The pollution of the planet represents a great challenge for humanity. The United Nations Environment Program devotes particular attention to pollutants with high toxicity, global mobility, resistance to degradation and accumulation in living beings. The search for solutions has led to green technology that exploits the ability of some trees to degrade these pollutants. Some tree species, especially poplars, are suitable for decontamination. The process works with solar energy absorbed by the tree, is environmentally friendly and inexpensive.