Uncertainties in modelling human and
ecological risks of chemicals, nanomaterials
and (micro)plastics
Ad M.J. Ragas
Department of Environmental Science, Radboud University, Nijmegen, The Netherlands
Department of Science, Open Universiteit, Heerlen, The Netherlands
OECD Workshop on
Managing Contaminants of Emerging Concern in Surface Waters: Scientific developments and cost-effective policy responses
Paris, 5 February 2018
Risks of chemicals, nanomaterials and (micro)plastics
Current management:
• Reactive
• Substance-per-substance
• Resource intensive
• New substances
Modelling aquatic risks of chemicals, nanomaterials and
(micro)plastics
SOURCES
• Consumers
• Agriculture
• Industry
• Etc.
EMISSION
• Point source
• Diffuse
FATE
• Partitioning
• Degradation
• Bioaccumu-
lation
EXPOSURE
• Spatial
variation
• Behaviour
EFFECTS
• Human
• Ecosystems
• Economy
Example: modelling pharmaceuticals in the environment
National
Consumption Data
Substance
Properties
Water & Sediment
Concentrations
MODEL
Uncertainties in modelling aquatic risks of chemicals
SOURCES
• New
substances
• Product
composition
• Spatially
explicit use
data
EMISSION
• Linking use to
emission
FATE
• Ionising
compounds
• Biodegradation
• Secondary
effects (e.g.
Antibiotic
Resistance)
EXPOSURE
• Exotic
exposure
routes (e.g.,
vultures &
bees)
EFFECTS
• Untested
substances =>
(eco)toxico-
genomics?
• Mixture effects
• Interaction
with other
stressors
Uncertainties in modelling aquatic risks of chemicals
SOURCES
• New
substances
• Product
composition
• Spatially
explicit use
data
EMISSION
• Linking use to
emission
FATE
• Ionising
compounds
• Biodegradation
• Secondary
effects (e.g.
Antibiotic
Resistance)
EXPOSURE
• Exotic
exposure
routes (e.g.,
vultures &
bees)
EFFECTS
• Untested
substances =>
(eco)toxico-
genomics?
• Mixture effects
• Interaction
with other
stressors
Uncertainties in modelling aquatic risks of nanomaterials
SOURCES
• New materials
• Specification of
products and
materials
• (Spatially
explicit) use
data
EMISSION
• Linking use to
emission
FATE
• Partitioning
(colloid
chemistry)
• Dissolution
• Aggregation
• Detection
• Long-term fate
EFFECTS
• Toxicity testing
protocols
• Physical effects
• Long-term
effects
• Detection
SimpleBox4Nano
EXPOSURE
• Exposure
metric: weight,
surface area,
other?
Uncertainties in modelling aquatic risks of nanomaterials
SOURCES
• New materials
• Specification of
products and
materials
• (Spatially
explicit) use
data
EMISSION
• Linking use to
emission
FATE
• Partitioning
(colloid
chemistry)
• Dissolution
• Aggregation
• Detection
• Long-term fate
EFFECTS
• Toxicity testing
protocols
• Physical effects
• Long-term
effects
• Detection
SimpleBox4Nano
EXPOSURE
• Exposure
metric: weight,
surface area,
other?
Uncertainties in modelling aquatic risks of (micro)plastics
SOURCES
• Macroplastics
• Cosmetics
• Tyres
• Synthetic
textiles
• ????
EMISSION
• Linking use to
emission
FATE
• Degradation
macro to micro
• Dispersal
behaviour in
relation to
specific weight
• Vehicle?
• Long-term fate
• Deep seas
• Detection
EFFECTS
• Physical effects
• Indirect effects
• Long-term
effects
• Detection
EXPOSURE
• Spatial
variation
Uncertainties in modelling aquatic risks of (micro)plastics
SOURCES
• Macroplastics
• Cosmetics
• Tyres
• Synthetic
textiles
• ????
EMISSION
• Linking use to
emission
FATE
• Degradation
macro to micro
• Dispersal
behaviour in
relation to
specific weight
• Vehicle?
• Long-term fate
• Deep seas
• Detection
EFFECTS
• Physical effects
• Indirect effects
• Long-term
effects
• Detection
EXPOSURE
• Spatial
variation
Key messages
• We need to get more grip on product composition and (spatially
explicit) use data in order to produce reliable emission estimates
• In order to improve the prediction of the fate of chemicals in the
environment we need to focus on degradation data and the
behaviour of ionizing compounds
• In order to improve the prediction of effects of chemicals we need to
focus on Quantitative Structure Activity Relationships (QSARs),
(eco)toxicogenomics and mixture effects
• The two most important questions for (micro)plastics and
nanomaterials are long-term fate (degradation) and effects

Session 2 - Prof. A.M.J Ragas (AD)

  • 1.
    Uncertainties in modellinghuman and ecological risks of chemicals, nanomaterials and (micro)plastics Ad M.J. Ragas Department of Environmental Science, Radboud University, Nijmegen, The Netherlands Department of Science, Open Universiteit, Heerlen, The Netherlands OECD Workshop on Managing Contaminants of Emerging Concern in Surface Waters: Scientific developments and cost-effective policy responses Paris, 5 February 2018
  • 2.
    Risks of chemicals,nanomaterials and (micro)plastics Current management: • Reactive • Substance-per-substance • Resource intensive • New substances
  • 3.
    Modelling aquatic risksof chemicals, nanomaterials and (micro)plastics SOURCES • Consumers • Agriculture • Industry • Etc. EMISSION • Point source • Diffuse FATE • Partitioning • Degradation • Bioaccumu- lation EXPOSURE • Spatial variation • Behaviour EFFECTS • Human • Ecosystems • Economy
  • 4.
    Example: modelling pharmaceuticalsin the environment National Consumption Data Substance Properties Water & Sediment Concentrations MODEL
  • 5.
    Uncertainties in modellingaquatic risks of chemicals SOURCES • New substances • Product composition • Spatially explicit use data EMISSION • Linking use to emission FATE • Ionising compounds • Biodegradation • Secondary effects (e.g. Antibiotic Resistance) EXPOSURE • Exotic exposure routes (e.g., vultures & bees) EFFECTS • Untested substances => (eco)toxico- genomics? • Mixture effects • Interaction with other stressors
  • 6.
    Uncertainties in modellingaquatic risks of chemicals SOURCES • New substances • Product composition • Spatially explicit use data EMISSION • Linking use to emission FATE • Ionising compounds • Biodegradation • Secondary effects (e.g. Antibiotic Resistance) EXPOSURE • Exotic exposure routes (e.g., vultures & bees) EFFECTS • Untested substances => (eco)toxico- genomics? • Mixture effects • Interaction with other stressors
  • 7.
    Uncertainties in modellingaquatic risks of nanomaterials SOURCES • New materials • Specification of products and materials • (Spatially explicit) use data EMISSION • Linking use to emission FATE • Partitioning (colloid chemistry) • Dissolution • Aggregation • Detection • Long-term fate EFFECTS • Toxicity testing protocols • Physical effects • Long-term effects • Detection SimpleBox4Nano EXPOSURE • Exposure metric: weight, surface area, other?
  • 8.
    Uncertainties in modellingaquatic risks of nanomaterials SOURCES • New materials • Specification of products and materials • (Spatially explicit) use data EMISSION • Linking use to emission FATE • Partitioning (colloid chemistry) • Dissolution • Aggregation • Detection • Long-term fate EFFECTS • Toxicity testing protocols • Physical effects • Long-term effects • Detection SimpleBox4Nano EXPOSURE • Exposure metric: weight, surface area, other?
  • 9.
    Uncertainties in modellingaquatic risks of (micro)plastics SOURCES • Macroplastics • Cosmetics • Tyres • Synthetic textiles • ???? EMISSION • Linking use to emission FATE • Degradation macro to micro • Dispersal behaviour in relation to specific weight • Vehicle? • Long-term fate • Deep seas • Detection EFFECTS • Physical effects • Indirect effects • Long-term effects • Detection EXPOSURE • Spatial variation
  • 10.
    Uncertainties in modellingaquatic risks of (micro)plastics SOURCES • Macroplastics • Cosmetics • Tyres • Synthetic textiles • ???? EMISSION • Linking use to emission FATE • Degradation macro to micro • Dispersal behaviour in relation to specific weight • Vehicle? • Long-term fate • Deep seas • Detection EFFECTS • Physical effects • Indirect effects • Long-term effects • Detection EXPOSURE • Spatial variation
  • 11.
    Key messages • Weneed to get more grip on product composition and (spatially explicit) use data in order to produce reliable emission estimates • In order to improve the prediction of the fate of chemicals in the environment we need to focus on degradation data and the behaviour of ionizing compounds • In order to improve the prediction of effects of chemicals we need to focus on Quantitative Structure Activity Relationships (QSARs), (eco)toxicogenomics and mixture effects • The two most important questions for (micro)plastics and nanomaterials are long-term fate (degradation) and effects