Sources: Ganga Hettiarachchi, 785-532-7209, ganga@k-state.edu;
and Sabine Martin, 785-532-6474, smartin1@k-state.edu
Pronouncer: Ganga is Gone-ga and Hettiarachchi is Hettia-raw-chee
News release prepared by: Kay Garrett, 785-532-3238, anuenue@k-state.edu

Tuesday, May 18, 2010

RESEARCHERS AT K-STATE SHOWING HOW LOCAL FOOD CAN GROW SAFELY ON BROWNFIELDS

MANHATTAN -- The thousands of brownfields sites blighting the nation could turn to green with the assistance of Kansas State University researchers.

The U.S. Environmental Protection Agency's brownfields training, research and technical assistance grants program awarded $750,000 to a K-State team for a five-year brownfields-to-urban agriculture research and public education project, now in year two of the research phase. K-State contaminated soils experts Ganga Hettiarachchi, assistant professor of agronomy, and Sabine Martin, program associate with the Center for Hazardous Substance Research, direct the project.

The project works with select community-based gardening initiatives to evaluate the uptake of heavy metals and other contaminants by food crops, and then to develop recommendations for preparing the soil and for corrective or protective actions as needed.

The team selects three to four brownfields sites a year that have attracted local community interest; does on-site testing for the trace element contamination; and a detailed soil analysis in K-State labs. At each community garden site, they set up a monitoring plot on the most contaminated portion to get data about plant and soil health. Ultimately, they will be able to recommend gardening protocols for brownfields -- appropriate soil amendments, best management practices and preferred crops -- to help the nation's urban gardeners safely produce more food locally.

Team members include Blase Leven and Larry Erickson of the Center for Hazardous Substance Research; DeAnn Presley, an extension specialist; Rhonda Janke, horticulture and organic farming expert; Gary Pierzynski, agronomist; and Ashley Raes, Phillip Defoe and Chammi Attanayake, all K-State graduate students in agronomy.

Brownfields are vacant, abandoned property, the reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant or contaminant. Estimates are that from 450,000 to a million brownfields -- nearly 5 million acres of land -- exist in the U.S.

The availability of this idle land coincides with the huge interest in community gardening and in growing food locally. More than 18,000 community gardens now exist in the U.S. and Canada, and the U.S. Department of Agriculture estimates there were 4,385 farmers' markets in 2008.

"There is abundant interest in gardening and farming on the sites, but the soil on some sites can pose health risks if it is contaminated with potentially toxic compounds," Hettiarachchi said. "We won't be able to convert all the possible sites to gardens. Environmental conditions at some sites will not allow for this use."

However, gardening is only one of several potential uses for brownfields sites, and K-State offers an existing EPA technical assistance to brownfields program, directed by Martin, that provides help to the public for other uses for the brownfields.

"Brownfields may look brown and kind of sad, for sure, but not all the sites are really highly contaminated," Hettiarachchi said. "Maybe there's not any real contamination at a particular site, but the potential presence of some environmental contamination could put a site into the broad brownfields category."

When contacted about such a site for possible gardening, Martin and Hettiarachchi ask first how the site has been used throughout its history. "We can't test for everything under the sun, so knowing as much as possible about site history narrows the list of possible contaminants we should test for," Hettiarachchi said.

Next comes on-site and laboratory soil testing and analyses. "Even if you find soil is contaminated, that does not mean you need to stay away from gardening completely," she said. "Unless contamination is too high, there will be a range within which you can garden safely while taking certain precautions."

In addition to the type of contaminants and the levels, other factors are soil conditions and if a contaminant is present in a chemical form that's bioavailable to soil microbes, plants or humans.

According to Hettiarachchi, common metals and metalloids such as lead and arsenic do not transfer easily from soil to crop. If a site is highly contaminated, there's danger, especially to younger children with their hand-to-mouth behavior, of directly ingesting microscopic lead paint particles, for example.

Certain crops are problematic.

"We would advise against growing the waxy, leafy crops like spinach and Swiss chard on lead contaminated sites," Hettiarachchi said. The waxy, edible leaves of crops emerge through the soil, becoming covered with tiny contaminated soil and/or paint particles. Typical vegetable washing practices in the home aren't sufficient to remove lead soil particles, which are almost glued to the waxy layers of leafy vegetables.

"In some cases, we would have to advise to completely avoid leafy vegetables and root or tuber crops like potatoes and carrots," she said.

The good news, Hettiarachchi said, is that there are methods to minimize human exposure to lead in soils, and there are soil amendments that will help bind the contaminant into the soil and assure that it stays put.

"This project will contribute to using brownfields sites in an environmentally, socially and economically beneficial manner," she said. "In the long run, we should be able to reduce the number of these underutilized brownfields sites."

Sites selected and tested in the K-State study to date include Gary, Ind.; the Washington-Wheatley site in Kansas City, Mo.; Flagstaff, Ariz.; and Seattle and Tacoma, Wash. Testing in Akron and Burlington, Colo., will take place this summer.

The study was presented at K-State's 2010 Sustainability Conference in January.