Nanoparticles in the environment – how small is the risk? Anders Baun Nanna Hartmann Khara Grieger Michael Andersen Steffen Foss Hansen

Is nanotechnology dangerous? No!

Nano is not one thing!

Where is the nano? No exposure – no risk of toxic effects Nano is many things… If we don’t know where it is to begin with – how can we know where it ends up? Location of the nanostructure!

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

Particles

Categorization of the 243 consumer products in the DK market

Expected exposures Stuer-Lauridsen et al. (2007).

Nano is not one thing! Natural > < Engineered

Ecotoxicity of nanoparticles Ecotoxicity towards base set organisms Fish Crustacean Algae

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?!

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?

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 112:

Before the beginning: C 60 in water – how...? +2 months Photos by Sara Sørensen, Rikke Rasmussen, Nanna Hartmann

TEM images of suspensions TEM analysis by Christian Bender Koch, KU LIFE 100 nm 500 nm In water: Not ”free” nanoparticles

Comparing the toxicity to B. subtilis of four differently prepared nC 60 water suspensions THF/nC 60 son/nC 60 aq/nC 60 PVP/C Minimum inhibitory conc. (mg/L) Controls with solvents & other ingredients showed no toxicity Lyon et al. (2006). ES&T 40,

Different methods for making nC 60 produce different kinds of colloids d a b c TTA/nC60 THF/nC60 Son/nC60 aqu/nC60 Brant, J.A., Labuille, J., Bottero, J.Y., Wiesner, M.R., Langmuir, in press, 2006.

A) P. subcapitata B) TiO 2 nanoparticles in algal medium A+B = … TiO 2 in algal medium Hartmann (2007). M.Sc. Thesis.

Characteristics relevant for hazard identification of nanoparticles Chemical composition Size Shape Crystal structure Surface charge Surface chemistry Solubility Adhesion Hansen et al. (2007). Nanotoxicology (accepted)

What has been characterized in toxicity studies? Hansen et al. (2007). Nanotoxicology (accepted)

Toxicity of nanoparticles and nanotubes How much been tested? Hansen et al. (2007). Nanotoxicology (accepted)

Ecotoxicity! Ecotoxicity!

Algae C 60 : We find up to 30% inhibition of algal growth at 35 mg/l* TiO 2 : EC 50 of 44 mg/l (25 nm TiO 2 )** No toxicity of 100 nm TiO 2 in conc. p to 50 mg/l** But we find: EC 50 ~ 7.5 mg/l for both*** * Andersen (2007). M.Sc. Thesis; **Hund-Rinke & Simon (2006). Environ Sci & Pollut Res.; ***Hartmann (2007). M.Sc. Thesis.

Crustacean Daphnia magna exposed to TiO 2 and fullerenes* Mortality C 60 > TiO 2 C 60 : 50% dead at 0.46 mg/l TiO 2 : 50% dead at 5.5 mg/l Disorientation TiO 2 ** No dose-response relationship (max conc. 3 mg/l) *Lovern & Klaper (2006). Environ Toxicol Chem. **Hund-Rinke & Simon (2006). Environ Sci & Pollut Res.

Crustacean Picture by Hartmann (2007) Picture by Rosenkrantz (2006) Daphnids can modify the solubility of nanotubes (Roberts et al. (2007). ES&T, 41, )

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.

Fish Kashiwada (2006). Environ. Health Perspect.´,114,

Developmental toxicity of nC 60 (Zebrafish) Zebrafish larva with pericardial edema due to nC 60 exposure Hours Post-Fertilization Pericardial Edema (%) nC 60 /THF nC 60 /THF+GSH Mitigation by GSH suggest that toxicity is related to oxidative stress X. Zhu et al. (2007). Environ. Toxicol. Chem.

Nanoparticles as contaminant carriers 1000 nm

Why look at interaction? Risk assessment of nanoparticles: No exposure = No risk! Low exposure = Low risk? Nanoparticles may act as carriers of contaminants C 60 present: Increased toxicity of phenanthrene in algae and fish * TiO 2 present: Enhanced uptake of Cd in carp ** * Baun et al. (2007), Aquatic Toxicol. (accepted) ** Zhang et al. (2007), Chemosphere, 67,

Toxicity of phenanthrene towards algae nC 60 : 6-8 mg/l (measured) Control: 16% inhibition EC 50,48h = 720 µg/l [691;750] 95% EC 50,48h = 581 µg/l [531;635] 95% EC 50,48h = 427 µg/l [393;465] 95% Without nC 60 With nC 60 Baun et al. (2007). Aquatic Toxicol. (accepted)

Algal toxicity of Cd(II) expressed as Cd 2+ TiO 2 : 2 mg/l (P25) EC 50,48h = 44 µg/l Cd 2+ [39;49] 95% EC 50,48h = 7.5 µg/l Cd 2+ [5.7;10] 95% With TiO 2 Without TiO 2 Hartmann (2007). M.Sc. Thesis. Technical University of Denmark

Toxicity of Cd(II) in the presence of nanosized TiO 2 Know your test system and the influence of TiO 2 nanoparticles on toxicity can be predicted! Hartmann (2007). M.Sc. Thesis. Technical University of Denmark

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!

Any Questions? Risk perception….