NTPC BARH
BSTPP- BARH SUPER THERMAL POWER PLANT
CONTENT: Overview; BSTPP at a glance; Various parts of BSTPP; Electrical Overview; Switch Yard; Transformer; Generator...
NTPC BARH
BSTPP- BARH SUPER THERMAL POWER PLANT
CONTENT: Overview; BSTPP at a glance; Various parts of BSTPP; Electrical Overview; Switch Yard; Transformer; Generator...
Chemical Risk Assessment and Translation to Socio-Economic AssessmentsOECD Environment
OECD Workshop on SocioEconomic Impact Assessment of Chemicals Management, Helsinki, 7 July 2016
Background paper 1: Chemical Risk Assessment and Translation to Socio-Economic Assessments, by Weihsueh A. Chiu, Texas A&M University
Presentation by Prof. George Gray, Director of the Centre for Risk Science and Public Health, George Washington University, at the Workshop on Risk Assessment in Regulatory Policy Analysis (RIA), Session 15, Mexico, 9-11 June 2014. Further information is available at http://www.oecd.org/gov/regulatory-policy/
Presentation by Prof. George Gray, Director of the Centre for Risk Science and Public Health, George Washington University, at the Workshop on Risk Assessment in Regulatory Policy Analysis (RIA), Session 5, Mexico, 9-11 June 2014. Further information is available at http://www.oecd.org/gov/regulatory-policy/
The TCE Revolution and Its Permanent Impact on Environmental Due DiligenceEDR
EDR INSIGHT WEBINAR: THE TCE REVOLUTION AND ITS PERMANENT IMPACT ON ENVIRONMENTAL DUE DILIGENCE
June 24, 2015
Presented by:
-David Gillay, Partner and Chair of Brownfields & Environmental Transactional Diligence Practice Areas, Barnes & Thornburg LLP
-Dr. Michael Dourson, Ph.D., Alliance for Risk Assessment
Following decades of studies, scrutiny and debate, the U.S. EPA updated its TCE’s toxicity profile in the IRIS database, dramatically lowering the toxicity value. For transactional due diligence, this more stringent limit has important implications, including markedly more extensive and expensive cleanup processes. Given the focus on vapor migration in the new ASTM Phase I ESA standard, environmental professionals need to be increasingly cautious when making REC determinations and recommendations to clients.
Adding to the confusion is the significant variability in how regulators are using the updated TCE toxicity profile when making closure decisions at contaminated properties. For instance, U.S. EPA Regions 9, 10 and states like Minnesota, Indiana and Massachusetts (among others) have implemented profoundly different approaches to address TCE risk at contaminated sites. Thus, it is critical for environmental professionals to stay abreast of the how TCE guidance is being interpreted and applied across the country. In the latest development, the Agency for Toxic Substances & Disease Registry is proposing a dramatic change to its TCE toxicity profile for the first time in 18 years. The comment period ended on March 16, 2015, and if the update is finalized in its current form, there will be more intense scrutiny on exposure risks which will further complicate transactional due diligence.
This timely webinar will bring together an attorney and a national subject matter expert to address the various impacts of TCE’s toxicity update on transactional due diligence. This panel will help EPs answer the following questions:
-Does TCE in groundwater constitute a VEC and/or a REC?
-How should an EP manage variability in TCE standards in multi-state transactions?
-How can an EP take steps to minimize exposure to potential liability?
-How can an EP make sense of the science and available guidance?
-How should an EP communicate potential risks associated with TCE to clients?
Alan Krupnick (Resources for the Future)'s keynote presentation to the OECD workshop on the socioeconomic impact assessment of chemicals management. Helsinki, 6 July 2016.
A presentation on Risk Analysis in the Marine Environment for MEOPAR's Annual Training Meeting 2017.
Established in 2012 through Canada's federal Networks of Centres of Excellence Program, the Marine Environmental Observation Prediction and Response (MEOPAR) Network is a national network of academic researchers and students, government scientists, and partners in the private, NGO and community sectors working together to reduce vulnerability and strengthen opportunity in Canada's marine environment.
5th International Disaster and Risk Conference IDRC 2014 Integrative Risk Management - The role of science, technology & practice 24-28 August 2014 in Davos, Switzerland
GHME 2013 Conference
Session: New directions in cost-effectiveness analysis
Date: June 18 2013
Presenter: Josh Salomon
Institute:
Harvard School of Public Health
ndicators, Tracers and Surrogates - Why Use Them, Probability Analysis, Defin...Chris Lutes
Lutes, C., C. Holton, J, Kurtz and R. Truesdale “Indicators, Tracers and Surrogates - Why Use Them, Probability Analysis, Definitions and Examples” presented at EPA/AEHS, 21 March 2017 - Workshop: Finding Practical Solutions for the Chlorinated Vapor Intrusion, San Diego.
The Public Health Case for Risk-Based Regulation, George GrayOECD Governance
Presentation by Prof. George Gray, Director of the Centre for Risk Science and Public Health, George Washington University, at the Workshop on Risk Assessment in Regulatory Policy Analysis (RIA), Session 3, Mexico, 9-11 June 2014. Further information is available at http://www.oecd.org/gov/regulatory-policy/
● Assignment #1 and assignment #2 combine into a health risk .docxoswald1horne84988
● Assignment #1 and assignment #2 combine into a health risk
assessment report
● Assignment #1 is a description of the background associated
with the environmental hazard (Due February 17)
● Assignment #2 is an application and a site specific health risk
assessment that determines the impact of a hazard on a
population in a Canadian city (Due March 31)
This is a 1000-1500 word report on an environmental
hazard. The purpose of the report is to find and then
summarize key literature on an environmental hazard of
your choice. The literature must be from peer reviewed
journal articles and official government reports (from
Health Canada, the CDC and other major agencies). In
this report you must use your research to describe the 1)
origin, source and properties of a hazard 2) the route of
exposure, 3) the concentration of exposure thought to be
harmful to humans and 4) the suspected relationship
between exposure to hazard and a specific health
outcome.
General health risk assessment report (20%)
General health risk assessment report (20%)
● Must choose a hazard and specific health outcome
● Hazard must be something present in the environment of a
typical Canadian city
○ NO2 (ok)
○ Parasite that causes malaria (not ok)
● Health outcome needs to be specific
○ Hospitalization due to asthma (ok)
○ Type 2 diabetes (ok)
○ Influenza (ok)
○ Mortality (not ok)
○ Infant mortality (not ok)
The impact of student noise pollution on sleep
quality
•Hazard: Noise from students
•Route of exposure: Auditory contact/sound
•Health outcome: disrupted sleep
•Concentration of noise likely to cause sleep disturbance: 65 dB
Assignment #2
• Concentration of exposure in Westdale: number of days with level of
exposure in neighbourhood above 65 between 11 pm and 6 am = 4
• Vulnerable population: persons 65+
• Key finding: Upper limit of exposure concentration 750 people x 4 days =
3,000 disrupted person-nights of sleep per year
Example topic #1
The benefits of existing recreational play space on the
physical health of children
•Determinant (‘hazard’): Access to green space
•Route of exposure: Proximity (to child-friendly play space)
•Health outcome: Likelihood of independent play
•Concentration of exposure that would be beneficial: 1.6 Km considered
walkable by school boards in Ontario
Assignment #2
• Number of walkable parks/playgrounds within 1.6 Km of Strathcona: > 20,
though most would require crossing major street; only 1 large park that does
not require street crossing. This is a multi-use recreational space with a small
play area for young children
• Vulnerable population < 8 ~ 150
• Key finding: Children in the Strathcona neighbourhood have access to one
large park, but as a multi-use space, there is little infrastructure available for
young children
Example topic #2
The effect of radon gas on lung cancer risk
•Hazard: Radon gas
•Route of exposure: inhalation; most exposure is in the residential setting,.
Chemical Risk Assessment and Translation to Socio-Economic AssessmentsOECD Environment
OECD Workshop on SocioEconomic Impact Assessment of Chemicals Management, Helsinki, 7 July 2016
Background paper 1: Chemical Risk Assessment and Translation to Socio-Economic Assessments, by Weihsueh A. Chiu, Texas A&M University
Presentation by Prof. George Gray, Director of the Centre for Risk Science and Public Health, George Washington University, at the Workshop on Risk Assessment in Regulatory Policy Analysis (RIA), Session 15, Mexico, 9-11 June 2014. Further information is available at http://www.oecd.org/gov/regulatory-policy/
Presentation by Prof. George Gray, Director of the Centre for Risk Science and Public Health, George Washington University, at the Workshop on Risk Assessment in Regulatory Policy Analysis (RIA), Session 5, Mexico, 9-11 June 2014. Further information is available at http://www.oecd.org/gov/regulatory-policy/
The TCE Revolution and Its Permanent Impact on Environmental Due DiligenceEDR
EDR INSIGHT WEBINAR: THE TCE REVOLUTION AND ITS PERMANENT IMPACT ON ENVIRONMENTAL DUE DILIGENCE
June 24, 2015
Presented by:
-David Gillay, Partner and Chair of Brownfields & Environmental Transactional Diligence Practice Areas, Barnes & Thornburg LLP
-Dr. Michael Dourson, Ph.D., Alliance for Risk Assessment
Following decades of studies, scrutiny and debate, the U.S. EPA updated its TCE’s toxicity profile in the IRIS database, dramatically lowering the toxicity value. For transactional due diligence, this more stringent limit has important implications, including markedly more extensive and expensive cleanup processes. Given the focus on vapor migration in the new ASTM Phase I ESA standard, environmental professionals need to be increasingly cautious when making REC determinations and recommendations to clients.
Adding to the confusion is the significant variability in how regulators are using the updated TCE toxicity profile when making closure decisions at contaminated properties. For instance, U.S. EPA Regions 9, 10 and states like Minnesota, Indiana and Massachusetts (among others) have implemented profoundly different approaches to address TCE risk at contaminated sites. Thus, it is critical for environmental professionals to stay abreast of the how TCE guidance is being interpreted and applied across the country. In the latest development, the Agency for Toxic Substances & Disease Registry is proposing a dramatic change to its TCE toxicity profile for the first time in 18 years. The comment period ended on March 16, 2015, and if the update is finalized in its current form, there will be more intense scrutiny on exposure risks which will further complicate transactional due diligence.
This timely webinar will bring together an attorney and a national subject matter expert to address the various impacts of TCE’s toxicity update on transactional due diligence. This panel will help EPs answer the following questions:
-Does TCE in groundwater constitute a VEC and/or a REC?
-How should an EP manage variability in TCE standards in multi-state transactions?
-How can an EP take steps to minimize exposure to potential liability?
-How can an EP make sense of the science and available guidance?
-How should an EP communicate potential risks associated with TCE to clients?
Alan Krupnick (Resources for the Future)'s keynote presentation to the OECD workshop on the socioeconomic impact assessment of chemicals management. Helsinki, 6 July 2016.
A presentation on Risk Analysis in the Marine Environment for MEOPAR's Annual Training Meeting 2017.
Established in 2012 through Canada's federal Networks of Centres of Excellence Program, the Marine Environmental Observation Prediction and Response (MEOPAR) Network is a national network of academic researchers and students, government scientists, and partners in the private, NGO and community sectors working together to reduce vulnerability and strengthen opportunity in Canada's marine environment.
5th International Disaster and Risk Conference IDRC 2014 Integrative Risk Management - The role of science, technology & practice 24-28 August 2014 in Davos, Switzerland
GHME 2013 Conference
Session: New directions in cost-effectiveness analysis
Date: June 18 2013
Presenter: Josh Salomon
Institute:
Harvard School of Public Health
ndicators, Tracers and Surrogates - Why Use Them, Probability Analysis, Defin...Chris Lutes
Lutes, C., C. Holton, J, Kurtz and R. Truesdale “Indicators, Tracers and Surrogates - Why Use Them, Probability Analysis, Definitions and Examples” presented at EPA/AEHS, 21 March 2017 - Workshop: Finding Practical Solutions for the Chlorinated Vapor Intrusion, San Diego.
The Public Health Case for Risk-Based Regulation, George GrayOECD Governance
Presentation by Prof. George Gray, Director of the Centre for Risk Science and Public Health, George Washington University, at the Workshop on Risk Assessment in Regulatory Policy Analysis (RIA), Session 3, Mexico, 9-11 June 2014. Further information is available at http://www.oecd.org/gov/regulatory-policy/
● Assignment #1 and assignment #2 combine into a health risk .docxoswald1horne84988
● Assignment #1 and assignment #2 combine into a health risk
assessment report
● Assignment #1 is a description of the background associated
with the environmental hazard (Due February 17)
● Assignment #2 is an application and a site specific health risk
assessment that determines the impact of a hazard on a
population in a Canadian city (Due March 31)
This is a 1000-1500 word report on an environmental
hazard. The purpose of the report is to find and then
summarize key literature on an environmental hazard of
your choice. The literature must be from peer reviewed
journal articles and official government reports (from
Health Canada, the CDC and other major agencies). In
this report you must use your research to describe the 1)
origin, source and properties of a hazard 2) the route of
exposure, 3) the concentration of exposure thought to be
harmful to humans and 4) the suspected relationship
between exposure to hazard and a specific health
outcome.
General health risk assessment report (20%)
General health risk assessment report (20%)
● Must choose a hazard and specific health outcome
● Hazard must be something present in the environment of a
typical Canadian city
○ NO2 (ok)
○ Parasite that causes malaria (not ok)
● Health outcome needs to be specific
○ Hospitalization due to asthma (ok)
○ Type 2 diabetes (ok)
○ Influenza (ok)
○ Mortality (not ok)
○ Infant mortality (not ok)
The impact of student noise pollution on sleep
quality
•Hazard: Noise from students
•Route of exposure: Auditory contact/sound
•Health outcome: disrupted sleep
•Concentration of noise likely to cause sleep disturbance: 65 dB
Assignment #2
• Concentration of exposure in Westdale: number of days with level of
exposure in neighbourhood above 65 between 11 pm and 6 am = 4
• Vulnerable population: persons 65+
• Key finding: Upper limit of exposure concentration 750 people x 4 days =
3,000 disrupted person-nights of sleep per year
Example topic #1
The benefits of existing recreational play space on the
physical health of children
•Determinant (‘hazard’): Access to green space
•Route of exposure: Proximity (to child-friendly play space)
•Health outcome: Likelihood of independent play
•Concentration of exposure that would be beneficial: 1.6 Km considered
walkable by school boards in Ontario
Assignment #2
• Number of walkable parks/playgrounds within 1.6 Km of Strathcona: > 20,
though most would require crossing major street; only 1 large park that does
not require street crossing. This is a multi-use recreational space with a small
play area for young children
• Vulnerable population < 8 ~ 150
• Key finding: Children in the Strathcona neighbourhood have access to one
large park, but as a multi-use space, there is little infrastructure available for
young children
Example topic #2
The effect of radon gas on lung cancer risk
•Hazard: Radon gas
•Route of exposure: inhalation; most exposure is in the residential setting,.
Similar to Assessing and communicating uncertainties for risk assessment and risk management (20)
Highlights on the EFSA Opinion on the appropriate age range for introduction ...EFSA EU
FENS 2019 - Dublin
Highlights on the EFSA Scientific Opinion on the appropriate age range for introduction of complementary feeding into an infant's diet, Prof M Fewtrell
Horizon scanning for emergence of new viruses in animal and public healthEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Livestock disease drivers, ecology and pathogen evolutionEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Discovering novel pathways of cross-species pathogen transmissionEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Relations between pathogens, hosts and environmentEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
People, animals, plants, pests and pathogens: connections matterEFSA EU
Presentation of the EFSA's second scientific conference, held on 14-16 October 2015 in Milan, Italy.
DRIVERS FOR EMERGING ISSUES IN ANIMAL AND PLANT HEALTH
Vietnam Mushroom Market Growth, Demand and Challenges of the Key Industry Pla...IMARC Group
The Vietnam mushroom market size is projected to exhibit a growth rate (CAGR) of 6.52% during 2024-2032.
More Info:- https://www.imarcgroup.com/vietnam-mushroom-market
Hamdard Laboratories (India), is a Unani pharmaceutical company in India (following the independence of India from Britain, "Hamdard" Unani branches were established in Bangladesh (erstwhile East Pakistan) and Pakistan). It was established in 1906 by Hakeem Hafiz Abdul Majeed in Delhi, and became
a waqf (non-profitable trust) in 1948. It is associated with Hamdard Foundation, a charitable educational trust.
Hamdard' is a compound word derived from Persian, which combines the words 'hum' (used in the sense of 'companion') and 'dard' (meaning 'pain'). 'Hamdard' thus means 'a companion in pain' and 'sympathizer in suffering'.
The goals of Hamdard were lofty; easing the suffering of the sick with healing herbs. With a simple tenet that no one has ever become poor by giving, Hakeem Abdul Majeed let the whole world find compassion in him.
They had always maintained that working in old, traditional ways would not be entirely fruitful. A broader outlook was essential for a continued and meaningful existence. their effective team at Hamdard helped the system gain its pride of place and thus they made an entry into an expansive world of discovery and research.
Hamdard Laboratories was founded in 1906 in Delhi by Hakeem Hafiz Abdul Majeed and Ansarullah Tabani, a Unani practitioner. The name Hamdard means "companion in suffering" in Urdu language.(itself borrowed from Persian) Hakim Hafiz Abdul Majeed was born in Pilibhit City UP, India in 1883 to Sheikh Rahim Bakhsh. He is said to have learnt the complete Quran Sharif by heart. He also studied the origin of Urdu and Persian languages. Subsequently, he acquired the highest degree in the unani system of medicine.
Hakim Hafiz Abdul Majeed got in touch with Hakim Zamal Khan, who had a keen interest in herbs and was famous for identifying medicinal plants. Having consulted with his wife, Abdul Majeed set up a herbal shop at Hauz Qazi in Delhi in 1906 and started to produce herbal medicine there. In 1920 the small herbal shop turned into a full-fledged production house.
Hamdard Foundation was created in 1964 to disburse the profits of the company to promote the interests of the society. All the profits of the company go to the foundation.
After Abdul Majeed's death, his son Hakeem Abdul Hameed took over the administration of Hamdard Laboratories at the age of fourteen.
Even with humble beginnings, the goals of Hamdard were lofty; easing the suffering of the sick with healing herbs. With a simple tenet that no one has ever become poor by giving, Hakeem Abdul Majeed let the whole world find compassion in him. Unfortunately, he passed away quite early but his wife, Rabia Begum, with the support of her son, Hakeem Abdul Hameed, not only kept the institution in existence but also expanded it. As he grew up, Hakeem Abdul Hameed took on all responsibilities. After helping with his younger brother's upbringing and education, he included him in running the institution. Both brothers Hakeem Abdul Hameed and Hakim Mohammed
Ang Chong Yi Navigating Singaporean Flavors: A Journey from Cultural Heritage...Ang Chong Yi
In the heart of Singapore, where tradition meets modernity, He embarks on a culinary adventure that transcends borders. His mission? Ang Chong Yi Exploring the Cultural Heritage and Identity in Singaporean Cuisine. To explore the rich tapestry of flavours that define Singaporean cuisine while embracing innovative plant-based approaches. Join us as we follow his footsteps through bustling markets, hidden hawker stalls, and vibrant street corners.
Roti Bank Hyderabad: A Beacon of Hope and NourishmentRoti Bank
One of the top cities of India, Hyderabad is the capital of Telangana and home to some of the biggest companies. But the other aspect of the city is a huge chunk of population that is even deprived of the food and shelter. There are many people in Hyderabad that are not having access to
MS Wine Day 2024 Arapitsas Advancements in Wine Metabolomics Research
Assessing and communicating uncertainties for risk assessment and risk management
1. Assessing and communicating uncertainties
for risk assessment and risk management:
recent international developments
Andy Hart
Fera, York, UK
Visiting Professor of Risk Analysis Practice, Newcastle University
andy.hart@fera.co.uk
EFSA EXPO Conference, 15 October 2015
2. Some recent developments…
• Codex Working Principles for Risk Analysis, 2003-
• EFSA Uncertainties in Exposure Assessment, 2006
• IPCS Uncertainties in Exposure Assessment, 2008
• ECHA REACH Guidance, Chapter R19, 2008
• IPCS Uncertainties in Hazard Characterisation, 2014
• EFSA Draft Guidance on Uncertainty, 2015
• and others…
2
3. Example 1: Red River
Red River Flood, Grand Forks USA, 1997
• Levee height: 51 feet
• River height prediction: 49 feet
After: Nate Silver, The Signal and the Noise, 2012
• Actual flood height: 54 feet
3
51
49
4. Example 1: Red River
Red River Flood, Grand Forks USA, 1997
• Cost: $3-4 billion + credibility & trust
4
51
49
5. Example 1: Red River
Red River Flood, Grand Forks USA, 1997
• Levee height: 51 feet
• River height prediction: 49 feet
• Uncertainty: ±9 feet (Silver 2012)
51
49
±9
5
6. Example 1: Red River
51
49
±9
6
Risk managers and stakeholders need to
know:
• How much higher might the river rise?
− Quantitatively
− Taking account of as much of the
uncertainty as possible
• How likely is it to exceed the levee height?
7. Example 2: ‘Likely’
• What probability do you associate with the
word ‘Likely’?
• Write down your probability, expressed as a
percentage between 0 and 100%
7
0% 100%
8. Example 2: ‘Likely’
• Words are ambiguous –
mean different things to
different people
8
Experts
Risk manager/
stakeholders
‘Likely’
‘Likely’
??
Macleod&Pietravalle
9. “We couldn't know for certain… even though I thought it
was only 50-50 that Bin Laden was there, I thought it was
worth us taking the shot.”
“At the conclusion of a fairly lengthy discussion where
everybody gave their assessments I said: ‘this is basically
50-50’…”
President Obama: “Some of our
intelligence officers thought that
it was only a 40 or 30% chance
that Bin Laden was in the
compound. Others thought that
it was as high as 80 or 90%.”
Example 3: Bin Laden
9‘Bin Laden: Shoot to Kill’, Channel 4 television, 7 September 2011
Quantify likelihoods if possible
• For expert judgements as well as statistical estimates
Different experts may give different judgements
• This is okay - and important to know!
Ultimately it’s the risk managers’ understanding
of the uncertainty that will matter
And it’s the risk manager’s job
to decide what to do about it
10. Key principles
• ‘Uncertainties…should be explicitly
considered at each step in the risk
assessment and documented in a
transparent manner’
• ‘Expression of uncertainty…may
be qualitative or quantitative, but
should be quantified to the extent
that is scientifically achievable’
• ‘Responsibility for resolving the
impact of uncertainty on the risk
management decision lies with the
risk manager, not the risk
assessors’
10
Codex Working Principles
for Risk Analysis (2003-)
11. The same principles apply to all
EFSA’s scientific advice
• How different might the outcome be?
• How likely are the outcomes of interest to
risk managers?
• Quantify as much of the uncertainty as
possible
• Leave risk management to risk
managers
11
Criticallevel
OutcomeExposure
ADIorTDIAdequateintake
IntakeGMtrait
Conventional
equivalent
12. Draft EFSA Guidance (2015)
• Systematic
identification of
uncertainties
• Flexible toolbox of
assessment methods
− Qualitative and
quantitative
• Start simple; refine as
far as needed
• Express overall
uncertainty
quantitatively
12
Assessed
qualitatively
Not individually
assessed by any
method
Assessed
quantitatively
Identified uncertainties
Individually
quantified
uncertainties
Quantify combined
contribution by
expert judgement
Combine by calculation or expert judgement
to assess overall uncertainty
Public consultation draft, July 2015
13. Example: T-2 and HT-2 toxins
• Hazard: Tolerable Daily Intake (TDI) = 100 ng/kg bw/day
• Exposure: 95th percentile for Toddlers (12-36 months)
− 23 ng/kg bw/day assuming non-detects are zeroes
− 91 ng/kg bw/day assuming non-detects = limit of detection
• Other sources of uncertainty assessed qualitatively
13EFSA, 2011
14. Example: T-2 and HT-2 toxins
• Hazard: Tolerable Daily Intake (TDI) = 100 ng/kg bw/day
• Exposure: 95th percentile for Toddlers (12-36 months)
− 23 ng/kg bw/day assuming non-detects are zeroes
− 91 ng/kg bw/day assuming non-detects = limit of detection
• Other sources of uncertainty assessed qualitatively
14EFSA, 2011
• Expert judgement of overall uncertainty:
• This is a quantitative judgement: <50% probability that risk is
under-estimated
• Panel also concluded ‘No health concern’
Many assessments already imply quantitative
judgements about overall uncertainty
15. Defined scales may help…
• EFSA suggests an optional scale for probabilities
− adapted from a similar scale used by IPCC*
15
Probability term Probability range
Extremely likely 99-100%
Very likely 90-100%
Likely 66-100%
As likely as not 33-66%
Unlikely 0-33%
Very unlikely 0-10%
Extremely unlikely 0-1%
Intergovernmental Panel on Climate Change
• Record the rationale for judgements
• Consider using formal expert elicitation techniques
16. Limits to quantification
• EFSA Draft Guidance recognises assessors may
not always be able to quantify overall uncertainty
− In such cases, they should not give qualitative
expressions that imply quantitative judgements
− Instead, they should:
o Report that the overall uncertainty cannot be
quantified
o Consider partial quantification, conditional on
assumptions about the unquantified uncertainties
o Highlight & describe the unquantified uncertainties
16
17. IPCS Guidance (2014)
• Focus on uncertainty in
chemical hazard
characterisation
• Guidance and Excel
spreadsheet tool
17
18. IPCS Guidance (2014)
• Quantifying uncertainty requires precise
definition of the parameter to be estimated
• Existing reference doses are ambiguous
− E.g. Tolerable Daily Intake = ‘dose that can be
ingested daily over a lifetime without posing
significant risk to health’
• IPCS Guidance defines HDM
I: the Human Dose at
which a fraction (or incidence) I of the population
shows an effect of magnitude (or severity) M or
greater
18
19. IPCS Guidance (2014)
• Quantifies uncertainty of HDM
I based on:
− Databases on intra- and inter-species variation
for multiple chemicals
− Statistical modelling
• Example: Deoxynivalenol
− BMDL10 for body weight = 170 μg/kg bw/day
− Conventional reference dose = 1.7 μg/kg bw/day
− HD05
01 : 90% CI = 0.44 – 19.2 μg/kg bw/day
− Probabilistic reference dose = 0.44 μg/kg bw/day
− Conventional reference dose has 68% coverage
19
20. Implications for risk assessors
• Need to apply the Codex Working Principles
• EFSA Guidance provides a general toolbox
− flexible and scalable to the needs of each case
− basic approaches require expert judgements
comparable to current assessments, with
increased transparency
• IPCS Guidance offers specific tools for chemical
hazard characterisation
− similar initiatives may be needed in other areas
• Training and specialist help will be needed
20
21. Implications for risk managers &
stakeholders
• Better information on uncertainty
− Range and likelihood of possible outcomes
− Identify and describe unquantifiable uncertainties
• More transparency about:
− Justification for expert judgements
− Variation in expert opinion
• Better basis for decision-making
− Including participatory approaches
• More transparency about how the impact of
uncertainty on decision-making is resolved
21
22. Challenges ahead
• Culture change for risk assessors & managers
− Recognition of need
− Understanding of roles
− New methods
− Quantification
• Communication
− New strategies needed
22