Society of Environmental Toxicology and Chemistry – Hudson-Delaware Chapter
2008 Fall Workshop
Perspectives on Regulatory Criteria and Screening Levels
Based on Fish and Wildlife Tissue Residues
Wednesday, October 8, 2008
Rutgers University EcoComplex (Bordentown. New Jersey)
Presentation
Abstracts
Society of Environmental Toxicology and Chemistry – Hudson-Delaware Chapter
2008 Fall Workshop
Linking Fish and Wildlife Tissue Residues to Contaminant Concentrations in Water and
Sediment
David Glaser (QEA)
Critical body residues and dose-based toxicity reference values for bioaccumulative chemicals
must be translated into concentrations in the water and sediment in order to meet the
requirements of the Clean Water Act and in order to design effective sediment remediation
plans. Such translations have been performed in developing the Great Lakes Initiative water
quality criteria to protect wildlife; in developing human health water quality criteria; and in
performing remedial investigations for contaminated sediment sites. Approaches have ranged
from simple bioaccumulation factors to dynamic computer simulation models. This talk
focuses on considerations associated with the use of bioaccumulation factors (BAFs). BAFs are
site-specific primarily due to the nature of the food web and the fate processes that govern the
relationship in concentration between water and sediment. Consistency among regulatory
programs must be maintained: for example, fish advisories and water quality criteria for PCBs
are not always consistent. Achievability must be considered: current methods result in PCB
criteria (wildlife and human health) that are at or below the limits of detection and below
background levels. Finally, BAFs for other chemicals, exhibit additional site-specificity due to
variation in bioavailability; for mercury, methylation dynamics can affect the relationship
between total mercury in biota and in water dramatically.
Observations on the History and Utility of Tissue-Based Wildlife Critical Body Residues
(CBRs) for Regulatory Use
Tim Kubiak (United States Fish and Wildlife Service)
Risk from bioaccumulative compounds to upper-trophic-level wildlife receptors can be
evaluated either by developing an estimated daily dose (the amount of a contaminant ingested
in prey) that can be compared to literature-based toxicity reference values (TRVs; an ingested
dose causing measurable harmful effects), or by comparing tissue concentrations in uppertrophic-level wildlife species to literature-based CBRs. The history and utility of wildlife
critical body residues has been around in various forms for decades. As our analytical
capability improved and interpretive knowledge of exposures in target tissues as opposed to the
more historic norm of dietary doses, we have been able to utilize this information to construct
risk assessments, injury determinations for NRDAR, water quality standards and sedimentbased remediation goals. This can be accomplished by integrating CBRs with bioaccumulation
factors (BAFs), biomagnification factors (BMFs), biota / bedded sediment accumulation factors
(BSAFs) and to biota / suspended sediment accumulation factors (BSSAFs). This presentation
will address some of the history of body and tissue residues and the utility and uncertainty
reduction value of CBRs for regulatory use as a needed supplement to more traditional
approaches using TRVs.
Society of Environmental Toxicology and Chemistry – Hudson-Delaware Chapter
2008 Fall Workshop
Learning from Implementation of Wildlife Criteria in the Great Lakes
Kari Evans and Fred Andes (Barnes & Thornburg LLP)
In the early 1990s, U.S. EPA set out to develop wildlife criteria for mercury, PCBs, dioxin and
DDT for the Great Lakes System to fulfill Congressional obligations in the Clean Water Act.
Following adoption of the Great Lakes Initiative rulemaking, each Great Lakes state set about
considering these new wildlife criteria in implementation of Clean Water Act programs, such as
NPDES permits, listing of impaired waters, and development of total maximum daily loads.
This presentation will address the history of development of wildlife criteria for the Great Lakes
System in the early 1990s, including the admitted limitations and uncertainties in available
scientific knowledge. It will also explore the implementation issues that have arisen since
adoption of the criteria. When enacted, the criteria were below levels that could be detected by
available test methods. As new test methods were developed, it was discovered that
background levels exceed the criteria in many waterbodies. Furthermore, end-of-pipe treatment
technologies are extremely costly (millions of dollars per pound removed), and are unlikely to
meet the criteria even if affordable. These circumstances have lead states to develop
compliance options, such as statewide variances, to deal with unattainable standards. As we
revisit this history, we can learn a great deal about developing protective human health and
wildlife criteria that are also reasonable and attainable.
Overview of NJDEP’s Use of Fish and Wildlife Tissue Residues in Regulatory & Advisory
Programs
Gary A. Buchanan and Nancy Hamill (New Jersey Department of Environmental Protection)
A number of programs within the New Jersey Department of Environmental Protection
(NJDEP) are actively using fish and wildlife tissue residues for regulatory and advisory
purposes. Examples include programs responsible for remediation of contaminated sites, water
quality standards, damage assessments, dredging, and fish consumption advisories. Data uses
include decisions on remediation and disposal of sediments, development of water quality
criteria for the protection of human health and wildlife, habitat restoration, assessment of
commercial shellfish as well as sport-caught fish, permit support, and research.
The Site Remediation program uses tissue residues in three primary areas: ecological risk
assessment, preliminary remediation goals, and post-remedial monitoring. Ecological risk
assessment includes food-chain exposure modeling and evaluation of direct effects of tissue
contaminant residues. Fish and crustacean (e.g., crab) tissue residues are an integral part of
developing fish consumption advisories for the state. Since 2002, the NJDEP has sampled
more than 25 species of marine, estuarine and freshwater species as part of the Routine
Monitoring Program for Toxics in Fish. These data have been used to update the advisories on
a regular basis. An overview of these programs will be discussed and examples of how tissue
residue data are used will be presented.
Society of Environmental Toxicology and Chemistry – Hudson-Delaware Chapter
2008 Fall Workshop
Brominated Flame Retardants: The Human/Wildlife Connection
Rob Hale (Virginia Institute of Marine Science, College of William & Mary)
Polybrominated diphenyl ethers (PBDEs) are contemporary flame retardants that are
structurally similar to PCBs and PBBs. Despite being in use in the U.S. since the late 1970s,
the presence of PBDEs in the environment here went largely unnoticed until about 2000. The
compounds are now ubiquitous due to their persistence and widespread use. Some congeners
exhibit high bioaccumulation potentials. An incomplete picture remains as to the patterns of
PBDE burdens in abiotic compartments and in wildlife. Differences in PBDE accumulation
appear to exist between terrestrial (e.g. birds of prey) and aquatic (e.g. fish) organisms.
Regulatory limits have generally not been established, as our understanding of their modes of
toxicity and toxic body burdens continue to evolve. PBDEs have been used in consumer
products such as electronics and furniture at percent levels. Hence, sources and exposure risks
differ from those of historical industrial chemicals. The three commercial mixtures of PBDEs
(Penta, Octa and Deca) were used in varying products and behave differently in the
environment. Humans exhibit some of the highest body burdens, in part due to our proximity to
PBDE sources in the home and workplace.
Environmental fate and distribution of cyclic volatile methylsiloxane materials: Modeling
and monitoring data
Charles Staples1; Ellen Mihaich2; Kathy Plotzke3; Gary Koserski3; Shihe Xu3; Reinhard
Gerhards4; Joe Bazinet5
1. Assessment Technologies, Inc., Spotsylvania, VA, USA
2. Environmental and Regulatory Resources, Durham, NC, USA
3. Health and Environmental Sciences, Dow Corning Corporation, Midland, MI, USA.
4. Evonik Goldschmidt GmbH, Essen, Germany.
5. Clariant LSM Inc., Gainesville, FL, USA.
Low molecular weight cyclic volatile methylsiloxane (cVMS) materials are used in a wide
variety of consumer products and may be released to various environmental compartments. The
volatile cVMS materials have very low water solubilities and high Henry’s Law constants.
Together with their unique inter-compartment partition coefficients, these properties strongly
influence the behavior of these materials in the environment. Modeling data as well as
screening monitoring results will be presented to describe the fate and distribution of cVMS
materials released to the environment. Challenges of measuring unbiased environmental
concentrations of cVMS will be discussed. If released to air, cVMS materials appear to remain
in air and degrade by reacting with hydroxyl radicals. If released to water, cVMS materials
appear to be removed from the water column by volatilization, deposition to sediment, and
hydrolytic degradation. Because of the very low water solubility and high affinity for organic
matter, cVMS materials that do not evaporate from the water column or hydrolyze, deposit to
sediment and are predicted to be confined to the vicinity where released. (Sponsored by the
Silicones Environmental, Health and Safety Council).
Society of Environmental Toxicology and Chemistry – Hudson-Delaware Chapter
2008 Fall Workshop
Considerations for scientifically rigorous development and application of critical body
residues in ecological risk assessment
Jennifer Sampson, Judi Durda, and Leslie Williams (Integral Consulting Inc.)
Critical tissue residues (CTRs) can be applied effectively to ecological risk assessment (ERA)
and natural resources damage assessment (NRDA), but the scientific strength of the supporting
study or studies and the toxicological relevance of the CTR must be carefully vetted. For
application to ERA and NRDA, any published study should provide detailed methods, indicate
controlled exposures, and provide treatment replication and reasonable statistical certainty.
Ideally, any individual study should provide both a no-observed-adverse-effects-level
(NOAEL) and a lowest-observed-adverse-effects-level (LOAEL). For CTRs, their toxicological
relevance must be evaluated, or risk assessors and regulators may generate more uncertainty
than they resolve. Ecologically meaningful CTRs can be derived for chemicals when the
toxicological mechanism is understood, the tissue concentration is expressed in the appropriate
terms (e.g., lipid normalized for hydrophobic organic compounds), the study provides adequate
time to estimate a steady state in the tissues of tested organisms, and there’s evidence of a
concentration-response relationship. Under these circumstances, single-value CTRs can be
derived; data from multiple studies meeting these standards can be aggregated to derive species
sensitivity distributions to help address species not directly represented in the literature.
Requiring scientific rigor in derivation and application of CTRs for risk assessment creates a
high threshold of acceptability, but provides more meaningful predictions and improved
confidence. In the absence of such rigorous information, alternative lines of evidence should be
pursued.