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 Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>