Program - Society of Toxicology

44 th Annual Meeting
and ToxExpo
Program Description
MONDAY
Monday Afternoon, March 7
4:30 PM to 6:00 PM
Room RO6
SUNSET SESSION: BROMINATED FLAME RETARDANTS: NEW
FINDINGS
Chairperson(s): Arnold Schecter, University of Texas School of Public Health,
Dallas, TX and Linda Birnbaum, U.S. EPA, Research Triangle Park, NC.
Endorsed by:
Neurotoxicology SS
Occupational and Public Health SS*
Reproductive and Development SS
Risk Assessment SS
The brominated flame retardants are new potential public health hazards. They
resemble PCBs and are found worldwide. They can be found in carpets, styrofoam,
and in household and office electrical equipment. Brominated flame
retardants (BFRs), especially the common polybrominated diphenyl ethers
(PBDEs) have recently been reported in humans at markedly increasing levels
in blood and milk. The highest levels in humans and food worldwide have been
reported in US samples. Studies of milk report 10-100 times higher levels in US
than in European women. US food levels are highest in fish, then meat, and
finally dairy. All human and food samples measured to date are contaminated
with many of the 13 commonly reported PBDE congeners, although the
congener pattern can vary in different specimens. Blood and milk levels in the
USA are currently similar. PBDEs cannot be measured in 1973 blood, and are
increasing markedly in humans in the USA (at the same time dioxins and PCBs
are decreasing). No human health studies of these compounds have been
published but cell culture and laboratory animal studies suggest certain adverse
health effects, similar to those reported for PCBs which the PBDEs structurally
resemble. New findings will be presented for human tissue levels and food
levels in the USA and worldwide in the general population and in specially
exposed workers. The uncertainty regarding toxicity of various congeners will
be reviewed and compared to the dioxin toxic equivalency factor concept. No
such toxicity comparison factors are available for the PBDEs at the present time
making it difficult to decide which congeners should be measured. There is
currently no consensus on which to be measured; this topic will be reviewed and
recommendations made. Temporal trends in human PBDE levels will be
presented and compared with temporal trend for dioxins, dibenzofurans and
PCBs. New toxicological findings with respect to pharmacokinetics, neurological,
reproductive and developmental, endocrine, and cancer endpoints will be
presented. Finally, human risk assessment will be considered.
#309 4:30 BROMINATED FLAME RETARDANTS: NEW
FINDINGS. L. Birnbaum 1 and A. J. Schecter. 1 U.S.
EPA, Research Triangle Park, NC and 2 Environmental
Sciences, University of Texas School of Public Health,
Dallas, TX.
#310 4:40 PBDES IN US HUMANS, FOOD AND
ENVIRONMENTAL SAMPLES. A. J. Schecter 1 , O.
Paepke 2 , J. Ryan 3 , L. Birnbaum 4 , D. Staskal 5 and K.
Tung 1 . 1 Environmental Sciences, University of Texas
School of Public Health, Dallas, TX, 2 ERGO
Laboratory, Hamburg, Germany, 3 Health Canada,
Ottawa, ON, Canada, 4 U.S. EPA, Research Triangle
Park, NC and 5 UNC, Chapel Hill, NC.
#311 4:55 TOXICOKINETICS OF BDE 47 IN MICE. D.
Staskal 1 , J. J. Diliberto 2 , M. J. DeVito 2 and L. S.
Birnbaum 2 . 1 UNC Curriculum in Toxicology, Research
Triangle Park, NC and 2 ETD, NHEERL, ORD, U.S.
EPA, Research Triangle Park, NC.
#312 5:10 DEVELOPMENTAL NEUROTOXICITY OF
PBDES IN MICE AND RATS. H. Viberg, A.
Fredriksson and P. Eriksson. Environmental Toxicology,
Uppsala University, Uppsala, Sweden.
#313 5:25 PBDE LEVELS AMONG US WOMEN, DAILY
INTAKE AND RISK OF HARM TO THE
DEVELOPING BRAIN AND REPRODUCTIVE
ORGANS. T. A. McDonald. Office of Environmental
Health Hazard Assessment, California Environmental
Protection Agency, Oakland, CA. Sponsor: L. Zeise.
Monday Afternoon, March 7
4:30 PM to 6:00 PM
Room RO8
SUNSET SESSION: DEVELOPMENTAL TOXICOLOGY
EVALUATIONS: ISSUES WITH INCLUDING NEUROTOXICOLOGY
AND IMMUNOTOXICOLOGY ASSESSMENTS
Chairperson(s): Gregory S. Ladics, DuPont Co., Newark, DE and Leigh Ann
Burns Naas, Pfizer, Inc., San Diego, CA.
Endorsed by:
Immunotoxicology SS*
Neurotoxicology SS
Risk Assessment SS
Evaluation of offspring following maternal exposures during gestation and
lactation (i.e. reproductive/developmental toxicology [RDT]) has historically
been a routine part of the safety assessment process. Recently, increased attention
has focused on the effects of agricultural and industrial chemicals, as well
as pharmaceuticals, on the developing nervous and immune systems of the fetus
and newborn. This new focus on developmental neurotoxicology (DNT) and
developmental immunotoxicology (DIT) is based on the premise that the developing
nervous and immune systems may be qualitatively and/or quantitatively
more susceptible to chemical perturbation compared to the adult and studies
conducted currently may be insufficient to protect the young. DNT studies have
become common for agricultural chemicals, following the preparation of test
guidelines from the U.S. EPA (OPPTS 870.6300, 1998) and OECD (TG 426,
draft). With increased DNT testing and the prospect of new DIT test guidelines,
there has been considerable interest in both DNT and DIT, with many scientific
workshops, roundtables, symposia, as well as sponsored research devoted to the
subjects. The intent of this session is to highlight and discuss issues that are
common to RDT, DNT, and DIT, including the consequences of high dose selection
and maternal toxicity; the adequacy of pup exposure during lactation;
whether a different dosing paradigm should be applied to RDT vs. DNT or DIT
studies; whether DIT and DNT endpoints can be incorporated into a single
(RDT) study for hazard identification purposes (e.g., for screening purposes,
what endpoints have proven their value and should be retained). This session
will provide a forum to discuss how assessment of RDT, DIT, and DNT could
be integrated for hazard identification purposes and to reduce animal usage.
#314 4:30 DEVELOPMENTAL TOXICOLOGY
EVALUATIONS: ISSUES WITH INCLUDING
NEUROTOXICOLOGY AND
IMMUNOTOXICOLOGY ASSESSMENTS. G. S.
Ladics 1 and L. Burns-Naas 2 . 1 DuPont Co., Newark, DE
and 2 Pfizer, Inc., San Diego, CA.
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SOT’s 44 th Annual Meeting