Transcript of 40 Years of Exposure and NOW the “New Exposure Science”
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40 Years of Exposure and NOW the New Exposure Science
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Office of Research and Development 2 A little history What is
the new exposure science What do we need to do to move it
forward
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Office of Research and Development 3 40 Years was a long time
ago!! Me Computational Methods Visualization Communication
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Office of Research and Development 4 My First Foray into
Exposure Science The opportunity: Analytical chemistry was for the
first time good enough to measure many, many chemicals in the
environment The time: 1976 The place: MIT The mentor: Ron Hites The
problem: The Delaware River
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Office of Research and Development 5 Organic Chemicals in the
Delaware River-- Results Hundreds of chemicals identified Naturally
occurring, municipal discharge, and industrial chemicals Industrial
chemicals were of three types General urban pollution Industrial
sources Specific sources Rohm &Haas chlorinated reaction
products of pesticide manufacturing Controversy Rohm & Haas
Impact final piece of information for replacing the water treatment
system in Philadelphia
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Office of Research and Development 6 A quick trip though the
last 40 years Why is human exposure science so narrow point of
contact? Why hasnt it taken a systems approach to the science? The
way modern exposure science started explains but it should and is
evolving Systems approaches will be key to the future
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Office of Research and Development 7 Human Exposure Science in
the 80s Humans are at risk to stressors (mostly chemical) because
of what they come in contact with Reducing exposure is a way to
protect health Many surrogates were used to estimate exposure and
dose Ambient monitors Source emissions Simple questionnaire
Analytical chemistry was good enough to test hypotheses about
surrogates for exposure and determine what was important
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Office of Research and Development 8 Seminal Research: TEAM
Studies 1979 to 1985 Measured 20 volatile organic chemicals in
outdoor air, indoor air, personal air, and drinking water Samples
collected daytime and nighttime over 2 seasons Over 600
participants from Elizabeth/Bayonne NJ Contra Costa County, CA
Devils Lake, SD Greensboro, NC Participants selected to represent
the population in each area Hypotheses: People in most polluted
areas should have highest exposure.
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Office of Research and Development 9 TEAM Study Findings No
matter where you lived Personal exposures > indoor >outdoor
Personal concentrations were 5 to 10 times higher than outdoors For
many chemicals correlations between outdoor air and personal
exposures were poor Conclusions Indoor environments and activities
were significantly more important than environmental
concentrations
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Office of Research and Development 10 Thus began our obsession
to understand the Indoor environment, activities, point of contact
and Research to improve the estimates for exposure
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Office of Research and Development 11 Many Field Studies and
Emission Tests Later Tens of thousands of participants in field
studies General population Life stages children and elderly
susceptibilities Hundreds of materials and products testes
Different chemicals PAHs, phthalates, PM, VOCs, aldehydes,
pesticides, CO, NO2 Different Matrices water, air, soil, dust,
food, wipes, and biological samples Different Settings homes,
schools, vehicles, offices, hospitals California, New York, Texas,
Virginia, Massachusettes
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Office of Research and Development 12 To name a few studies
TEAM Nursing Mothers study EPA Indoor Air study CARB VOC Exposure
Study CARB PAH and Phthalate Study EPA PTEAM CARB PAH Indoor Air
Study CARB Commuter Study SoCAL School Study EPA NHEXAS EPA
Agricultural Health Study EPA Brownville Study NYSERDA Exposure to
Combustion Products NYSERDA Radon Study Cal Public Heath Trust
Emissions Study PM Panel Studies
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Office of Research and Development 13 And some Kids Studies
Childrens Total Exposure to Persistent Pollutants (CTEPP) First
National Environmental Health Survey of Child Care Centers (CCC)
American Healthy Home Study (AHHS) Biological and Environmental
Monitoring for Pesticide Exposures in Children Living in
Jacksonville, Florida (JAX) Agricultural Community Exposure Study
(CHAMACOS) Childrens Pesticide Post-Application Exposure Study
(CPPAES) Feasibility of Macroactivity Approach to Assess Dermal
Exposure (Daycare) Distribution of Chlorpyrifos Following a Crack
and Crevice Type Application in the US EPA Indoor Air Quality Test
Research House Characterizing Pesticide Residue Transfer
Efficiencies (Transfer)
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Office of Research and Development 14 The Science (methods and
knowledge) was being built Results showed strong influence of the
built environment and activities in the environment on exposure
Materials Product Use Combustion sources Human activities are
critical to exposure The environments we live in The products we
use Our contact with chemicals Building construction and operation
are important for both ambient and indoor pollutants Understanding
was summarized in models both processes and inputs
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Office of Research and Development 15 Crucial Impacts Many
toxic chemicals were taken out of products and materials PM
exposure studies supported the science behind the 1997 PM NAAQS PM
at ambient sites can be used to predict personal exposure Studies
provided important understanding, data, and models for estimating
kids exposure for FQPA Information used to delist certain
pesticides for indoor applications
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Office of Research and Development 16 Dose at the target Linked
Exposure/PBPK Models PBPK/PD Model Tissue metric distributions
Biomarker distributions Activity and environmental concentration
distributions Exposure pathways lung brain kidney stomach skin
liver Exposure Model
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Office of Research and Development 17 Internalizing exposure
Biologically effective dose Exposure as Part of a Systems Approach
for Assessing Risk Linda S. Sheldon1 and Elaine A. Cohen Hubal2
1National Exposure Research Laboratory, and 2National Center for
Computational Toxicology, U.S. Environmental Protection Agency, A
biomonitoring framework to support exposure and risk assessments
Jon R. Sobus, Yu-Mei Tan, Joachim D. Pleil, Linda S. Sheldon
National Exposure Research Laboratory, Office of Research and
Development, U.S. Environmental Protection Agency, Adapting
concepts from systems biology to develop systems exposure event
networks for exposure science research Joachim D. Pleil*, and Linda
S. Sheldon National Exposure Research Laboratory, Office of
Research and Development, U.S. Environmental Protection Agency, The
endpoint for exposure is biologically effective dose Integrated
models can predict exposure and dose at the target organ, cell, AOP
are needed
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Office of Research and Development 18 New Exposure Science We
were developing Methods, data, and models to understand exposure It
was useful and having impact But we needed more, much more And a
transformative change was needed
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Office of Research and Development 19 It is important. Exposure
science provides real world context for describing risk,
well-being, and sustainability Complex societal problems and
growing demand for information to address Climate change, Security
threats, Population pressure Habitat loss, Increases in childhood
illness Advances in measurements and computational techniques
provide new tools EPA with NIEHS commission an NRC report to
provide a transformation for exposure science Used as a catalyst to
develop a new science Drivers for a New Exposure Science
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Office of Research and Development 20 Changes the perspective
on exposure science and how it is conducted Extends beyond the
exposure event to the transport and transformation of agents from
their source to a dose Is multi-scale and includes multiple
stressors across scales of time, space, and biological organization
Exposure science must deliver knowledge that is effective, timely,
and relevant Provides a Conceptual Systems Framework for exposure
science Stresses collaborations within and outside the Federal
Government should be developed Concepts in the NRC Report
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Office of Research and Development 21 stressors as well as
receptors Actions or Events Disasters Climate change Market demands
Population growth Policy decisions 1 Health Function Service
Societal Demands Dynamic System *Adaptation from NRC Report in red
Role of Human Activities NRC Report: Conceptual Systems
Framework
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Office of Research and Development 22 NRC Vision: Use advanced
technologies to move the science forward Methods to track sources,
concentrations and receptors at multiple scales Remote sensing
Ubiquitous and embedded sensing Biomonitoring Methods and Tools for
Analysis Geographic Information Systems Multi-scale exposure
modeling Statistical methods and tools for predictive modeling
Informatics Information Management Publicly available systems for
data sharing Community Engagement and Promoting Public Trust
Protecting research volunteers Managing issues of privacy Citizen
Science
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19952014 and beyond Field/Lab direct measurements
Omic/informatics/sensors/ Computational predictive measurements
Stand alone empirical models Integrated systems & Predictive
models Targeted chemical exposure modeling High through-put
exposure modeling Gathering dataMining data New Exposure Science
Transition in Research
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Office of Research and Development 24 Cool Tools but with a
purpose Broaden Scope Increase Pace Improve Accuracy Increase
Public Engagement Reduce burden/cost
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Office of Research and Development 25 EPA Exposure Summit Goal
to understanding the new science, its value to EPA, and what needs
to be done to implement Exposure Speed dating on the New Science
Sensors for Air Monitoring Ubiquitous Sensing Biomonitoring New
Methods to Extend Analytical Space New Data sources Twitter,
Nielsen, Apps Rapid computational Exposure Models - computationally
lean and linked models All can be found on
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Office of Research and Development 26 Ubiquitous Sensing
Methods of obtaining information about an object within coming in
contact Rapid, cheap, real-time, field-deployable Public engagement
Water quality measures such as turbidity, chlorophyll-a,
cyanobacteria, etc. Unexpected capabilities: crowd sourcing Low
[conc] High [conc] Grand Lake St. Mary in 2010. Satellite derived
cyanobacteria indices are consistent with Ohio EPA samples. Ohio
EPA sampled for microcystin blooms on June 14 th and concentrations
jumped from
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Office of Research and Development 27 Applications to Air
Pollutants Collaborations with NASA to improve use of satellites
for health applications Discover AQ and Tempo Joint research to
develop/evaluate air quality parameters using satellite data
Provide data for improving fine-scale air quality simulations NASA
P-3B NASA King Air EPA, Sate, Local, and temporary Ground
sites
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Office of Research and Development 28 Untargeted Analysis
extends limited analytical space Testing Feasibility of Application
to Environmental Samples Chemicals for risk assessment and
regulation are often driven by Analytical Space Analytical Space
has been gradually increasing for the past 40 years Advanced MSTOF
methods have been applied to tens of thousands of chemicals in
biological samples We are now applying these methods to
environmental samples
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Office of Research and Development 29 House-Dust or Water
Sample Dust samples (~50) from National Homes Survey TOFMS +/-
SCREEN Easier More Difficult Most Difficult Presence of a DB
matched peak Presence of a confirmed compound Quantitation of a
compound Yes/No Analysis Approaches --ALL ARE POSSIBLE Water -Polar
Organic Chemical Integrative Sampler (POCIS)
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Office of Research and Development 30 Summary of number of
peaks during 45min running by Liquid Chromatography/Time-of-Flight
MS
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Office of Research and Development 31 Computational Exposure:
Integrating Disparate Data Streams and Models to Rapidly Predict
Exposure to Chemicals Integrated HT Models Fate and Transport Human
Behaviors and Exposure Factors Multiple Scenarios
Extensible/Scalable Exposures and Doses Sensitivity and Uncertainty
Chemical Functional Use Chemical Functional Use Chemical Structures
Chemical Structures Consumer Product Characterization Consumer
Product Characterization Consumer Product Use Consumer Product Use
Population Characterization Population Characterization Exposure
Scenarios/Equations Exposure Scenarios/Equations Composition/
Emission Sources Composition/ Emission Sources Prevalence,
Frequency, Amount Prevalence, Frequency, Amount Demographics,
Behavior, Physiology Demographics, Behavior, Physiology
Population-level Evaluation And Calibration Case Study Evaluation
Chemical Properties Chemical Properties QSAR
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Office of Research and Development 32 Framework for
Computational Exposure 32 Framework requires information on
Physical Chemical properties that drives fate and transport methods
to predict stochastic decisions that drive human behaviors
important for chemical use and exposure Current focus on consumer
use chemicals highest human exposure potential
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Office of Research and Development 33 SHEDS-HT: Merging
Multiple Data Streams to Produce Exposure Predictions for 1000s of
Chemicals Exposures By Lifestage
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Office of Research and Development 34 Moving the Science
Forward
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Office of Research and Development 35 Exposure is contact of a
stressor at the external boundary of a receptor Exposure Science is
the collection and analysis of information to understand the nature
of the contact chemical, physical, and biological stressors
Exposure is the experience of the environment Includes both human
and ecological receptors Must describe the entire environment
including both positive and negative stressors Embraces the idea of
cumulative impacts Suggests a dynamic system Allow us to grow along
the trajectory from Should the Definition be Changed? Risk - Impact
of negative stressors Well-being -Impact of positive And negative
stressors Sustainability -For current and future generations
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Office of Research and Development 36 Fundamental Principles
Early findings must be transmitted and retained Importance of
indoor environments and products to humans Computational exposure
efforts PFOS/PFOA Individual vs. population exposure and
riskdifferent goal and different requirements Standards and
ontologies preliminary work should be extended Standard methods Air
infiltration methods Biomonitoring collection methods ISES COULD
PLAY A MAJOR ROLE IN THESE
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Office of Research and Development 37 New Science must be
evaluated Difficult but needed not just method evaluation but
evaluation of the data relative to the intended use Computational
Exposure example Identify and acquire multiple data streams
traditional or nontraditional; of known or potential value Combine
data streams to estimate exposure/dose for large set of chemicals
(not one at a time) Evaluate exposure/dose estimates for chemical
sets vs. known estimates; Identify key data limitations and sources
Iterate process Biomonitoring as an exposure metric
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Office of Research and Development 38 Big Data Crucial to
Exposure Science especially data on activities However society, in
general, is struggling with privacy and accessibility So, what data
will be most useful, how can we use it without and identifiers, how
do we protect human subjects, how do we apply this data to
populations How do we make all data accessible ISES COULD/SHOULD
PLAY A MAJOR ROLE IN THIS
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Office of Research and Development 39 Exposure Science MUST be
Multidisciplinary Human and Eco Exposure Scientist and Toxicologist
Air Modelers and Epidemiologist Exposure Science and Life
Cycle
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Office of Research and Development 40 These are exciting times
with many, many new tools that will allow us to do things we have
never done before We need to learn how to use them and demonstrate
how they can be applied As you move forward BE BOLD, BE INNOVATIVE,
BE SMART, COMMUNICATE, COMMUNICATE, COMMUNICATE
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Office of Research and Development 41 Nothing presented here
was done alone, Many, Many Thanks to all I have collaborated
with