Ground contamination from crude oil and tar is notoriously difficult to clean up because these substances cling tenaciously to the soil. Remediation of such pollution at some of the hundreds of hazardous-waste sites around the United States has proved inefficient and costly.
This could be one place where nanotechnology can make a difference, say researchers at Cornell University who have designed polymer vesicles that, when pumped through soil, trap contaminants and carry them to the surface.