Emerging Issues in Exposure Assessment

1
Emerging Issues in Exposure Assessment

• Elizabeth Pullen, CIH
• Chair, EASC

2
EASC Emerging Issues

• Mathematical modeling
• Dermal exposure assessment
• Integration with other methodologies
• E. A. for chemicals without OELs
• HPV chemicals lack of exposure knowledge
• Biological exposure assessment - molds
• Ways to better implement E. A. programs

3
Mathematical Modeling

• Need for
• Data to validate existing air concentration
  models
• data experimentally generated or derived from
  real-world data
• Funding for opportunities to generate data to
  validate (either confirm or deny) the accuracy of
  the models

4
Mathematical Modeling

• Conventional approach to validating models?
• As predictive models are increasingly used, how
  will the need to objectively evaluate the
  appropriate use of the tools be met?

5
Mathematical Modeling

• Dermal exposure models
• AIHA WEEL committee is looking at setting BEELs,
  based on dermal exposure and absorption data
• Need to develop models to estimate the
  quantitative transfer of agents from the
  environment to the skin and kinetics of the
  subsequent penetration through the skin

6
Mathematical Modeling

• PDCs and Educational Tools
• Due to growing demand (due in part by EPAs HPV
  and VCCEP programs), there is a need for
• Courses and tutorials
• Peer review of educational tools
• Incorporation of modeling algorithms into
  computer programs
• Simple computer tools that make it easier to use
  these models

7
Mathematical Modeling

• Recognition of the value of models in E..A.
• Subcommittee has doubled in size in the last 2
  years, which is an indication of the need for
  more modeling knowledge
• Need to better communicate the value of modeling
  and when / where / how to apply the models

8
Mathematical Modeling

• Stochastic (i.e. random, probabilistic) processes
  underlie exposure models
• All exposure assessment and modeling uses
  statistical estimation of parameters best derived
  from a modeled stochastic process
• This is a conceptual tool successfully used in
  many engineering problems, but its importance is
  overlooked in some EHS models

9
Dermal Assessment - Goals

• Create broader understanding of dermal E.A. and
  how it can be used to build a more comprehensive
  E.A. program
• Determine how Dermal E.A. fits into the AIHA
  model, and then modify the model as needed to
  address the issues of dermal exposure assessment

10
Dermal Assessment Next 5 years

• Evaluate routes of Dermal Exposure
• Develop appropriate definitions of health
  outcomes related to Dermal Exposure
• Integrate Dermal E.A. techniques more seamlessly
  into the overall E.A. process
• Develop applied guidance on Dermal E.A. that EASC
  can provide to the IH community

11
Dermal Assessment Issues

• Determine state-of-the-art in Dermal E.A.
• evaluation techniques, strategies, research needs
  and existing models
• Determine what gaps in knowledge exist
• Identify or develop quick, straight-forward
  assessment techniques for dermal hazards, general
  rules of thumb, prioritization schemes, and/or
  surrogate techniques for assessing dermal hazards
  

12
Dermal Assessment Issues

• Consider the establishment of Dermal OELs
• versus
• Validating controls
• Evaluation of the ALARA concept and its
  application to dermal exposure
• Examination of other surrogate techniques (i.e.
  fluorescence)

13
Dermal Assessment - Ways to Address Issues

• Utilize Dermal E.A. experts to identify new
  research and new E.A. methodologies that are
  available or under development
• Collaborate with those experts to develop quick,
  straight-forward Dermal E.A. techniques
• Consider the establishment of dermal OELs versus
  the other methods of control

14
Dermal Assessment - Potential New Jobs or
Specialty Areas

• Creation of additional positions in Dermal Risk
  Assessment, at university / research level and at
  field assessment level
• Dermal E.A. is currently under-explored, with
  tremendous opportunity for new jobs, new
  technologies and a better understanding of the
  likelihood of dermal exposures to a wide variety
  of substances

15
Integration with other methodologies

• How to integrate the traditional AIHA approach
  with other accepted methods, such as the COSHH
  Essentials
• COSHH focuses more on methods of control based on
  the qualitative assessment, and utilizes
  task-specific control guidance sheets (for common
  factory tasks)
• Where could AIHA incorporate these ideas to help
  small and medium sized businesses

16
E. A. for chemicals without OELs

• AIHA method is based on evaluating chemicals with
  OELs
• How do we assess the many thousands of chemicals
  without OELs?
• Should we use a banding approach, similar to
  whats used in Europe and some pharmaceutical
  industries?
• Are there other ways to evaluate them?

17
HPV Chemicals

• High Production Chemical Initiative will be
  generating lots of toxicity data in the next 5
  years
• Many of those chemicals lack exposure data, to
  adequately evaluate the overall risk of exposure
  to those chemicals
• EASC, Risk Assessment and Tox Committees are
  jointly working on this issue to help educate IHs
  on how to use the new data

18
Biological Exposure Assessment

• Increase in awareness of health hazards of molds
  has increased the need for systematic methods to
  properly assess potential exposure to molds
• Need to work with Biological Monitoring committee
  to incorporate valid methodologies into the
  comprehensive Exposure Assessment process and
  communicate to IHs

19
Ways to Better Implement E. A.

• Develop practical, easy-to-use guideline for
  smaller companies with limited resources to use
• Find ways to make E. A. practical to implement in
  complex situations, such as batch plants and
  research laboratories that handle hundreds to
  thousands of chemicals in numerous tasks