Exposure to Certain Pesticides Increases Risk of Heart Disease, Study Finds

Exposure to organochlorine pesticides like DDT and Lindane, increases the risk of heart attack and stroke, according to the findings of a new study.

Organochlorine pesticides were used up until the mid-2000s before they were banned by the U.S. government, due to neurological side effects. However, Swedish researchers now indicate that they may also increase the risk of suffering from cardiovascular disease.

In a report published last week in the medical journal JAMA Network Open, researchers conducted a nested case-control study including data from two cohorts, the Swedish Mammography Cohort-Clinical (SMC-C) and the Cohort of 60-year-olds with matched control subjects.

Overall, the study included 1,528 participants. Of those, 345 patients suffered myocardial infarction and 354 suffered an ischemic stroke. They were matched with 829 control participants. Researchers took baseline blood sampling from November 2003 to September 2009, and August 1997 to March 1999. A total of 25 organochlorine compounds were measured in the blood at baseline.

According to the findings, blood biomarkers linked with exposure to organochlorines showed a significant link with increased risk of stroke and heart attack. The researchers found that for every 25% increase in organochlorine pesticides in the blood, the risk of cardiovascular disease increased by 71%.

Pesticides Containing Organochlorines Banned in U.S.

Organochlorines were a class of pesticides commonly used in the United States before 2010. Common formulations include dichlorodiphenyltrichloroethane or DDT, as well as Marlate, Metox, Aldrin, Octachlor, Lindane, and others.

The U.S. Environmental Protection Agency (EPA) began banning the use of organochlorine pesticides in 1972, beginning with DDT.

DDT was one of the first modern pesticides and was used in the U.S. and around the world to kill insects carrying malaria and typhoid. The ban came after reports of human side effects, including seizures, liver problems, and reproductive problems, began to emerge.

Other brands of organochlorine pesticides, such as Octachlor, Marlate, and Lindane, continued to be used in the United States for decades, until the EPA banned them decades later. Octachlor was banned in 1988, Marlate in 2003, and Lindane wasn’t banned until 2007.

While organochlorines are no longer used in the U.S., they persist in nature and can have long-term effects on the water supply and wildlife. Organochlorines continue to be used in developing countries to combat diseases like malaria.

Research has linked exposure to organochlorine pesticides to an increased risk of Parkinson’s disease later in life. Exposed individuals also face a heightened risk of developing amyotrophic lateral sclerosis (ALS) also known as Lou Gehrig’s disease.

Some critics say the latest findings are not relevant since the pesticides have been banned for 10 years or more. But many people living in the U.S. and around the world were widely exposed to the pesticides for years, if not decades, and the chemicals may persist in many water sources.

“In this prospective nested case-control study, participants with higher exposures to organochlorines had an increased probability of experiencing a cardiovascular event, the major cause of death worldwide,” the researchers concluded. “Measures may be required to reduce these exposures.”