Neurological disorders are now the leading source of disability around the world. Within that category, Parkinson’s Disease (PD) is the fastest-growing neurological disorder, impacting more than 8.5 million people globally. Researchers have identified a number of environmental factors that contribute to the disease’s unprecedented rise — and the evidence is increasingly pointing to pesticides.
Unfortunately, despite the growing body of evidence connecting Parkinson’s Disease and pesticides, many potentially hazardous pesticides are still in use. With that in mind, researchers from the Netherlands Institute for Neuroscience led an effort to develop a step-by-step testing approach to guarantee pesticide safety. The proposed approach was recently published in the journal npj Parkinson’s Disease. Read on to find out more about the research and its potential implications for Parkinson’s Disease risk factors.
Evidence Connecting Pesticides and Parkinson’s Disease
Experts now believe that Parkinson’s Disease could be linked to a number of environmental factors, including exposure to heavy metals, air pollution, and pesticides. For example, last year, researchers at Harvard University and the University of California Los Angeles (UCLA) sought to pinpoint the pesticides most likely to impact neurological function. Through their research, they identified 10 pesticides found to be confirmed neurological toxins and 53 total toxins that could be implicated in PD. The pesticides were found to impact dopaminergic neurons, the neurons in the human body that play a role in voluntary movement and often serve as one of the primary indicators of Parkinson’s Disease. Unfortunately, most of the flagged pesticides are still in use. To address this problem, the Netherlands Institute for Neuroscience (NIN) team proposed a solution to identify the most harmful pesticides, ideally reducing or eliminating their use.
Evaluating Pesticide Safety with Animal Models
The NIN researchers proposed four testing phases for all existing and new pesticides, with the final two phases involving animal models. The following are the proposed testing phases:
- Brain cell damage: Researchers should analyze whether a substance could cause damage to brain cells by screening databases
- Effect on brain cells: If hazardous potential cannot be excluded, researchers should perform research to identify the effect on brain cells.
- Testing with early animal models: If significant potential damage is identified, researchers should test the substances on animal models bearing little resemblance to humans. Those animal models might include worms or flies.
- Testing with advanced animal models: Finally, researchers should expose mice and rats to the pesticide, either in a short, intense exposure or over an extended period of time by adding the substances to the animals’ drinking water or air supply.
Preventing Toxin Exposure for Parkinson’s Disease
The research into pesticide toxins and Parkinson’s Disease is still in fairly early stages; however, the NIN researchers are now entering into discussions with industry and regulatory authorities, with the support of other members of the scientific community. Eventually, the experts aim to implement this screening protocol for all potential toxins in the environment — not just pesticides.
“We are still largely in the dark about the safety of these substances,” said neurologist and research co-author Bas Bloem. “The current admission criteria for pesticides provide insufficient insight into the risk of Parkinson’s and other brain diseases. We now propose a clear plan of action to properly assess safety.”
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