Kinney's research showed that no less than nine different biosolid products were produced by municipal wastewater treatment plants in seven different states -- Washington, Arizona, Wisconsin, Kansas, Colorado, Texas and Iowa. These biosolid products were analyzed for 87 different organic wastewater contaminants, which represents a cross section of medicinal, industrial and household compounds.
These compounds are able to enter wastewater treatment plants and may be discharged without being completely metabolized or degraded -- causing them to show up in the sludge that is then processed into certain garden and yard fertilizers. In fact, 55 of the contaminants were detected in at least one biosolid product sold as lawn and garden enhancements, and 25 compounds were found in every single one of the samples.
Kinney went on to say that "No matter what biosolid we looked at, there were some of these compounds in it." His research was published in online edition of the journal Environmental Science and Technology. Kinney, who is a postdoctoral fellow at the United States Geological Survey (USGS), has the support of the USGS's Toxic Substance Hydrology Program as well, who supports his research.
Government regulators and health officials say there is no immediate risk to public health; however, the study's authors called for more research on the long-term impact on the environment. Thomas Burke -- a professor of public health policy at Johns Hopkins University in Baltimore -- believes that Kinney's research is a sobering reminder for the Environmental Protection Agency, which has promoted biosolids for decades because they contain the same nutrients found in fertilizers.