Effects of Biosolids Application on the Levels of Dioxins in Plant Tissues

Land application of biosolids or treated municipal sewage sludge as a source of plant nutrients and organic matter is a common practice in the United States. Recently, detectable levels of dioxins in biosolids have been reported. This led to concerns that farmland biosolids application may result in accumulation of dioxins in soil and their subsequent translocation through the human food chain.

Dioxins (polychlorinated dibenzodioxins) and their derivatives are known to cause birth defects and cancer. A group of scientists from the Metropolitan Water Reclamation District of Greater Chicago investigated the effects of continuous and long-term application of biosolids on the levels of dioxins in soil and corn tissues. They found out that biosolids applications increased the levels of dioxins in soil but did not affect dioxins uptake by corn. It would take over 100 years of continuous sludge application to reach the limit for dioxin in soils set up by the U.S. Environmental Protection Agency (USEPA).

For more information, read https://www.agronomy.org/press/releases/2008/0714/171/ . The paper published by the Journal of Environmental Quality can be downloaded for free at http://jeq.scijournals.org/cgi/content/full/37/4/1497.