Study shows benefits of wooden surfaces in fight against spread of coronavirus

Details of the study on the survival of viruses on wooden surfaces were shared in an article on the Forest.fi website run by the Finnish Forest Association and focus on a project started last summer by the universities of Eastern Finland and Jyvaskyla.

The first tests would seem to indicate, among other things, that the contagiousness of coronaviruses decreases much more rapidly on a wooden surface than on other materials, such as plastics.

Paperboard and paper, too, appear to perform better than plastics against coronaviruses, though the viruses do survive longer on them than on wood.

The study shows wooden surfaces have twofold hygienic properties: wood even when dirty destroys bacteria clearly better than glass, for example. Coronaviruses, too, lose their contagiousness fairly rapidly on a wooden surface, compared to something like plastics.

The project, which runs until the end of 2021, compares the survival and contagiousness of viruses on wooden and wood product surfaces, both treated and untreated. It also studies packaging materials and paper products, as well as glass, stone, plastic and textile surfaces.

“You could say we’re studying all of the surfaces that people will come in contact with in their daily lives,” says Associate Professor Antti Haapala from the University of Eastern Finland Haapala.

The contagiousness is studied under varying periods of time, temperatures and degrees of humidity.

In her doctoral thesis, Tiina Vainio-Kaila from VTT Technical Research Centre of Finland found that in particular, extractives in the heartwood and sapwood of Scots pine, but to some extent also those in Norway spruce prevent the growth of several pathogenic bacteria, including the MRSA bacterium (Staphylococcus aureus), which is often behind hospital-acquired infections.

However, no single extractive compound alone can explain the antibacterial effect of wood.

“This is true for pine and spruce at least, the two species that I’m most familiar with,’ says Ms Vainio-Kaila.

She continued to say that particularly resin acids, which are found in both the heart- and sapwood of pine and spruce, have been found to be antibacterial.

Other substances known to be antibacterial are certain stilbenoids only found in pine heartwood.

“Certain combinations can also enhance the effect,” added Ms Vainio-Kaila. “Some substances can reciprocally intensify the effect of one another.”

The Puhdas puu [Clean Wood] study made at the South-Eastern Finland University of Applied Sciences (XAMK) found that even birch appears to have antibacterial properties, despite being different from pine and spruce in many respects, also as regards the extractives it contains.