Trees and shrubs not only produce oxygen and absorb carbon dioxide. Through their stomata in the leaves, they get inside and neutralize other gases that are dangerous to us. They are part of the so-called smog. In the spaces between cells, they combine with water to form acids and other compounds that are later used as food for the plant. These gases include sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone. In turn, the so-called solid particles or suspended dust marked with the symbol PM10 and PM2.5. They are also very dangerous components of smog.

Various groups of scientists from different countries have studied the potential of plants, including trees and shrubs, to reduce smog. The research shows that a park with an area of 1 ha, properly planted, absorbs approx. 8 kg of carbon dioxide (CO2) per hour. And 100 large trees are able to remove 460 kg of pollutants per year, including 136 kg of PM10 and PM2.5 particulate matter. Large trees clean the air 70 times more effectively than small greenery. The conclusion is that planting trees and shrubs should not be delayed. You have to plant them systematically because for many species of greenery you have to wait 10 or even 20 years before they reach large sizes.