1 / 29

Can USEPA-RAGS Risk Assessment Methodology be Applied to the Workplace?

Can USEPA-RAGS Risk Assessment Methodology be Applied to the Workplace?. Michael J. Sullivan, Ph.D., CIH, REA California State University at Northridge. This sentence assembled itself. What Can We Use?. OELs. PELs. Protecting The Worker. Precautionary Principle. USEPA RAGS HRA.

amie
Télécharger la présentation

Can USEPA-RAGS Risk Assessment Methodology be Applied to the Workplace?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Can USEPA-RAGS Risk Assessment Methodology be Applied to the Workplace? Michael J. Sullivan, Ph.D., CIH, REA California State University at Northridge

  2. This sentence assembled itself.

  3. What Can We Use? OELs PELs Protecting The Worker Precautionary Principle USEPA RAGS HRA

  4. Outline • PEL-Setting Process • USEPA Risk Assessment Process • Comparison of Processes • Comparison of Results • Recommendation

  5. PEL-Setting Process • OSHA must propose and promulgate the PEL • Input received from NIOSH in form or Recommended Exposure Level (REL) • Other OELs can be considered

  6. PEL-Setting Process • Over 400 OSHA PELs • Both toxicology and epidemiology information considered in weight-of-evidence process • Process weighted towards use of worker epidemiology data

  7. USEPA Risk Assessment Process Hazard x Exposure = Risk

  8. USEPA Risk Assessment Process • Over 700 chemicals in USEPA database • Both toxicology and epidemiology information considered in weight-of-evidence process • Process weighted towards use of toxicology data

  9. USEPA Risk Assessment Process • Calculations slightly different for carcinogens vs. non-carcinogens • Based on assumption of non-threshold vs. threshold mechanisms of action

  10. USEPA Risk Assessment Process • Carcinogenic risks is Incremental Lifetime Cancer Risk (ICLR) • Non-carcinogenic risk is Hazard Quotient (HQ)

  11. USEPA Risk Assessment Process • Carcinogens • Hazard = Cancer Slope Factor (CSF) (units = 1/exposure units) • Exposure = Lifetime Average Daily Dose (LADD) (units = exposure units) • Hazard x Exposure = Risk (unitless)

  12. USEPA Risk Assessment Process • Carcinogens • LADD = EPC x Exposure Parameters • EPC = Exposure Point Concentration (e.g., concentration in air – mg/m3) • mg/m3 x exposure parameters x CSF = ILCR • mg/m3 = ILCR/(exposure parameters x CSF) • mg/m3 = Risk-based workplace conc. (RBWC)

  13. USEPA Risk Assessment Process • Non-Carcinogens • Hazard = Reference Concentration (RfC) (units = mg/m3) • Exposure = Average Daily Dose (ADD) (units = mg/m3) • 1/Hazard x Exposure = Risk (unitless)

  14. USEPA Risk Assessment Process • Non-Carcinogens • Exposure = EPC x Exposure Parameters • EPC = Exposure Point Concentration (e.g., concentration in air – mg/m3) • mg/m3 x exposure parameters x 1/RfC = HQ • mg/m3 = (HQ x RfC)/exposure parameters • mg/m3 = Risk-based Workplace Conc. (RBWC)

  15. USEPA Risk Assessment Process • USEPA has published risk-based concentrations (706 chemicals): Regional Screening Levels – RSLs • Residential soil • Residential air • Residential water • Industrial soil • Industrial air http://www.epa.gov/region9/superfund/prg/

  16. USEPA Risk Assessment Process • USEPA Industrial Air RSLs based on: • ILCR = 1 x 10-6 • HQ = 1.0 • Exposure Parameters • 25 years • 250 days/year • 8 hours/day • 70 kg body weight

  17. USEPA Risk Assessment Process • USEPA RSLs (306) • 127 for carcinogenic chemicals • 134 for non-carcinogenic chemicals • 45 for both C and NC chemicals

  18. PEL Process vs. USEPA Process • PELs • Require consensus • Enforcable • Weighted towards workplace epidemiology • RSLs • Easy to calculate • Not enforceable • Weighted towards toxicology data

  19. PEL Process vs. USEPA Process • Comparisons of PELs vs. RSLs • 120 chemicals with both PELs and RSLs • 120 PELs higher than RSLs (C + NC) • Additional 290 PELs without RSLs • Additional 186 RSLs without PELs

  20. PEL Process vs. USEPA Process • Comparisons of PELs vs. RSLs • Differences range from 2 x 100 to 2 x 107 • Average difference = 3 x 105 • Average difference = 4 x 104 (top 3 removed) • Overall: a 1000-fold adjustment needed in RSLs to be roughly comparable

  21. PEL Process vs. USEPA Process • Comparisons of PELs vs. RSLs for Carcinogenic Chemicals • All PELs are higher than RSLs • Difference ranges from 2 x 102 to 5 x 105 • Average difference 9 x 104 • A 10,000-fold adjustment needed in RSLs to be roughly comparable

  22. PEL Process vs. USEPA Process • Comparisons of PELs vs. RSLs for Non-Carcinogenic Chemicals • All PELs are higher than RSLs • Difference ranges from 2 x 102 to 2 x 105 • Average difference is 5 x 103 • A 100-fold adjustment needed in RSLs to be roughly comparable

  23. PEL Process vs. USEPA Process • Comparisons of PELs vs. RSLs • For carcinogenic chemicals, PELs much larger than RSLs • Adjustments of 10,000 or 100 needed for carcinogenic or non-carcinogenic chemicals • A straight-use of the RSLs would not be a good substitute for chemicals without PELs

  24. PEL Process vs. USEPA Process • Comparisons of Selected PELs vs. RSLs

  25. PEL Process vs. USEPA Process • Comparisons of Selected PELs vs. RSLs-recc

  26. Recommendation • The PEL process is appropriate for protecting workers • Use adjusted USEPA RSLs (USEPA process) for new chemicals for new chemicals without PEL or appropriate OEL • Use the PEL process to approve or replace any USEPA RSLs with new PELs

  27. Conclusion • The combined use of the PELs and RSLs can effectively protect worker health

  28. Contact Information Michael J. Sullivan, Ph.D., CIH, REA Department of Environmental and Occupational Health California State University at Northridge 18111 Nordhoff Street Northridge, CA 91330 michael.sullivan@csun.edu

More Related