Studies show that even low-level exposure to Paraquat can significantly increase the risk of developing Parkinson’s disease. This is because Paraquat causes the loss of the cells that make the neurotransmitter dopamine. When less dopamine is produced, the coordination between our brain and muscle movement suffers. This can create issues in movement, including common symptoms of Parkinson’s disease. Generally, when a person is diagnosed with Parkinson’s disease, he or she has lost 50 to 60 percent of dopamine neurons.