Paraquat Exposure May Impact Brain and Contribute to Neurodegenerative Diseases Like Parkinson’s: Study

The findings of new research raises additional concerns about the Parkinson’s disease risk from Paraquat exposure, indicating even inhaling small amounts of the toxic herbicide may impact the brain and lead to the development of neurodegenerative diseases.

Paraquat is a controversial herbicide, which has been on the market since the early 1960s. Although it is banned in several countries since it is known to be toxic, it remains widely used in the United States under U.S. Environmental Protection Agency (EPA) restrictions. However, increasing evidence suggests there may be a direct link between Parkinson’s disease and Paraquat-based herbicides.

in a study published in the medical journal Toxicological Sciences, researchers with the University of Rochester School of Medicine report inhaling Paraquat caused a loss of smell in mice, in a way similar to the early symptoms of Parkinson’s disease.

“Despite recognition that airborne particles and solutes can be directly translocated to the brain via olfactory neurons, the potential for inhaled [Paraquat] to cause olfactory impairment has not been investigated,” the researchers wrote in the report published December 29. “This study sought to determine if prolonged low-dose inhalation exposure to [Paraquat] would lead to disposition to the brain and olfactory impairment, a prodromal feature of Parkinson’s disease.”

The researchers exposed adult male and female mice to Paraquat aerosols, then examined the brain, lungs and kidney via mass spectrometry to evaluate the potential side effects of the herbicide.

According to the findings, inhaling Paraquat placed “an appreciable burden in all examined brain regions”, with the highest burden on the olfactory portions of the brain. In addition, researchers were able to detect paraquat in the lung and kidneys of the mice. However, the levels in the mice’s body returned to control levels within four weeks of exposure, the researchers noted.

All of the affects were male specific, however. The female mice appeared to be unaffected.

“These data support the importance of route of exposure in determination of safety estimates for neurotoxic pesticides, such as (Paraquat),” the researchers concluded. “Accurate estimation of the relationship between exposure and internal dose is critical for risk assessment and public health protection.”

Years of Warnings In Paraquat Studies

The findings join a raft of studies in recent years which have linked Paraquat and similar herbicides to an increased risk of Parkinson’s disease.

In 2012, researchers from UCLA found another link between pesticide use and a risk of developing Parkinson’s. Those findings were published in the journal Neurology, indicating that patients who suffered a traumatic brain injury (TBI) and were exposed to Paraquat were three times more likely to develop Parkinson’s disease.

Another study published in May 2013 found yet another link between pesticide exposure and an increased risk of developing Parkinson’s disease. Researchers found pesticide exposure increased the risk of developing the disease by 60 percent.

That study also found the risk increased with exposure to any type of pesticide, herbicide or solvent; but exposure to specific chemicals doubled the risk. Chemicals used in the test included Paraquat, Maneb and other pesticides.

In March 2016, the EPA announced that it would be re-evaluating the health risks with Paraquat, and a number of health experts and consumer advocacy groups have called on the agency to remove Paraquat-based herbicides from the market in the U.S. However, it continues to be used by farmers and other industries for weed and grass control, potentially exposing individuals handling, mixing or applying the Paraquat to life-long health risks.

Parkinson’s disease affects more than 500,000 Americans, with approximately 50,000 new cases each year. The disease causes the loss of motor functions, causing imbalance and shaking, which gets progressively worse over time.

A number of lawyers are now investigating potential Paraquat Parkinson’s disease lawsuits for individuals nationwide.