The equipment was purchased "as a complementary means of disinfection" from the municipal means of transport and rooms of the municipality, and also made available to merchants and schools as "an additional measure to the cleaning and disinfection plan" revealed to Lusa Ana Silva, from the veterinary office and public health of the municipality.

According to the official, "a four-minute cycle allows to disinfect a 20 square metre room", with the device being operated "without people in the space", with the added value of the machine being "self-sufficient", without the need for "use detergents or disinfectants".

These devices work by "capturing oxygen molecules from the environment" and converting them to ozone, a "very unstable" gas that, when it binds to bacteria and viruses, "destroys" them, releasing oxygen back into the atmosphere, being also effective for the coronavirus, stressed Ana Silva.

However, regional health authorities question the effectiveness of this method and claim that there is no scientific evidence to prove its effect in combating the new coronavirus, which causes the covid-19 disease.

Contacted by Lusa, the president of the Regional Health Administration (ARS) of the Algarve stated that "there is no scientific evidence to prove its effectiveness from the point of view of covid-19", and warned of possible problems in people more sensitive to the presence of ozone.

According to Paulo Morgado, there are people "very sensitive to the presence of ozone", feeling "cough and respiratory irritation" as a result of high concentrations of that gas in the air and, therefore, "using it in closed spaces" without measuring its concentration afterwards in the air "can possibly be dangerous".

For this reason, health authorities are not recommending ozone "as a methodology" to mitigate covid-19 since, despite being a gas with an action on bacteria and viruses, it is also "polluting", which is why" their concentrations are monitored in what is ambient air".

Therefore, Paulo Morgado defended the ventilation of spaces as a way to fight the virus, reinforcing that the action is effective in itself - even being one of the ARS recommendations -, because it removes particles with suspended virus, reducing the risks of infection.

According to the Câmara de Monchique, ozone values ??"are not measured" after use, but the equipment used "is supplied by a company certified" by the European Union that works "with the minimum effective doses that allows no residues".

The two devices purchased by the municipality are used in the "offices and meeting rooms" of the municipality's headquarters, as well as in the "means of transport", as a complementary means of "disinfecting schools and community spaces" such as the church and the centre of support to the family, and can also be "given to traders for use in their commercial spaces".