1 / 19

Misuse of Exposure Reporting in Acute Risk Assessment

Misuse of Exposure Reporting in Acute Risk Assessment. John S. Morawetz International Chemical Workers Union Council/UFCW Center for Worker Health & Safety Training Cincinnati, Ohio (513) 621-8882 JMorawetz@ICWUC.org. Acute Exposure Guideline Levels.

gella
Download Presentation

Misuse of Exposure Reporting in Acute Risk Assessment

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. Misuse of Exposure Reporting in Acute Risk Assessment John S. Morawetz International Chemical Workers Union Council/UFCW Center for Worker Health & Safety Training Cincinnati, Ohio (513) 621-8882 JMorawetz@ICWUC.org

  2. Acute Exposure Guideline Levels Since 1996 the EPA has convened meetings of a National Advisory Committee for Acute Exposure Guideline Levels (AEGLs) Committee of Toxicology of the National Research Council and National Academy of Sciences “Once in a lifetime short term exposures” for general public

  3. Health Outcomes • AEGL-1 Notable discomfort • AEGL-2 Irreversible or serious, long lasting effects including impaired ability to escape • AEGL-3 Death or life threatening

  4. Time Periods • Levels are set for 5 time periods: • 10 and 30 minutes, 1, 4 and 8 hours for each health outcome • Total of 15 levels per chemical

  5. Application • General population including infants, children, asthmatics and other susceptible groups • Unlike occupational recommendations, intended for once in a lifetime exposure

  6. Caveats Primary - Control Exposures; hierarchy of controls Substitution Pollution Prevention Need Multi disciplinary efforts Toxicologists, Physicians, Epidemiologists, Industrial Hygienists, Statisticians, Engineers

  7. Caveats • “Intended to be used as planning tools” • “when an actual chemical emergency occurs, there often is no time to measure airborne concentrations” • “Not to be used as safe limits for routine operations or definitive delineators between safe and unsafe exposure conditions” (AIHA, ERPG handbook, 2000)

  8. AEGL Committee’s misuse of human studies • Inaccurate reporting in draft report • Time period of sample • Area vs. personal vs. bulk • TWA vs. instantaneous • Anecdotal vs. case or full study • Rejection of reconstruction studies • Inappropriate use of range of data

  9. Inaccurate Reporting • Inaccurate summary of level • “No exposure measurements” SOP • Incorrect range reported - phosphine • Time period associated with measurement • “No exposure time noted” phosphine (Wilson) • Range of levels with no time period • trichloroethane – fatality reconstruction • methanol – NIOSH HHE

  10. Inaccurate Reporting • Area vs. personal samples • Propylene Glycol Dinitrate • Hydrogen Cyanide (Leeser) • Reported only "routine" instantaneous samples (1 to 3 ppm) rather than available personal samples

  11. Inaccurate Reporting • Area vs. personal samples • Methanol • AEGL stated "measured in the vicinity of the duplicators". • NIOSH HHE (1981) states "Breathing zone samples were collected for methyl alcohol vapors over a 25 minute sampling period".

  12. Inaccurate Reporting Bulk vs. Area vs. Personal samples • “raw acetylene contained less than 3 ppm “ Used as a personal exposure – phosphine Case reports described as anecdotal - phosphorous trichloride - trichlorethylene

  13. Rejection of fatality reconstruction studies • Simulation of task with sampling • Phosphine (Hager) • Trichloroethane

  14. Inappropriate use of range of data • Attributed to which exposure level? AEGL - Single Upper limit of range Examples: Propylene Glycol Dinitrate • Maximum value of 400 inst. Samples Hydrogen Cyanide • 34 samples in 8 job titles

  15. Hydrogen Cyanide Exposures by Job TitleLeeser, 1990

  16. Summary • Multi disciplinary Risk Assessment committees • Draft reports • Committee discussion and recommendation • Final approval • Accurate summary of original articles • Uranium Hexafluoride

  17. Composition of CommitteePreponderance of one expertise Bias towards one expertise

  18. Current Issues • Hydrogen Cyanide • Leeser: used as primary study • Grabois study, 1954 • Industrial Hygiene survey with NO health survey • Occupational Application of AEGLs • Emergency Response

More Related