Heavy metal worms

Earthworms may not be glamorous or especially appealing to the eye but they are immensely useful. Worms are the main contributors to enriching and improving soil for plants, animals, and even humans. They create tunnels in the soil by burrowing, which aerates the soil to allow air, water and nutrients to reach deep within the soil. They eat the soil which has organic matter such as decaying vegetation or leaves. Plants cannot use this organic matter directly but after a worm digests it is released as waste from their bodies called castings. These castings contain many nutrients that can be used by plants. Worms it seems, have done enough to justify their place in the biosphere but new research is suggesting that they might be able to do even more.

The new study was done because as urban populations increase, especially in the developing world, there is an increasing need to deal with organic household waste and also waste from vegetable markets and even supermarkets. These researchers from Pondicherry University, India say that an unfortunate reality is that much of this waste is dumped on the outskirts of many towns causing pollution, disease risk, and ecological damage.

According to these researchers worms may be coming to the rescue. They say that three species of worm Eudrilus eugeniae, Eisenia fetida, and Perionyx excavates could be used to compost this household waste. In the process of this “vermicomposting” the worms would remove heavy metals like cadmium, copper, lead, manganese, and zinc from the waste. Eudrilus eugeniae was shown to be the most effective at doing this.

Based on their studies, the researchers say that worms can remove around 75 per cent of heavy metals from solid waste reducing the content into the safe range. The worms lock the metals into their body tissues and the separation of dead worms from organic waste is relatively straightforward.

There you have it, yet again we see that worms are more than just fish bait and they are into heavy metal into the bargain: probably Steppenworm, or Compost Glory, or maybe Deep Purple?