Boston University Superfund Basic Research Program

The Superfund Basic Research Program (SBRP), in collaboration with the Environmental Protection Agency (EPA) Technology Innovation Program, presents the 2008 edition of Risk e Learning: "Bioavailability - Metals, Organics, and Use at Hazardous Waste Sites". This series of online seminars focuses on the science and policy issues of incorporating bioavailability into risk and exposure assessments. Largely drawing from the successful SBRP Bioavailability Workshop: "Assessing Bioavailability as a Determinant of Pollutant Exposure" held in Tampa, FL (February 2008), the web seminar series features SBRP-funded and other academic researchers and EPA senior staff. The first seminar "Bioavailability of Metals" was May 28th, the second seminar "Bioavailability of Organic Compounds: Methods and Case Studies" is June 11th, and the third seminar "Use of Bioavailability Information at hazardous Waste Sites" is June 18th.

This, the second of the three sessions, will feature Dr. Edward Neuhauser, Principal Environmental Engineer, National Grid, and Dr. Danny Reible, the Bettie Margaret Smith Chair of Environmental Health Engineering at the University of Texas.

Dr. Neuhauser's presentation is titled: True Measurement of PAH Bioavailability in Sediments - Traditional regulatory guidance for screening PAH contaminated sediments have used the total EPA 16 parent PAH's and have correlated these values with summary values from a wide variety of studies. This approach has given very inconsistent results when comparing the EPA total 16 PAH's with actual laboratory toxicology testing. This study has developed a PAH measurement method, the Solid-Phase Microextraction (SPME) method, that actually measures the true bioavailability of PAH's in sediments. The SPME method does not measure the total amount of PAH's present in a sediment sample, but rather only that fraction of PAH's in sediments that are actually present in sediment pore water and are available to benthic organisms. This research has shown that the actual PAH toxicity is concentrated in the alkylated low molecular weight PAH's and that 5- and 6-ring PAH's actually contribute very little to sediment toxicity.

The definition of exposure and risk to contaminants in sediments depends upon access to those contaminants, the extent to which accessible contaminants are bioavailable and the extent to which contaminants accumulate in organisms of interest. Dr. Reible's presentation will focus on efforts to understand and quantify these processes. Recent research associating interstitial water concentrations of PAHs and PCBs to bioaccumulation in benthic organisms will be reviewed. This research has provided an increasingly strong basis for the use of interstitial water concentrations as an indicator of bioavailability, bioaccumulation and ultimately exposure and risk of these contaminants to the benthic community. Building on this basis, field deployable solid phase microextraction devices were developed and used to evaluate bioavailabilty and mobility of organic contaminants in sediments. The use of these devices to assess, in situ, mechanisms and rates of chemical transport and the effectiveness of permeable containment or sorptive barriers (sediment caps) will be summarized.

The session will be moderated by Dr. Karl Gustavson, Contaminated Sediment Liaison to US EPA, US Army Engineer Research and Development Center.

The Superfund Basic Research Program (SBRP), in collaboration with the Environmental Protection Agency (EPA) Technology Innovation Program, presents the 2008 edition of Risk e Learning: "Bioavailability - Metals, Organics, and Use at Hazardous Waste Sites". This series of online seminars focuses on the science and policy issues of incorporating bioavailability into risk and exposure assessments. Largely drawing from the successful SBRP Bioavailability Workshop: "Assessing Bioavailability as a Determinant of Pollutant Exposure" held in Tampa, FL (February 2008), the web seminar series features SBRP-funded and other academic researchers and EPA senior staff. The first seminar "Bioavailability of Metals" was May 28th, the second seminar "Bioavailability of Organic Compounds: Methods and Case Studies" was June 11th, and the third seminar "Use of Bioavailability Information at hazardous Waste Sites" is June 18th.

This, the third of the three sessions, will feature Mr. Mike Beringer, U.S. EPA Region VII toxicologist, and Dr. Mark Maddaloni, U.S. EPA Region II toxicologist.

Site-specific bioavailability is an important consideration in determining potential threats to human health that are posed by metals-contaminated soils at waste sites. It is important to consider bioavailability because metals may be absorbed to a lesser or greater extent following ingestion of contaminated soils as compared to the fraction absorbed in the studies used to establish toxicity values, such as a reference dose or a cancer slope factor. U.S. EPA's Office of Superfund Remediation and Technology Innovation (OSRTI) has led an effort to develop guidance on evaluating and incorporating bioavailability adjustments into human health risk assessments. The guidance outlines a decision framework for deciding when to collect and incorporate site-specific bioavailability information; recommends a process for documenting the data collection, analysis, and site-specific implementation of a validated method; as well as provides recommended method validation and regulatory acceptance criteria for evaluating alternative methodologies. OSRTI has used these criteria to evaluate two separate methodologies for predicting the relative bioavailability of lead in soil and soil-like materials. OSRTI has determined that both an in vivo swine bioavailability bioassay and an in vitro bioaccessibility assay have sufficiently satisfied these criteria. Thus, they are considered regulatory methodologies appropriate for determining the relative bioavailability of lead for quantitative use in site-specific risk assessments. Mr. Beringer's presentation will summarize the bioavailability guidance document and the basis for OSRTI's decision regarding the two methodologies for predicting lead relative bioavailability.

EPA's bioavailability guidance provides a framework for using bioavailability/bioaccessibility data to inform and refine site specific risk assessments. In the case of lead, which benefits from well-characterized studies on the absorption of this metal when bound to soil, the guidance is highly prescriptive. For many other metals that have limited characterization of their absorption profiles, the guidance is more open to interpretation. The bioavailability guidance will be "test driven" so to speak in a situation where the roadmap is less detailed. In this presentation Dr. Maddaloni will go over a case study involving a RCRA Corrective Action site with arsenic-contaminated soil.

The session will be moderated by Dr. Fred Pfaender, Professor of Environmental Microbiology, Environmental Sciences and Engineering, and Public Health.

Do you manage a Superfund landfill site? Is it producing methane gas? Have you wondered how to evaluate and responsibly manage the landfill methane gas? During this training we will discuss resources available to project managers to assess methane productivity at Superfund landfills as well as potential ways to use it as a source of energy or flare it, thereby reducing greenhouse gas emissions. EPA has a wealth of knowledge and experience with landfill gas that may have applicability to Superfund sites. This training will provide a brief overview of the tools available to evaluate, use and flare landfill methane gas and how they may apply to Superfund sites.

Keep in mind that Superfund landfills are typically older, closed sites where codisposal of hazardous and municipal waste has occurred. The emissions will be different from a typical municipal landfill. Because of the age and types of waste, the volume of gas is likely less and concentration of hazardous air pollutants is likely higher. Therefore, before proceeding with exploring economics of energy recovery, the amount and characteristics of the landfill gas need to be evaluated. We will discuss how to conduct an evaluation using EPA's Guidance for Evaluating Landfill Gas Emissions From Closed or Abandoned Facilities (EPA-600/R-05/123a). We will also identify options for controlling emissions through either flaring the gas or recovery for its energy potential.

McCoy KA, Bortnick LJ, Campbell CM, Hamlin HJ, Guillette LJ Jr, and St. Mary CM. 2008. Environ Health Perspect: doi:10.1289/ehp.11536.

Lee DH, Jacobs Jr. DR, Kocher T. 2008. Environ Health Perspect: doi:10.1289/ehp.11425.

At some point, citizens involved in watershed protection face the question - How do we pay for this? Most quickly realize that there are not enough grant funds to meet the needs for water quality projects. The Clean Water State Revolving Fund is a large, flexible, and largely untapped source of funding for watershed projects. It provides over $5 billion each year for traditional stormwater and wastewater projects, as well as over $200 million for nonpoint source projects, such as land conservation, agricultural best management practices, and clean-up of contaminated sites. Join us to hear more about how you can access the Clean Water State Revolving Fund to protect your watershed.

The Environmental Protection Agency (EPA) SBIR Phase I Solicitation is now closed and the next SBIR solicitation will open in March 2009. However, there are nearer term opportunities for SBIR funding of environmental technologies in the National Science Foundation (NSF) SBIR Phase I Solicitation closing on December 4, 2008. Nearly all of EPA's technology needs have significant synergy with this NSF Solicitation.

The CLU-IN Upcoming Courses and Conferences section was updated on July 2, 2008. There is 1 new entry, for a total of 163 upcoming courses and conferences related to hazardous waste remediation:

• ITRC Vapor Intrusion Pathway: A Practical Guideline, Jul 29 , 2008, INTERNET

A newsletter for environmental professionals that features a combination of articles on innovative, in-situ technologies for the characterization and treatment of soil, sediment, and ground water.

Perchlorate contamination exists in water and soil, and occurs widely throughout the United States. Public awareness and concern regarding perchlorate has increased in recent years. Perchlorate occurrence in drinking water and food supplies is a human health concern because it can interfere with iodide uptake by the thyroid gland and result in decreased thyroid hormone production. The ITRC Perchlorate Team was formed in 2004 to address technical issues associated with perchlorate. Many technologies are available to remediate perchlorate contamination, but only a few are commonly used.

This training introduces state regulators, environmental consultants, site owners, and community stakeholders to Remediation Technologies for Perchlorate Contamination in Water and Soil (PERC-2, 2008), created by ITRC's Perchlorate Team to assist reviewers in assessing the adequacy of perchlorate remediation projects. This course gives the student a background in the available remediation technologies to treat perchlorate contamination, discusses emerging technologies, and presents case studies of applications.

The first document produced by the ITRC Perchlorate Team, Perchlorate: Overview of Issues, Status, and Remedial Options (PERC-1, 2005) and associated Internet-based training provide regulators and other stakeholders a basic overview of a broad spectrum of information regarding perchlorate sources, sampling and analysis techniques, a discussion of risk issues, risk management strategies and regulatory status, and included a brief summary of remediation technologies. It is recommended that the registrant review the Perchlorate: Overview of Issues, Status, and Remedial Options (PERC-1, 2005) document and associated Internet-based training archive (available from http://www.itrcweb.org/ibt.asp#Perchlorate_CurrentInfo) for more information.

The May 1-31, 2008 Technology Innovation News Survey has been posted to the CLU-IN web site. The Survey contains market/commercialization information; reports on demonstrations, feasibility studies and research; and other news relevant to the hazardous waste community interested in technology development.

Meeker JD, Rossano MG, Protas B, Diamond MP, Puscheck E, Daly D, Paneth N, Wirth JJ. 2008. Environ Health Perspect: doi:10.1289/ehp.11490.