Nanoparticles in the environment

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Nanoparticles in the environment how small is
the risk?

• Anders Baun
• Nanna Hartmann
• Khara Grieger
• Michael Andersen
• Steffen Foss Hansen

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Is nanotechnology dangerous?
No!
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Nano is not one thing!
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Where is the nano?

• No exposure no risk of toxic effects
• Nano is many things
• If we dont know where it is to begin with how
  can we know where it ends up?
• Location of the nanostructure!

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Surface

• Structured on the nanoscale same material
• Nanoscale thickness,
• unpatterned film
• Patterned film
• Film at nanoscale in thickness
• Surface pattern having nanoscale dimensions

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Particles
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Categorization of the 243 consumer products in
the DK market
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Expected exposures
Stuer-Lauridsen et al. (2007).
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Nano is not one thing!
Nanoparticles

• Natural gtlt Anthropogenic gtlt Engineered

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Ecotoxicity of nanoparticles

• Ecotoxicity towards base set organisms
• Fish
• Crustacean
• Algae

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Environmentally problematic?

• Designed to last Persistent?
• Penetrates biological membranes
  Bio-accumulative?
• Biologically active Toxic?
• Carriers of heavy metals and POPs?
• Extremely mobile
• Difficult to detect

PBT and mobile?!
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Environmental impacts what makes nano special?

• Properties change at nano-scale reactivity vs.
  surface area
• Environmental impacts change?
• Which impacts?
• Are existing methods for evaluation of fate and
  effects adequate?
• Dissolved or particulate?

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Nanoparticles and Ecotoxicity the beginning

• Juvenile largemouth bass exposed to fullerenes
• Concentrations 0.5 and 1 ppm
• Duration 48 h
• Results Significant increase in lipid
  peroxidation of the brain
• Problem Solvent content (THF)

Oberdörster (2004). Environ Health Perspect
1121058-1062
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Before the beginningC60 in water how...?
2 months
Photos by Sara Sørensen, Rikke Rasmussen, Nanna
Hartmann
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TEM images of suspensions
In water Not free nanoparticles
TEM analysis by Christian Bender Koch, KU LIFE
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Comparing the toxicity to B. subtilis of four
differently prepared nC60 water suspensions
1.2
1.0
0.8
0.6
Minimum inhibitory conc. (mg/L)
0.4
0.2
0.0
THF/nC
son/nC
aq/nC
PVP/C60
60
60
60

• Controls with solvents other ingredients showed
  no toxicity

Lyon et al. (2006). EST 40, 4360-4366
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Different methods for making nC60 produce
different kinds of colloids
TTA/nC60
THF/nC60
Brant, J.A., Labuille, J., Bottero, J.Y.,
Wiesner, M.R., Langmuir, in press, 2006.
aqu/nC60
d
c
Son/nC60
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TiO2 in algal medium

• A) P. subcapitata
• B) TiO2 nanoparticles in algal medium
• AB

Hartmann (2007). M.Sc. Thesis.
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Characteristics relevant for hazard
identification of nanoparticles
Crystal structure

• Chemical composition

Shape
Surface chemistry
Surface charge
Adhesion
Size
Solubility
Hansen et al. (2007). Nanotoxicology (accepted)
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What has been characterized in toxicity studies?
Hansen et al. (2007). Nanotoxicology (accepted)
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Toxicity of nanoparticles and nanotubes How much
been tested?
Hansen et al. (2007). Nanotoxicology (accepted)
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Ecotoxicity!
Ecotoxicity!
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Algae

• C60
• We find up to 30 inhibition of algal growth at
  35 mg/l
• TiO2
• EC50 of 44 mg/l (25 nm TiO2)
• No toxicity of 100 nm TiO2 in conc. p to 50
  mg/l
• But we find
• EC50 7.5 mg/l for both

Andersen (2007). M.Sc. Thesis Hund-Rinke
Simon (2006). Environ Sci Pollut Res.
Hartmann (2007). M.Sc. Thesis.
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Crustacean

• Daphnia magna exposed to TiO2 and fullerenes
• Mortality C60 gt TiO2
• C60 50 dead at 0.46 mg/l
• TiO2 50 dead at 5.5 mg/l
• Disorientation
• TiO2
• No dose-response relationship (max conc. 3 mg/l)

Lovern Klaper (2006). Environ Toxicol Chem.
Hund-Rinke Simon (2006). Environ Sci
Pollut Res.
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Crustacean
Picture by Rosenkrantz (2006)
Picture by Hartmann (2007)

• Daphnids can modify the solubility of nanotubes
• (Roberts et al. (2007). EST, 41, 3025-3029)

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Fish

• SWCNT in juvenile rainbow trout resulted in
  dose-dependent increases in
• Ventilation rate
• Gill pathologies
• Mucus secretion
• Drinking behaviour
• Aggressive behavior
• Swellings on surfaces in the brain
• Cells in abnormal nuclear division in liver cells
• 35.6 lethal effect in embryos exposed to 39.4 nm
  polystyrene nanoparticles at 30 mg/l

Smith et al. (2007). Aquatic Toxicol.,
Kashiwada (2006). Environ. Health Perspect.
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Fish
Kashiwada (2006). Environ. Health Perspect.,114,
1697-1702
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Developmental toxicity of nC60 (Zebrafish)
Mitigation by GSH suggest that toxicity is
related to oxidative stress
100
80
nC60/THF
nC60/THFGSH
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Pericardial Edema ()
40
20
0
48
60
72
84
96
108
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Zebrafish larva with pericardial edema due to
nC60 exposure
Hours Post-Fertilization
X. Zhu et al. (2007). Environ. Toxicol. Chem.
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Nanoparticles as contaminant carriers
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Why look at interaction?

• Risk assessment of nanoparticles
• No exposure No risk!
• Low exposure Low risk?
• Nanoparticles may act as carriers of contaminants
  
• C60 present Increased toxicity of phenanthrene
  in algae and fish
• TiO2 present Enhanced uptake of Cd in carp

Baun et al. (2007), Aquatic Toxicol.
(accepted) Zhang et al. (2007), Chemosphere,
67, 160-166
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Toxicity of phenanthrene towards algae

• nC60 6-8 mg/l (measured)
• Control 16 inhibition
• EC50,48h 720 µg/l 69175095
• EC50,48h 581 µg/l 53163595
• EC50,48h 427 µg/l 39346595

With nC60
Without nC60
Baun et al. (2007). Aquatic Toxicol. (accepted)
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Algal toxicity of Cd(II) expressed as Cd2
With TiO2
Without TiO2
EC50,48h 44 µg/l Cd2 394995 EC50,48h 7.5
µg/l Cd2 5.71095

• TiO2 2 mg/l (P25)

Hartmann (2007). M.Sc. Thesis. Technical
University of Denmark
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Toxicity of Cd(II) in the presence of nanosized
TiO2

• Know your test system and the influence of TiO2
  nanoparticles on toxicity can be predicted!

Hartmann (2007). M.Sc. Thesis. Technical
University of Denmark
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Conclusion

• Nano is not one thing!
• NPs are as different as ordinary chemicals
  the extra nano dimension!
• Effects have been observed in aquatic organisms
• Characterization in media and in vivo is lacking!
• The role of nanovectors is important in hazard
  assessment
• Potential environmental hazards must be
  considered in developments of nanoproducts!

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Any Questions?