9.3 Cocker
Click here to load reader
-
Upload
kate-jones -
Category
Health & Medicine
-
view
262 -
download
6
Transcript of 9.3 Cocker
An Agency of the Health and Safety Executivewww.hsl.gov.ukAn Agency of the Health and Safety Executive
A perspective on biological monitoring guidance values
John Cocker
An Agency of the Health and Safety Executive
From Hazard to Disease
EXPOSURE UPTAKE EFFECT DISEASE
HAZARD
Biological EffectMonitoring
Environmental Monitoring
DiagnosisWell-being
E.g.Air samplesSurface wipes
E.g.CholinesteraseAsthma/allergy
E.g. Urine: PAHsCarcinogensMetalsIsocyanates
BiologicalMonitoring
Occupational
Environmental
Exposure Assessment Health Surveillance
© Crown Copyright 2013
Increasing exposure/dose
An Agency of the Health and Safety Executive
Who uses BM & why ?
• Occupational health providers
• Occupational hygienists
• Employers & managers• Researchers• Epidemiologists• Regulators
• Compliance with regulation (e.g.lead)
• Are the exposure controls working?
• Do I have a problem?• Publications• Links to disease• ‘Safe’ levels
All motivated by a desire to prevent ill-health but all with different requirements
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Requirements for BM
• Ethics – informed consent– Why, what, when, how, meaning of results
• Matrix– Blood, urine, saliva, breath etc
• Analyte– Specific, metabolite, related to toxicity,
stability, kinetics, dose-response• Analytical Method
– Specific, accurate, precise, • Quality assurance
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Requirements for BM guidance values
• Data to establish a relationship between – BM value & (absence of) ill-health– BM value & exposure– BM value & good occupational hygiene practice– BM value & ‘normal’ levels
• Peer reviewed publications– Workplace studies– Volunteer studies– Population studies
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Biological Guidance Values
• Health-based– HBM 1 & 2 (HBM Commission)
– BEIs 44 (ACGIH)
– BATs 66 (MAK/DFG)
– BLVs ?? (SCOEL)
– BMGVs 10 (HSE)
• Non-health-based– Reference values– BARs 30 (MAK/DFG)
– BLWs 8 (MAK/DFG)
– EKAs 26 (MAK/DFG)
– Good OH practice BMGVs (90% values) 7(HSE)
© Crown Copyright 2013
Confusing?• Differing types/basis• Differing values for the same substances
• E.g. HSE’s BMGV for Mercury ~35μg/g, BEI 10 μg/g• HSE’s BMGV for TDI ~1μg/g, proposed BEI 5μg/g
• Some might impossible to achieve – e.g. BLVs at background levels e.g BAR for Cd 0.8 μg/l cf BEI 5 μg/l
An Agency of the Health and Safety Executive
BM Guidance values
• Health-based • Non-health-based
Exposure or absence of ill-health
BM value
BMGV
Health-based exposure limit e.g TLV or MAK
BM value
BMGV
Non-health-based exposure limit e.g. TRK
e.g BAT,Or BEI
e.g EKA
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Good-practice-based BMGVs• UK good occupational hygiene practice (or ‘benchmark’)
values are based on the 90th percentile of data fromworkplaces with good control of exposure.
• Not health-based
• Easy to set up, require fewer data
• Suitable for:
• Carcinogens & mutagens
• Data-poor substances
• ‘In-house’ use
• Examples include: Chromium VI, Glycerol trinitrate, Isocyanates, MbOCA,
4,4’-Methylenedianiline (MDA),Polycyclic aromatic hydrocarbons
© Crown Copyright 2013
An Agency of the Health and Safety Executive
90% BMGV helps to reduce exposure
Cl
NH2 CH2
Cl
NH2
Each bar is the 90th percentile of results from 79 – 400 urine samples from 20 – 35 companies each year
© Crown Copyright 2013
0
5
10
15
20
25
30
35
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
MbOCA S
tudy
2006
2007
2nd s
tudy2
008
2009
2010
1996 Biological Monitoring Guidance value
1987 Biological Monitoring Guidance value
90%
val
ue M
bOC
A µ
mol
/mol
cre
atin
ine
Firmer guidance improves control and reduces exposure
Do 90% BMGVs need regular updating to maintain effect?
An Agency of the Health and Safety Executive
90% Guidance value for PAHs
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 600
20
40
60
80
100
120
140
Frequency distribution of urinary 1-hydroxypyrene
90% all workplaces < 7 μ mol/mol creatinine
μmol/mol creatinine
Freq
uenc
y
90% value from workplaces with good control < 4μmol/mol creatinine
1 µmol/mol ~ 2 µg/g
© Crown Copyright 2013
Survey of 25 workplaces
An Agency of the Health and Safety Executive
Urinary 1-hydroxypyrene: perspective
m edian va lues in 12 bac kground s tud ies& 207 s am ples from the HS E s urvey
smokers non-smokers HSE0 .0
2 .5
4
1 0
2 0
3 0
1-O
H-P
um
ol/m
ol
90% value from places with good occupational hygiene practice (UK)
Upper limit of non-occupational exposure (USA, BEI)
BM Equivalent to airborne limit (DFG - EKA)
© Crown Copyright 2013
An Agency of the Health and Safety Executive
• Examples:– Mercury, MEK, MIBK, xylene, CO, chlorobenzene (UK)– ACGIH BEIs, (USA)– DFG BATs (Germany)
• If value exceeded unlikely to see health effects• Regularly exceeding the BEI/BAT suggests
exposure controls could be improved• Good occupational hygiene practice should be to
reduce exposure
Deutsche Forschngsgemeinschaft List of MAK and BAT values 2012 Wiley VCH ISBN 978-3-527—33470-4ACGIH 2012 TLVs and BEIs published by ACGIH Worldwide ISBN 978-1-607260-48-6
Action for Health-Based BMGVs
© Crown Copyright 2013
An Agency of the Health and Safety Executive
• Examples:– DFG EKAs, BLWs
• acrylonitrile, benzene, cobalt, hydrazine, nickel, etc
• UK ‘Benchmark’ (90%) values
• If BMGV is exceeded it indicates control ofexposure may not be adequate
• Good occupational hygiene practice should be toreduce exposure ALARP
Deutsche Forschngsgemeinschaft List of MAK and BAT values 2012 Wiley VCH ISBN 978-3-527—33470-4
Action for Non Health-based BMGVs:
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Summary
• BM is a tool for exposure assessment• Guidance values available (not ‘limits’)
– Set by different organisations– Set in different ways– Same substance can have different BMGVs– If BMGV exceeded the action is the same –
examine controls and reduce exposure – For long half-life substances action is
needed before BMGV reached• Should we provide simpler guidance?
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Would a traffic light system help?
Levels << 90% value or in the background range - regular monitoring
Levels > a 90% value or half the BMGV
Look for a reason – Check controls
Levels > BMGV
Collect another sample, Check controls urgently
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Pleas• On behalf of organisations setting BMGVs:
– Please publish your studies– Please include details of exposure controls
• PPE, exposure levels, process & task details– Please visit as many workplaces as possible
• To referees & editors– Please ask for these details– Please recognise that the ‘real world’ rarely
lends itself to ‘ideal’ studies or academic perfection
• Most of all – do more biological monitoring!
An Agency of the Health and Safety Executive
• BM is a tool for exposure assessment • Guidance values are available• Guidance values are not ‘limits’
• If BMGV exceeded - reduce exposure• For long half-life substances act before BMGV
reached• 90% value BMGVs need updating
• We need guidance values for more substances• 90%value BMGVs are easier to develop• Do more research – and publish!
• We need to help our ‘customers’ understandBMGVs
Conclusions
© Crown Copyright 2013
An Agency of the Health and Safety Executive
Conclusions• BM for isocyanate exposures recommended
and increasingly used.
• Guidance values available as well as adviceon interpretation.
• Potential confounding by amine exposuresbut BM still reflects body burden tohazardous chemicals.
• Further research on-going to find anisocyanate-specific metabolite.
Thank you for [email protected]