Litmus paper uses a lichen-derived dye. Other lichens have been used for wool and silk dyes, making browns, yellows, reds and similar colors. Erosion Control or Acceleration Lichens that live on rocks often secrete acids that cause the rock to disintegrate and create soil. Lichens living on sand cover it from the erosion-causing wind, binding the sand together. Recently, environmental scientists have begun using lichens to analyze polutants in the air.
Lichens tend to absorb chemicals in the atmosphere.
These chemicals are later analyzed by scientists to determine atmospheric levels of hazardous polutants in remote areas.