Scientific & Technical Support: Components of Human Health Risk Assessment
Assessing the potential health risks associated with chemical exposure in air,
food, water, occupational, domestic, or recreational environments has become an
issue of critical importance to the registration, regulation and safe use of
commercial chemical products. A thorough understanding
of
potential health risks is also important in liability determination and in toxic
tort litigation.
TSG's outstanding team of fully accredited toxicologists
are highly skilled in the four basic components of risk assessment — hazard
identification, dose-response determination, exposure assessment and risk
characterization — and fully conversant with applicable regulatory guidelines
and procedures. TSG specializes in unique, custom-designed assessments employing
alternative methodologies most suited to the proper resolution of specific
problems.
Hazard Identification
Complete, qualitative understanding of the major types of toxic effects
inherent in a given chemical typically requires the identification, careful
review, interpretation and evaluation of a
large
and diverse amount of highly specialized data. TSG has direct access to a
wide variety of electronic databases which provide a rapid and effective
means of searching peer-reviewed scientific literature and identifying
toxicity studies which will support regulatory strategy.
TSG's
toxicology staff has many years of experience in the evaluation and
interpretation of data from in vivo, in vitro, and mechanistic studies,
employing a total-weight-of-evidence approach to develop an overall
toxicological profile. While fully adhering to the appropriate evaluation
criteria, TSG makes full use of newly emerging information from the
scientific community and developing advances in evaluation and assessment
methods.
Dose-Response Assessment
TSG's consulting staff has
outstanding experience in determining dose-response relationships from
animal studies and in extrapolating such data to humans. TSG determines
NOEL-based reference doses and uses a number of models to develop cancer
potency factors from chronic oncogenicity data. In conducting dose-response
assessment, TSG employs scientifically rigorous approaches and
state-of-the-art methodologies, including:
▲ Mechanistic information
▲
Pharmacokinetic modeling
▲ Meta analysis
Exposure
Assessment
TSG offers clients extensive experience in multimedia
exposure assessment to
pesticides and other chemicals and utilizes the most
advanced software, databases and methodologies available, including its own
DietRisk© software for dietary exposure/risk assessments of
pesticide
residues in food. Members of TSG's staff were also instrumental in
developing the EPA-approved Pesticide Handler's Exposure Database (PHED) and
have expertise in using this database to provide information on exposures
during mixing/loading and application operations. The range of programs
offered by TSG allows selection of the model best suited to the client's
needs and, at the same time, increases the accuracy and decreases the
uncertainty in the exposure assessment process.
Risk
Characterization
Risk characterization conveys the presence or
absence of risks, along with information about how the risk was assessed and
where uncertainties or assumptions still exist. With extensive experience in
all facets of human risk characterization, TSG continuously seeks to develop
and use new techniques that improve the level of confidence of the risk
assessment. TSG also defines and quantifies uncertainty, including
route-specific pharmacokinetic considerations, less-than-lifetime exposure
and risk estimations, and distributionally based approaches for
exposure/risk analysis and for quantifying uncertainties.
