The mysterious health complaints of Canadian and US diplomats in Cuba that were blamed by US authorities on suspected acoustic attacks may have been caused by neurotoxins in anti-mosquito pesticides, a clinical study found.

The Canadian study said the symptoms suffered by some 40 Canadian and US diplomats and their families at missions in Havana were possibly triggered by "low-dose exposure to neurotoxins."

Those affected suffered a range of unusual symptoms including hearing and vision complications, dizziness, fatigue and headaches.

The incidents from late 2016 into 2018 led Ottawa and Washington to reduce their embassy staffs in Havana, with the administration of US President Donald Trump claiming that the diplomats had been attacked by some sort of secret sonic weapon.

Routine pesticide use

The study, carried out by a team affiliated with the Brain Repair Centre and the Nova Scotia Health Authority, gave no credence to the acoustic weapon theory.

"There are very specific types of toxins that affect these kinds of nervous systems ... and these are insecticides, pesticides, organophosphates — specific neurotoxins," the study's lead author, Alon Friedman, was quoted as saying by Canadian broadcaster CBC.

Cuba routinely uses pesticides to kill insects that might carry disease and carried out an intensive program of spraying from 2016 to stop the spread of the Zika virus. Embassy records cited by Radio-Canada said that the offices and homes of diplomats were among the sites to be sprayed.

The study involved 26 people, including a control group of people who have never lived in Cuba. Participants were subjected to blood tests and brain scans. A pet dog that had died in Canada also had its brain studied.

Friedman said there were plans to extend the study to members of the broader Cuban population in cooperation with local scientists to see if other residents had also been affected by the neurotoxins.

Read more: The most dangerous mosquito-borne diseases

tj/sms (dpa, Reuters, AFP)

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