A study by UCLA researchers has found a strong link between long-term exposure to the pesticide chlorpyrifos and a higher risk of Parkinson's disease. The study, published in Molecular Neurodegeneration, analyzed data from over 1,600 people and found that those with prolonged residential exposure to chlorpyrifos had more than 2.5 times the risk of developing Parkinson's compared to those without exposure. The researchers also conducted laboratory experiments to investigate how chlorpyrifos damages brain cells. They found that the pesticide interferes with the brain's ability to remove damaged proteins, leading to the loss of nerve cells essential for controlling movement. This is a key feature of Parkinson's disease, which affects nearly one million Americans and causes tremors, muscle stiffness, and difficulties with coordination. The study's findings suggest that chlorpyrifos exposure could reproduce several characteristics of Parkinson's in laboratory animals, including movement difficulties and the loss of dopamine-producing neurons. The researchers also discovered that the pesticide disrupts autophagy, a natural cellular maintenance process that helps remove damaged proteins and other unwanted material. However, the study also found that restoring the cellular cleanup process or removing the synuclein protein in experiments protected neurons from damage. This suggests that the pesticide's harmful effects may depend partly on a biological pathway that researchers could potentially target with future treatments. The discovery raises the possibility of developing therapies that strengthen the brain's cellular cleanup mechanisms and help protect vulnerable neurons. While the protective effects have only been demonstrated in laboratory models, the findings could lead to new treatments for people exposed to chlorpyrifos or other pesticides that disrupt similar processes.