Over 200 Cornwall Health Professionals Warn of Cancer Risk from Weedkiller Plans

More than 200 healthcare professionals in Cornwall have signed an open letter to Cornwall Council urging it to abandon plans to reintroduce glyphosate-based weedkiller on urban roads and pathways, citing serious concerns about cancer, birth defects and neurological disease.

The letter, organised by Dr Robert Cook, a GP partner at Bodriggy Health Centre in Hayle, was handed in to Cornwall Council this morning, Monday 20th April 2026. It carries the signatures of over 200 Cornwall healthcare professionals and allied services, including more than 70 doctors currently working in the county.

What the Letter Says

Addressed to Cllr Frost and Cornwall Council, the letter states: “We, the undersigned health professionals of Cornwall, write to express our collective concern regarding the planned reintroduction of glyphosate for weed control on urban highways. As advocates for the health and well-being of our residents, we urge you to reconsider this decision considering growing scientific evidence highlighting the health risks associated with glyphosate and the adjuvants combined with it.”

The signatories point to the classification of glyphosate as “probably carcinogenic to humans” (Group 2A) by the International Agency for Research on Cancer (IARC), part of the World Health Organization, in 2015. That classification was based on sufficient evidence of carcinogenicity in animals and limited evidence in humans, with particular concern around non-Hodgkin lymphoma.

The Health Risks Outlined

The letter sets out a range of health concerns linked to glyphosate exposure, drawing on published scientific research:

Cancer: Studies published as recently as 2025 and 2026 suggest an increased risk of lymphomas associated with glyphosate exposure.

Liver disease: Research has shown that glyphosate-based herbicides can cause liver disease, including non-alcoholic fatty liver disease in animal studies.

Birth defects: Studies have found associations between glyphosate-based herbicides and foetal malformations.

Neurological disorders: Research suggests links between glyphosate exposure and conditions including Alzheimer’s and Parkinson’s disease.

The letter also raises concerns about adjuvants, the additional chemicals combined with glyphosate in commercial weedkiller formulations, noting that many have been shown to be toxic to human cells and that long-term safety data remains inadequate.

📷Cllr Leigh Frost - Cornwall Council with Dr Robert Cook and Paula Bright

Schools, Waterways and Wildlife

A particular concern raised in the letter is where the weedkiller would be applied. The healthcare professionals say they are “especially concerned” that the planned application is on the urban highway network, including areas close to schools and healthcare settings.

They also warn of environmental risks, noting that application on hard surfaces near drains and waterways could lead to runoff into rivers and the sea, potentially contaminating bathing waters and bypassing any natural breakdown by soil microorganisms.

The letter adds that glyphosate is known to harm beneficial insects, aquatic life and soil health, describing biodiversity protection as “not just an environmental concern” but “a matter of public health that affects us all directly.”

📷Dr Robert Cook and Paula Bright, a local physiotherapist holding the letter

The Call to Cornwall Council

The letter concludes: “Given the substantial scientific evidence regarding the health risks associated with glyphosate, we implore Cornwall Council to prioritise the safety of our community by refraining from its use on urban highways. The health of our residents and the integrity of our environment must be at the forefront of our decision-making processes.”

Cornwall Council has not yet responded publicly to the letter. CornishStuff has approached the council for comment.

📷Dr Robert Cook and Paula Bright, a local physiotherapist.