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Parkinson's: The Pesticide Link

Scientists are closing in on an inescapable conclusion: Pesticides may be a cause of Parkinson's disease

Jackie Christensen was 32 when her body began to betray her. She had just returned to work after the birth of her second son and when she tried to type, two fingers on her left hand refused to cooperate. "They wouldn't go where I would want them to on the keyboard," says Christensen, who at the time -- it was 1997 -- was co-director of the food and health program at the Institute for Agriculture and Trade Policy, a Minneapolis think tank. "I also had what they frequently call frozen shoulder, with a very low range of motion in my left arm."

The first neurologist Christensen went to responded flippantly to her suggestion that she might have multiple sclerosis, which she had self-diagnosed because of her relatively young age and the fact that she was female. "If you want me to write that down, I will," she remembers him saying, refusing to pursue the matter further. A second neurologist thought it was all in Christensen's mind and referred her to a psychiatrist. Over the next several months, her symptoms got progressively worse, and she finally consulted neurologist number three. His startling diagnosis: Parkinson's disease.

"I thought, 'I can't have Parkinson's because I'm not old,'" Christensen recalls. But a trial of the standard treatment, a drug called L-dopa, seemed to work. Based on that clinical observation, the diagnosis was confirmed. This was in 1998, when Christensen was not quite 35, and she has been on L-dopa, with varying degrees of success, ever since.

Pesticide Alert

Three kinds of pesticides have been implicated as possible causes of Parkinson's disease. Scientists believe that the mechanism of damage is different for each category.

Herbicides Chemicals such as Paraquat that destroy broadleaf weeds are thought to stimulate an increase in the protein alpha-synuclein in the brain, which is known to destroy the cells in the substantia nigra that are responsible for producing dopamine.

Insecticides Agents that kill insects, either naturally (such as the botanical Rotenone) or chemically (such as Dieldrin), increase the production of alpha-synuclein in the brain and also damage dopamine-producing brain cells directly. Rotenone, in particular, also seems to lead to dysfunction of the mitochondria, the energy-producing component of a cell, and to oxidative stress in the brain.

Fungicides Antifungal chemicals such as Maneb and Benomyl are thought to affect the mitochondria of certain brain cells and to injure the repair mechanisms of dopamine-producing neurons, making them more vulnerable to stress. This priming function may help explain observations that exposure to Maneb plus Paraquat is much more damaging than exposure to either agent alone.

Why did a disease that usually affects people in their sixties and seventies, and that affects men more often than women, strike this vibrant young mother? Christensen, a lifelong environmental activist, suspected an environmental cause -- not only because she was politically inclined to, but because she knew that accumulating scientific information was pointing in that direction. In the past few years, Christensen has been part of a movement exploring a possible connection between exposure to environmental toxins -- in particular, the organophosphate pesticides -- and Parkinson's disease, through her work with the Collaborative on Health and the Environment, a national network of advocacy and scientific organizations. She is co-founder of CHE's working group on Parkinson's Disease and the Environment.

A cause-and-effect relationship between environmental neurotoxins and Parkinson's is difficult to prove. As with many other scientific efforts to establish disease causation through population studies, there will probably never be a smoking gun that settles things once and for all. Population studies can detect associations between certain suspected agents and diseases such as cancer, but it's hard to draw conclusions about what causes a disease from studies that can register only correlations. In the case of Parkinson's and the environment, however, there has been a steadily mounting consensus about such a connection, and the pace has quickened in the past year or so.

A January 2009 consensus statement from CHE, in collaboration with the Parkinson's Action Network, a patient advocacy group, found that there was "limited suggestive evidence of an association" between pesticides and Parkinson's, and between farming or agricultural work and Parkinson's. This followed by just a few months the publication of Environmental Threats to Healthy Aging, a report co-authored by the Science and Environmental Health Network, a consortium of advocacy groups based in Ames, Iowa; it included a summary of 31 population studies that have looked at the possible connection between pesticide exposure and Parkinson's. Twenty-four of those studies, according to the report, found a positive association, and in 12 cases the association was statistically significant. In some studies, the group found, there was as much as a sevenfold greater risk of Parkinson's in people exposed to pesticides. In addition, in April 2009, scientists at the University of California, Los Angeles (UCLA), published a provocative study connecting the disease not only to occupational pesticide exposure but also to living in homes or going to schools that were close to a pesticide-treated field.

Taken together, 30-plus years of research add up to an increasingly persuasive conclusion: exposure to pesticides and other toxins increases the risk of Parkinson's disease, and we are only now beginning to wrestle with the true scope of the damage.

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Robin Marantz Henig is a contributing writer to the New York Times Magazine. She is the recipient of a 2009 Guggenheim Foundation fellowship, and is the author of eight books on science, including The Monk in the Garden (Houghton Mifflin), a finalist... READ MORE >

There is one (see A Structural Strategy for
Global Warming, Renewable Energy, and the Environment
) that just does that.

It has a powerful global warming component, but also addresses other issues such as contaminant, packaging, resource conservation, etc.

Tags: cap-and-trade problems and carbon emission alternative solutions

After reading this article in the print magazine, I noted the absence of any reference to the Veterans Affairs(VA) research and treatment related to Parkinson's conditions. The VA's Parkinson website can be found at Veterans were deliberately exposed to herbicide/pesticide inundation during the Vietnam War. I , personally, know Vietnam combat veterans who are now suffering from Parkinson's. The Defense Department in collusion with Monsanto and Dow Chemical tried every means to maintain secrecy over the true human effects of Agent Orange and the other chemicals used during the war. Too many of the studies were controlled and edited by the chemical companies and aided by the DOD and the VA in response to court cases. Most studies restricted their focus to cancer and birth defects despite the well-documented neurological effects of the chemicals. Since that time, the VA has attempted to bring some truth to the chemical effects despite the continuing denials and impediments by the Pentagon and the chemical corporations(Military/Industrial Complex). Soon many of the exposed military personnel will have died before any true analysis of the neurological effects are completed. Any Parkinson's research related to chemicals must include the veterans' databases where large quantities of data are available. The VA states they are treating 40,000 veterans with Parkinson's at the current time. The relation to chemical exposure and this condition must be independently and completely researched to bring truth and justice to all exposed human beings.

Thanks, Robin, for doing a great job with my story. I want to encourage people with Parkinson's disease and their family members who are passionate about PD-related issues to get involved with the Parkinson's Action Network. You can visit their website at or call 800-850-4726.

If you have a story to tell about your Parkinson's disease, you can do so on the Alliance for Parkinson's Health Activists (alpha) website at

I thought it was an interesting article although it lacked depth. My main reason for writing is the use of the word pesticide on the top of the left hand column on page 53. Ms. Henig wrote "that manganese is an ingredient in the widely used fungicide Maneb. But pesticides remain the clearest culprit." This implies that Maneb is not a pesticide. Yet at the top of the right hand column she makes it clear that fungicides are definitely pesticides. I assume that she is referring back to the earlier statements telling of manganese as an air pollutant.

My husband was diagnosed with Parkinson's 7 years ago at age 66. As a science student and biology teacher he had constant exposure to formalin and other preservatives. My son was born in 1962 with Spina Bifida and other deformities. He died in '64. Have there been any studies about the use of formalin in relation to Parkinsons or birth defects?

I have no doubt that scientists may find a causal link between pesticide exposure and Parkinson's disease. Some minor errors in Robin Marantz Henig's article, however, make me wonder how reliable her statements are since it appears that fact checking was not done before it was published. The author refers to fruit bats as rodents, which of course they're not. And states that they eat nectar, when the Neurology article she refers to clearly states that the bats biomagnify the neurotoxin BMAA from by eating seeds of the cycad (a non-flowering plant that presumably doesn't even produce nectar). Of course these errors have nothing to do with the author's main suggestion about a link between pesticides and neurological disorders but they raise concern that her article was not well, or accurately, researched. The author and the editorial staff of onearth need to take care; the details are important, even the tangential ones.

I have been a wholistic practitioner for the past 25 years. I have seen two people with Parkinson's. One was an aerial pilot who sprayed pesticides in the intensely agricultural San Fernando Valley. He had come to testify before Congress in 1981 when they were updating the FIFRA Laws (Federal Insecticide, Fungicide, Rodenticide Act)and he stated that he quit flying as a pesticide applicator after he was diagnosed with Parkinson's. I had gone to testify also and bring testimonials from citizens in the Hudson Valley of New York State about the problems and symptoms they had after their neighborhoods were sprayed with the pesticides Dylox and Sevin to control the Gypsy Moth. I had joined with other citizens to form the Affiliated Coalition Against Aerial Spraying, ACTFAS, and then Congressman Benjamin Gilman sponsored our group to participate in the hearings.

The second Parkinson's case I had a personal relationship with. He was a retired gentleman who lived in the Catskill Mountains, where I live. I would care for him when his family called on me for help. I noticed he was always getting into arguments with his farm manager. He had a 2000 acre estate and on one of the hills above his house, he had an apple orchard. He was always asking the farm manager if he had sprayed the orchard and the manager would reply that he had. But the old man would insist he must spray again and so the manager would spray against his judgment but he wanted to keep his job. They were talking about two different kinds of spraying I later learned. The old man was talking about dormant oil spray and the farm manager was talking about pesticide spray. But neither of them realized they were talking about different things. As time went by, the old man was diagnosed with Parkinson's and passed away at the age of 103 years.
Several years after that, I saw a progam on PBS
about pesticides and realized that must have been what the farm manager had been spraying and it would drift right down the hill from the orchard right into the old man's study which was on the corner of the house and was essentially a solarium, with the windows open.
I now make it a part of my intake interviews when people come to me for detoxification, to ask what the client's history is of exposure to agricultural chemicals. Over the years, I have discovered a correlation between prostate cancer and exposure to pesticdes, particularly Atrizine, which is the most widely used chemical in American agriculture today.

Yes on the chemical companies protecting themselves by overt and covert means.
A scandal in the public health area a couple of years ago relating to agent orange studies. It was determined that one of the most highly regarded public health scientists, Sir Richard Doll, was himself secretly on the payroll of chemical companies during the time Doll was doing reports to NewZealand and Australia governments about agent orange. His reports, now obviously tainted, saying essentially that the chemicals were not to blame, were used to weaken and deny claims by veterans that they were harmed by the chemical. Doll was being paid by Monsanto (1970-1990). Secret Ties to Industry and Conflicting Interests in Cancer Research see:

The author, in describing a disease found in Guam refers to a "local dietary staple: a rodent known as a fruit bat." It's surprising that such an old myth would be found in OnEarth. All bats, including fruit bats, of which there are many species, are not rodents. Bats belong to the order Chiroptera and are, in fact, more closely related to humans than they are to rodents.

Jackie cardinal exposure is fundamentally clear - exposure or rather over exposure to Monsanto ROUNDUP the chemical from HELL. I have seen early photos of those using this type of agent in the late 1940's wearing space suits 30 years ahead of their times.

Guam should be looked at for the reason behind these diseases. The ALS/PDC of Guam is well known but never has there been a complete study of the amount of pesticides used on this island and or the severe contamination.
In 1944 we took Guam from the Japanese. After the battle there were about 20,000 dead, about 15,000 Japanese and about 5000 US. The war was still going on and the dead were allowing the disease carrying insects of Guam to multiply by the billions. The insects were using the bodies as host for their young. Enter DDT. The entire island for months was sprayed day after day by air and land with this insecticide. Now at the same time we were rebuilding the infrastructure of Guam and building 10 military installation. Herbicides were the order of the day. My understanding is that sodium arsenite and Agent White were the herbs of choice. Herbs are used in all facets of maintenance, base building and upkeep.
Now you also would have to add in radiation for Guam as well as it was a part of the radiation zone for the nuclear weapons testing in the pacific. It was also a decontamination site for many of the ships involved. It was also a storage facility for the contaminated munitions and other military items used in the tests. One more thing to add in this time frame that fits perfectly with the outbreak of ALS/PDC of Guam. That is the contaminants of war. Cases have been won for ALS and Guam in military personnel, there on the BVA website. There are many cases for Parkinsons in veterans that did service on Guam as well. Somehow most of the scientist and all the US scientist involved seem to have missed this contamination. The head scientist of the project on Guam even lied to me, stating there are no cases for ALS or Parkinsons disease in veterans on Guam. He dismissed the contamination out of hand giving no reason.
Here's a little background on how the DDT was used. The bodies were sprayed, bagged and ddt'd again then into pits and ddt'd again. To make Guam friendly for shipping the lagoons on this coral atole are sprayed with ddt, then munitions are set after all the coral dies and viola you have nice sandy lagoon. The coral is almost impossible to blow holes in without the ddt. I hope this helps.

I was at Anderson Air Force Base in 1959 and 60. I spent a lot of time in all parts of the island eating local food at the Saints Festivals. 5 years ago I was diagnosed with Parkinson's. Please tell me if you know of anyone gathering statistics or groups looking to discuss the possibility of Guam being a possible case for Parkinson's disease. Thank you for information you can give me.

The article may not be critically accurate in all senses but the overall impression is damning against pesticides and anyone who quibbles over small points has a point but the message after more than 50 years is going in one ear of those that kill us and out the other.

Jackie cardinal exposure is fundamentally clear - exposure or rather over exposure to Monsanto ROUNDUP the chemical from HELL. I have seen early photos of those using this type of agent in the late 1940's wearing space suits 30 years ahead of their times.

Today we use the same chemicals in bikinis and wonder why we get some disease 10 to 15 years down the line.

The miracle is not do we get AD, PD, ALS, GBS etc etc but why we dont get ill. The reason simply is the power of people to survive chemical insults.

Everytime we take a meal, that is not organic, we get sleepy for an hour as the body goes into overtime detoxifying us.

The link of chemicals that destroy nervous systems of insects and that of humans almost 100 per cent the same but on a grander scale is SIMPLE SCIENCE ignored in the rush for the ALMIGHTY DOLLAR.

The nature of the metal spanner in the works with these mimics of our DNA is also becoming painfully obvious not only to the sufferers but those amongst us that cant be bought for a thousand pounds a day to be the industry deniers of harm.

I am open to offers!

Only joking; the only JOKE here unless you count Monsanto scientific expertise.