The air in the classrooms in Bulgaria - dangerous for the health of children, data from an international school air quality survey shows. It was held in 6 European capitals, including Sofia.

Eight schools in the capital participated in the survey. Values ​​of fine particulates way above the normal were reported in 5 of the 8 buildings. There is also a problem with the increased amount of nitrogen and carbon dioxide - the latter of which, according to health experts, leads to a lower concentration of the students and difficult absorption of the material.

Sofia's 97th school has found a way to purify the air. This is taken care of by hundreds of pots with plants down the hallways and in classrooms. Thus, it is the only school with lower levels of carbon dioxide even from the outside. The idea was proposed by a biology teacher.

"They absorb the harmful gases and process them accordingly into the oxygen needed for the breathing process," Maria Dikova explained.

However, in almost all other schools extreme levels of carbon dioxide are detected.

"It is not dangerous, but it is worrying that classrooms are not ventilated enough," said Dr. Alexander Simidchiev, a pulmonologist.

In some classrooms, the other pollutant, dust particles, is up to 4 times above the norm. Experts advise the schools to build a better ventilation and to clean the rooms more frequent with a damp cloth. It is found that almost every student in Europe breathes dirty air.

”Nitrogen dioxide has been measured inside the classrooms of all schools. Because there are no sources of nitrogen dioxide in schools, these levels can only come from outdoor air pollution and traffic in particular, ”said Anne Stauffer of the Health and Environment Alliance.

“Naturally, schools which were closer to major thoroughfares, had higher levels of pollution than those in large gardens outside Sofia's major transport corridors," added Dr. Alexander Simidchiev.

The municipality is considering creating buffer zones around schools to prohibit traffic during peak morning hours. According to experts, more parents will take their children to school on foot rather than by car. The proposal has been sent to all school principals in Sofia, and three have already given their consent.

Next school year it will become clear whether the changes will enter into force.