Technical Work Group

1

Pollutant Scope and Setting Concentration Levels

June 29, 2016

Pollutant Scope and Setting Concentration Levels

2

Scope of Pollutants • What pollutants and why • Concentration averaging times

Setting Concentration Levels

• How risk-based concentrations are calculated • Inclusion of multiple exposure pathways

What air toxics are included in other programs?

3

Regulated in California

Federally Listed Hazardous Air Pollutants

Regional Concerns

Evaluated by Workplace Safety and

Public Health Agencies

Regulated Pollutants

Fees

Permitting

Reporting

What is the basis for including or excluding pollutants?

4

Monitored at levels of

concern

Modeled at levels of concern

Designated high priority by other agencies

Listed by EPA

Significance to public health

Federally regulated

Based on program structure

Broad Definition

Other states

State specific

Federal agencies

Highly Inclusive

What are the pros and cons for different groups of pollutants?

5

Considerations: • Ability to focus on and prioritize problem pollutants • Flexibility to address new pollutants of concern • Certainty/Predictability • Complexity for users • Workload to update and maintain • Links pollutants to program structure or needs

What are the pros and cons for different groups of pollutants?

6

1. Significance to public health

Monitored at levels of

concern

Modeled at levels of concern

Designated high priority by other agencies

What are the pros and cons for different groups of pollutants?

7

Broad Definition

Other states

State specific

Federal agencies

2. Highly Inclusive

What are the pros and cons for different groups of pollutants?

8

Listed by EPA

3. Federally regulated

What are the pros and cons for different groups of pollutants?

9

4. Based on program structure

Regulated Pollutants

Fees

Permitting

Reporting

What risk-based concentration (RBC) averaging times do

other programs use?

Annual to lifetime duration

• cancer effects

• chronic non-cancer effects

Short-term duration

• 24-hr exposure

• 8-hr exposure

• 1-hr exposure

10

Importance of RBC averaging times?

Averaging time should be relevant to exposure duration

and/or modeling/monitoring period

• Comparing a sample collected over 24 hours to a chronic protective

value will be very conservative, likely over-conservative.

• RBC values generally increase as averaging times decrease.

What modeling/monitoring durations are currently used

by Oregon’s program?

• Has been 24-hour and annual durations

11

What are the advantages and limitations of shorter-

term RBCs?

12

Considerations: • Protectiveness against high

intensity, short-term exposures

• Context for short-term monitoring results

• Difficulty of finding/deriving/maintaining short-term RBCs

Pros and Cons of Shorter-Term RBC’s?

13

Advantages/limitations of using cancer risk as a

basis for short-term RBCs?

Considerations

• Some programs use Occupational Exposure Levels as basis of

short term RBCs, many of which are based on cancer

• Scientific certainty about effect of short term exposure on

overall lifetime cancer risk

14

Pros and Cons of using cancer risk as a basis for

short-term RBCs?

15

Topics for July Technical Workgroup Meeting

discussions:

• Pros and Cons of methods other programs use for setting

RBCs

• Advantages/limitations of adjusting RBCs for cross-media

exposure pathways?

16

Pollutant Scope & Setting Concentration Levels

Final thoughts?

• Any last questions?

• Do we need further discussion in July?

17