Environmental (Ecological) Risk Assessment for ?· Environmental (Ecological) Risk Assessment for Nanomaterials…

Download Environmental (Ecological) Risk Assessment for ?· Environmental (Ecological) Risk Assessment for Nanomaterials…

Post on 01-Sep-2018




0 download


  • Environmental (Ecological) Risk Assessment for Nanomaterials

    Dana Khnel (UFZ)

    David Rickerby (JRC)

    Summer School, Tallin,


  • Agenda

    1. Fundamentals of ERA

    2. Release of NM

    3. Fate & Exposure of NM

    4. Ecotoxicity / Hazard

    5. Risk management

    6. Regulation (REACh and Co.)

    7. Nano-specific RA tools

  • Perspectives of ERA

  • Fundamental principles of RA














    Organisms (Algae,

    fish, water flea)

    Endpoints (growth,

    survival, mobility,





  • Fundamental principles of RA

    Key steps in risk assessment:

    1. Problem formulation

    2. Hazard identification

    3. Release assessment

    4. Exposure assessment

    5. Risk estimation

  • Ecological Risk Assessment

    PEC: predicted environmental concentration

    PNEC: predicted no effect concentration

    Exposure assessment PEC

    Effect assessment NOEC PNEC

    (representative species)

    Assessment factors


    Risk evaluation

    PEC vs. PNEC

    PEC/PNEC > 1

    Possible risk

    PEC/PNEC < 1

    No risk


    Exposure assessment PEC

  • From ENM to an effect



    Transport Transformation



    Effect Toxicology Effect?

  • Risk of Release and Distribution Routes


    Need to understand the relationship between the local emission routes and the distribution processes for different environmental compartments

    Specific fate and distribution models are applicable for individual compartments

  • production




    use phase

    final disposal

    Releases into the environment can take place from processes at any stage of the life cycle:

    Technical Guidance Document on Risk Assessment, European Chemical Bureau, 2003

    Potential Life Cycle Scenarios

  • Page 10

    Indium tin oxide (ITO)

    Lacquer and plastics additive

    Touch screens




    Skin care, sun screen

    Anti-fogging agents


    Facade and wall colour


    Photovoltaic cell



    Wound dressings

    Free Embedded

    Release of nanomaterials

  • Pathways for Release into the Environment


    Release may occur during production, transport, storage, distribution, use and final disposal

    S. Friedrichs and J. Schulte, Sci. Technol. Adv. Mater. 8 (2007) 12-18

  • From textiles equipped with Ag for antibacterial purposes

    Release of nAg or ions?

    Benn et al. (2008) ES&T 42, 41334139.

    Example I: Washing off of nAG

  • Example II: nTiO2 in facade paint

    Release during weathering

    Modified NM reach the environment: paint matrix

    Environmental exposure not to as-produced NM

    Kaegi et al. (2008) Environmental Pollution 156 (2): 233-239

  • From Release to Exposure Environmental Fate Modelling

    The models calculate concentrations in environmental media and the mass fluxes of the substance between these media

    Need to identify properties of nanomaterials that govern distribution processes to derive input parameters for the models

    M. Scheringer, Nature Nanotechnol. 3 (2008) 322-323

  • Physical-chemial characteristics of NM will determine their fate (in which compartments an accumulation of NM is observed)

    transport, distribution, accumulation, transformation processes for NM in the different compartments (soil, sediments, surface water, ground water) need to be further studied

    The physical-chemical characteristics differ from that of chemicals and hence the parameters of the models need to be adopted, e.g. log Kow

    Several test guidelines are used to study these processes suitable for NM

    From Release to Exposure Environmental Fate Modelling

  • Sanchis et al. (2012) ES&T 46, 1335-1343.

    Fulleres (C60 and C70) were detected in the Mediterranean atmosphere (ng/m3)

    Occurence can be related to industrial activity, but the release/emission path is unclear

    Probably side products of combustion processes, unintentially produced NM?

    Example : Occurence of fullerens

  • Predicted Environmental Concentrations

    Predictions are based on:

    - production volumes

    - categories of products containing nanomaterials

    - paths of particle release Mueller and Nowack (2008) Environ. Sci. Technol. 42: 4447-4453.

    Sun TY et al. (2014) Environ Pollut 185, 69-76.

    NM Soil Sludge treated soil

    Surface water

    STP effluent

    STP sludge

    sediment air Year

    Nano-TiO2 1.28 89.2 0.015 3.47 136 358 2008

    0.13 1200 0.53 16 170 1.9 0.001 2014

    Nano-ZnO 0.093 3.25 0.010 0.432 17.1 2.90 2008

    0.01 0.01 0.09 2.3 24 0.32

  • Predicted Environmental Concentrations

    Sun TY et al. (2014) Environ Pollut 185, 69-76.


    concentration NM

    Modelled concentration






  • Fate and transformation

    Little knowledge on transformation and degradation of NM

    e.g. dissolution processes / degradation of arganic coating

    Sorption of organic materials present in the environment will influence fate

  • Exposure

    Unsufficient measurement techniques for complex environmental media (especially for water and soil)

    the parameters of importance for the environmental behaviour of NM are not clear yet (e.g. surface modifications are not considered)

  • Ecological Risk Assessment

    PEC: predicted environmental concentration

    PNEC: predicted no effect concentration

    Exposure assessment PEC

    Effect assessment NOEC PNEC

    (representative species)

    Assessment factors


    Risk evaluation

    PEC vs. PNEC

    PEC/PNEC > 1

    Possible risk

    PEC/PNEC < 1

    No risk


    Effect assessment NOEC PNEC

    (representative species)

  • Ecotoxicity Testing

    Representative species (for the different compartments)

    According to test guidelines (OECD, ISO)

    Dose-response relationships ( NOEL)

  • High variation in LC50

    Different types of NM

    and test protocols

    Likewise observed for

    the nAg we worked

    with in NanoValid

    Beispiel aus Supplement: Poynton et al. (2012). ES & T 46, 6288-6296.

    Ranges of toxicity nAg in Daphnia magna

  • Ranges of toxicity CNT Aquatic toxicity classification


    Not toxic > 100

    Harmful 10-100

    Toxic 1-10

    Very toxic 0.1-1

    Extremely toxic < 0.1

  • Comparison of CNT studies

    154 studies in total

    78 11 58

  • Interferences with test systems

    shading (relevant for autotrophic organisms)

    Schwab et al. (2011) ES&T, 45, 61366144.

  • Interferences with test systems

    Binding of components in the test media (e.g. fluorescent dyes)

    Wrle-Knirsch et al, NANO LETTERS, 2006 6(6):1261-1268


    MTT WST-1


    As prepared


  • Uncertainties in the Risk Assessment for Nanomaterials

    Quantitative risk assessment depends on exposure limits based on dose-response relationships and the quantitative evaluation of the exposure

    For nanomaterials neither the hazards or the exposure can be quantified

    This leads to major uncertainties and a need for nanospecific risk assessment

    C. Ostiguy et al. J. Phys. Conf. Series 151 (2009) 012037

  • Towards the improvement of RA procedures

    Are the guidelines, developed for traditional chemicals suitable for the testing of NM?

    Specific NM properties not considered, e.g. agglomeration, sorption

    Amendments necessary?

    OECD-Working Party on Manufactured Nanomaterials (WPMN), expert meetings

    D. Khnel & C. Nickel (2014) Science of The Total Environment, 472, 347353.

  • Scope of the expert meeting

    Discuss suitability of TGs relevant to ecotoxicity and environmental fate testing of NM, compartments water and soil & sediment

    Provide recommendations to WPMN on (1) the need for updating TGs or developing new ones, and (2) guidance needed for NM

    Ecotoxicology Fate & Behaviour

    Aquatic tests

    TG 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test) TG 202 (Daphnia sp. Acute Immobilisation Test) TG 211 (Daphnia magna Reproduction Test) TG 225 (Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment)

    TG 105 (Water solubility) TG 305 (Bioconcentration: Flow-through Fish Test ) (additionally discussed: GD 24 and biodegradation tests in general)

    Soil & sediment tests

    TG 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei)) TG 225 (Sediment-Water Lumbriculus Toxicity Test Using Spiked Sediment)

    TG 106 (Adsorption) TG 312 (Leaching in Soil Columns) TG 315 (Bioaccumulation in Sediment-dwelling Benthic Oligochates) TG 317 (Bioaccumulation in Terrestrial Oligochaetes)

  • Testing steps to consider

    Dispersion of NM in water or media (e.g. enery input)

    Application of NM to the test

    Physical-chemical characterisation before, during and after the test

    NM behaviour during the tests (e.g. sedimentation), test duration

    Interactions with organisms, media components

    Detection of NM in organisms or environmental matrices

    High variations in existing protocols for the different NM

    Many analytical limitations (e.g. NM charact. in soils)

    D. Khnel & C. Nickel (2014) Science of The Total Environment, 472, 347353.

  • Expert recommendations

    The majority of TGs was considered as generally applicable to NMs

    Suggestions for nano-specific amendments: application of NM to the test, behaviour of NM during the test, data analysis, selection of test media

    For several guidelines, critical points were identified, where current knowledge does not justify a recommendation, but which need future clarification

    The development of new TGs suggested

  • Data gaps and research needs

    Physical-chemical characterisation of NM was considered essential for all subsequent steps of testing

    Many data gaps are due to inappropriate methods for NM

    Chronic tests

  • Page 34


    Few regulations specifically apply to NM:

    For chemicals, extensive testing before application is mandatory

    The size of a material alone is so far no basis for RA

    Hence, no specific procedures for NM are compulsory (with the exception of the Biocidal Products Directive 98/8/EEC)

  • REACh (Industrial chemicals)

    no explicit regulation for `nano-size, the need for adoptation of the legislation is under debate

    REACH implementation Project on Nanomaterials (RIPoN)

    `Principle of Similarity` (Use of data derived with similar substances, e.g. bulk material possible)


  • REACh (Industrial chemicals)

    Amendments in Exposure assessment


    Meesters et al. 2013 Integr Environ Assess Manag 9(3): e15-e26

  • REACh (Industrial chemicals)

    lower tonnage thresholds for different REACH obligations

    Adaptation of REACh requirements and test performance to different physico-chemical characteristics of different nanoforms of the same substance

    Schwirn et al. Environmental Sciences Europe 2014, 26:4


  • EU-Biocidal Products Regulations (came into force by 1. Sep. 2013)

    considers `nano, NM in biocidal products need to under go a special assessment

    More strict demands for approval / permission, labelling required http://echa.europa.eu/regulations/biocidal-products-regulation/understanding-bpr


    Labelling in cosmetic products in EU mandatory



  • Nano-specific strategies and tools

    Nano Risk Framework

    Precautionary Matrix for Synthetic Nanomaterials (Vorsorgeraster)

    Risk Assessment of Manufactured Nanomaterials

    NanoCommission Assessment Tool

    Precautionary Strategies for Managing Nanomaterials



    Work Health & Safety Assessment Tool for Handling Engineered Nanomaterials

    Stoffenmanager Nano



    Grieger et al. 2012 Nanotox. 6(2): 196-212.

  • Not implemented in legislation and hence not regulatory binding

    Preliminary assessments, e.g. to deduce occupational safety measures (Aim: Precaution!)

    Many uncertainties (release, exposure, persitence, transport, transformation, ecotoxicology), as these processes are poorly understood for NM

    Nano-specific strategies and tools

  • Nano-specific RA-tools Example 1: Nano Risk Framework

    Traditional risk-assessment paradigm similar to that used by the US EPA

    Complicated to apply - requires data on physical-chemical properties, hazards, exposures, ecotoxicity, and environmental fate


  • Enables assessment of the need for nanospecific precautionary measures and identification of potential risks in production, use and disposal

    Simpler to apply provides an early warning capability enabling the risk potential to be classified to determine what action is appropriate


    Nano-specific RA-tools Example 2: Swiss Precautionary Matrix

  • Risk assessment NM?

    exposure assessment

    Release depends of NM application

    No data on environmental concentrations

    Predicted values

    Development of methods suitable for NM

    hazard assessment

    Several studies, high variance


    Amendments in methodology necessary

  • Wrap up: risk assessment nanomaterials?

    Currently low environmental concentrations of NM

    Predicted concentrations below effect concentrations determined in lab experiments

    But: high uncertainties

    Research needs in many areas Release and exposure data for NM

    Nanospecific amendments in test protocols for toxicology

    Adaptation of models (release, QSAR, LCA)

    Amendments in laws & regulations necessary

  • References / Further Reading

    Technical Guidance Document on Risk Assessment (European Chemical Bureau, 2003)


    C. Ostiguy et al. J. Phys. Conf. Series 151 (2009) 012037

    S. Friedrichs and J. Schulte, Sci. Technol. Adv. Mater. 8 (2007) 12-18

    M. Scheringer, Nature Nanotechnol. 3 (2008) 322-323

    Technical Guidance Document on Risk Assessment, European Chemical Bureau, 2003



  • Page 46

    Thank you for your attention! Questions?

  • http://www.oecd.org/department/0,3355,en_2649_34373_1_1_1_1_1,00.html

    International Test Guidelines on

    physical-chemical properties,

    ecotoxicity, environmental fate,

    human health effects developed

    by the OECD

    Environmental Risk Management


View more >