Your mission...

How polluted is the air around us?

Discover how polluted the local air is by identifying lichens growing on trees.

Mission Information

You may not have noticed lichens before, but they can be found growing on many trees and are an excellent indicator of local air quality.

Some lichens are sensitive to air pollution, while other are less so. By identifying the lichens growing near you, you can discover more about local air pollution.

Visit the OPAL website and download the field guide and workbook, which includes full instructions.

Once you've recorded your lichens, submit your findings on the OPAL website and you'll help contribute to valuable scientific research.

Bonus Question!
Which of the following lichens is nitrogen-sensitive - Usnea, Parmelia, Xanthoria?
Mission Risk: Low

Low. This should be easy but take care.

Take a responsible friend with you to help with this challenge.

Tags: air pollution lichens trees

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Risky business

Doing missions on this website can be dangerous. Always get permission before exploring and make sure your plans are reasonably safe. A place that is safe one moment can become dodgy the next so keep your wits about you. We cannot take any responsibility for any injuries or harmful effects resulting from your actions. It's your job to survive your explorations intact.

To increase your chances of success complete our training and safety tips before starting. That way you are more likely to win points and keep your head on.

Mission Id: 3153