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

August 30, 1999
3:00 p.m.-4:00 p.m.

On Monday, August 30, 1999, 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 Life Sciences (Action Team Co-Chair)
James Ryan, U.S. Environmental Protection Agency (EPA) (Action Team Co-Chair)
Rufus Chaney, United States Department of Agriculture (USDA)
Mark Doolan, EPA
Sally Brown, University of Washington
David Mosby, Missouri Department of Natural Resources (DNR)
Gary Pierzynski, Kansas State University
Mike Ruby, Exponent Environmental Group
John Yang, University of Missouri-Columbia

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

INTRODUCTION

Bill Berti said that several IINERT Action Team members met in Columbia, Missouri, on May 25, 1999, to discuss the data collected from the Joplin site. He said that several action items were identified during this meeting; these were summarized in a report and distributed prior to the conference call. Berti said that the purpose of this call was to follow up on the action items and to learn more about recent activities at the Joplin site. Data collected from Joplin have been generated via in vitro soil analyses, plant studies, rat dosing studies, soil chemistry research, and pig dosing studies.

IN VITRO SOIL ANALYSES

Three conference call participants reported on the status of in vitro analyses:

• Mike Ruby said that in vitro analyses were performed on nine Joplin samples. The SBRC protocol was used, he said, and the analyses were performed at four pH levels: 1.5, 2..0, 2.3, and 2.5. The results--expressed as a reduction in lead bioavailability--have been compared to those obtained from the pig dosing studies. (The in vitro test is a chemical extraction that mimics the gastrointestinal tract of an animal. Ideally, the Action Team would like to show that the results obtained from the in vitro test are the same as those performed using animal studies.) Ruby said that the results obtained with the in vitro test were underpredictive when performed at a pH of 1.5 and 2.0, but were overpredictive when performed at 2.5. Ruby's findings indicated that a pH of 2.3 yields the most accurate results. Sally Brown asked Ruby to elaborate on the results obtained with a pH of 2.5, asking whether one could simply correct the overprediction by applying a correction factor. Ruby did not think so, explaining that the increase in overprediction between 2.3 and 2.5 is not linear. Ruby agreed to e-mail the in vitro results to Berti, David Mosby, and Rufus Chaney. Chaney said that he will notify Ruby if he thinks the results should be interpreted in a different manner. (Chaney had asked whether Ruby evaluated the data on the basis of r². When Ruby said that he had not, Chaney advised considering r², pointing out that this is the test that evaluates predictability best. Chaney agreed to expand on this topic offline.)

• Brown said that she performed the physiologically based extraction test on soils collected from USDA's Joplin plots. Analyses were conducted immediately before the soils were amended, immediately after, and 6 months after the amendment, Brown explained. The test results have already been sent to John Drexler, Brown said, and will be sent to Ruby in the near future. (Brown also said that she has started writing a report that summarizes the in vitro data. An update of her progress is included below under "Plant Studies.")

• Berti said that he has completed both of the action items that were assigned to him at the May 1999 meeting. That is, he determined that (1) certain composite samples were extra and (2) all of the treatments collected in May 1998 have been analyzed via the SBRC method. Brown asked whether Berti has thought about running these samples through another in vitro test, but using a higher pH. Berti said that this will be decided after he receives the results that Ruby obtained using pHs of 1.5, 2.0, 2.3, and 2.5.

PLANT STUDIES

Brown was assigned two action items at the May 1999 meeting. She said that she plans to make significant headway on the first--statistically analyzing plant data from three sampling events--as soon as she has the appropriate computer programs operating. The second action item was producing a manuscript on plant and in vitro data; the manuscript, she said, will be drafted by the end of September. In addition, Brown said, she has forwarded a copy of all of the raw plant data to Mosby.

RAT DOSING STUDIES

Four action items were identified for Chaney at the May 1999 meeting:

• Verifying sample identification. Chaney said that he and Brown have confirmed that the rats were fed with USDA's 0.32% phosphorus-2.5% iron treatment. He said that Berti's summary of the May 1999 meeting proceedings contains the accurate information.

• Sending data to Mosby. Chaney said that all of the rat data were given to Mosby at the May 1999 meeting. He encouraged Mosby to contact him with any questions.

• Recalculating slopes of tissue versus dose using control points. Chaney said that this item was adequately addressed at the May 1999 meeting. Expanding on the issue, he said that the slopes were calculated using the same methodology used by Stan Casteel.

• Generate written protocol. Chaney said that USDA will start writing a protocol for the rat dosing studies after September 1.

SOIL CHEMISTRY RESEARCH

John Yang said that he has completed one action item--sending a soil sample to James Ryan--and is moving forward on two others:

• Submitting an article to Environmental Science and Technology (ES&T) on the soil chemistry of laboratory studies. Yang said that he is waiting for Mosby's comments on the draft article before moving forward.

• Compiling a draft paper on the soil chemistry of Joplin field sites. Yang said that this is in progress.

In addition, Yang said, he will send Mosby and Casteel the first draft of another paper that he has written.

REPORTS

At the May 1999 meeting, Berti said, Mosby agreed to summarize the Joplin data in two reports, a Master's thesis and an EPA report. Berti asked Mosby to give an update of his progress and to identify any additional data that he needs. Mosby said that he plans to complete a draft of his thesis by mid- to late September. The EPA report will take longer, he said: a first draft will be completed in October or November. Mosby said that he would like to have help on this second report, stating that it might be helpful to release one large, all-inclusive, multi-authored report under the auspices of the IINERT Action Team. Brown and Chaney responded to his request, saying that they would be happy to forward protocols for the plant and rat dosing studies, respectively. Ruby said that he is also willing to help Mosby with his manuscript by preparing the section on in vitro testing performed by Exponent and the SBRC (methods, results, and interpretation) and comparison to in vivo data from the young swine model.

Berti thought that it might be useful to incorporate all of the Action Team's work in one report, but said that the Team must be sensitive to the plans that individual team members have regarding distribution of data. On this note, he polled the conference call participants quickly and learned that (1) Casteel plans to publish the pig dosing study data and has already completed some EPA reports on this topic; (2) USDA plans to publish the rat dosing study data in the future, after more data are collected; and (3) Brown plans to publish the plant and in vitro data that have been collected from the USDA plots. Expanding on the latter, Berti noted that Mosby and Brown may want to work together to combine the results obtained from the USDA and DNR plots. He suggested exploring this suggestion offline.

Berti expressed great enthusiasm for the reports that are in progress, stating that the Action Team has collected enough data to start making some interesting comparisons between the reduction in bioavailability calculated using pig dosing data, rat dosing data, and in vitro testing. In fact, he said, four samples have been dosed through the pigs and the rats, as well as being analyzed via in vitro analyses at pH 1.5, 2.0, 2.3, and 2.5.

MISCELLANEOUS

Mosby said that performing a statistical analyses revealed a significant difference between control plots and the 1% phosphorus plots. Mosby said that the statistical analysis involved an evaluation of covariants on lead dose response in blood. In addition, he said, some orthogonal contrast was performed.

Mosby asked Brown whether she plans to evaluate zinc and cadmium uptake in plants. She said that she does, because the uptake of these chemicals was significantly affected by treatments.

Mosby asked Brown to provide some information on grass composite samples. Brown said that the samples were cut about 2 to 3 centimeters above ground and that five grab samples were collected per plot. Chaney asked Brown to indicate what types of plants were used. She said it was Kentucky 31 tall fescue.

Mosby said that he will ask Casteel to provide input on an in vivo study summary that Ruby is writing.

NEXT CONFERENCE CALL

The next conference call has been set for September 20, 1999, from 3:30 p..m. to 4:30 p.m. EDT.

ACTION ITEMS

• Ruby said that in vitro analyses were performed on nine Joplin samples. He will distribute the analytical results to Berti, Mosby, and Chaney. Chaney will notify Ruby if he thinks the results should be interpreted in a different manner.

• Brown said that she performed in vitro analyses on soils collected from USDA's plots. She agreed to distribute the results to Ruby.

• In the near future, Brown will analyze plant data from three sampling events, then draft a manuscript summarizing plant and in vitro data.

• Chaney said that USDA will start writing a protocol for the rat dosing studies.

• Yang will submit an article to ES&T on the soil chemistry of laboratory studies after receiving comments from internal reviewers. In addition, he will continue to compile a draft paper on the soil chemistry of Joplin field sites. Also, he will distribute a third paper to Mosby and Casteel in early September.

• Mosby plans to complete his Master's thesis in September. In addition, he is aiming to release a broader report in October or November. To assist in the writing of the second report, Brown and Chaney agreed to send Mosby protocols for the plant and rat dosing studies, respectively. Ruby said that he is also willing to help Mosby with the manuscript writing.

• Mosby will ask Casteel to provide input on an in vivo study summary that Ruby is writing.

• ERG will set up the next conference call for September 20, 1999, from 3:30 p.m. to 4:30 p.m EDT.