Study Examines Potential Cardiovascular Effects of Chlorpyrifos Pesticide Exposure

New research is raising questions about whether exposure to chlorpyrifos and other organophosphate pesticides may affect cardiovascular health. A study published in August 2026 found evidence of inflammation, cell damage, and problems with blood vessel function following exposure to chlorpyrifos and dimethoate. The findings add to ongoing research examining the potential adverse health effects of chlorpyrifos, an agricultural pesticide that has also been the subject of lawsuits alleging neurological injuries.

Study Examines Chlorpyrifos Exposure and Cardiovascular Injury

This new study, published in the Journal of Applied Toxicology, examined whether chlorpyrifos and another organophosphate pesticide, dimethoate, may affect the heart and blood vessels. Researchers found signs of inflammation, cell damage, and impaired blood vessel function following pesticide exposure in laboratory models.

The findings suggest that chlorpyrifos may affect cardiovascular health through processes involving inflammation and oxidative stress, which can damage cells and tissues. However, the study did not establish that chlorpyrifos causes cardiovascular disease in humans. Additional research is needed to determine whether similar effects occur in people exposed to the pesticide.

What Is Chlorpyrifos?

Chlorpyrifos is an organophosphate pesticide that has been used in the United States since 1965. It has primarily been used to control insects that can damage agricultural crops. Organophosphate pesticides work by interfering with an enzyme that is necessary for normal nerve function. Although this makes the chemicals effective against insects, exposure may also affect the human nervous system.

Agricultural workers may encounter chlorpyrifos while mixing, loading, or applying pesticide products or while working in areas where the chemical has been used. Other potential routes of chlorpyrifos exposure include skin contact, inhalation, pesticide drift, and contact with pesticide residues.

Chlorpyrifos and Its Alleged Link to Parkinson’s Disease

The chlorpyrifos cardiovascular study comes as researchers continue to investigate other potential health effects associated with exposure to the pesticide. Recent research has examined an alleged link between long-term chlorpyrifos exposure and Parkinson’s disease. Several lawsuits have already been filed by farmers, pesticide applicators, and other individuals alleging that occupational or environmental exposure to chlorpyrifos contributed to their development of Parkinson’s disease.

Study Finds Changes in Heart and Blood Vessel Function

This new research examines a different potential health concern. Rather than focusing on neurological damage, researchers investigated how chlorpyrifos may affect the heart and blood vessels in exposed individuals. One area researchers examined was the endothelium, the thin layer of cells lining the inside of blood vessels. These cells help control blood flow and keep blood vessels functioning normally.

The study authors found that chlorpyrifos exposure was associated with inflammation and damage to these cells in the experimental models. Laboratory testing also showed increased oxidative stress and other changes that could interfere with normal blood vessel function.

The researchers stated that these findings may help scientists better understand how organophosphate pesticides could potentially affect cardiovascular health. However, because the study relied on animal and laboratory models, its findings cannot establish that chlorpyrifos causes heart disease or other cardiovascular conditions in people.

Further research involving humans would be necessary to determine whether people exposed to chlorpyrifos experience similar biological changes or face an increased risk of cardiovascular disease.

EPA Continues to Review Chlorpyrifos Uses

Federal regulation of chlorpyrifos has changed considerably in recent years. In 2021, the U.S. Environmental Protection Agency revoked chlorpyrifos tolerances for food, effectively ending its use on food crops. That decision was challenged, and a federal appeals court vacated the rule in November 2023. The court’s mandate reinstated all chlorpyrifos tolerances in December 2023.

Since 2022, the approved uses of chlorpyrifos have been significantly reduced. In September 2024, the EPA approved updated product labels limiting its food and animal feed uses to 11 crops in certain states, along with other restrictions on how and where the pesticide can be used. The EPA has since proposed revoking all chlorpyrifos tolerances except those needed for use on those 11 food and feed crops: alfalfa, apples, asparagus, tart cherries, citrus, cotton, peaches, soybeans, strawberries, sugar beets, and spring and winter wheat.

The EPA’s registration review of chlorpyrifos remains ongoing. The agency previously indicated that it expected to issue an amended Proposed Interim Decision for public comment in 2026, followed by an Interim Decision. 

Chlorpyrifos Lawsuits Allege Injuries From Long-Term Exposure

Chlorpyrifos lawsuits in the U.S. have primarily focused on alleged neurological injuries rather than cardiovascular conditions. Farmers, agricultural workers, pesticide applicators, and others have filed or investigated claims alleging that repeated chlorpyrifos exposure contributed to Parkinson’s disease and other neurological injuries. Some lawsuits allege that pesticide manufacturers failed to adequately warn users about the potential health risks associated with long-term exposure.

The new chlorpyrifos cardiovascular study does not establish that chlorpyrifos caused injuries alleged in existing lawsuits or provide evidence that a particular person’s health condition resulted from pesticide exposure. Instead, it adds to scientific research examining how long-term chlorpyrifos exposure may affect different systems in the body.

As additional studies examine the potential health effects of chlorpyrifos exposure, the pesticide remains the subject of scientific research, federal regulatory review, and product liability lawsuits alleging serious injuries and illnesses.