Parkinson's Disease and Pesticides

There are now many reports concerning the relationship between some pesticides and Parkinson's Disease. The disturbing aspect of this recent study(abstract below) is that they found high levels of two commmon pesticides in the nigra region of Parkinson's patients. This region of the brain is typically referred to as the substantia nigra. It is a rather small round nuclei that contains a great many dopamine producing neurons. These neurons play a critical role in modulating motor function, hence the classic gait of Parkinson's patients and the slow loss of control over motor function. It is important to note though that loss of movement control is not the only problem in Parkinson's patients, cognitive and emotional problems also arise. There is also evidence of neural destruction beyond the nigra region and this can extend into the temporal lobes. As always, when we look at the actual results of neuroscience studies we find that the living brain is not as neat and tidy as our lovely diagrams of it.

Parkinson's Disease is one the strangest neuropathologies. We have very little idea concerning the etiology of Parkinson's Disease but the linkage with some pesticides is very strong. Rotenone, a "natural" pesticide favoured by organic farmers, is great at killing neurons in this region. Epidemiological studies have established very strong linkages with occupational exposure to some pesticides and the incidence of Parkinson's Disease. If you enjoy playing golf make damn sure that in the very least you wash your hands after each game, preferably have a shower. Make sure you don't wear your golf shoes in the house, the residues could spill onto the floor surface where your kiddies love to play. Golf courses are toxin sinks, so much so that a few studies have found a direct correlation with living near a golf course and in the incidence of cancer in children and pets. If you are an active gardener who uses pesticides be very careful. Follow the safety instructions and be very careful about spillages. You have been warned.





Neuroreport. 2008 Aug 27;19(13):1317-20.
Synergistic microglial reactive oxygen species generation induced by pesticides lindane and dieldrin.
Mao H, Liu B

Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida, USA.
Elevated environmental exposure to pesticides is a known risk factor to the development of sporadic Parkinson's disease resulting from the degeneration of nigral dopamine neurons. Among the suspected agents are the highly persistent and bioaccumulative organochlorinated pesticides (OCPs). We report here that lindane and dieldrin, two widely present OCPs that are found enriched in the nigra of postmortem Parkinson's disease brains synergistically induced the production of reactive oxygen species (ROS) in microglia. Inhibitor studies indicated that the lindane and dieldrin-induced ROS generation was mediated by NADPH oxidase. As microglial ROS is a key contributor to the degeneration of the oxidative damage-vulnerable dopamine neurons, our findings shed significant light on the role of OCPs in the development of Parkinson's disease.