Sometimes in winter we tend to ventilate the house in the evening. Sometimes we do it if it’s too hot. This is not very good. During a conference last year, Cesara Copacianu, Airly’s communications manager, said that in winter we have very high levels of pollution at night.

pollutionPhoto: David J. Phillip/AP/Profimedia

This is due to the fact that there is a factor called “thermal inversion”. This phenomenon occurs especially in winter, and the level of pollution is very high.

What is really going on?

“During the day we pollute, but in the evening, because we normally expect pollution to rise into the atmosphere, it actually descends. All the pollution during the day that we produce reaches our level and we breathe it in winter,” Copacianu said.

Therefore, she says, it is not recommended to open the window in winter and ventilate the house at night.

So, if you ventilate your home, you should do it in the morning or in the afternoon.

In cities with heavy traffic, this is a problem, as well as in those with various factories.