instructions of usage should be followed to minimize human exposure to OP pesticides.”
The review examines literature discussing the impacts of SARS-CoV-2 on patients’ heart and how exposure to the virus and OPs could intensify cardiovascular injury. Using studies on cardiovascular health and Covid-19 patients, researchers compare the results to cardiovascular health and OP exposure patients. The review observes the overlapping health issues among COVID-19 and OP-exposure patients to determine the collective impact on the cardiovascular system. Overall, symptoms of cardiotoxicity include weakened heart muscles (myocarditis), elevated levels of proteins (troponins) in heart muscles, abnormal electrical activity in the heart (ECG), heart attack (myocardial infarction), heart failure (systolic dysfunction), blood clotting impairment (coagulopathy), inflamed blood vessels (endotheliitis), heart cell death (necroptosis), vascular damage, hypertrophy, fluid leakage around heart sac (myocardial edema) and tissue scarring of the heart (myocardial fibrosis). The researchers review the viral and chemical impact on redox reactions (oxidative state changes), Renin-Angiotensin System (RAS) responsible for water and sodium (liquid) homeostasis, blood pressure, cardiac physiology, and proteins for signaling cells (cytokine) to produce the cardiotoxic symptoms.
The review finds both OPs and SARS-CoV-2 can disrupt redox, RAS, and cytokine homeostasis, promoting cardiovascular illnesses. Simultaneous exposure to SARS-CoV-2 and OPs disrupts RAS via down-regulation of the enzyme ACE-2 (blood pressure regulation), up-regulation of ANG II (vasoconstriction and blood pressure), and hyperactive ANG/AT1R signaling pathway. The down-regulation of Nrf antioxidant (a cellular defense against oxidative stress) and ensuing excessive production of reactive oxygen species is evidence of altered redox homeostasis, indicative of oxidative stress. Oxidative stress results in cardiovascular tissue damage that can lead to myocarditis. Lastly, stimulation of NF-kB (a protein controlling of transcription of DNA, cytokine production, and cell survival) mediated signaling cascade via viral and chemical exposure increases proinflammatory cytokine levels. Thus, these subcellular alterations in cardiologic function lead to various aforementioned heart diseases. The review notes exposure to specific OPs like malathion, paraoxon, and chlorpyrifos stimulates ROS, cardiac-lipid peroxidation (oxidative degradation of lipids leading to lipoxidation, which plays a role in the onset of heart diseases), and protein damage in heart tissues.
The immune system offers the best defense against coronavirus-infection, as the virus stimulates an innate and adaptive immune response to expel viral particles from the body. Innate immune responses are the first line of defense against viral infections. However, coronavirus infections can suppress/delay protein production responsible for defending against viral infections, causing a lapse in the innate immune response. Injury to cells responsible for safeguarding against viral infections can induce more severe disease progression, immunocompromising the cardiovascular system of COVD-19 patients. COVID-19 is a systemic (general) disease that overwhelmingly impacts the respiratory system of many patients. The respiratory system is essential to human survival, regulating gas exchange (oxygen-carbon dioxide) in the body to balance acid and base tissue cells for normal function. Damage to the respiratory system can cause many issues—from asthma and bronchitis to oxidative stress that triggers the development of extra-respiratory, systemic manifestations like rheumatoid arthritis and cardiovascular disease. However, like this review demonstrates, the respiratory system is far from the only bodily system affected by the virus. Furthermore, underlying medical conditions (i.e., heart/kidney disease, diabetes, cancer, high blood pressure, obesity, etc.) heighten risks associated with severe illness from disease, including COVID-19.
Overall, OP compounds are immunotoxicants (toxic to the immune system), causing injury and alterations to various cells within the body. Additionally, these compounds lower antibody concentration and reduce autoimmune response to stimuli. The review finds current OPs, including chlorpyrifos and malathion, induce oxidative stress, DNA, and cellular damage in the cardiovascular system. Moreover, OPs can disrupt the homeostasis of proinflammatory and anti-inflammatory responses of cytokine proteins responsible for immune protection.
This review adds to the growing body of research demonstrating the many immunotoxic similarities between OP exposure and coronavirus. Both OPs and the virus cause injury and alteration to the cells in the heart. Additionally, these compounds lower antibody concentration and reduce autoimmune response to stimuli. The review finds current OPs, including the insecticides chlorpyrifos and malathion, induce oxidative stress, DNA, and cellular damage in the cardiovascular system. Moreover, OPs can disrupt the homeostasis of proinflammatory and anti-inflammatory responses of cytokine proteins responsible for immune protection. Although coronavirus can induce other adverse immunological outcomes, such as cardiac dysfunction, gastrointestinal issues, kidney damage, and dermal reactions, studies find OP exposure can have similar adverse multi-organ effects. Therefore, co-exposure to OPs and coronavirus can exacerbate disease effects in COVID-19 patients, with additional exposure to OPs intensifying inflammatory response and respiratory issues that can lead to death.
Cardiovascular disease is becoming increasingly prevalent and is the leading cause of death in the U.S. in 2022, followed by cancer. Therefore, understanding the risk that pesticide exposure plays in disease development is essential to consider since these chemicals can cause disproportionate health effects on individuals working in occupations like firefighters, farm workers, and landscapers. With too many diseases in the U.S. associated with pesticide exposure, reducing pesticide use is a critically important aspect of safeguarding public health and addressing cost burdens for local communities. Policies should enforce stricter pesticide regulations and increase research on the long-term impacts of pesticide exposure. Beyond Pesticides tracks the most recent studies on pesticide exposure through our Pesticide-Induced Diseases Database (PIDD). This database supports the clear need for strategic action to shift from pesticide dependency. For more information on pesticide-related illnesses, see PIDD pages on cardiovascular disease, cancer, and other diseases. Learn more about how pesticides can adversely affect human and environmental health by reading Beyond Pesticides’ Pesticides and You article “Highly Destructive Pesticide Effects Unregulated.”
One way to reduce human and environmental contamination from pesticides is to buy, grow, and support organic. Considering 90 percent of Americans have at least one pesticide compound in their body, primarily from dietary exposure, including food and drinking water, advocates maintain that current restrictions on their use must adequately detect and assess total chemical contaminants. Thus, Beyond Pesticides advocates a precautionary approach to pest management in land management and agriculture by transiting to organic. Furthermore, given the wide availability of non-pesticidal alternative strategies, families, chemical occupational workers, and the agricultural sector can apply these methods to promote a safe and healthy environment. For more information on the benefits of organic, see the Beyond Pesticides webpage, Health Benefits of Organic Agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.