Is Parkinson’s Caused by Pesticides?

Even in some of the more open-minded circles I move in, a concern about the pesticides used in conventional agriculture can still seem a little fringe*.

For years and years, I’ve erred on the side of buying organic food where possible and reasonable. But admittedly, I can’t say this is because I’ve undertaken a cold, hard reading of the relevant evidence and been convinced that this is indisputably the healthier course of action.

It’s more that I reasoned it couldn’t exactly be any less healthy, so going for the organic option always seemed like a straightforward and relatively thoughtless way to bump up the nutritional quality of my diet without incurring any costs beyond a small financial one (at least not personally—you can make arguments for the utility of conventional agriculture from the perspective of land use or supply chain predictability).

However, my pro-organic position has begun to harden and thankfully become marginally better informed.

A piece was recently published in Politico that consolidated and crystallised findings I’d been spotting here and there in research on pesticides and their health risks.

It challenges the notion that Parkinson’s is a natural byproduct of the ageing process and argues that, at least in part, we might better think of it as a disease caused primarily by exposure to environmental toxins—particularly what we spray on our food.

When Parkinson’s was discovered in the early 1800s, it was rare. But cases have been rising globally and are expected to continue doing so in the decades ahead. The number of cases doubled between 1990 and 2015 and is predicted to double again by 2040.

Parkinson’s UK estimates that two people in the UK are diagnosed with the disease every hour and predicts that the number of people living with the condition in 2030 will be 20% higher than in 2023.

I imagine this has to be partly a function of us living longer lives—as populations age, diseases that mostly afflict the old will naturally become more prevalent. But the article outlines the views of those who believe that this trend alone can’t explain the scale of the increase observed.

Researchers claim that you can neatly map the rise in the prevalence of Parkinson’s onto the hike in the pervasiveness of intensive—that is, industrial, mechanised, and productivity-focused—agriculture (occurring in roughly the mid-to-late 20th century). There are contemporary studies from around the world that tightly correlate increased pesticide use in a given region with a subsequent jump in the rates of Parkinson’s suffered by those living in that region.

It’s not that authorities are totally unaware of the possible risks posed by pesticides (for instance, we looked at DDT in the last post and how it’s banned in most countries). After all, you’d think it’d be hard not to be at least a little aware. Think about it—we’re talking about substances designed for no purpose other than the destruction of biological life. While the dose obviously makes the poison here, what’s bad for insects and weeds probably isn’t great for us either. We’re merely another strand in the same web of life.

But, the Politico article points out, we tend to take action only once we’ve accumulated substantial evidence of the dangers of a particular chemical—by which point it’s often too late and significant damage has already been done.

As I remember hearing someone say once, we have a habit of searching for our blind spots so that we can do business there. A lack of knowledge presents an opportunity to use and enjoy the benefits of a newly formulated substance before research inevitably emerges attesting to its toxicity, closing the knowledge gap.

Then, a brand-new substance arrives on the scene—generally to satisfy a business need—about which we know much less, which is used until we understand enough to consider it unsafe, which then prompts us to search for a replacement by developing new compounds, and the cycle repeats.

The answer the article offers is of course to shift from a reactive to a proactive approach—to ensure that we know as much as we reasonably can (and ideally a bit more) about the long-term effects of a substance, how it behaves in the real world, and how it interacts with other toxins it’s likely to come into contact with before declaring it safe to spew into the environment.

*To be clear, it isn’t the case that organic agriculture involves no pesticide use at all. Though regulations aren’t completely uniform across all contexts, organic farmers generally aren’t allowed to use synthetic pesticides (like those the article is referring to). They can use a limited set of natural or naturally derived pesticide products, which I, without knowing anything about them, have to imagine have a better safety profile.

On the road: what should we make of claims of water purity?

I’m currently doing some travelling in Europe and have inevitably been eagerly searching for information on the quality of the tap water in whatever location I’ve just arrived in before filling myself up with it.

Luckily, the proclaimed purity of the drinking water in the countries I’ve visited has been high. For example, one of the first pieces of communication I received, having just arrived at Helsinki Airport, informed me that Finland is home to some of the best potable water in the world. And as I sat preparing to send this post, a waiter in Vilnius was kind enough to proudly let me know that Lithuanian water is ‘the best’.

This is all wonderful—but I’ve been thinking: what exactly am I meant to understand by this? What are these assessments based on? Can I expect to spend my time in these countries enjoying drinking water totally free of PFAS and microplastics?

The short answer: not really, but it’s complicated.

Traditionally, drinking water regulations have focused on things like microbial contamination, heavy metals, and general cleanliness—not hidden hazards like microplastics or PFAS.

However, this is actually starting to change. The EU recently updated its directives on water quality and will require member states to test for and limit the presence of PFAS in tap water by January next year. And while restrictions are yet to be introduced, it’s also making moves to get a grip on the prevalence of microplastics in the water of EU countries. (The UK has mentioned water-borne PFAS and microplastics in government documents and guidelines but is very much lagging behind on this front.)

But even now, ahead of any major regulatory changes, my reading of the situation is that while it’s far from any sort of guarantee, generally speaking, tap water that’s been heavily and effectively treated will probably contain slightly lower levels of PFAS and microplastics overall.

Even if they’re not designed specifically to remove these hidden hazards, standard treatment processes can still reduce the degree to which they exist in treated water, so water considered purer in general is also likely lower in PFAS and microplastics.

Somewhere like Finland also benefits from the fact that it sources much of its drinking water from groundwater and protected surface water in relatively pristine areas, which are naturally lower in industrial waste products and other pollutants to begin with.

And crucially—it’s always worth remembering that tap water, unless explicitly categorised as unsafe to drink, is purer and less contaminated in the main than bottled water, particularly, of course, if the bottle in question happens to be plastic.

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