Transcript 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)

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
[email protected]
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
Health Outcomes
• AEGL-1
Notable discomfort
• AEGL-2
Irreversible or serious,
long lasting effects
impaired ability to
including
escape
• AEGL-3
Death or life threatening
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
Application
• General population including infants,
children, asthmatics and other
susceptible groups
• Unlike occupational recommendations,
intended for once in a lifetime exposure
Caveats
Primary - Control Exposures; hierarchy of
controls
Substitution
Pollution Prevention
Need Multi disciplinary efforts
Toxicologists, Physicians, Epidemiologists,
Industrial Hygienists, Statisticians,
Engineers
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)
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
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
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
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".
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
Rejection of fatality
reconstruction studies
• Simulation of task with sampling
• Phosphine (Hager)
• Trichloroethane
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
Hydrogen Cyanide
Exposures by Job Title
Geo. Mean
n
tio
C
om
pa
c
ut
si
m
in
g
Low
Li
Le
ad
in
g
Fi
ni
sh
ed
High
de
O
ifu
ge
r
C
en
tr
vi
so
Su
pe
r
ol
3.5
3
2.5
2
1.5
1
0.5
0
C
on
tr
ppm
Leeser, 1990
Summary
• Multi disciplinary Risk Assessment committees
– Draft reports
– Committee discussion and recommendation
– Final approval
• Accurate summary of original articles
• Uranium Hexafluoride
Composition of Committee
Preponderance of one expertise
Bias towards one expertise
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