Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Composted biosolids bind lead in soil, reducing danger of poisoning

03.03.2003


Adding composted biosolids rich with iron, manganese and organic matter to a lead-contaminated home garden in Baltimore appears to have bound the lead so it is less likely to be absorbed by the bodies of children who dirty their hands playing outside or are tempted to taste those delicious mud pies they "baked" in the backyard.



The garden soil in the study is similar to potentially hundreds of thousands of yards contaminated with lead in Baltimore and other inner cities, according to Sally L. Brown, University of Washington research assistant professor of forest resources and lead author of an article in the current issue of the Journal of Environmental Quality.

Even yards that were never near smelter operations can have contaminated soils because of lead-based paints from older buildings and auto exhaust from leaded gasoline. The Centers for Disease Control and Prevention says that 50 percent of inner-city children in the United States have lead levels in their blood high enough to cause irreversible damage to their health.


Children swallow particles of lead if they are still at the age when they’ll put anything – including dirt – into their mouths or if they pick up particles on their hands and clothes and then go inside to eat a snack.

The bioavailability – that is the amount of lead available to enter the bloodstream – was lowered 20 percent to 38 percent after mixing composted biosolids with the contaminated garden soil, according to Brown and her co-authors, Rufus Chaney, Judith Hallfrisch and Qi Xue of the U.S. Department of Agriculture, Agricultural Research Service, Maryland. The best mixture for reducing bioavailability was one made from Baltimore biosolids that contained more iron and manganese than the others tested.

Biosolids are the organic residuals produced during wastewater treatment. Once composted, biosolids look like other commercially available composts and are approved for use by the U.S. Environmental Protection Agency as a soil amendment by home gardeners, farmers and others.

Using composted biosolids to remediate soils would be far less costly than other alternatives, Brown says. While soil contaminated with lead might be removed and replaced if it was at a Superfund site, that is just not possible within cities.

"We’re not going to be able to ’remove’ Baltimore," Brown says.

Co-author Chaney, a metals specialist, says, "Ever since we found the extensive urban-soil lead problems in the mid ’80s, we’ve been seeking a lower-cost option to soil removal. This appears to be the answer."

In the study, funded by the non-profit Water Environment Research Federation headquartered in Virginia, the scientists tested seven different biosolids and composted biosolid treatments, adding 3 inches of each to different areas of the garden, then thoroughly mixing the soils weekly for 30 days. Soil samples and laboratory rats exposed to the soils were tested for changes in lead levels. Since then, findings from a pilot program adding composts to other home gardens in Baltimore and East St. Louis, Ill., appear to confirm the findings.

Brown says researchers still need to find out how long the effects last and if similar results can be obtained using compost that doesn’t come from biosolids.

They’d also like to investigate exactly why composted biosolids change the nature of lead so it’s not so readily absorbed by the body. Brown and her co-authors hypothesize that this happens because biosolids are generally more than 50 percent organic matter, often contain high concentrations of iron, as well as high levels of phosphorous and manganese. Studied singly by other groups of scientists, each of these soil conditions was shown to reduce lead availability in soils, according to studies published in 1999 and 2000. Brown and her co-authors studied all three components at once and monitored effects on living organisms as well as changes in soils.

Sandra Hines | EurekAlert!
Further information:
http://www.washington.edu/

More articles from Agricultural and Forestry Science:

nachricht Interaction with fungus containing N2-fixing endobacteria improves rice nitrogen nutrition
26.11.2019 | American Society of Plant Biologists

nachricht Strengthening regional development through old growth beech forests in Europe
20.11.2019 | Hochschule für nachhaltige Entwicklung Eberswalde

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Detailed insight into stressed cells

05.12.2019 | Life Sciences

State of 'hibernation' keeps haematopoietic stem cells young - Niches in the bone marrow protect from ageing

05.12.2019 | Life Sciences

First field measurements of laughing gas isotopes

05.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>