The Polluting of a Park

Biologist Howard Neufeld has spent 20 years documenting the impact of ozone on native plants in the Great Smoky Mountains National Park. He has studied changes to the plants' fertility, photosynthesis and growth and observed how these mutations are influenced by shifts in pollution and weather patterns.

It's important to study these plants, Neufeld says, because any damage to their health can indicate possible stress to other species and the eco-system.