Industrial heavy metal pollution is contaminating earthworms, threatening entire ecosystems

(NaturalNews) Earthworms in New England forests are absorbing heavy metal pollution, thereby poisoning the animals that feed on them, according to a study conducted by researchers from Dartmouth College and the University of Vermont, and published in the journal Soil Biology and Biochemistry.

This phenomenon may partially explain an observed decline in the populations of wildlife in the area, the researchers said.

Earthworms have long been known to play a complex role with North American environments, both human and wild. Although prized for their promotion of soil health in agricultural and garden settings, earthworms are not, in fact native to the northern United States or Canada. After being driven from the region by a cooling climate, they were reintroduced by European settlers and proceeded to dramatically change the character of East Coast forests.

Metals build up in worms' bodies

In recent years, earthworms have been pushing into new areas of the Midwest and Northeast, causing destructive habitat changes. For example, a recent study in the journal Landscape Ecology found that, as earthworms have moved into hardwood forests in Minnesota's Chippewa National Forest and Wisconsin's Chequamegon-Nicolet National Forest, they have removed the formerly thick layer of leaf litter from the forest floor. This has removed cover for the ground-nesting songbird known as the ovenbird (Seiurus aurocapilla), as well as eliminated habitat for the litter-dwelling insects that the birds eat.

Scientists had also previously demonstrated the ability of earthworms to take up heavy metals, and had even suggested that earthworms could be used to remove the toxic substances from highly contaminated soil.

In the new study, researchers analyzed nine separate forest locations in New Hampshire and Vermont, findings earthworms in every one of them. These soils have been heavily contaminated with pollution from the region's long industrial past, including the burning of coal and leaded gasoline. Consistent with prior studies, the researchers found that heavy metals -- especially mercury and lead -- were accumulating in the bodies of earthworms at higher concentrations than in the surrounding environment.

Protect yourself: test your food

The levels of mercury and lead in the worms' bodies were high enough to be fatal to animals that might eat them.

"Our results suggest that exotic earthworms could be responsible for the high levels of toxic metals in ground foraging animals such as birds, amphibians and even mammals across New England," lead author Justin Richardson, PhD, said. "Our research highlights two important messages: Earthworms are not native in the forests of New England and they may negatively impact what forest soils do well: retaining pollutant trace metals from food webs."

The surprise in the new study is that earthworm consumption can be a source of heavy metal contamination, not that heavy metal contamination can be lethal. This latter fact is well established, in humans as well as animals.

Consumers concerned about heavy metal contamination in their food can take advantage of a project by the Consumer Wellness Center and Natural News to test various off-the-shelf food products for levels of heavy metals. The results of these tests -- for aluminum, arsenic, cadmium, copper, lead, mercury and the radioactive elements cesium and uranium -- are available free of charge at Labs.NaturalNews.com.

"This food science project is about providing transparency to consumers so they can make informed decisions about what foods they wish to consume or avoid," said Health Ranger Mike Adams, executive director of the Consumer Wellness Center.

"Many people also have health conditions which are worsened by toxic heavy metals, and given that these elements can stay in the body for decades, consumers are empowered by knowing which foods are safer for them to consume."

Sources:

http://phys.org

http://www.eurekalert.org

http://smithsonianscience.si.edu

http://labs.naturalnews.com

http://labs.naturalnews.com