Revealed: The secret push to bury a weedkiller’s link to Parkinson’s disease

The global chemical giant Syngenta has sought to secretly influence scientific research regarding links between its top-selling weedkiller and Parkinson’s, internal corporate documents show.

While numerous independent researchers have determined that the weedkiller, paraquat, can cause neurological changes that are hallmarks of Parkinson’s, Syngenta has always maintained that the evidence linking paraquat to Parkinson’s disease is “fragmentary” and “inconclusive”.

But the scientific record they point to as proof of paraquat’s safety is the same one that Syngenta officials, scientists and lawyers in the US and the UK have worked over decades...