by : Abigail Boyle

Bacteria are single-cell microorganisms and the world's recycling mini-machines. Besides taking part in a vast array of nutrient cycles, scientists have discovered that a type of bacterium is keen on eating dioxins, a powerful substance known to cause cancer.

Dioxins aren't an intentional product of our industries, like other pollutants; dioxins are the unwanted, and highly toxic, leftover from pulp and paper bleaching, plastics manufacture and incineration of toxic and hospital wastes (www.cancer.gov. There are over 100 types of dioxins and all of them share one dangerous characteristic: they are tough to get rid of.

The damage they cause it's amplified when this resistance is taken into account. Even if humans stay out of a contaminated site, they still could get exposed and even ingest dioxins. Animals that live around polluted areas ingest dioxin, which then accumulates in their fat. People become exposed to dioxin by consuming products made from these animals (fish, meat, dairy products).

This carcinogen-eating bacterium was first discovered in Spittelwasser, Germany, in the sediment of a very polluted arm of the Elbe river. An army of these bacteria could be set loose on contaminated sites that are too large to be cleaned up by already-existing methods like incineration at high temperatures or ultra violet light exposition. These large contaminated sites are the most problematic, since they are hard to keep isolated from wildlife.

The product of the digestion is not entirely safe but it's much less toxic and, what must be the biggest plus, it's easier to clean up and it's not as persistent in the environment, it doesn't last that long. However, there's work ahead. These particular strain of bacteria is not easy to grow and scientists don't know exactly how the bacteria manages the breakdown of the harmful dioxin.