Development of Normal Human Colonocyte Cultures to Identify a Carcinogenic Potential   for Priority Disinfection Byproducts
Carlton Jones, US Environmental Protection Agency, Research Triangle Park, NC
Anthony DeAngelo, US Environmental Protection Agency, Research Triangle Park, NC


Comparison Assessment of the Dermal Bioavailability of Soil-Aged Polycyclic Aromatic Hydrocarbons
Mohamed S. Abdel-Rahman, Ph.D., Pharmacology and Physiology Dept., UMDNJ - New Jersey Medical School, Newark, NJ 
Gloria A. Skowronski, Ph.D., Pharmacology and Physiology Dept., UMDNJ - New Jersey Medical School, Newark, NJ
Rita M. Turkall, Ph.D., Clinical Laboratory Sciences Dept., UMDNJ - School of Health Related Professions, Newark, NJ

A Practical Approach to Addressing Urban Garden Soil Contamination
Wendy Heiger-Bernays, Boston University School of Public Health, Boston , MA
Alicia J Fraser, Department of Environmental Health, Boston University School of Public Health, Boston , MA
Dan Brabander, Geosciences Department, Wellesley College , Wellesley , MA  
Valerie Burns, Boston Natural Areas Network, Boston, MA
Robert Maxfield, EPA New England Regional Laboratory, North Chelmsford, MA
Dan Boudreau, EPA New England Regional Laboratory, North Chelmsford, MA
H. Patricia Hynes, Department of Environmental Health, Boston University School of Public Health, Boston, MA

Risk Assessment Provisions in the European REACH Regulation
Brian Magee, Ph.D., AMEC Earth & Environmental, Westford , MA
Benefits of Using Site-specific Measurements and Innovative Approaches in an Ecological Risk Assessment
Margaret E. McArdle, Exponent, Inc., Winchester , MA
Pieter Booth, Exponent, Inc., Bellevue , WA

Benefits of Using Site-specific Measurements and Innovative Approaches in an Ecological Risk Assessment
Margaret E. McArdle, Exponent, Inc. Winchester , MA
Pieter Booth, Exponent, Inc., Bellevue , WA

Development and Application of Recreational, Ecological and Conservation Reuse Risk Assessments for Contaminated Lands
Christopher S. Warren, Ph.D., ExxonMobil Biomedical Sciences, Inc., Annandale , NJ
Gregory R. Biddinger, Ph.D., ExxonMobil Biomedical Sciences Inc., Houston , TX
Rosemary T. Zaleski, Ph.D., ExxonMobil Biomedical Sciences Inc., Annandale , NJ
Charles G. Johnson, Colorado Department of Public Health and Environment, Denver, CO

 

Development of Normal Human Colonocyte Cultures to Identify a Carcinogenic Potential   for Priority Disinfection Byproducts
Anthony DeAngelo, US Environmental Protection Agency, 108 TW Alexander Drive , Research Triangle Park , NC 27701USA, Tel: 919-541-2568, Fax: 919-541-0329, Email: deangelo.anthony@epa.gov.
Carlton Jones, US Environmental Protection Agency, 108 TW Alexander Drive , Research Triangle Park , NC 27701USA, Tel: 919-541-4346, Fax: 919-541-0694, Email: jones.carlton@epa.gov 

Epidemiological studies have linked the consumption of disinfected surface waters to an increased risk of colorectal cancer.  Of the approximately >600 disinfection byproducts (DBPs) identified, the US EPA regulates 11 DBPs for an increased risk of cancer.  An in-depth mechanism-based structure activity analysis undertaken to rank the carcinogenic potential of the >600 DBPs, identified 50 unregulated DBPs with the highest potential for carcinogenicity.  We set out to develop an in vitro/in vivo model system to test the potential of unregulated DBPs to transform normal human colon cells to a malignant state.  Two DBPs identified as rodent carcinogens, bromochloroacetic and dichloroacetic acid, two priority DBPs, dibromonitromethane and tribromonitromethane, and the colon carcinogen, azoxymethane, were tested.  Human colon mucosal cells (NCM460) were exposed to 1E+-06 M (≥ 90% viability) of each test chemical for 10 days.  Following chemical removal, the cells (monolayer) were maintained in the growth media for 14-21 days.  Cells growing in suspension (S fraction) were transferred to new flasks and grown for another 14-21 days.  The process was repeated with suspended cells to generate an S1 fraction.  These steps were necessary to deplete stem cells which have the capacity to grow in soft agar (Transformation Assay).  The S1 fraction cells were grown in soft agar for 21-28 days.  All of the treated S1 fractions formed colonies in the soft agar; S1 fractions from untreated cells did not form colonies.  Colonies from each treatment were selected and propagated to provide cells to place into immunoincompetent mice (Tumor Formation Assay).  Gene expression and immunohistochemical staining of the treated cells demonstrated activation of the WNT signaling pathway and Adherens Junction, activations important in the development of colon cancer.  The characterization and validation of this model continues.  (This is an abstract of a proposed presentation and does not necessarily reflect the opinion of the USEPA)       

Comparison Assessment of the Dermal Bioavailability of Soil-Aged Polycyclic Aromatic Hydrocarbons
Mohamed S. Abdel-Rahman, Ph.D., Pharmacology and Physiology Dept., UMDNJ - New Jersey Medical School, 185 South Orange Avenue, Newark, NJ, 07101, Tel: 407-568-5122, Email: abdelrms@umdnj.edu 
Gloria A. Skowronski, Ph.D., Pharmacology and Physiology Dept., UMDNJ - New Jersey Medical School, 185 South Orange Avenue, Newark, NJ, 07101, Tel: 732-721-9432, Email: skowroga@optonline.net 
Rita M. Turkall, Ph.D., Clinical Laboratory Sciences Dept., UMDNJ - School of Health Related Professions, 65 Bergen Street, Newark, NJ, 07107, Tel: 407-568-5122, Email: turkalrm@umdnj.edu

Health risk assessments often do not consider the amount of chemicals in soil that is absorbed by the body (bioavailability). Instead, they rely on the total concentration of chemicals that can be extracted from soil by rigorous procedure and ignoring the complex interaction between chemicals and soil. Therefore ,the health risks and soil remediation can be overestimated .The aim of these studies was to determine the dermal bioavailability of soil contaminated chemicals with aromatic hydrocarbon [benzo(a)pyrene (B(a)P) and naphthalene (N)] and examine the relative contribution of soil matrix and chemical sequestration in soil with time (“aging”).  In vitro, flow-through diffusion cell studies were performed utilizing dermatomed male pig skin and radioactive chemicals to measure total penetration (sum of each chemical in skin and receptor fluid).  Volatilization was predominant in reducing the dermal penetration of N following immediate contact with clay soil. Aging further reduced skin penetration by 23 and 54 fold in sandy and clay soil, respectively. B(a)P penetration was reduced >88% following immediate contact with soil, with further reduction occurring after aging for 3 months particularly with clay soil. The data represent that aging decreased the bioavailability of both B(a)P and N, while the effect on N was much greater. This investigation indicates that the potential health risk from dermal exposure to the polycyclic aromatic chemicals studied can be significantly reduced by soil and aging.

A Practical Approach to Addressing Urban Garden Soil Contamination
Wendy Heiger-Bernays, Boston University School of Public Health, 715 Albany St. T4W Boston, MA 02118, USA, Tel: 617 638-7724, Fax: 617 638-4857, Email: whb@bu.edu 
Alicia J Fraser, Department of Environmental Health, Boston University School of Public Health, 715 Albany St. T4W Boston, MA 02118, USA, Tel: 617 638-8357, Fax: 617 638-4857, Email: afraser@bu.edu
Dan Brabander, Geosciences Department, Wellesley College, 106 Central Street, Wellesley, MA  02481, USA, Tel: 781 283-3056, Fax: 781 283-3642, Email: dbraband@wellesley.edu
Valerie Burns, Boston Natural Areas Network, 62 Summer Street, Boston , MA 02110 , USA , Tel: 617-542-7696, Fax: 617-542-0383, Email: valerie@bostonnatural.org
Robert Maxfield, EPA New England Regional Laboratory, 11 Technology Drive, North Chelmsford , MA 01863 , USA , Tel: 617 918-8300, Email: maxfield.robert@epamail.epa.gov
Dan Boudreau, EPA New England Regional Laboratory, 11 Technology Drive, North Chelmsford , MA 01863 , USA , Tel: 617 918-8300, Fax: 617 918-8397, Email: boudreau.dan@epamail.epa.gov
H. Patricia Hynes, Department of Environmental Health, Boston University School of Public Health, 715 Albany St. T4W, Boston, MA, USA,  02118  Tel: 617 638-7720, Fax: 617 638-4857, Email: hph@bu.edu

Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants.  Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices.  This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil.

Risk Assessment Provisions in the European REACH Regulation
Brian Magee, Ph.D., AMEC Earth & Environmental, Westford , MA , 01886 , Tel: 978-692-9090, Fax: 978-692-6633, Email: brian.magee@amec.com

In June 2007, the European Union began implementation of far reaching legislation that creates a new system for chemical regulation in all EU countries.  Registration, Evaluation and Authorization of Chemicals (or REACH) governs all aspects of businesses that manufacture, import, process, and use chemicals in Europe , including end users of chemicals.  REACH is the European counterpart to the U.S. Toxic Substance Control Act.  The conduct of risk assessment is evident in many REACH provisions. Registration of certain substances requires Chemical Safety Reports (CSR) consisting of human health hazard assessment, human health hazard assessment of physicochemical properties, environmental hazard assessment, and PBT/vPvB assessment.  In some cases, CSRs also require exposure assessment (exposure scenario(s)/exposure estimations), and risk characterization. Exposure scenarios must be included in Safety Data Sheets that must be sent to all downstream users.  Other formal uses of risk assessment methodologies are within the authorization provision. Listed chemicals cannot be manufactured or used unless authorized. Applications for authorization may require demonstrations of the efficacy of risk management practices, socio-economic analyses, and alternatives analyses. REACH also requires that each chemical be registered for every use. The definition of chemical uses and generic chemical use categories inherently involves risk assessment. Similarly, REACH allows for chemicals to be grouped into “categories.” Risk-based decision making will be required to define defensible chemical categories. US companies have several decades of experience with risk assessment principals and practice, both site-specific and chemical-specific.  REACH, however, will place a massive burden on the conduct of risk assessment, because thousands of chemicals will require risk assessments for all of their uses in society within a few years time. This paper will compare and contrast the types of chemical risk assessments performed in the US and the types of risk assessment required by REACH.