Farfield Exposure: Bringing the Environmental Elements into ComET™ – Estimating Emissions Dr. Michael Jayjock The LifeLine Group Slides and Materials Copyright Protected

Recap -The Two Parts of ComET™ The Nearfield part of ComET™ estimates exposure from Sentinel Products from the personal use of Consumer Products. The Nearfield part of ComET™ estimates exposure from Sentinel Products from the personal use of Consumer Products. The Farfield ComET™ portion estimates exposure to man to the DSL substance from environmental sources. The Farfield ComET™ portion estimates exposure to man to the DSL substance from environmental sources. Total human exposure to the DSL substance is the sum of the two. Total human exposure to the DSL substance is the sum of the two.

s s s s Small Sources within the Microenvironment (Nearfield) Large but distant Environmental Sources (Farfield)

Glossary of Terms in this Talk De minimus – a small and relatively insignificant part or portion of the total human exposure estimated for the DSL substance. De minimus – a small and relatively insignificant part or portion of the total human exposure estimated for the DSL substance. NFComET™ – Portion of ComET™ that estimates human exposure to DSL substances from products used near the person (Nearfield). NFComET™ – Portion of ComET™ that estimates human exposure to DSL substances from products used near the person (Nearfield). FFComET™ – Part of ComET™ that estimates human exposure to the DSL substances from the environment (Farfield). FFComET™ – Part of ComET™ that estimates human exposure to the DSL substances from the environment (Farfield).

NFexposure – estimated human exposure from NFComET™. NFexposure – estimated human exposure from NFComET™. FFexposure – estimated human exposure from FFComET™. FFexposure – estimated human exposure from FFComET™. Actual emission rate – an estimate of the kg/hr that might realistically be expected to flow into the standard Canadian geographical area being modeled for FFComET™. Actual emission rate – an estimate of the kg/hr that might realistically be expected to flow into the standard Canadian geographical area being modeled for FFComET™. Glossary of Terms in this Talk (cont)

3-Step Sequential Elements of FFComET™ 1. ChemCAN estimation of “unit concentrations” in environmental media (air, water, soil), biota and food from “unit” release rates to the environment. (John Arnot- CEMC) – previous presentation 2. Estimation or assignment of actual DSL substance release rates and use of these rates to estimate actual or potential concentrations in the above media, biota and food. (MAJ – LLG) – this presentation 3. ComET™ conversion of these concentrations to potential human exposure to the DSL substance from the environment. (CFC – LLG) – next presentation

Step #1 CEMC – ChemCAN estimation of “Unit Concentrations” A standard emission rate is modeled separately in air, soil and water using a modified version of ChemCAN and a “standard” Canadian geological/geographical area determined and used by CEMC. A standard emission rate is modeled separately in air, soil and water using a modified version of ChemCAN and a “standard” Canadian geological/geographical area determined and used by CEMC. The resulting environmental concentrations are output by the model including concentrations in air, water, other environmental media (e.g., freshwater zooplankton) and 23 human food items (fish, game, and agricultural items). The resulting environmental concentrations are output by the model including concentrations in air, water, other environmental media (e.g., freshwater zooplankton) and 23 human food items (fish, game, and agricultural items).

Step #2 Estimation or Assignment of Actual or Potential DSL Substance Emissions Actual emission rates applied to the “standard” Canadian geographical/geological area used by ChemCAN can be estimated from actual, estimated or assigned annual production volumes for any DSL substance. Actual emission rates applied to the “standard” Canadian geographical/geological area used by ChemCAN can be estimated from actual, estimated or assigned annual production volumes for any DSL substance. All concentrations calculated from ”unit emissions” are directly scaleable to “actual” or potential concentrations in any environmental compartments and food items by multiplying them by the ratio of actual/unit emission rate. All concentrations calculated from ”unit emissions” are directly scaleable to “actual” or potential concentrations in any environmental compartments and food items by multiplying them by the ratio of actual/unit emission rate.

Step #3 Conversion of CEMC Environmental Concentrations Estimates to Human Exposure from the Environment Estimated exposure to man from the environment by any DSL substance comes from combining concentration estimates for the environmental media and food with estimates of human intake for these items. Estimated exposure to man from the environment by any DSL substance comes from combining concentration estimates for the environmental media and food with estimates of human intake for these items. This will be done by the LifeLine Group and the results will be integrated into a final output for Farfield ComET™ (FFexposure) which will, in turn, be added to the exposure estimate from near-field ComET™ (NFexposure) for an estimate of Total Human Exposure from the DSL substance. This will be done by the LifeLine Group and the results will be integrated into a final output for Farfield ComET™ (FFexposure) which will, in turn, be added to the exposure estimate from near-field ComET™ (NFexposure) for an estimate of Total Human Exposure from the DSL substance.

A possible approach is outlined here It includes a 3-tier treatment designed to first set-aside substances that will not be anticipated to present significant exposure to man from the environment, proceeding to a more realistic estimation of the emission and exposure potential for those substances that might present significant exposure from the environment. Final approach not decided at this time: Step #2 (estimate actual emissions/exposures)

1.Set FFexposure to a de minimus (x %) of NFexposure as calculated by NFComET™ (x to be determined in subsequent deliberations) 2.Determine the environmental emission rate that would give this FFexposure. 3.IF this emission rates is IMPOSSIBLY High then set FFexposure aside. OVERVIEW of Proposed Linear Process for Estimating Farfield Exposure

4.IF NOT THEN estimate FFexposure using emission rates derived from binned production levels for the GPE, IPE and LPE substances. 5.IF FFexposure calculated from #4 above is less than a de minimus (x %) of NFexposure determined by NFComET™ THEN set FFexposure aside. 6.IF NOT THEN modify the emissions using available factoring schemes (e.g., EUSES 2.0 Table for Chemical Industry Releases: BASIC CHEMICALS TABLE to estimate fraction of total production/emission that would be released to air, water and soil) and then calculate FFexposure. OVERVIEW of Proposed Linear Process for Estimating Farfield Exposure

7. de minimus (x %) of NFexposure determined by NFComET™ THEN set FFexposure aside. 8. IF NOT THEN report FFexposure as determined by the calculations derived in #6 as FFComET™ 9. Add FFComET™ to NFComET™ for TOTAL ComET™ exposure. OVERVIEW of Proposed Linear Process for Estimating Farfield Exposure

Step-by-Step Procedure (a possible approach) for estimating actual emission and Farfield Exposure to Man from the Environment (1 of 5) Step 1 – Get unit concentrations for the DSL substance from CEMC modeling of unit emissions. Step 1 – Get unit concentrations for the DSL substance from CEMC modeling of unit emissions. Step 2a – Run NFComET™ and SET the FFexposure to be a de minimus level (less than x%) of the NFexposure estimate from NFComET™. Step 2a – Run NFComET™ and SET the FFexposure to be a de minimus level (less than x%) of the NFexposure estimate from NFComET™. Note: de minimus % to be determined.

Step-by-Step Procedure (a potential approach) for estimating actual emission and Farfield Exposure to Man from the Environment (2 of 5): Run CEMC software* to answer the question: Could the actual emission rate that caused this FFexposure be realistically possible?** (i.e., Is it less than some impossibly high value of kg/hr emission). Run CEMC software* to answer the question: Could the actual emission rate that caused this FFexposure be realistically possible?** (i.e., Is it less than some impossibly high value of kg/hr emission). * CEMC software will be made available with ComET™ ** Note: Realistic maximum rate of emission to be determined.

Step-by-Step Procedure (a potential approach) for estimating actual emission and Farfield Exposure to Man from the Environment (3 of 5): IF the answer is NO then set aside FFexposure as de minimus (compared to NFexposure); that is, NFexposure = Total Exposure. IF the answer is NO then set aside FFexposure as de minimus (compared to NFexposure); that is, NFexposure = Total Exposure. IF the answers is YES go to Step 2b. IF the answers is YES go to Step 2b.

Step-by-Step Procedure (a possible approach) for estimating actual emission and Farfield Exposure to Man from the Environment (4 of 5): Estimate FFexposure using emissions calculated from GPE, IPE or LPE “binned” or substance-specific assigned levels for annual production. Estimate FFexposure using emissions calculated from GPE, IPE or LPE “binned” or substance-specific assigned levels for annual production. IF estimated FFexposure is still above the de minimus (x%) portion of NFexposure proceed to Step 2c, IF estimated FFexposure is still above the de minimus (x%) portion of NFexposure proceed to Step 2c, IF NOT THEN FFexposure is de minimus, can be set aside and Total Exposure = NFexposure IF NOT THEN FFexposure is de minimus, can be set aside and Total Exposure = NFexposure

Step 2c – Use a standard scheme to estimate the fraction of total emissions that would go to air, water and soil (e.g., the EUSES 2.0 Table for Chemical Industry Releases: BASIC CHEMICALS TABLE) Step 2c – Use a standard scheme to estimate the fraction of total emissions that would go to air, water and soil (e.g., the EUSES 2.0 Table for Chemical Industry Releases: BASIC CHEMICALS TABLE) Then run estimate FFexposure. IF estimated FFexposure is still above x% of NFexposure THEN include this value as the Farfield ComET™ exposure, ELSE Total Exposure = Nearfield exposure. Then run estimate FFexposure. IF estimated FFexposure is still above x% of NFexposure THEN include this value as the Farfield ComET™ exposure, ELSE Total Exposure = Nearfield exposure. Step-by-Step Procedure (a possible approach) for estimating actual emission and Farfield Exposure to Man from the Environment (5 of 5): Note: Specific scheme to estimate fraction remains open.

Example Release Factors from EUSES 2.0 – Basic Chemicals Solubility less than 100 mg/l Solubility less than 100 mg/l –VP less than 100 Pa  Proportion to air = 0.65  Proportion to waste water = 0.25  Proportion to soil = –VP greater than 1,000 Pa  Proportion to air = 0.95  Proportion to waste water = 0.05  Proportion to soil = 0.001