Some of the Parkinson's disease we file under bad luck looks, on the evidence now accumulating, closer to something we are doing to ourselves. In a 2025 study in JAMA Network Open, a Mayo Clinic team led by Brittany Krzyzanowski found that people living within a mile or two of a golf course had markedly higher odds of Parkinson's than those living nineteen miles away, with the risk tracking the groundwater that carries the turf pesticides downhill from the fairway toward the tap. It is one thread in a rope that now ties a meaningful share of the disease to named industrial chemicals, the degreaser trichloroethylene and the weedkiller paraquat chief among them, and to the air and water that carry them into homes that never agreed to receive them.
Let me be careful here, because the field around it often is not. The strong version of the claim, that Parkinson's is "largely preventable," is an advocacy position rather than settled science, and I would not build anything on it. What the evidence will carry is narrower and still consequential: that specific, named neurotoxicants raise the risk, that millions of people are exposed to them without knowing and without consenting, and that little of that exposure is measured or priced. The disease is contested. The exposure is not.
The stakes are not modest. Parkinson's was the fastest-growing neurological disorder in the world across the generation to 2016, roughly 2.5 million cases in 1990 becoming 6.1 million by 2016, and it is on track to roughly double again by 2040 (the Global Burden of Disease study, in Lancet Neurology). Ageing accounts for much of that climb. But the environmental share, unlike ageing, is the part we could act on, if only we could see it. Ray Dorsey, who has done as much as anyone to reframe the disease as substantially man-made, calls it the fastest-growing brain condition on earth and one we are, in part, manufacturing.
Which points to the actual problem, the one worth organising a response around. The chemicals are named. The harms are documented. The tools to act, bans, substitution, remediation, filtration, disclosure, mostly already exist. What is missing is the layer in the middle that turns an invisible externality into a measured, disclosed fact a regulator, an insurer or a home-buyer can do something with. Donella Meadows put the flow of information, what gets measured and who is allowed to see it, near the very top of her list of places to intervene in a system. The binding constraint here is not the chemistry. It is the information.
This is an old insight wearing new clothes. Rachel Carson did not ban a single pesticide in 1962; she made an invisible harm visible, and the banning followed. The task now is the same, and the instrument that fits it is neither a charity nor a startup but a fund that backs a mission across a portfolio of levers. Pooled, patient philanthropy has already done exactly this for one neurotoxicant: a recent fund aimed at childhood lead exposure more than tripled global spending on the problem inside a year, by paying for the unglamorous public goods, the measurement, the standards, the coalition, that no single company could justify funding because none could capture the return. No one has yet built that engine for the adult brain.
Pointed at neurotoxicants, the levers are legible:
- Research and measurement. The exposure epidemiology that moves a chemical from "associated with" to "priced at", including the public-data mapping behind the golf-course finding.
- Standards. Agreed exposure thresholds a regulator, insurer or buyer can act on. None exists today, and building one is probably the first task.
- Policy. Finishing the trichloroethylene cleanup the United States began when it banned the chemical in December 2024, retiring paraquat, and putting exposure on a property listing the way flood risk now is.
- Transparency. Open maps and plain disclosure that hand the fact to the person carrying the exposure.
- Orchestration. A neutral coalition that lines governments, utilities and funders up behind a single dated reduction target.
There is a sixth lever, the one that eventually pays: direct investment into safer substitutes, remediation and testing, where a working market finally rewards the whole effort. That belongs to commercial capital, not philanthropy, and in an honest design it sits in a separate, walled vehicle, ineligible for the fund's grants and recused from them, allocation set by an independent panel. The market-building layer has to be un-ownable to be trusted. It is also what makes the thing durable, and worth calling an instrument rather than a campaign. A fund like this is not meant to run forever; it is meant to build a market and then leave, the way the lead effort is building toward a world that no longer needs it. What lasts is not the fund. It is the standard, the disclosure norm and the priced-in externality it leaves behind.
I should say where I sit, because I would rather name it than have it surface later. I wrote the public analysis this grew out of. I would build it with Michael Lindenmayer, my long-standing partner on this systems-fund work, anchor the science on Ray Dorsey, and bring in Brittany Krzyzanowski and the Mayo team who found the golf-course signal to lead the exposure mapping. My firm may separately run a commercial vehicle in the same space; if it does, it would be walled off from the fund and recused from its grants, because a market-builder that comes to own the market it is building is not a market-builder at all.
What persuades me this is worth doing is the ladder underneath it. Measure the exposure, price it, disclose it, and the bans and filters and clean-ups that follow stop being feats of political will and start being acts of ordinary self-interest, the same logic that moved money toward lead once the harm was finally legible. We have made an invisible poison visible once. The adult brain is the next place to point the same machine. The companion to this piece, on a very different disease, is the cost of guessing, and it runs on exactly the same structure.