A neurologist who believes his patients are suffering from a suspicious illness has pleaded with the Canadian government to carry out environmental testing he thinks will show the involvement of the herbicide glyphosate.
For more than two years, dozens of people in the Canadian province of New Brunswick have experienced a distressing array of neurological symptoms, initially prompting speculation that they had developed an unknown degenerative illness – and that figure is believed to be far higher than official reports.
A year ago, the New Brunswick government announced that there was no mystery illness, and closed its investigation. An independent oversight committee, created by the province, determined the patients in the “cluster” were most likely misdiagnosed and were suffering from known illnesses like cancer and dementia.
The government also cast doubt on the work of neurologist Alier Marrero, who was initially referred dozens of cases from baffled doctors, and who has since become a fierce advocate for patients he feels have been neglected by the province.
On 30 January, Marrero sent a letter to both Canada’s top public health official and the province of New Brunswick’s chief medical officer, warning them of “troubling” new developments and pleading for action and warning some of his parents were in “advanced stages of clinical deterioration and near end of life”.
Among those developments, he said recent laboratory tests on a number of patients showed “clear signs of exposure” to glyphosate, as well as other compounds linked to herbicides, adding that many of those tested had levels “many times over the detection limit”, according to the letter obtained by the Guardian.
Marrero said he was not requesting the study of any “mysterious diseases” but was instead concerned the presence of glyphosate and other compounds could be linked to known toxins in the region, known for their harmful effects on the brain.
“Moreover, I underline again that many of our patients are young. This is concerning as it is quite rare for young patients to present with such symptomatology.”
Multiple patients have provided the Guardian with their recent test results, which show clearly detectable levels of glyphosate other metabolites.
It is unclear if the elevated levels of glyphosate, widely used by forestry companies in the province to limit vegetation growth, have had any bearing on the patients with neurodegenerative illnesses. And experts say more testing would be needed to determine how “elevated” these results are, compared with the community.
But in his letter, Marrero told officials he worried that the presence of glyphosate could be linked to blue-green algae blooms in water sources. In the past, these blooms have released toxins like BMAA (B-methylamino-L-alanine), which experts initially suspected could be a culprit for the unexplained cases that baffled officials two years ago.
Marrero referred to studies that have shown some species of cyanobacteria such as blue-green algae are resistant to glyphosate and even use the herbicide as a source of phosphorus, which in turn can create the toxic blooms.
More than 1,000 pages of internal documents obtained by freedom of information requests and seen by the Guardian show that early on in the investigation, the province’s department of environment and public health units began exploring the possibility of environmental causes, including blue-green algae.
The documents also demonstrate how officials were aware of numerous hazardous algae blooms throughout the province, including in three municipal reservoirs, including the city of Moncton.
Staff even flagged glyphosate, a controversial herbicide, as a possible avenue of investigation.
On 23 March 2021, a senior environmental epidemiologist requested information on the scope and quantity of glyphosate spraying in the province over a two-decade period, spanning 2000 to 2021.
In an email the next day, Dr Cristin Muecke, the province’s deputy chief medical officer of health, asked if there was “anything linking glyphosate to neurological disorders”.
Experts have previously cautioned that extensive environmental testing is more work that the public realises, including determining what an “elevated” level of a possible toxin is compared with the broader population.
Marrero declined to comment on the letter, instead directing questions to the province’s health authority.
The province reiterated its conclusion there was “no evidence of a neurological syndrome of unknown cause” and said that while it has the power to conduct environmental testing “as warranted”, the health authority did not say it would conduct any tests in response to Marrero’s letter.
The public health agency of Canada said it was aware of the letter, adding that environmental testing fell under the jurisdiction of New Brunswick.
Marrero’s letter highlights his growing desperation amid fears his patients have been forgotten – and are unlikely to receive answers from the province.
And a recent report from the Canadaland news site that the province declined C$5m (£3m) in emergency funding for investigations has further angered families.
In the case of Gabrielle Cormier, a 21-year-old now unable to walk unassisted, a PET scan of her brain showed reduced cerebral blood flow, according to her family.
“It also showed what looked like a scar on her brain that we were told was likely caused by inflammation. She has no history of any medical condition that would cause inflammation of the brain,” Stacie Quigley Cormier, Gabrielle’s stepmother, said. “Something else caused this, and these parts of her brain will not recover.”
One patient, who is now unable to work, received a letter from the province – despite never meeting with a doctor – that listed possible diagnoses, all of which had previously been ruled out through testing.
“Not one neurologist from the oversight committee talked to me or reached out to my family doctor for my medical history,” the patient said, calling the process “incredibly unprofessional” and “frustrating”.
Families also feel they were misled by the province’s earlier promise to investigate environmental concerns, which never happened, and are holding out hope the federal health agency can help.
“They just have to choose that we are worth helping. Our family are firm believers in people in and their capacity to doing the right thing,” said Quigley Cormier. “It is not too late for [the public health agency] to do the right thing and make the decision to help us.”
