Nanomaterialer i miljøet – den lille forskel Anders Baun Professor i risikovurdering af nanomaterialer
Nanomaterialer i miljøet – den lille forskel
Anders Baun
Professor i risikovurdering af nanomaterialer
Definition af nanomaterialer
At nanoscale the physical, chemical and biological properties of materials
differs in fundametal and valuable ways from bulk properties and
individual atoms Definition: National Nanotechnology Initiative (USA), Strategy Plan, Dec 2004
Nanomaterial: nano-scale AND added functionality due to the scale
Altså: En lille størrelse (1-100 nm) OG en ekstra (evt. tidligere ukendt)
funktionalitet på grund af størrelsen
Kommissionens anbefaleded NM
definition – 18 Okt, 2011
A natural, incidental or
manufactured material
containing particles, in an
unbound state or as an
aggregate or as an
agglomerate and where, for
50 % or more of the
particles in the number size
distribution, one or more
external dimensions is in the
size range 1 nm - 100 nm.
Nanomaterialer har været brugt i
mange år • 3 nm Pt, Pd og Rh nanopartikler
• Omdanner skadelige udstødingsgasser til ufarlige
CO+O2→CO2
CxHy+O2→CO2+H2O
NO+CO→N2+CO2
Metal ”bitavle”’
Bilkatalysator
Al2O3 bæremateriale
Rhodium Platin
Ce-Zr Oxide
iNANO, University of Aarhus
Nanomaterialer har været brugt i
mange år
Og der har været fokus på miljørisici de
seneste 10 år
… men hvordan er det nu…?
”Udgør de egentlig en miljørisiko
eller hva´?”
NanoDen
Hartmann, Skjolding, Hansen,
Kjølholt, Gottschalck, Baun
Predicted environ-
mental concentrations
Predicted
No-effect
concentrations
Risk
Assessment
2015
1 2
3 4
Nanomaterialer i miljøet
– en risiko?
Generic modelling &
ecotox extrapolations:
Hold øje med:
Cu(X)
Ag
Miljørisikovurdering af nanomaterialer
i Danmark
Nanomaterial Sewage treatment plant effluent Surface water, fresh
"Average"1 "High end"2 "Average"1 "High end"2
TiO2 (p-stable) Risk unlikely Risk possible Risk very unlikely Risk very unlikely
TiO2 (p-cat.) Risk very unlikely Risk unlikely Risk very unlikely Risk very unlikely
ZnO Risk very unlikely Risk very unlikely Risk very unlikely Risk very unlikely
Ag Risk very unlikely Risk possible Risk very unlikely Risk very unlikely
CNT Risk very unlikely Risk very unlikely Risk very unlikely Risk very unlikely
CuO Risk possible3 Risk likely3 Risk very unlikely3 Risk very unlikely3
nZVI (Risk very unlikely)4 (Risk very unlikely)4 (Risk very unlikely) (Risk very unlikely)
CeO2 Risk very unlikely Risk very unlikely Risk very unlikely Risk very unlikely
QD (Risk very unlikely) (Risk very unlikely) (Risk very unlikely) (Risk very unlikely)
CB (Risk possible) (Risk possible) Risk very unlikely Risk very unlikely 1 Average = Based on most probable exposure concentration (modelled) 2 High end = High end of 95% confidence interval of modelled exposure concentrations 3 Theoretical (worst case) scenario 4 Scenario irrelevant
NanoDen – COWI, DTU Miljø, SMC
Fysiske
effekter
Opløselighed
Optag/afgivelse
Kendt virke-
måde for NP
Skjolding, L.M., Sørensen, S.N., Hartmann, N.B., Hjorth, R., Hansen, S.F., Baun, A. (2016) A Critical Review of Aquatic
Ecotoxicity Testing of Nanoparticles – The Quest for Disclosing Nanoparticle Effects: Angewandte Chemie
doi: 10.1002/anie.201604964
Er der nano-specifikke effekter?
Fysiske
effekter
Opløselighed
Optag/afgivelse
Kendt virke-
måde for NP
T!
C!
Skjolding, L.M., Sørensen, S.N., Hartmann, N.B., Hjorth, R., Hansen, S.F., Baun, A. (2016) A Critical Review of Aquatic
Ecotoxicity Testing of Nanoparticles – The Quest for Disclosing Nanoparticle Effects: Angewandte Chemie
doi: 10.1002/anie.201604964
Er der nano-specifikke effekter?
Omdannelsesprocesser foregår
under testningen
Dispersion Dissolution
Agglomeration / Aggregation
Sedimentation
Absorption In situ functionalization
Biomodification
Sørensen, Hjorth, Delgado, Hartmann, Baun (2015) Nanoparticle ecotoxicity – physical and/or chemical effects? Integrated Environmental Assessment and Management, 11, 722-724 - den lille forskel
Tab af kontrol…
Partikler
Ikke opløste
Partikler opfører sig ikke ”pænt””
Koncentationer (!)
Fortynding…
Test medier
Organismer
Tid!
Ikke ligevægt
Ukontrollerbare dynamiske ændringer af vigtige
parametre under testingen
Effekt = f(konc|t,org,medie) ?
- den lille forskel
Før, under og efter - kontrollér og beskriv…
Hartmann, N.B., Engelbreckt, C., Zhang, J., Ulstrup, J., Kusk, K.O., Baun, A., 2013. The challenges
of testing insoluble metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold
nanoparticles as case studies. Nanotoxicology DOI: 10.3109/17435390.2012.710657
Effekt = f(konc|(tid, organisme, medie) …?
- den lille forskel
TiO2 nanopartikler i algetest
flere spørgsmål end svar?
Figure 3. Encapsulation of algal cells (Pseudokirchneriella subcapitata) exposed to TiO2 nanoparticles. A: Scanning electron microscopy (SEM) image of an algal cell after exposure to 50 mg/L TiO2 in ISO algal test media for 48 h. B: Corresponding SEM-EDX dot map shows the distribution of Ti. It can be seen that the TiO2 nanoparticles cover the surface of the algae (Modified from Hartmann et al., 2010 – Paper I). C: Transmission electron microscopy (TEM) images showing the formation of algae-particle heteroaggregates (scale bar: 2 μm). (Modified from Hartmann et al., 2011b – Paper IV)
C
A B
Hvad er den egentlige
eksponering/dosis? Giver
det mening at snake om
vandfase koncentrationer?
Hvordan måler man egentlig
om algerne er hæmmede?
Alger udskiller stoffer
(exudater) – er det dem der får
det hele til at klumpe
sammen?
Sker der en skygning på
celleniveau?
Hartmann et al.,2013, Nanotoxicology, 7(6)1082-1094.
Hartmann et al., 2010, Toxicology, vol 269, pp. 190-197 - den lille forskel
Fysiske eller “kemiske” effekter?
Figure 4. Uptake and adhesion of nanoparticles in crustaceans. A1 & B1: C60 and TiO2 is seen in the digestive tract of Daphnia magna after 48 hour exposure to 3 mg/L nC60 and 40.5 mg/L TiO2 prepared by prolonged stirring in indirect sunlight and sonication respectively. A2, B2 & C2.: Adhesion of nanoparticles to the exoskeleton of D. magna and Acartia tonsa (Modified from Baun et al. Scale bars correspond to 200 μm. (2008a – Paper VI)).
Attachment to
the organisms
can impair
movement
Accumulation in
the gut can
reduce food
uptake
Baun et al., 2008, Ecotoxicology, vol. 17, no. 5, pp. 387395 - den lille forskel
Fysiske
effekter
Opløselighed
Optag/afgivelse
Kendt virke-
måde for NP
T!
C!
Skjolding, L.M., Sørensen, S.N., Hartmann, N.B., Hjorth, R., Hansen, S.F., Baun, A. (2016) A Critical Review of Aquatic
Ecotoxicity Testing of Nanoparticles – The Quest for Disclosing Nanoparticle Effects: Angewandte Chemie
doi: 10.1002/anie.201604964
Er der nano-specifikke effekter?
Anerkend at “den lille forskel” indebærer, at
and account for the confounding factors…
Baalousha & Lead (2013). Nature Nanotechnology, 8, 308-309
Baun, et al. (2008).. Ecotoxicology, 17 (5), 387-395
Hartmann et al.. (2013)..Nanotoxicology DOI: 10.3109/17435390.2012.710657
.
EnvNano
Effect = f(konc.,tid, organisme, medie etc)
Hvordan får jeg mit syn tilbage?
Formål:
At dokumentere de
mekanismer, der er involverede
i algevæksthæmning af platin-
nanopartikler i standard test til
farlighedsidentifikation
- og beskriv, beskriv, beskriv…
Exposure concentration
Response
”Hvad er farligt?” – find 5 fejl (EEA, 2001)
Nyt
Vidtspredt (mobilt)
Bioakkumulerbart
Persistent
Irreversible effekter (fx toksicitet)