Differences in the Dermal Bioavailability of Toluene and Phenol Aged in Soil
Mohamed S. Abdel-Rahman, University of Medicine and Dentistry of New Jersey, Newark, NJ
Gloria A. Skowronski, University of Medicine and Dentistry of New Jersey, Newark, NJ
Rita M. Turkall, University of Medicine and Dentistry of New Jersey, Newark, NJ  

Oral Bioaccessibility of Dioxina/Furans at Low Concentrations (50-350 ppt TEQ) in Soil
Mike Ruby, Exponent, Boulder, CO
Kurt A. Fehling, Exponent, Oakland, CA
Dennis J. Paustenbach, Exponent, Menlo Park, CA  

Volatile Air Emissions from Soil or Groundwater - Are They as Significant as Models Say They Are?
Jackie Wright, URS Australia Pty Ltd, North Sydney, NSW,  Australia
Martin Howell, URS Australia Pty Ltd, North Sydney, NSW,  Australia  

Groundwater to indoor Air - The Exposure Pathway of the Future
David L. Thompson, J M Sorge, Inc., Somerville, NJ
Todd. Huffman, J M Sorge, Inc., Somerville, NJ
Joseph M. Sorge, J M Sorge, Inc., Somerville, NJ  

The Assessment of Toxicity and Biodegradability of New Energetic Ingredient Hexanitrohexaazaisowurtzitane (CL-20) in Soil
Nikolay S. Strigul, Stevens Institute of Technology, Hoboken, NJ
Nikolai S. Panikov, Stevens Institute of Technology, Hoboken, NJ
Christos Christodoulatos, Stevens Institute of Technology, Hoboken, NJ
Steven M. Nicolich, US Army TACOM-ARDEC, Picatinny Arsenal, NJ

Risk Assessment Applications in Atypical Circumstances
Christopher Teaf, Florida State University, Tallahassee, FL
Douglas J. Covert, Hazardous Substance & Waste Management Research, Tallahassee,  FL 
R. Marie Coleman, PhD, Hazardous Substance & Waste Management Research, Tallahassee,  FL 

Communicating Risk to Diverse Stakeholders: A European Case Study
Candace S. Chandra, Canary Strategies, LLC, Florence, Italy
Daniel Merendoni, Canary Strategies, LLC, Florence, Italy  

Differences in the Dermal Bioavailability of Toluene and Phenol Aged in Soil

Mohamed S. Abdel-Rahman, Ph.D., Pharmacology and Physiology Department, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Room I-681, 185 South Orange Avenue, P.O. Box 1709, Newark, New Jersey  07101-1709, Tel: 973-972-6568, Fax:  (973) 972-4554
Gloria A. Skowronski, Ph.D., Pharmacology and Physiology Department, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Room I-624, 185 South Orange Avenue, P.O. Box 1709, Newark, New Jersey  07101-1709, Tel: 973-972-6690, Fax:  (973) 972-4554
Rita M. Turkall, Ph.D., Pharmacology and Physiology Department, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Room I-683, 185 South Orange Avenue, P.O. Box 1709, Newark, New Jersey  07101-1709, Tel: 973-972-5096, Fax: 973-972-4554
Clinical Laboratory Sciences Department, University of Medicine and Dentistry of New Jersey, School of Health Related Professions, Room 110, 65 Bergen Street, Newark, New Jersey  07107-3001, Tel: 973-972-5577, Fax: 973-972-7028

When organic chemicals age in soil, they become more sequestered with time and less bioavailable.  The dermal bioavailabilities of toluene and phenol aged for 3 months in two soils (Atsion and Keyport) were compared to the bioavailabilities of the chemicals without soil (pure chemicals), and freshly spiked in soil.  In vitro flow-through diffusion cell methodology measured the amount of radioactive chemical which penetrated dermatomed male pig skin into receptor fluid and which became bound to skin following soap and water decontamination, as well as the volatility of the chemicals. Although the majority of pure toluene was volatilized (88% of initial dose), 9% of the remaining dose penetrated skin. Because the volatility of pure phenol (39% of initial dose) was less than toluene, the total penetration of phenol (sum of initial dose in receptor fluid and bound to skin) was 52%. Therefore, the bioavailabilities of the chemicals after volatilization were 77% and 84%, respectively, for toluene and phenol.  Adding the chemicals to soil for a brief time (16 h), reduced toluene bioavailability to 4-6% and phenol bioavailability to 26-30%.  After aging, the bioavailability of toluene (3-4%) was similar to toluene in soil for a short time.  However, aged phenol was decreased to 15-22% bioavailability.  As a result of decreased bioavailability, the environmentally acceptable endpoint (EAE) of toluene would increase about 25-fold after aging in soil relative to pure toluene.  In contrast, the EAE of phenol would be about 6-fold higher relative to pure phenol. The data indicate that chemical characteristics such as volatilization, not only produce differences in the bioavailabilities of toluene and phenol but also impact the EAEs of the compounds. (Supported through funding from the Hazardous Substance Management Research Center and the New Jersey Commission on Science and Technology).

Oral Bioaccessibility of Dioxins/Furans at Low Concentrations (50-350 ppt TEQ) in Soil

Michael V. Ruby, Exponent, 4940 Pearl East Circle, Suite 300, Boulder, CO  80301 , Tel: 303- 444-7270, Fax: 303-444-7528
Kurt A. Fehling, Exponent, 1970 Broadway, Suite 250, Oakland, CA 94612, Tel: 510-208-2000, Fax: 510-208-2039
Dennis J. Paustenbach, Exponent, 149 Commonwealth Drive, Menlo Park, CA 94025, Tel: 650-326-9400, Fax: 650-688-1799

Animal studies in rodents have indicated that the oral bioavailability of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in environmentally contaminated soils can range from 0.5 to 50%.  To estimate the oral bioavailability of TCDD, and the 16 other 2,3,7,8-substituted dioxin/furan congeners, this study used a physiologically based extraction test, designed around the anatomic and physiologic characteristics of the human digestive tract.  This test measures the fraction of dioxins/furans in soil that would be solubilized in the gastrointestinal tract (i.e., that would be bioaccessible), and therefore available for absorption.  The concentrations of TCDD in the eight soils tested were 1.7 to 139 pg/g (ppt), while the total TEQ concentrations were 6 to 340 ppt.  Bioaccessibility of dioxins/furans from these soils ranged from 19 to 34% (averaged across the 17 2,3,7,8-substituted dioxin/furan congeners), with an average of 25%.  The total organic carbon (TOC) in these soils was low—less than 4%—particularly for the soil series from which they were collected.  Bioaccessibility of individual congeners did not appear to be correlated with degree of chlorination; however, it did appear to be inversely related to TOC.  Even though these dioxin/furan concentrations are much less than studied previously, these results are consistent with those from animal studies at other sites, which have generally yielded values of 20–50% relative bioavailability of TCDD in soil.

Volatile Air Emissions from Soil or Groundwater – Are They as Significant as Models Say They Are?

Jackie Wright, URS Australia Pty Ltd, Level 3, 116 Miller Street, North Sydney, NSW 2060, Australia, Tel: 61 2 8925 5500, Fax: 61 2 8925 5555
Martin Howell, URS Australia Pty Ltd, Level 3, 116 Miller Street, North Sydney, NSW 2060, Australia, Tel: 61 2 8925 5500, Fax: 61 2 8925 5555

Human health risk assessments often involve the evaluation of volatile chemicals in either subsurface soils or groundwater. The inhalation of volatile chemicals following volatilisation and diffusion to the soil surface is often found to be the most significant exposure pathway. This is primarily due to the use of models to predict the transport processes and emissions across the soil surface for volatile chemicals present at depth in soil or groundwater. These models are simplistic and often result in conservative and unrealistic results leading to over-estimations of chemical concentrations in breathing zones. The implication of the use of vapour transport models has been investigated by URS at a number of sites in Australia over the last 7 years. Modelled estimates of surface emission rates have been compared with measured emissions data (collected using a surface emissions flux hood and a soil gas probe). The results of these investigations bring into question the validity of these models for use across sites with varying subsurface chemicals and characteristics. Commonly used simplistic models (such as the Johnson and Ettinger Model and others as recommended in RBCA guidance) were found to over estimate the measured surface emission rate to varying degrees at all sites. For some chemicals, such as benzene, the modelled results were inconsistent, ranging from an order of magnitude to several orders of magnitude greater than the measured results (depending on subsurface conditions). However, for other chemicals particularly chlorinated hydrocarbons such as vinyl chloride and 1,2-dichloroethane, the use of models greatly over estimated the measured surface emissions rates. This observation was consistent at a number of sites with varying subsurface conditions resulting in the model predicting unrealistic and inaccurate air concentrations in breathing zones both indoors and outdoors. This paper presents the results of comparisons undertaken at a number of different sites in Australia and discussion on the observations made and potential use of models in predicting emissions from a range of subsurface sources.

Groundwater to Indoor Air - The Exposure Pathway of the Future

David L. Thompson, P.G., Todd. Huffman, and Joseph M. Sorge, J M Sorge, Inc., 50 County Line Road, Somerville, New Jersey 08876, Tel:  908-218-0066, Fax:  908-218-9185

The Federal government and several states are focusing attention on the often neglected exposure pathway associated with groundwater contamination off-gas effects on indoor air quality in buildings.  Currently, the state of the science required to assess this exposure pathway is primitive at best.  There are only a few models available for the projection of indoor air quality effects associated with groundwater off-gas and soil vapor.  To date the Johnson and Ettinger model is the most comprehensive model available, yet it falls short of providing reliable and reasonable results for all but the simplest of sites and the possible input parameter values are seemingly limitless.  Other more direct methods such as soil gas sampling and indoor air sampling are also fraught with uncertainty in obtaining reliable results and comparing them to meaningful standards.  Since indoor air quality effects associated with site remediation are obviously going to be a major exposure pathway to consider, especially in the new age of natural attenuation, additional, significant research is needed to adequately evaluate this exposure pathway.

The Assessment of Toxicity and Biodegradability of New Energetic Ingredient Hexanitrohexaazaisowurtzitane (CL-20) in Soil

Nikolay S. Strigul and Nikolai S. Panikov, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ, 07030, Tel: 201-216-8193, Fax: 201-216-8240
Christos Christodoulatos, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ, 07030, Tel: 201-216-5675, Fax: 201-216-8303
Steven M. Nicolich, US Army TACOM-ARDEC, Armament, Research and Engineering Center, AMSTA-AR-WEE, Building 3022, Picatinny Arsenal, NJ 07806-5000, Tel: 973-724-2065, Fax: 973-724-4308

The energetic compound, hexanitrohexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.03,11] dodecane), also known as CL-20,  is a high power low signature explosive  that has the potential to replace currently used high explosives due to its higher performance in terms of ballistics, detonation velocity, and safety.  In addition, CL-20 containing no halogens is expected to be more environmentally friendly as compared with older propellant formulations. The widespread, high-level interest in CL-20 has resulted in an increase in its industrial production up to several thousands of pounds per year and its eventual environmental fate and transport. The aim of the present study was to assess the potential impact of CL-20 on natural environments such as soils and soil organisms including microbes, animals and plants.  Small amounts of CL-20, provided by the US Army, Picatinny Arsenal NJ, was added to forest and meadow soils (New Jersey) at a rates 0, 500, 1000 and 2000 ppm and incubated at 20^oC and constant soil moisture 50 % of WHC. In the first series of experiments, the natural input of organic carbon was simulated by soil amendments with glucose, starch, or cellulose at a rate 1,000-4,000 ppm.  During one month of incubation, respiration (CO₂ formation) was continuously recorded using an IR gas analyzer (Li-800) and the composition of microbial community followed by direct microscopy (bright field, UV-, AMF, SEM) and isolations.  We were able to identify soil fungi, microarthropods, and some bacterial species. No evident changes in the composition of the soil community was established, while soil respiration was slightly stimulated (by 1-5%) after addition of CL-20, the stimulation being proportional to CL-20 amendment rate.  In the second series of experiments, soil was mixed with 2000 ppm of CL-20, planted (bean and ryegrass) and incubated under artificial light (300 mmols/m²/sec of PAR) with 16:8 h light: dark cycle. The plant photosynthesis and soil-plant respiration was recorded continuously with Li-800 during 2 months from the seedling stage to flowering and seed formation. Contrary to our expectation, the effect of CL-20 on plant growth was stimulating rather than toxic: the standing plant crop and photosynthesis rates were 10-20% higher than those of the control, and senescence stage was significantly delayed. In the third series of experiments, we followed the dynamics of residual CL-20 in soil samples incubated at 10-60^oC by spectrophotometry of the soil extract. It turned out that decomposition dynamics followed first order kinetics with 50%-decay time varied from 7 days (40 ^oC) to several years (10^oC). Thus, we can conclude that CL-20 has no toxicity to soil community and has unusual bio-simulative effects needed further clarification.

Risk Assessment Applications in Atypical Circumstances

Christopher M. Teaf, PhD, Center for Biomedical & Toxicological Research, Florida State University, 2035 East Dirac Drive, Suite 226 HMB, Tallahassee,  FL  32310, Tel: 850-644-3453 , Email: cteaf@mailer.fsu.edu
Douglas J. Covert, and R. Marie Coleman, PhD, Hazardous Substance & Waste Management Research, 2976 Wellington Circle West, Tallahassee,  FL  32309, Tel: 850- 681-6894, Email: staff@hswmr.com

Historically, the phrase “Risk Assessment” would bring to mind a three inch thick Superfund-type baseline risk assessment document filled with pages of tables with endless seemingly unrelated algorithms and numbers.  Over the past decade, the principles of risk assessment have gained much more wide-reaching acceptance and risk-based solutions may be utilized for many environmental, occupational or other technical problems.  The typical objective of the classic risk assessment is to evaluate current risks or future projected risks from exposure to contaminated media within the framework of state or federal waste management and remediation programs.  In addition to those still-viable applications, risk-based techniques also are increasingly being used on a voluntary basis (i.e., outside of the standard regulatory arena) to demonstrate the presence, absence, or extent of environmental or health-related concerns in specific exposure circumstances.  Likewise, a risk evaluation may be useful in determining the need for, or the legitimacy of, a public health advisory, alone or in conjunction with remedial actions.  Finally, risk-based techniques often find their way into the courtroom.  Three case studies are presented in which risk-based solutions were employed in a somewhat unconventional manner to assist in the resolution of environmental or health-related issues:  reversal of a fish consumption advisory, evaluation of arsenic in soil on and adjacent to a school facility and challenge to a case of alleged methyl bromide exposure in a litigation context.

Communicating Risk to Diverse Stakeholders: A European Case Study

Candace S. Chandra, Canary Strategies LLC, Via Verdi 1, Florence 50122 Italy, Tel: +39 348 035 8708, Email: Candace@canarystrategies.com
Daniel Merendoni, Canary Strategies, LLC, Via Verdi 1, Florence 50122 Italy, Tel: +39 340 901 8427, Email: Daniel@canarystrategies.com

Many European ports are beginning the lengthy and costly process of clean up. Remediation technologies are being reviewed and considered. Policymakers are considering with the longevity and cost of different technologies. Furthermore, local public groups are just becoming aware of the environmental and public health concerns associated with large scale cleanup projects. Finally, the industrial groups which have been closely associated with ports are concerned about changing legislation and resulting responsibilities and possible negative press.

With the integration of policies and standards around the European Union, many port sites are struggling with changing cleanup standards for various contaminants. For instance, sediment standards are just being set now around the EU. Quite often, the remediation engineering firms chosen to work at particular sites are from different countries, and therefore language and work culture are completely different. All of these variables make clear communication between stakeholders crucial in a port remediation project.

Bilbao, Spain provides an interesting case study of the diversity and scope of stakeholders at a European port site. The primary concerns are to clean the surrounding freshwaters and sediments and to involve industry in the process (to ensure less contamination in the future). The political situation in Bilbao makes for many levels of bureaucracy and oversight from the EU, federal, regional, and local governments. Furthermore, the surrounding population is very concerned about environmental health problems coming from the port’s remediation project.

To date, many scientific reports have been issued on the quality of water and soil within Bilbao’s port. However, to ensure different stakeholder acceptance, an integrated and proactive communication strategy is necessary, to ‘translate’ the technical information to non-scientific stakeholders. Additionally, the flow of information must travel in the other direction  (from the non-scientific community to the engineering firm and scientists) to address local concerns and changing perspectives.

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