Fifty-three children and four teachers went down with symptoms of serious poisoning in the public school No. 8 in Cherkasy, a city of 280,000 people nearly 200 kilometers southeast of Kyiv, on May 8.
The children lost consciousness during a ceremony to honor the victims of the World War II in the schoolyard and were hospitalized, with 11 students being treated in an intensive care unit.
The children who were poisoned were students of second to seventh grades, ages seven to 12. They suffered from dizziness, nausea and headaches.
Two days later, it is still unknown how the poisoning occurred and even what substance sickened the victims.
The State Emergency Service took samples of air, water and soil from the schoolyard but found no trace of any poisons.
This led to speculation that the children were poisoned deliberately, by an unknown substance sprayed in the school.
Police have started a criminal investigation into a possible violation of sanitary rules and failure to prevent a mass poisoning.
One possible explanation for the incident is that a poisonous gas escaped from a sewer near the school, authorities say.
Heavy rain two days before the incident could have led to some poisonous substances getting into the sewer through storm drains, according to Kostyantyn Protsenko, the assistant of the head of the State Emergency Service in Cherkasy Oblast.
On the day before the incident, local residents also complained about an unpleasant smell near the school, according to Protsenko. However, the children who were poisoned said they don’t recall noticing any strange smell.
According to another theory, the children were poisoned by a release of chemicals from a nearby nitrogen fertilizer plant.
However, the press service of the plant denied this, saying there had been no accidents that could have led to a leak of poisonous chemicals.
School poisonings are common in Ukraine, but in all previously reported cases the cause was food poisoning.
But in the school in Cherkasy, the children hadn’t eaten together that day, according to Acting Health Minister Ulana Suprun.
According to Suprun, judging by their symptoms, the victims must have inhaled a poisonous substance.
