Cuba 'Sonic Attack' Was Likely Caused by Pesticides, Study Finds
A mysterious sudden onset of extreme symptoms that overtook American and Canadian diplomats stationed in Cuba may be linked to an overexposure to pesticides, according to new research.
Symptoms of "Havana Syndrome" were first reported in August 2017 when officials working in Cuba experienced a myriad of health problems with symptoms similar to those of a mild brain injury, reported The Guardian at the time. Characterized by ringing in the ears, vertigo, blurred vision and difficulty concentrating and speaking, the cause was first thought to be the result of an acoustic attack by the Cuban Government.
Preliminary findings from a study funded by Global Affairs Canada now suggest that the condition was likely caused by "organosphosphorus insecticides" that inhibited cholinesterase (ChE), a family of enzymes that ensures proper functioning of the nervous system, especially in the nervous tissue, muscle and red cells.
Organosphosphorus insecticides are chemicals used to kill many types of insects and account for a large share of those used in the U.S. including on food crops, according to the Center for Disease Control and Prevention. People become exposed to these chemicals when eating food treated with them, by breathing in particles through the air, or absorbing them through the skin. Sudden exposure can result in nausea, vomiting, difficulty breathing and weakness whereas long-term exposure to smaller amounts can make a person "feel tired or weak, irritable, depressed, or forgetful."
A multidisciplinary team of researchers – including researchers from toxicology, neurology and psychiatry – assessed 26 Canadian participants, 23 of whom were diplomats that lived with their family members in Havana, plus three who did not live in Cuba.
"We were also able to test several of the subjects before and after they returned from Cuba," said study author Alon Friedman Friedman. "Our team saw changes in the brain that definitely occurred during the time they were in Havana."
Researchers asses the medical history and cognitive ability of participants, as well as conducted blood tests and a self-reported symptom questionnaire. Further MRI tests showed neurological, visual and audio-vestibular injury in the brain.
"We followed the science, and with each discovery we asked ourselves more questions," said Friedman. "Pinpointing the exact location of where the brain was injured was an important factor that helped lead us to perform specific biochemical and toxicological blood tests and reach the conclusion that the most likely cause of the injury was repeated exposure to neurotoxins."
The pesticide in question is one that is used across the island nation to protect against Zika virus, reports CNN.
"The study validates the need for us to continue to learn more about the use of pesticides and other toxins," said Friedman. "It is a global health issue that reminds us how much we still have to learn about the impact that toxins have on our health."
The findings "confirm brain injury" and raise questions to overexposure to cholinesterase inhibitors. The results have not yet been published in a peer-reviewed publication but will be presented at the Breaking the Barriers of the Brain in New York City conference on Oct. 27.