New approach to pollution monitoring in soil

Research lead

Researchers at Cardiff and Edinburgh Universities, Imperial College London and the Centre for Ecology & Hydrology (CEH) in the UK are developing a new approach to monitoring pollution levels in soils by assessing the effects of toxic chemicals on gene expression in earthworms.

Researchers from used a systems toxicology approach to understand the impact of four contaminants on the earthworms Lumbricus rubellus. Peter Kille from Cardiff, who led the research team, noted that although the earthworm is widely used as a model organism for soil testing standard laboratory tests do not reveal how pollutants interact with its genome and, and how the system adapts to deal with it.

“Although the earthworm genome has not been sequenced, we’ve been able to create a comprehensive expressed sequence tag dataset, that enables the development of tools that bring the earthworm into the genomics arena, and makes it the soil pollution equivalent of a canary in a coalmine.”

Using a new 8,000-element gene microarray the researchers tested the effects of copper, cadmium, the polyaromatic hydrocarbon fluoroanthene, and the agrochemical atrazine. The tests revealed subtle changes, induced by the toxins, in the gene expression patterns of worms. Copper exposure, in particular, prompted genetic and metabolic changes as well as massive deterioration in the worms’ physical health.

Kille believes the method will provide a powerful tool for understanding how ecologically important organisms like the earthworm respond to contaminants and also opens up the possibility of new, more effective, soil monitoring and bioremediation strategies.