Plants that track air pollution
Using biotechnology to fight pollution is the challenge for a European Union MOSSCLONE research project. Under the spotlight - a specific kind of moss. At the University of Freiburg in Germany, a team of biologists is growing moss, in a controlled environment.
Mosses are especially well suited as bio-indicators for airborne contaminants as they have no roots and a very high surface-to-mass ratio.
Eva Decker, of the university’s Faculty of Biology, explained: “We use moss, because, by mass, it has a huge surface area. You can see all the structures and it can clean the dirt particles out of the air. Moss has shoots or spores, and from one of these spores you can grow a new plant. And using these spores we started to cultivate new plants in the laboratory.”
Monitoring the levels of nitrogen and sulphur oxides, as well as airborne heavy metals like cadmium, lead and nickel, is hard to achieve with existing technologies as they are either imprecise or very expensive.
One innovation is the cultivation of huge amounts of a peat moss under controlled laboratory conditions.
Ralf Reski, at the Faculty of Biology at the University of Freiburg told euronews: “We not only reduce the plant’s genetic variability to the smallest possible level – one single genetic clone – but also through controlling conditions in the moss bio-reactor we can guarantee that the level of pollution in the moss, as well as its growth, are always identical. And you cannot obtain this consistency with material you have just collected from nature.”
The moss plants are transferred to air-permeable bags, then moved to monitoring stations at a variety of different European locations where they absorb pollutants from the air.
This technique is currently being tested in Santiago di Compostela, Spain.
Carlos Brais Carballeira Braña, from the Faculty of Biology, at the University of Santiago de Compostela, Spain said: “Three different samples are exposed for three weeks in order to accumulate all the pollutants in the area, in this case from passing cars or industrial plant, but primarily it’ll be general road traffic”.
Following that exposure, the moss is dried and powdered, then analysed, to measure the levels of different pollutants in it.
This approach, combining molecular biology and material sciences with ecology and bionics, could be, in the future, extended to other critical environmental contexts.
José Angel Fernández Escribano at the Faculty of Biology, University of Santiago de Compostela, said the plan is to expand the habitats where this principle is used including rivers, fields and industrial areas.
He explained the thinking behind that: “These contaminants can affect rivers, which then flow into the sea, and pollute the marine environment. It will be possible to develop these tools and to discover all the pollutants that are affecting the whole ecosystem.”