SUMMARY OF THE REMEDIATION TECHNOLOGIES DEVELOPMENT FORUM
IN-PLACE INACTIVATION AND NATURAL ECOLOGICAL RESTORATION
TECHNOLOGIES SOIL-METALS ACTION TEAM
CONFERENCE CALL

June 26, 2000
4:00 p.m.-5:00 p.m.

On Monday, June 26, 2000, the following members of the In-Place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Action Team met in a conference call:

Bill Berti, DuPont Central Research and Development (Action Team Co-Chair)
James Ryan, U.S. Environmental Protection Agency (EPA) (Action Team Co-Chair)
Sally Brown, University of Washington
Rufus Chaney, U.S. Department of Agriculture (USDA)
Mark Doolan, EPA
Mike Ruby, Exponent Environmental Group
Qi Xue, U.S. Department of Agriculture

Christine Hartnett of Eastern Research Group, Inc. (ERG), was also present.

THE JOPLIN, MISSOURI, SITE

Sampling Events

Rufus Chaney said that USDA collected soil samples from the Joplin site in May 2000. Ten samples were collected per plot; a 3-inch bucket auger was used to collect the samples to a depth of 10 centimeters. The samples were air dried, Chaney said, and some have already been sieved through a 250-micron screen. About 400 grams of soil has been given to Qi Xue for use in rat-feeding studies. The remainder is available for other studies; Chaney advised Action Team members to contact him if they need soil samples.

Call participants talked about future sampling efforts. For the last few years, Sally Brown said, the Action Team has collected soil and plant samples in the fall. She said that she and Bill Berti collected samples in October 1999, but experienced great difficulty getting their sampling probes into the ground because the soils were dry and hard. She asked whether the 2000 soil and plant sampling event should be conducted earlier in the year, when the ground is wet. She said she would be able to collect samples this summer, because she has several visits to Missouri scheduled in July and August. After making the suggestion, Brown herself expressed reservations about collecting samples during the summer. She said that it might be better to collect samples at the same time each year, noting that metal concentrations exhibit annual fluctuations. Call participants agreed that it would be best to collect samples in the fall. Chaney said that an irrigation system could be set up if the soils are too dry and hard to collect in October. As an alternative, Berti said, samplers could abandon soil probe devices for techniques that work better under dry conditions. While call participants agreed that the official sampling event should be held in fall 2000, they also discussed the possibility of collecting a small set of soil samples this summer and using these to develop a protocol for soil extraction studies that correlate to plant uptake.

Animal-Dosing Studies

Rat Studies

Xue said that USDA has performed dosing studies to determine how rats are impacted by pure lead minerals. He said that analyses are still being performed on liver and kidney tissues. Results will be available soon.

Xue said that USDA is also making preparations to initiate another rat-dosing study. This one will involve feeding rats soils from three of the Joplin site's treatments. (Soils for two of the treatments were collected in late 1999. John Yang has provided these. The other sample was collected in May 2000 and provided by Chaney.) Xue said that diets are being prepared, and that the feeding will be initiated on July 11, 2000, and carried out over a six-month period.

Swine Study

Call participants said that the University of Missouri-Columbia plans to perform a swine-dosing study. At least two of the samples fed will be the same as the ones used in USDA's rat-dosing study. None of the call participants knew whether the study had been initiated yet.

Soil Extraction Studies

Berti said that he thinks it would be a good idea to analyze contaminant concentrations in plants, and to correlate these results with those obtained using soil extraction methods. He said that Sebastian Sauve may be able to assist the Action Team with this effort. Sauve has coauthored several articles which discuss how Anodic Stripping Voltametry (ASV) has been used to evaluate Pb²⁺ in soil extracts. This information has been correlated to plant concentrations. Berti said that the extractions and AVS measurements could be performed at DuPont, and that Sauve could help by making sure that the results are accurate. Chaney said that researchers in Europe have used 0.1 molar calcium chloride in some of their studies. He said that the chloride causes some problems: using it leads to a higher concentration of metals that are complexed by chloride. Berti said that he and Brown have talked about using calcium nitrate as an extraction solution. Brown said that this extract is easy to use, noting that she has used it at the Bunker Hill site and the Leadville site. It has also been used at sites in Pennsylvania and Poland.

In Vitro Analyses

Brown asked Mike Ruby for information on the glycine that is used in in vitro tests. Ruby said that powder forms should be used, and advised obtaining ultra-pure formulations. Less pure forms, he said, have arsenic in them. Brown asked Ruby to comment on the pH that should be used when performing in vitro studies. Ruby said that he prefers a pH of 2.3, but that this was just a judgement call.

Ruby said that he performed in vitro analyses on the samples that the University of Missouri-Columbia plans to use in their swine-dosing studies. These data will soon be finalized and distributed to Action Team members. Based on the in vitro results, Ruby said, he predicts that the swine studies will show that a reduction in lead bioavailability has occurred in the 1% phosphorus treatments.

Chaney said that in vitro analyses will also be performed on the samples that are used in USDA's rat-dosing studies. James Ryan plans to perform these analyses.

Reports and the Action Team's Symposium

Mark Doolan asked whether Action Team members had come to a decision about how to present their data. He said that he would like plant, soil, animal, and in vitro data compiled into one report. Berti said that the Team has agreed that their collective work should be presented in a symposium, which will have two components: a conference and a publication. The conference will be held in Charlotte, North Carolina, in fall 2001, as part of the American Society of Agronomy / Soil Science Society of America annual meeting. The publication, which will compile a number of papers, will be released at the same time as or soon after the conference. (Action Team members plan to release their publication in the Journal of Environmental Quality.) Berti said that the publication will have an introduction, which will be followed by a series of papers that summarize the results for the Joplin site. He said that he and Ryan are working together to develop an outline for the conference that lists proposed topics and speakers.

Berti asked whether the symposium would meet EPA's needs. Doolan said that he just wants to make sure that all of the data are compiled and available in one location. If EPA requests it, Berti said, the Action Team could probably pull together summary reports before the fall 2001 deadline.