1. Health Assessment and Contaminants:
Workshop on pathways of human exposure
Juliana Grant, MD MPH
Agency for Toxic Substances and Disease Registry
Regional Representative - Alaska

2. Outline
Introduction to health assessment and pathways of human exposure
Case study
Applying exposure pathways
Additional resources

3. Public Health Assessment
ATSDR term for process of evaluating environmental contaminants and determining whether they are impacting human health
Multi-step process
Includes evaluating pathways of human exposure

4. Are humans exposed? Gold ore smelter Mercury released in smoke
Acidic wastewater released into river
Are humans exposed?

5. Pathway of Human Exposure
Describes how people come into contact with contaminants from a specific source
Useful for
Understanding exposures
Doing environmental sampling
Developing interventions

6. No one drinks from it or swims in it
Example pathways
Breathing
Smoke
Air
Nearby residents
No one drinks from it or swims in it
No one exposed
Waste water
River

7. Parts of pathways Source Media Point of exposure Route of exposure
Exposed population

8. Parts of pathways Source Media Point of exposure Route of exposure
Exposed population
What
How
Who

9. Example parts of pathways
Source
Media
Point of exposure
Route of exposure
Exposed population
Drums
Old buildings
Oil spill
Lead paint
Air
Soil
Water
Food
At home
Schools
At mine or dump site
Breathing
Eating
Contact with skin
School children
Workers
Subsistence users
Everyone

10. Case study: Open dump site
What exposures from the Toksook Bay dump site are you most concerned about?

12. Applying exposure pathways
Clear description of potential exposures
Which contaminants are most concerning
Examine how contaminants change as they move through environment
Environmental sampling
Where, When and What to sample

13. Applying exposure pathways
Interventions
Remove any part of pathway and exposure stops
Information gaps
What do we not know?
Analyzing environmental data
If exposure pathway is complete, is the exposure dangerous?

14. More information ATSDR website (www.atsdr.cdc.gov)
Public Health Assessment Guidance Manual
ToxProfile
ToxFAQs

15. Juliana Grant 907-271-4073 jgrant@cdc.gov www.atsdr.cdc.gov
Thank you!
Juliana Grant

16. Dump site example Complete pathway Source Media Point of exposure
Route of exposure
Exposed population
Trash at dump site
Smoke from burning
School children
Nearby school
Breathing
Complete pathway

17. Only burn when wind blowing away from school
Dump site example
Source
Media
Point of exposure
Route of exposure
Exposed population
Dump site
Smoke from burning
Only burn when wind blowing away from school
Incomplete pathway