Bioavailability
Considerations in Risk Management Decision-Making
William Frez, Earth Tech, Inc., Livonia, MI
Initial
Risk-based Screening of Potential Brownfield Development
Sites
Mary O'Reilly Brophy, New York State Department of
Transportation/ SUNY School of Public Health, Binghamton,
NY
Demystifying
Dioxin Data for the Environmental Decision-Maker
Nancy C. Rothman, New Environmental Horizons, Inc.,
Skillman, NJ
Bioavailability
Considerations in Risk Management Decision-Making
William Frez, Earth Tech, Inc., 36133
Schoolcraft Rd., Livonia, MI, 48150, Tel: 734-779-2839
Fax: 734-779-2860, Email: william.frez@earthtech.com.
Nicholas Basta, The Ohio State University, 2021 Coffey Rd,
410C Kottman, Columbus, OH
43210, Tel: 614-292-6282, Fax: 614-292-7432, Email:
basta.4@osu.edu.
Jeffrey Bryan, Earth Tech, Inc., 5010
Stone Mill Road, Bloomington, IN 47408, Tel: 812-336-0972, Fax: 812-336-3991, Email: jeffrey.bryan@earthtech.com.
Veronica Ewald, Earth Tech, Inc., 675
North Washington Street, Suite 300 Alexandria, VA 22314, Tel: 703-549-8728, Fax: 703-549-9134,
Email: veronic.ewald@earthtech.com.
Leta Maclean, Earth Tech, Inc.,
9675 Business Park Ave., San Diego, CA 92131, Tel:
858-536-5610 Fax: 858-536-5620,
Email: leta.maclean@earthtech.com.
Sarah Medearis, Earth Tech, Inc., 675
North Washington Street, Suite 300 Alexandria, VA 22314, Tel: 703-549-8728, Fax: 703-549-9134,
Email: sarah.medearis@earthtech.com.
Susan Walter, Earth Tech, Inc., 117A
Broadway Avenue, Oak Ridge, TN 37830, Tel: 865-483-9404
Fax: 865-481-3834, Email: susan.a.walter@earthtech.com.
Clint Zenigami, US Department of the Navy, NAVFAC
Pacific, 258 Makalapa Dr., Suite 100, Pearl Harbor, HI
96860, Tel: 808-471-9186, Fax: 808-473-5972, Email: zenigamict@efdpac.navfac.navy.mil
Bioavailability (BA), in a pharmacological context, is a
fundamental and well-accepted phenomenon when assessing
the therapeutic and toxic effects of a wide variety of
chemicals. Despite
this acceptance, the routine determination of BA in
site-specific risk assessments in support of environmental
remediation has been limited.
Using in-vitro methodology, we have determined the BA of
arsenic in soil samples collected from a former foundry at
the Pearl Harbor Naval Shipyard.
The method is designed to simulate mammalian
digestive processes and estimates the BA of contaminants
detected in an environmental medium.
The method, which has been verified with animal
testing, is also a precise and cost effective alternative
to performing BA tests using laboratory animals.
The foundry data show that the bioavailability of arsenic in
soil can range from 20 to 70 percent relative to arsenic
in a freely dissolved (i.e., 100% BA) state.
In a remedial context, these data suggest that
cleanup goals may be up to five times greater than default
cleanup goals that do not incorporate site specific BA.
Unless widely and regularly evaluated in the site-specific
risk assessment process, risk managers may be at a
disadvantage, finding it difficult to incorporate BA
routinely in their decision-making process.
We suggest that the regular and standardized use of
site-specific BA can help facilitate the decision making
process; ultimately supporting the regulatory mandate to
protect the public health.
Initial
Risk-based Screening of Potential Brownfield Development
Sites
Mary O’Reilly Brophy, New York State Department of
Transportation/SUNY School of Public Health, 44 Hawley
Street, Binghamton, NY, 10910, Tel: 607-721-8138, Fax:
607-721-8129, Email: mbrophy@dot.state.ny.us
Ronald Brink, Broome County Department of Health, 225
Front Street, Binghamton, NY 13905, Tel: 607-778-2887,
Fax: 607-778-3912, Email: rbrink@co.broome.ny.us
Brownfield redevelopment is sustainable only when it is a
transparent process protective of public health. The objective the brownfield health risk assessment matrix is
to provide a scientifically based, transparent process to
evaluate human health risks on proposed redevelopment
sites as well as a framework that can be critically
evaluated by both environmentalists and the community in
general. Public
discussion and understanding of current health risk
assessment, as well as the risks specific to each
brownfield redevelopment site, are essential for an
effective brownfield redevelopment program.
The Brownfields Redevelopment Program was started by EPA in
1995 and seeks to use already contaminated sites rather
than contaminate even more greenfields.
Two of the biggest difficulties are making
redevelopment profitable and protecting human health.
Traditional human health risk assessment evaluates
single chemical exposures and identifies the level below
which no adverse effect will occur to the most sensitive
subgroups of the population.
For cancer causing chemicals the risk must be lower
than 1:1,000,000. When brownfield redevelopment sites are associated with high
cost, extensive time and unmanageable uncertainty
additional greenfield sites will become contaminated and
the contamination on current brownfield sites will remain
un-remediated.
The citizens’ advisory group addressing brownfields in a
southern New York county has developed a risk banding
matrix to evaluate the uncertainty of the available data,
the toxicity of the known or suspected contaminants and
the likely exposure routes for each brownfield site in the
county. The
matrix categorizes sites as high, medium or low risk
according to exposure groups.
The risk matrix complements the triad approach
currently being developed by EPA to identify and manage
project decision uncertainties, addresses uncertainty as
well as toxicity and has the potential to reduce the cost
of traditional health risk assessment at brownfield
redevelopment sites.
Demystifying
Dioxin Data for the Environmental Decision-Maker
Nancy C. Rothman, Ph.D., New Environmental
Horizons, Inc., 34 Pheasant Run Drive, Skillman, NJ 08558,
Tel: 908-874-5686, Fax: 908-874-4786, Email: n.rothman@patmedia.net
Susan D. Chapnick, M.S., New Environmental Horizons, Inc.,
2 Farmers Circle, Arlington, MA 02474, Tel: 781-643-4294,
Email: s.chapnick@comcast.net
What is the difference between low resolution and
high resolution dioxin results?
What are “EDLs” and how do they differ from a
sample reporting limit?
Do EDLs have uncertainty?
If so, what is the source of the uncertainty and
are the non-detected results usable for environmental
decisions? Do detected dioxin results have uncertainty?
Will this uncertainty affect the way the data can
be used to make environmental decisions?
What is the “TEQ” and how is it derived?
These are basic, common questions that an
environmental decision-maker might ask in reviewing dioxin
results to compare to regulatory standards or to evaluate
potential risk to human health.
We will answer these questions and give key
information concerning dioxin analysis and interpretation
of results in terms of potential uncertainty that may bias
the resultant data. Topics
to be covered will include method issues that may affect
bias in results, reporting limit uncertainties (where they
come from and why this is a critical issue for data
users), and homologues versus specific isomers in terms of
toxicity interpretations.
Recommendations to reduce dioxin data uncertainty
will be given throughout the discussion.
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