Were it up to Alan Baker, a retired English botany professor, these areas would have long ago been restored to a clean, green, and fertile state. It was as a student, while exploring the site of a disused mine, that he first noticed that some plants were thriving despite the heavily contaminated soil. He began to investigate and, together with the US agronomist Rufus Chaney, identified what came to be known as hyperaccumulators: plants that absorb heavy metals from the soil and store them in high concentrations in their leaves. An example is a species of rock cress known as Arabidopsis halleri. This plant stores cadmium and zinc in such large quantities that it can be used to remediate industrial wastelands.