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NANOPESTICIDESState of knowledge,

environmental fate and implication for assessment

Melanie KAH

Nanotechnology and agriculture: Applications

Nanosensorsfor pathogens or pesticide residues

Delivery of genetic material into plant cell

Plant protection products

= Nanopesticides

Fertilizers

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Concept

RISKS and/or BENEFITS?

PESTICIDES

� Intentionally applied (agriculture)

� Toxic (e.g., insecticide)

Sorption Degradation Leaching5 cm

35

cm

fine sand

glass wool

coarse sand

Soil

FATE EFFECT

Efficacy Hazard

NANOTECH +

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Grey literature

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Emergence of nano agrochemicals

“Potential to reduce contamination through the reduction in application

rates and limited runoff” ETC, 2004

“Increased toxicity, bioavailability and longevity […] new kinds of

contamination ” E.g. Friend of the Earth, 2008

“Urgent need for regulatory system capable of managing many new risks”

Very controversial: environmental impact of nanopesticides

General agreement: nanotech will revolutionise agriculture

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Grey literature

Scientific literature

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(july 2015)

0

500

1000

1500

2000

2500

3000

2000 2005 2010 2015

Nu

mb

er

of

hit

s.o

n t

he

We

b o

f S

cie

nce

year

(nano* and agricult*)

(nano* and (pesticide or fertilizer)

(Figure adapted and extended from Gogos et al., 2012)

Emergence of nano agrochemicals

Many communities with different perceptions

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NANO COMMUNITY

Intentional and diffuse source of toxic nanoparticles

� Emerging contaminants

PESTICIDE COMMUNITY

� One solution for mitigation

atrazineDDT

Melanie Kah - Fate of Nanopesticides

REGULATORS

Risk or Risk/Benefit assessment

ENVIRONMENTAL SCIENTISTS

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Recent workshops and meetings

• Special symposium at ACS meeting Aug. 2014“Fate, effects and risks of nanopesticides “

• SETAC Asia/Pacific Keynote by Chief Regulatory Scientist of APVMA (Australian Pesticides and Veterinary Medicines Authority) (Sept 2014)

“Nanopesticides and veterinary nanomedicines: regulatory challenge ?”…

• FAO/WHO report, 2013 “State of the art on the initiatives and activities relevant to risk assessment and risk management of nano technologies in the food and agriculture sectors”

• JRC-IPTS workshop Nov. 2013 (Seville, E) “Nano technology for the agricultural sector: from research to the field”

• IUPAC workshop May 2013 (York, UK): “Nanopesticides : regulatory evaluation of environmental risks ”

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� Need to support decision-making

Patent/literature analysis to evaluate state of knowledge

Kah et al. (2013) Crit. Rev. Environ. Sci. Technol. 43:1823

Kah and Hofmann (2014) Environment International 63: 224-235

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CAN WE ASSESS THE RISKS?IS FRAMEWORK READY?

WHAT ARE NANOPESTICIDES?

Sorption Degradation Leaching5 cm

35 c

m

fine sandglass wool

coarse sand

Soil

FATE EFFECTEfficacy Hazard

Kookana et al. (2014) J. Food and Env. Chem. 62, 4227-4240

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Called “Nano”

Nanometer range (< 1000 nm)

Novel properties related to size

“My” nanopesticides =

Analysis boundaries

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Increase solubility Slow release Nano metals/oxides

Wide variety of products (development, ingredients, size, relevance etc…)

What are nanopesticides ?

Polymer-based (spheres, capsules,

gels and fibres)(10-300 nm)

Porous hollow silica(50-200 nm)

Solid lipid(200 nm - 100 µm)

Clays and layered double oxides

(µm)

as active ingredient

Associated with conventional

active ingredient

Nanopesticides ≠ single category

Nanoemulsion(20-200 nm)

Microemulsion(6-50 nm)

Nanodispersion(50-200 nm)

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Trends in scientific literature

Polymer-based

Metal

Nano-emulsion

Layered dble hydrox.

Metal + organic a.i.

Micro-emulsion

Porous hollow silica

Nano-dispersion

Solid Lipid

Number of peer reviewed papers

Increase solubilitySlow releaseMetal, metal oxides

>50 % 2011-2014

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Trends

Fungicide30 %

Herbicide15 %

Insecticide55%

Alternative AI (essential oil, pheromones)

“eco-friendly” carrier (biodegradable, natural origins)

Price? Efficacy?

Risks/benefits?

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Which types of Nanopesticides will soon emerge on t he market?

� market and regulatory constrains

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Nanopesticides

Environmental fate of nanopesticides

FATE

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What happens ?

How to measure?

What happens ?

How to measure?

„The environmental fate of nanopesticides is a big black hole “(Prof. Harper, Oregon State University, Jan. 2015)

Active Ingredient

(AI)

Nanopesticides

SorptionOECD 106

DegradationOECD 307

LeachingOECD 312

5 cm

35 c

m

fine sand

glass wool

coarse sand

Soil

Fate of nanoformulated vs pure active ingredient

Solute approach(equilibrium)

FATE2 agricultural soils

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Active Ingredient

(AI)

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Kah et al. (2014) Environ. Sci. Pollution. Res. 21:11699-11707

Sorption in soil

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Kd nano-AI < Kd AI

� Nano-AI remaining in suspension?

Nanoformulations affect interaction with soil (at least its measurement)

Kd nano-AI > Kd AI

� Nano-AI settling down?

Active Ingredient (AI)Nano-AI

OECD 106

Kah et al. (2014) Environ. Sci. Pollution. Res. 21:11699-11707

Degradation in soil

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No effect

� rapid release of AI and/or� nano-AI subject to degradation

Slower degradation kinetics

� toxicity of nanoformulation and/or� nano-AI protected

0

25

50

75

100

0 20 40 60 80 100 120

% r

em

ain

ing

Time (d)

Sandy soil

Nanoformulation can affect degradation kinetics

AI

Nano-AIOECD 307

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Nanopesticides

SorptionOECD 106

DegradationOECD 307

LeachingOECD 312

5 cm

35 c

m

fine sand

glass wool

coarse sand

Soil

Solute approach(equilibrium)

Nano approach(kinetic)

Characterization size distribution, zeta potential,

aggregation behaviour

FateAttachmnent efficiency

Transformation/durability of carrier

FATE

+

2 agricultural soils

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Fate of nanoformulated vs pure active ingredient

AI

Melanie Kah - Nanopesticides

� Nanopesticides = wide variety of products

� Current knowledge is not sufficient to evaluate benefit/risk

� Analytical methods, fate/effect properties, modelling

� Solute, Nano or both?

� Nanotechnology has a lot to offer!

Nanopesticides

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Take home messages

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Anne-KathrinWeniger

PatrickMachinski

DanielSchweizer

PetraKörner

HeleneWalsch

JacobRichter

ThiloHofmann

Acknowledgements

Department for Environmental Geosciences, University of Vienna

Melanie Kah - Nanopesticides