Collect plane tree bark to monitor air pollution

If you spot someone working on a plane tree in the coming weeks, it’s likely to be a citizen scientist taking part in ‘Plataancheck’, a new project by the University of Antwerp, Scivil and UCLouvain. Analysing the tree bark provides a wealth of information about particulate matter emissions in our cities.

 

What is particulate matter?

Particulate matter is the collective term for all the tiny particles in the air that can penetrate the human body. Every year in Flanders, thousands of people die prematurely as a result of excessive levels of particulate matter. Long-term exposure leads to an increased risk of, among other things, stroke, heart attack and premature birth during pregnancy. In Belgium, the standards set by the EU and the WHO are exceeded year after year, yet awareness of the particulate matter problem remains low.

 

Trees as particulate matter monitors 

UAntwerp, UCLouvain and Scivil – the Flemish knowledge centre for citizen science – want to change that. To do so, they are looking to… the plane tree. In Paris and in several Dutch and German cities, the tree has already been used successfully to map particulate matter emissions. With the Plataancheck project, the three partners now also want to send citizen scientists out into the field in Belgium.

 

“The plane tree is a remarkable tree: it is found throughout Europe and often grows in cities,” explains Roeland Samson (Faculty of Science). “The tree’s bark also has a good ‘memory’. Fine particulate matter, mainly from the combustion of fossil fuels, is absorbed into the tree’s bark. In the spring, the tree ‘sheds’ its bark and it comes loose. You can easily remove pieces of bark; it doesn’t bother the tree at all.”

Until the end of April, participants can collect pieces of bark from one or more plane trees in their neighbourhood. They can then hand in the bark at one of the collection points, or send the material directly to the University of Antwerp’s laboratory.

 

Not a snapshot of air pollution

Samson: “We analyse the bark and can thus map the distribution of particulate matter. This will provide us with very interesting data. Analysing the bark does not provide a snapshot, but gives a picture of total emissions throughout the year at a specific location. We are primarily interested in urban plane trees, but trees from more rural areas are certainly also relevant for comparison.”

 

The scientists expect to be able to present the first results in the autumn. The aim is to repeat the project in the coming years, both in Belgium and in other European countries, in order to make international comparisons.