State of knowledge, environmental fate and …21/10/2015 1 NANOPESTICIDES State of knowledge,...
Transcript of State of knowledge, environmental fate and …21/10/2015 1 NANOPESTICIDES State of knowledge,...
21/10/2015
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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)
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2000 2005 2010 2015
Nu
mb
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of
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s.o
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(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
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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
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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
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2 agricultural soils
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Fate of nanoformulated vs pure active ingredient
AI
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� 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