Examples include the siting of polluting factories (sewage treatment, smokestacks) in residential areas of particular ethnic or minority groups. It is also evident in the new political trend of eco-racism which talks of "demographic pollution" and blames immigrants for consumption of more resources, higher emissions of pollutants, and more waste.
Right-wing and discriminatory ecological tendencies go against the spirit of ecology. The heaps of rubbish and the dying forests have more to do with our environmental behaviour than with the so-called population density.