"Earthworms are excellent indicators of soil health, and provide vitally important ecosystem services by aerating the soil, cycling nutrients, and increasing microbial activity. The Alterra study, led by Doctoral candidate Merel van der Ploeg, compared the health and growth of earthworms in soil containing carbon and silver nanoparticles at varying amounts with worms in regular soil. Mr. Van der Ploeg found the soil containing nanoparticles reduced reproduction, slowed growth, and increased the mortality rate of exposed earthworms. Young worms are particularly sensitive to the effects of the nanomaterial. Mr. Van der Ploeg notes, 'I also found damage to the skin tissue and intestinal wall, often accompanied by damage to the underlying muscle, but even though tissue damage is usually associated with inflammation, I did not observe this in the earthworms. There seemed to be a suppression of the immune system.'"