Cumulative Risk Assessment

Transcription

1 Cumulative Risk Assessment Acropolis - Better tools Jørgen Schlundt Bodil Hamborg Jensen

2 Risk Analysis - DK Risk Assessment National Food Institute Independent science Risk Management Danish Vet. And Food Administration Regulation - Action Risk Communication Interactive exchange of information and opinions concerning risks

3 Organization of National food safety, quality and nutrition systems Risk Assessment Ministry of Science, Technology and Innovation Risk Management Technical University of Denmark Contract Ministry of Food, Agriculture and Fisheries National Food Institute Annex Danish Veterinary and Food Administration

4 "There is a pathway from good science to publication to evidence, and to programs that work. In this way research becomes an inherent part of problem-solving and policy implementation" Julio Frenk Former Mexican Minister of Health Dean, Harvard School of Public Health

5 But only if You manage to Communicate to all stakeholders While Industry involvement present Conflicts, Consumers involvement is necessary in determining an acceptable level of risk (accepting that this level is in many (most) cases not zero! Interactive communication with consumers should be the basis for including public opinion into food safety policy decisions. Unfortunately many scientists (and communicators) seem to think that this is too complicated for ordinary consumers. It is not! In many cases consumers are well aware of the need to accept some level of risk but consumers often assess in-voluntary risk (risk in food) significantly different from voluntary risk (risk from smoking) Accepting risk cannot be 0 does not equal accepting status quo!

6 Bridging the Know-Do gap in global health Research Problems Well, actually: In food safety we have this joint: Risk analysis

7 Chemical and microbiological risk assessment are not the same Chemical is old and well respected? - maybe lacking some new methodology - maybe overlapping into risk management ( acceptable.. ) Microbiological is new and over-complicated? - introducing probabilistic modelling - allergic to risk management?

8 Chemical and microbiological risk assessment are not the same Chemical risk assessment already from 1956? the creation of JECFA (WHO/FAO Expert Comm. Food add.) linking, but separating risk assessment and risk management basis for the WHO/FAO Codex Alimentarius Commission Acceptable Daily Intake (part of risk assessment!?) Microbiological risk assessment from 2000 introducing stochastic descriptions and probabilistic modelling Introducing microbiological criteria, but also risk reduction Attributing disease to food source, and estimating disease burden

9 Deterministic / Stochastic There are distributions of chemicals in food There are distributions of resistance in humans There are distributions of genetic traits There are distributions of metabolic pathways Deterministic descriptions do not deal well with distributions Deterministic descriptions do not deal well with probabilities Stochastic descriptions do

10 Toxicological Evaluation Exposure Assessment Key NOAEL Uncertainty factors Chemical analysis X Exposur e Food consumption Safety standard e.g. ADI/TDI=NOAEL/UFs Safety assurance: Exposure < ADI Exposure > ADI Managemen Decision

11 11? EDC s

12 Back to basis F. Bacon: Science is based upon pure observation Karl Popper: All observation is an interpretation of facts in the light of some theory Do we know the underlying risk assessment theory? A change of paradigm is most likely needed to include combined exposure to multiple chemicals in traditional risk assessment methodology

13 Multiple Chemicals Human risk assessment of combined exposure to multiple chemicals poses several challenges: the complexity of the terminology and problem formulation, the diversity of chemical entities, and the toxicological profiles and exposure patterns in test species and humans

14 A tiered approach combined exposure An example of high relevance is the risk assessment of combined exposure to multiple pesticides in food under Regulation (EC) 396/2005 for which Cumulative Assessment Groups have to be defined based on hazard data to set MRLs. Risk assessment for multiple chemicals is then conducted using a tiered approach for exposure assessment, hazard assessment and risk characterisation. The tiers range from qualitative/semi-quantitative tier 0 to fully probabilistic tier 3 (probabilistic models for exposure assessment and physiologically-based models for hazard assessment). The choice of the tier depends on data availability, the purpose of the risk assessment and the resources available.

15 Old school: Looking where the data is in stead of Looking for the right data

16 Mixture or Components whole mixture approach when toxicological data are available for the mixture or for a similar mixture which can then be used as a surrogate component-based approaches when dose response data for specific toxicity endpoints of individual components are known to aid in placing these in cumulative assessment groups/assessment groups (CAGs/AGs) - using assumptions of additivity (dose addition, response addition) or interaction (synergism, antagonism) amongst the multiple chemicals (often based on target organ toxicity)

17 International solutions? Most national and international frameworks apply step wise decision trees/tiered approaches for risk assessment of combined exposure - Original framework developed at the US-EPA. The main differences between the frameworks are in the lay-out rather than in the methodologies: WHO International Programme on Chemical Safety (IPCS) WHO JECFA (Joint Exp. Committee of Food Additives and contaminants) US-EPA, Agency for Toxic Substances and Disease Registry (ATSDR) Norwegian Committee for Food Safety (VKM), UK s Interdepartmental Group on Health Risks from Chemicals, Three Non-Food Committees of the European Commission EFSA

18 International differences? Key differences include the separation of two different frameworks for cancer and non-cancer effects (ASTDR) versus the use of single tiered approach (EU Non-Food Committees, WHO) the use of dose addition as the basis of the setting of assessment groups unless evidence demonstrates otherwise and requires refinement of the assessment (WHO, three Non- Food Committees, EFSA).

19 International differences? European Commission Regulation (EC) No 396/2005. Denmark became an associate partner to the Acropolis project in We deliver relevant data to the project and to EFSA. Monte Carlo Risk Assessment programme/tool can aid in estimating cumulative exposure basically as described in the guidance document from EFSA Estimation of cumulative intake for triazoles has been developed within the Acropolis umbrella..

20 Use of MonteCarlo? Deterministic risk assessment has been used in the chemical area for many years If we want more detailed, sophisticated assessments probabilistic method is clearly the future Monte Carlo probabilistic modelling can be used for all types of chemical risk assessment Acropolis Project has helped us introduce new tools

21 WTO standards and Food safety The SPS Agreement (Sanitary and Phytosanitary Measures) Members have right to take measures necessary for the protection of human health International standards related to food safety and recognized by SPS are those established by the FAO/WHO Codex Alimentarius Commission Members shall ensure that their measures are based on an assessment of the human health risk, using internationally agreed risk assessment techniques Members agree to facilitate the provision of technical assistance to other Members, especially developing country Members, either bilaterally or at international level Where substantial investments are required for an exporting developing country to fulfil sanitary requirements of an importing Member, the latter shall consider providing such technical assistance needed to maintain and expand market access of exporter

22 Lowering disease risk? Nations can maintain food safety benefits for their own citizens for a (limited) period If the rest of the world is not convinced how long will a production sector be able to uphold a higher level of protection Good food safety strategies must be exported experience must be shared Good models must be exported Good Science prevails

23 Continuous improvement Science Independence Resolve