Parkinson’s as a man-made disease

This blog post is the first in a series of blog posts about the relationship between Parkinson’s disease and pesticide exposure. With these blog posts I want to stand up for the interests of people who will get a neurodegenerative disease like Parkinson’s in the future because they are sensitive to the adverse effects of certain pesticides. Every preventable case is worth pursuing.

8th of october 2019

Part 1. An unfolding story

It seems safe to conclude that occupational exposure to pesticides brings about at least 50% increased risk for contracting a neurodegenerative disease | Gunnarsson, 2019

When I was diagnosed with Parkinson’s disease, I obviously had to shed a tear. When I realized that I had taken residence on the grounds of a pesticide spraying farmer when I was 24 for two years – and then for another four years across the street from the former ‘crime scene’ – those tears were somehow even more intense. Peculiar. I think that’s because I suddenly realised that things might have turned out differently.

Evidence that neurodegenerative diseases such as Parkinson’s disease are partly man-made has been piling up for years. (e.g. Mostafalou, 2012; Gunnarsson, 2019). A quick glance at the worldwide distribution of the 6.1 million people with Parkinson’s in 2016 shows that Parkinson’s is more common in the industrialized parts of the world. In addition, the disease is rapidly increasing. And the rapid increase cannot be explained by the increasing aging alone (GBD 2016 Parkinson’s Disease Collaborators, 2018).

Parkinson’s disease develops in many years. At present, the disease is only diagnosed when things in our basal ganglia – the conductor of our brain – are already quite awry. It is thought that Parkinson’s is triggered by an external factor such as a viral infection or toxin (Johnson, 2018).

Industrialisation – and the associated pollution of our environment by e.g. pesticides – increases the chances of winning the Parkinson’s bingo. For people who are professionally exposed to pesticides (i.e. for a long time and in relatively high concentrations), this higher chance is at least 50%. (Gunnarsson, 2019). To understand what that 50% means, you have to imagine that for every two people who get Parkinson’s, there will be an extra one who would not have had Parkinson’s if he or she had not been professionally exposed to certain pesticides.

Pesticides are chemicals that are toxic to ‘pests’. ‘Pests’ refers to any animal, insect or plant that is considered harmful to current agricultural practices and crop harvesting. Pesticides target different types of ‘pests’, such as insects (insecticide), weeds (herbicide) and fungi (fungicide).

Use of pesticides in the Netherlands and Europe

According to the CBS (he Dutch Bureau of Statistics) in 2016, in the Netherlands pesticides were used on 710.000 ha of agricultural soil. The frontrunners are mancozeb (used on 168000 ha), glyphosate (used on 156000 ha) and diquatdibromide (with a significant increase from 86000 ha to 112 612 ha between 2012 and 2016). The latter has now been banned. Of course, all these figures do not indicate how many kg have been used, nor does it mean that the most commonly used substance is the most harmful. Some substances are more active/harmful in lower concentration than others in higher concentrations, some mixtures of substances are more toxic than the individual components, etc.  It is complicated …

According to Eurostat, 185 million kilogram of pesticides were sold in the European Union in 2017. The figures for a number of Member States are not known. Unfortunately, the data from Eurostat and the CBS cannot be compared because they both use a different unit of measurement.

You must be wondering how I’m going to stand up for the interests of the people who are going to get Parkinson’s in the future. Of course I haven’t quite figured that out yet, but luckily I have joined a group within the Dutch Parkinson’s Association who – each with their own talent – want to dig into the scientific evidence about the relationship between Parkinson’s and the pesticides used in the Netherlands as a first step. I am in charge of the glyphosate files (more on that later).

In the meantime, in the last few weeks, I have been browsing and studying scientific articles, political documents, toxicity testing procedures and great initiatives for innovations in agriculture. And – as might be expected – I only get more questions. But possible routes are also slowly taking shape. I currently see three:

Fundamental change occurs when we start seeing from the whole and sense what is happening from within a situation | Peter Senge

Of course, pesticide designers have never wanted pesticides (framed as ‘crop protection’) to have such serious side effects. But in the meantime we know that massive pesticide spraying already leaves almost indelible traces worldwide. Pesticides do not adhere to the square patches of land they have initially been applied to. They appear in adjoining parcels (Silva, 2019), surface water and food (Gonçalves, 2019; Carles, 2019; Bai, 2016), bees (Motta, 2018), affect intestinal bacteria (Jin, 2017) and transgenerational effects have been found (Kubsad, 2019;  Nilsson, 2018).

Whether we get Parkinson’s from it or not, now we know what we know, it is wise to rethink the way we grow our crops.

It seems only logical that we should learn to think about how we pollute our own environment in a more overarching way.
It seems only logical that we should restrict the use of pesticides.
It seems only logical that some pesticides should be banned without delay.

But achieving what is logical without too much resistance is a lot easier if there are alternatives that take everyone’s interest into account. How do you ensure a win-win situation?

I am thinking of two parallel roads:

  • Encourage (discussions about) sustainable innovations in agriculture
    Encourage measures to promote diversity in crop protection and biodiversity. Help farmers (also financially) with the transition to a sustainable way of supplying food that is not going to harm our health via the backdoor. In this way we also protect farmers against themselves. In the Zembla broadcast of 16 September 2019 (in Dutch), it was quite poignant and distressing to see that a winegrower who had Parkinson’s disease nevertheless continued to spray because he did not know an alternative to his livelihood.
  • Put great initiatives in the spotlight
    In the Netherlands, two such initiatives recently made the headlines:

    • A farmer who has converted his pig farm into a sturgeon farm (Dutch) and started breeding fish in a responsible manner.
    • A food forest called Ketelbroek (Dutch) where people are experimenting with what the agriculture of the future could be. Over the next five years, the ‘Stichting Voedselbosbouw’ (Food Forestry Foundation) wants to establish at least 150 hectares of food forest on agricultural land in the Netherlands in order to ensure sustainable, commercial food production in the coming decades.

We should not think about replacing glyphosate with a new, less harmful synthetic molecule, we must change the type of agriculture and introduce new agricultural techniques to better manage unwanted herbs | Toretta, 2018

When I see a Parkinson’s patient, I can never prove what he was exposed to 10, 20 or 30 years ago, so I want good research to be done upon admission of pesticides. We must know for sure that it is safe | Professor Teus van der Laar,  Zembla, 19th of september 2019.

In this route I enter ’the battlefield’ to see what my circle of influence looks like there. A logical step in this arena is to ask the Ctgb, the Board for the Authorisation of Plant Protection Products and Biocides in the Netherlands, some questions.  I’m specifically curious about whether and if so, in what way (neuro)toxicity of pesticide(mixtures) is assessed. (Arcuri, 2019;  EFSA Panel on Plant Protection Products and their residues, 2017).

Another step is to focus on one or two pesticides with relatively strong epidemiological/scientific evidence for neurotoxicity. If I can contribute to getting these pesticides banned, then I most surely know this might turn out to be a short victory. New pesticides will replace the old ones and we will have to see whether we are better off.

There is a too great a discrepancy between the opinions of the various scientific institutions, mainly because of their different economic and social interests. The controversy and the debate are expected to continue. It is certain, however, that the population and the environment must be better protected, especially through the endorsement of new rules and limitations regarding the chemical in question. It is the duty of the institutions to place the “precautionary principle” before economic interests, namely the protection of citizens and the environment from exposure to a substance whose side effects are not yet known | Toretta, 2018

In addition to a scientific, economic, political and regulatory side, the discussion about exposure to pesticides and the effect on our health also has a moral/ethical side. Or at least it should have.

Think of questions such as:

  • If you have good reason to believe that a pesticide will adversely affect future generations, what do you do?
    The most used weed killer in the world – glyphosate – (Benbrook, 2016) has no effect on exposed rats, but does affect their grandchildren and great-grandchildren, who have never been exposed themselves (Kubsad, 2019). So I thought that theoretically it could also be that you get to win the Parkinson’s bingo because your ancestors have been exposed to a toxin that is now forbidden. The article of Kabasenche, 2014 about ’transgenerational environmental justice’ when using DDT, discusses this kind of dilemmas.

We now have good reason to believe, based on the evidence discussed above, that the use of DDT will impose burdens on individuals in the next two or four generations, at least, while the current generation enjoys the benefits of its use. Consideration of intergenerational justice invites us to examine how our practices and activities will impose burdens (and benefits) on those who will inhabit the world 50 or 100 or 500 years from now | Kabasenche, 2014

My thoughts so far

We will probably never be able to say with 100% certainty that a certain pesticide causes Parkinson’s. This line of thinking is far too linear. Parkinson’s is a complex disease and there are many more variables that play a role in winning the Parkinson’s bingo. In fact, Parkinson’s disease doesn’t even exist. There are many Parkinson’s diseases (Stecher, 2019). However, the evidence that it is easier to win one of the possible Parkinson’s bingos if you are exposed to certain pesticides is beyond any doubt. At the moment, we are simply increasing the chances of someone getting Parkinson’s disease. And if he or she doesn’t have to tick the pesticide box on his or her bingo card, the results may be different.

Everyone is not equal, and safety standards need to be updated in order to protect those who are more susceptible and may not even know it | Scott Ryan in a comment to his group’s article on the effect of the pesticides paraquat and maneb on stem cells of dopamine neurons (Stykel, 2018)

Because the good news is that we are talking about a modifiable risk factor. Not an easily modifiable risk factor, but a modifiable one. We can try to prevent a certain group of people – who don’t even know that they are vulnerable – from having to call out ‘bingo’ in the future. That is what I will be striving for.

Because Rumpelstiltskin was right:

All magic comes with a prize | Rumpelstiltskin

If, after reading the post, you have thoughts about great routes to follow, good questions to ask, good practices to follow, will you let me know?
Thanks in advance and to be continued …..




Arcuri, A., Hendlin, Y.H. (2019). The Chemical Anthropocene: Glyphosate as a Case Study of Pesticide Exposures. King’s Law Journal. (Open Access).

Bai, S. H., Ogbourne, S. M. (2016). Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination. Environmental Science Pollution Research International, 23, 18988–19001. (Closed Access).

Benbrook, C. M. (2016). Trends in glyphosate herbicide use in the United States and globally. Environmental Sciences Europe, 28 (3). (Open Access)

Carles, L. et al. (2019). Meta-analysis of glyphosate contamination in surface waters and dissipation by biofilms. Environment International, 124, 284-293. (Open Access).

EFSA Panel on Plant Protection Products and their residues (PPR) (2017). Investigation into experimental toxicological properties of plant protection products having a potential link to Parkinson’s disease and childhood leukaemia. ESFA journal. [Scientific Opinion]. (Open Access).

Gonçalves, B.B. et al. (2019). Ecotoxicology of Glyphosate-Based Herbicides on Aquatic Environment. Organic Pollutants [Book chapter]. (Open Access).

Gunnarsson, L., Bodin, L. (2019). Occupational Exposures and Neurodegenerative Diseases—A Systematic Literature Review and Meta-Analyses. International Journal of Environmental Research and Public Health 16 (3), 337. (Open Access).

GBD 2016 Parkinson’s Disease Collaborators (2018). Global, regional, and national burden of Parkinson’s disease, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurology, volume 17, issue 11, p 939-953. (Open Access).

Jin, Y., Wu, S., Zeng, Z., & Fu, Z. (2017). Effects of environmental pollutants on gut microbiota. Environmental Pollution, 222, 1–9. (Closed Access)

Johnson, M. E. , Stecher, B. , Labrie, V., Brundin, L., Brundin, P., (2018),  Triggers, Facilitators, and Aggravators: Redefining Parkinson’s Disease Pathogenesis. Trends in Neurosciences, 2 (1), 4-13. (Open Access)

Kabensenche, W.P, Skinner, M.P. (2014). DDT, epigenetic harm, and transgenerational environmental justice. Environmental Health, 13, Article number: 62. (Open Access).

Kubsad, D. et al. (2019). Assessment of Glyphosate Induced Epigenetic Transgenerational Inheritance of Pathologies and Sperm Epimutations: Generational Toxicology. Scientific Reports, 9, Article number: 6372. 

Mostafalou, S., Abdollahi, M. (2018). Pesticides and human chronic diseases: Evidences, mechanisms, and perspectives. Toxicology and Applied Pharmacology, 268 (2), 157-177. (Closed Access, indien gewenst bij mij te krijgen)

Motta, E.V.S., Raymann, K., Moran, N.A. (2018). Glyphosate perturbs the gut microbiota of honey bees. PNAS, 15 (41), 10305-10310. (Open Access)

Nilsson, E., Sadler-Riggleman, I., Skinner, M. K. (2018). Environmentally Induced Epigenetic Transgenerational Inheritance of Disease. Environmental Epigenetics, 4, 1–13. (Open Access).

Torretta, V., Katsoyiannis, I.A., Viotto, P., Rada, E.C. (2018). Critical Review of the Effects of Glyphosate Exposure to the Environment and Humans through the Food Supply Chain. Sustainability, 10(4), 950. (Open Access)

Silva, V., Molb, H.G.J., Zomer, P., Tienstra, M., Ritsema, C., Geiseena, V. (2018). Science of The Total Environment, 653, 1532-1545. Pesticide residues in European agricultural soils – A hidden reality unfolded. (Closed Access, indien gewenst bij mij te krijgen).

Stecher, B. (2019). The path to curing degenerative brain diseases. [Blogpost].

Stykel, M.G., Humphries, K., Kirby, M.P, Czaniecki, C., Wang, T., Ryan, T., Bamm, V., Ryan, S.D. (2018). Nitration of microtubules blocks axonal mitochondrial transport in a human pluripotent stem cell model of Parkinson’s disease. FASEB J., 32 (10), 5350-5364. (Open Access).

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