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

August 14, 1997

Sally Brown (U.S. Department of Agriculture) summarized results from a Sprague-Dawley weaning rat model that is being used to assess Pb-bioavailability of soil from the Joplin field site. The soil has about 4000 mg Pb/kg and was treated with several materials as part of a lab study. Results are limited to Pb concentrations in bone. Compared with the untreated control soil, adding compost alone was not effective in reducing Pb-bioavailability, although PBET results had indicated that compost would be an effective treatment. Adding 1% phosphorus (P) and adding 1% P + 2.5% Fe (as Iron Rich) to the soil reduced Pb-bioavailability 30% and 41%, respectively. These results compared well with that seen using the swine model and the work done by Stan Casteel, Bob Blanchar, and John Yang (University of Missouri). Sally is waiting for the blood-Pb results and will report on those at a later date.

Steve Burke (USDA), who works with Sally, will visit the Joplin site the week of Sept. 8 or 15 to collect plant shoots and soils from the plots. This work will be coordinated with the Missouri folks so that all samples will be collected at the same time. It was noted that some of the plots did not have a good plant cover, and so there may be a need for Steve to measure soil pH, apply additional lime if warranted, and reseed. Mark Doolan (U.S. EPA Region 7) will check to see if the Corps can help water the plots, if needed, to help establish the grass.

Pb-bioavailability of soils treated with 10,000 and 5,000 mg P/kg in the field at Joplin is being evaluated by Stan Casteel using the pig model. The soils have already been dosed to the pigs and Stan is waiting for analytical results.

The reduction in Pb-bioavailability so far is encouraging but not as great as may be needed to use inplace inactivation as a remediation alternative in Joplin. There is evidence (USDA and Missouri), however, that reductions in Pb-bioavailability in soils treated in the field will be greater than those treated in laboratory studies.

Sam Traina (Ohio State University) talked about some of the findings from his lab that bioavailability (to plants) and mobility has decreased dramatically over a 3-year period in soils with 1000 mg Pb/kg treated with apatite (a form of calcium phosphate).

Mark Doolan said that a conference on bioavailability, Bioavailability '97, will be held Dec. 11 and 12 in Scottsdale, AZ. It sounds like a good one to attend. Talks will cover both inorganics and organics, and bioavailability from ingestion, inhalation, and dermal contact. For more information, contact Pat Canney at 508/481-6400 Ext 281.

Information is needed before the end of the month to include in the RTDF Update, especially information that has happened since the meeting in May. Please send contributions to Bill Berti (DuPont Central Research and Development) bill.berti@usa.dupont.com 302/451-9138 (FAX)

Mark Maddaloni (U.S. EPA Region 2) has developed a first cut at the soil bioavailability matrix. If you would like a copy (electronic or FAX) please contact Mark at maddaloni.mark@epamail.epa.gov or 212/637-4315 or Bill Berti bill.berti@usa.dupont.com 302/451-9224. Please send comments, suggestions, and additions to Mark.

We are getting contributions to the IINERT bibliography for the web page. Send yours to Bill Berti bill.berti@usa.dupont.com or Carolyn Perroni cperroni@emsus.com. Call Bill if you have any questions (302/451-9224).

Jim Ryan (U.S. EPA National Risk Management Research Laboratory), Dean Hesterberg (North Carolina State University), and Bill Berti are working on putting together and distributing to everyone a questionnaire for soil collection.

Next conference call is scheduled for Sept. 11 at 1 EDT. Subsequent calls will be scheduled for the second Thursday of each month, beginning at 1:30 instead of 1.