A study by the University of Wisconsin compared five different floor types and their correlation with four harmful substances of the atmosphere: carbon dioxide, methane, nitrogen oxide, and particulate matter. These substances can cause atmospheric heating and respiratory diseases. The study showed that wooden floors didn’t emit methane, nitrogen oxide or other particles, and had low carbon dioxide emissions. Wood floors have more advantages, such as they do not carry allergenic microorganisms and rarely hold dust, mold and animal hair. In addition to their ease of cleaning, wooden floors can significantly improve the air quality of interiors.