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

Institute of Environment & ResourcesTechnical University of Denmark

Nanoparticles in the environmentNanoparticles in the environment– how small is the risk?– how small is the risk?

Anders BaunNanna Hartmann

Khara GriegerMichael Andersen

Steffen Foss Hansen


Is nanotechnology dangerous? Is nanotechnology dangerous?

No!No!


Nano is not one thing!Nano is not one thing!


Where is the nano?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!

http://www.nanotechproject.org/index.php?id=44&action=view&product_id=0591



SurfaceSurface

Structured on the nanoscale – same material

Nanoscale thickness,

unpatterned film

Patterned film – Film at nanoscale in thickness

Surface pattern having nanoscale dimensions


ParticlesParticles


Categorization of the 243 consumer Categorization of the 243 consumer products in the DK marketproducts in the DK market


Expected exposuresExpected exposures

Stuer-Lauridsen et al. (2007).


Nano is not one thing!Nano is not one thing!

Natural >< Anthropogenic >< Engineered


Ecotoxicity of Ecotoxicity of nanoparticlesnanoparticles

Ecotoxicity towards base set organismsFish

Crustacean

Algae


Environmentally problematic?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 Environmental impacts – what makes nano special?– 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 Nanoparticles and Ecotoxicity – the beginning– the beginning

Juvenile largemouth bass exposed to fullerenes

Concentrations: 0.5 and 1 ppmDuration: 48 hResults: Significant increase in

lipid peroxidation of the brain

Problem: Solvent content (THF)

Oberdörster (2004). Environ Health Perspect 112:1058-1062


Before the beginning:Before the beginning:CC6060 in water – how...? in water – how...?

+2 months

Photos by Sara Sørensen, Rikke Rasmussen, Nanna Hartmann

http://images.google.dk/imgres?imgurl=http://www.sussex.ac.uk/Users/kroto/FullereneCentre/images/c60a.gif&imgrefurl=http://www.sussex.ac.uk/Users/kroto/FullereneCentre/banner1.html&h=327&w=336&sz=42&hl=da&start=1&tbnid=oNh0dR1ioXJrvM:&tbnh=116&tbnw=119&prev=/images%3Fq%3Dfullerene%26ndsp%3D18%26svnum%3D10%26hl%3Dda%26lr%3D%26sa%3DN


TEM images TEM images ofof suspensions 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 Comparing the toxicity to B. subtilis of four differently prepared nCprepared nC6060 water suspensions water suspensions

THF/nC60 son/nC60 aq/nC60 PVP/C60

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Min

imu

m in

hib

ito

ry c

on

c. (

mg

/L)

• Controls with solvents & other ingredients showed no toxicity

Lyon et al. (2006). ES&T 40, 4360-4366


Different methods for making nC60 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) TiO2 nanoparticles in algal medium

A+B = …

TiOTiO22 in algal medium in algal medium

Hartmann (2007). M.Sc. Thesis.


Characteristics relevant for hazard Characteristics relevant for hazard identification of nanoparticlesidentification of nanoparticles

Chemical composition

Size

Shape

Crystal structure

Surfacecharge

Surfacechemistry

Solubility

Adhesion

Hansen et al. (2007). Nanotoxicology (accepted)


What has been characterized in What has been characterized in toxicity studies?toxicity studies?



Toxicity of nanoparticles and nanotubesToxicity of nanoparticles and nanotubes How much been tested? How much been tested?



Ecotoxicity!Ecotoxicity!Ecotoxicity!Ecotoxicity!


AlgaeAlgae

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.

0.0

0.2

0.4

0.6

0.8

1.0

0.1 1 10 100 1000

Concentration (mg/l TiO2)In

hibi

tion


CrustaceanCrustacean

Daphnia magna exposed to TiO2 and fullerenes*

Mortality C60 > TiO2

C60: 50% dead at 0.46 mg/l

TiO2: 50% dead at 5.5 mg/lDisorientation

TiO2**No dose-response relationship (max conc. 3 mg/l)

*Lovern & Klaper (2006). Environ Toxicol Chem.

**Hund-Rinke & Simon (2006). Environ Sci & Pollut Res.


CrustaceanCrustacean

Picture by Hartmann (2007)Picture by Rosenkrantz (2006)

Daphnids can modify the solubility of nanotubes(Roberts et al. (2007). ES&T, 41, 3025-3029)


FishFish

SWCNT in juvenile rainbow trout resulted in dose-dependent increases in*:

Ventilation rateGill pathologiesMucus secretionDrinking behaviourAggressive behaviorSwellings 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.


FishFish

Kashiwada (2006). Environ. Health Perspect.´,114, 1697-1702


Developmental toxicity of nC60 (Zebrafish)

Zebrafish larva with pericardial edema due to nC60 exposure

0

20

40

60

80

100

48 60 72 84 96 108 120

Hours Post-Fertilization

Pe

rica

rdia

l Ed

em

a (

%) nC60/THF

nC60/THF+GSH

Mitigation by GSH suggest that toxicity is related to oxidative stress

X. Zhu et al. (2007). Environ. Toxicol. Chem.


Nanoparticles as contaminant carriersNanoparticles as contaminant carriers

1000 nm


Why look at interaction?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


Toxicity of phenanthrene towards algaeToxicity of phenanthrene towards algae

nC60: 6-8 mg/l (measured)

Control: 16% inhibition

EC50,48h = 720 µg/l [691;750]95%

EC50,48h = 581 µg/l [531;635]95%

EC50,48h = 427 µg/l [393;465]95%

Phenanthrene in algal tests

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

10 100 1000 10000

Concentration of phenanthrene (µg/L)

Gro

wth

rat

e in

hibi

tion

Without nC60

With nC60

Baun et al. (2007). Aquatic Toxicol. (accepted)


0.0

0.2

0.4

0.6

0.8

1.0

0.1 1 10 100 1000

Concentration (µg/l Cd++)

Inhi

bitio

nAlgal toxicity of Cd(II) expressed as CdAlgal toxicity of Cd(II) expressed as Cd2+2+

TiO2: 2 mg/l (P25) EC50,48h = 44 µg/l Cd2+ [39;49]95%

EC50,48h = 7.5 µg/l Cd2+ [5.7;10]95%

With TiO2

Without TiO2

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


Toxicity of Cd(II) in the presence of Toxicity of Cd(II) in the presence of nanosized TiOnanosized TiO22

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

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


ConclusionConclusion

”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….

Documents

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