Lichens - making invisible nasties visible

Healthy human lives depend on clean air. But, air pollution is recognised by the World Health Organisation as one of the biggest environmental health issues of our time, contributing to around 40,000 UK deaths every year. So, how can you tell if the air is clean? The answer is now at hand, thanks to researchers at the Royal Botanic Garden Edinburgh (RBGE) who have published an easy-to-use air quality self-assessment package that could ultimately help save lives through people power.

The free user-friendly kit - which can be used by individuals, schools and community groups - provides the tools for us all to investigate the evidence for and against polluted air. The survey, which also offers resources for practical action to improve environmental health, has been developed at RBGE by Frances Stoakley, a Natural Talent trainee with The Conservation Volunteers (TCV) and RBGE Head of Cryptogams, Dr Chris Ellis. Information delivered by it will contribute to the Edinburgh Living Landscape initiative.

Having switched careers from the performing arts, Frances brought new perspectives on biodiversity engagement. She explained: “My career change happened because I wanted to start communicating more widely and in new ways about the need to protect the environment and this led me to a full time three-year BSc in Countryside Management  at Aberystwyth University.

“Then, I undertook a Natural Talent UK traineeship, funded by Esmée Fairbairn Foundation, which brought me to Edinburgh. During my training I was increasingly aware of a barrage of reports on air pollution, including the worrying statistic that outdoor air pollution contributes to 2,000 deaths annually in Scotland according to the NHS: Health Protection Scotland briefing paper of 2014.

“I also partnered-up with Sustrans Scotland, Edinburgh Council and the Field Studies Council to undertake lots of public engagement work: stalls, talks, events and activities throughout my traineeship year to discover what people want, or need, to be able to do the survey, and how best to communicate the story of lichens as indicators of air quality.”

Unlike the air pollution of the past, which was hard to ignore because it was smelly and visible as smog, today’s is almost invisible and can be easily overlooked. Which is where lichens come into their own. These extraordinary organisms that colonise trees and many other surfaces in both rural and urban areas are mostly very sensitive to air pollution because they absorb everything they need to live and grow directly from the atmosphere. As they have no mechanism to control and filter out harmful toxins found within the atmosphere, they are good indicators of environmental health and local air quality: if you know what to look for.”

John McFarlane, TCV Environment Development Officer, added : Air pollution is a huge global environmental health issue and while the air quality in Scotland is generally very good, we do have hot spots in our cities that regularly exceed national and EU limits for air pollution. If members of the public can be enthused and encouraged to participate in finding out about their local air quality we can start to make a real difference.”

To become involved, you can download Lichens-Making the Invisible Visible - An Air Pollution Survey at  and get started straight away.

The Royal Botanic Garden Edinburgh is a charity (registration number SC007983)