1 / 14

Risk Assessment - Scientific Challenges A Perspective from the NanoSafety Project Team

Risk Assessment - Scientific Challenges A Perspective from the NanoSafety Project Team. Jutta Jahnel. NanoSafety Project. NanoSafety – Risk Governance of Manufactured Nanoparticles

wilda
Download Presentation

Risk Assessment - Scientific Challenges A Perspective from the NanoSafety Project Team

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. Risk Assessment - Scientific Challenges A Perspective from the NanoSafety Project Team JuttaJahnel

  2. NanoSafety Project • NanoSafety – RiskGovernanceofManufacturedNanoparticles • Commissionedby STOA, carried out by KIT-ITAS, Karlsruhe (projectcoordination) and ITA, Vienna asmembers of ETAG • STOA Project Supervisor: Prof. Vittorio Prodi, MEP • Duration: January 2010 – October 2011 • The project deals with the governance of the potential environmental, health and safety risks of manufactured nanoparticles, the challenges for risk assessment and risk management and the regulation under uncertainty • Focus: Risk and concern assessments as well as risk management strategies as discussed or proposed for the EU or its member states | Jutta Jahnel | ITAS | 21.11.2011

  3. Preconditionsforriskassessmentstudy • The presentedresultsarebased on an up-to-date literaturereview • Working definition: Manufactured Particulate Nanomaterials (MPN) • Focus: safetyobjective „human health“ • Riskassessmentis a prerequisiteofscience-basedriskmanagementandmeansthequantificationoftheprobabilityofharmfuleffectscausedbyexposureto an agent • Situation:Thereisnogenerallyacceptedparadigmforriskassessmentfornanomaterialsorproductscontainingthem • Question: Couldscientificdataprovideappropriateknowledgeforpolicymakerstoperformriskassessment? | JuttaJahnel | ITAS | 21.11.2011

  4. RiskAssessmentParadigm According to OECD (2003): Environment Directorate. Description of selected key generic terms used in chemical/hazard assessment. OECD Series on Testing and Assessment Number 44. ENV/JM/MONO(2003). | Jutta Jahnel | ITAS | 21.11.2011

  5. Toxicity Tests for Hazard Assessment Nanotoxicologyusesclassicaltoolsfromtoxicology: • Cell-freeassays: propertieslikesolubility, reactivity, agglomerationstate, reactiveoxygenspecies (ROS) generating potential • In vitro assays: biologicaltestswithprimarycells, cell-lines, organs Challenge: potential evidencefor human disease? • In vivo studies: effects on a wholelivingorganism – laboratoryanimals - (acute/chronictoxicity, skin, respiratoryand gastrointestinal tract) Challenge: extrapolation of thedatatohumans, extrapolationfromhighertolowerdoses, safetyfactors? • Human andepidemiologicalstudies: occurrenceanddistributions of diseases in populations Challenge: diseasescausedbywhichkind of kownorunknownhazardendpoint? | Jutta Jahnel | ITAS | 21.11.2011

  6. ToxicityMechanismsforHazardAssessment Hazard endpoints: • Structure – toxicity relationship (free radical activity, chemical reactivity) • Increased production of reactive molecules like (ROS) • Inflammation (recruiting immune cells) • Genotoxicity (damage or changes of the DNA) • Cytotoxicity Predicting ? Identification ? Safety endpoints (impact on human health): • Respiratory, cardiovascular disease, allergic sensitisation • Fibrosis, cancer, bronchitis, immunopathology (asthma) | Jutta Jahnel | ITAS | 21.11.2011

  7. Material based View: Exposure Scenarios Material (chemicalcomposition) Manufacturing Manufacturing Application Human Uptake, distribution, accumulation Disease Suspended Embedded Surface bound others cosmetics Size distribution Morphology Aggregation others Form 1 Mat. 1 food Form 2 Consumer Mat. 2 others others others Worker Public Environment | Jutta Jahnel | ITAS | 21.11.2011

  8. Limitations for Exposure Assessment • Lack oflabellingandregistrationofnanoproducts • Missinglifecycleassessment of nanoproducts • Measurement anddetection: MPN undergochangesduringtransmissionintotheenvironment, difficultytodifferentiateengineeredfrom non-engineeredmaterials • Insufficientdataavailable | Jutta Jahnel | ITAS | 21.11.2011

  9. Entry intothe Human Body (Uptake) • Lung: mostimportantportofentryforairborneparticles, uptake via inhalation, occupationalexposure • Nasal cavity: uptake via inhalation, directexpositionoftheolfactory nerve • Gastro-intestinal tract: MPN cancrossepithelial, endothelialbarries, onlyveryfewstudiesavailable, importantentryforfoodapplications • Skin: penetrationofdamagedskincan not beexcluded, importantentryforcosmeticapplications • Parenteral via directinjection (medicalcontextwithowncriteriaforriskassessment) | Jutta Jahnel | ITAS | 21.11.2011

  10. Translocationand Distribution (ADME profile) • Penetration throughtheair–bloodtissuebarrier in thelung • Penetration oftheblood-brainbarrierandblood-placentabarrier • Transport bythelymphaticsystem • Transport intosecondaryorgans • Enrichment in liver, spleen, kidneys, reachingheart • Verylittleisknownaboutthemetabolization, excretionandelimination Thereare different kind of hazards: • atsitesofdeposition, • due totranslocationfrompulmonaryportal of entryintotheblood, systemicconsequencescould in theoryresult in additional healtheffectslikeneurophysiologicaldiseases | Jutta Jahnel | ITAS | 21.11.2011

  11. ChallengesforRiskAssessment | Jutta Jahnel | ITAS | 21.11.2011 • Definition of Manufactured Particulate Nanomaterials (MPNs) – a large variety of materials, different sizes and forms with a lack ofcommoncharacteristicsbesidethenanoscale, nohazardclasses • Detection (biological, technicalmatrices) andcharacterisation: intrinsiclimitations • Dose andamountof MPN: missingconcept Dose = total amountofsubstance / time period amount: mass? surfacearea? particlenumber? reactivity? • MethodologyforHazardAssessment: classicaltoxicology, lack of standardised methods, appropriate controls, suitability of high dose in vitro or in vivo studies • Exposure assessment: insufficient data for occupational, environmental and consumer scenarios, acute and chronic exposure • Case bycaseassessment (fulldatasetforeverykind of MPN) • Reliableevidenceforriskassessmentonlyfor a smallselectionofhigh abundant MPNs

  12. Conclusionsfor Selected MPN ENRHES (2010): Engineered Nanoparticles: Review of Health and Environmental Safety. http://nmi.jrc.ec.europa.eu/documents/pdf/ENRHES%20pdf. | Jutta Jahnel | ITAS | 21.11.2011

  13. Recent Toxicological Research Situation • Published interpretations of experimental results, especially those regarding potential impacts on human health and on the environment, are still insufficient, contradictory and controversial (concerns about quality, comparability and relevance) • Results of ‚no effects‘-experiments are usually not published • Questionable extrapolation of laboratory data (hazard endpoints) to an human health impact (safety endpoint) • Filling knowledge gaps by modelling, meta-analysis, well-linked and cross-talk between nanomedicine, nanoengineering and nanosafety (interdisciplinarity) • Systemic view in addition to separate analytic views for providing useful answers that can be translated into actions • Pragmatic preliminary risk assessment (levels of concern, risk classes) Criteria: physico-chemical properties, exposure, extent of knowledge | Jutta Jahnel | ITAS | 21.11.2011

  14. ThankYouforYour Attention Jutta.Jahnel@kit.edu Project Team: Torsten Fleischer Jutta Jahnel Stefanie Seitz Jutta Schimmelpfeng Ulrich Fiedeler Julia Haslinger Myrtill Simko | Jutta Jahnel | ITAS | 21.11.2011

More Related