Nanomaterials and definition; Implications for risk assessment, - - PowerPoint PPT Presentation

Nanomaterials and definition; Implications for risk assessment, regulation and the need for reference materials

Dr Laura-Jayne Ellis L.a.ellis@bham.ac.uk University of Birmingham

SCLF Conference: Advances in Land Contamination Assessment and Remediation Wednesday 7th September

Structure

 What are nanomaterials  EU Definition  Problems with the current definition  What are the risks (environmental contaminant)  Need for reference materials  Research at the University of Birmingham

What are Nanoparticles? EU Definition

A natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50 %

• r more of the particles in the number size

distribution, one or more external dimensions is in the size range 1 nm - 100 nm. In specific cases and where warranted by concerns for the environment, health, safety or competitiveness the number size distribution threshold of 50 % may be replaced by a threshold between 1 and 50 %.

What are Nanoparticles? Types

 Natural NPs: present in all compartments of the Earth including the

hydrosphere, geosphere and atmosphere.



Produced via volcanic eruptions, biological degradation, pollination, natural weathering, and erosion.

 Incidental NPs: by-products (waste) of industrial processes. Accidently

released into the environment during manufacturing, mining processes and

• ther anthropogenic activities.



examples are soot, exhaust fumes, wear of tyres, catalytic converters and fine particulates produced from combustion products

 Manufactured NPs: purposefully produced and are specifically designed to

carry a precise function



uniform in size and shape and have surface coatings.

What are Nanoparticles? Comparison by size

a) Sewing needle head b) Human hair c) Section of a cell d) Bacteria cell e) Clump of viruses f) Macromolecules g) A single atom

Problems with the current definition

 Insufficient legislation and understanding of nano-specific behavior  Lack of a standard definition for the term nanomaterial  A ‘one size fits all’ covering all general contaminants, fails to cover all

the potential risks when materials are presented in the nanoscale

 Definition avoids the important issues that engineered nanomaterials

behave significantly different to natural and incidental nanomaterials due to their design in functionality

 Nanotoxicological studies present findings from an array of exposures

to specific size dependent toxic responses

 Other studies may report on exposure to a boarder size fraction of

particles

 Often producing conflicting data when interpreting the risk and

exposures

Problems with the current definition: How regulators address the problem

 Generally, regulators categorize the associated risks with

nanomaterials (NMs) under existing frameworks

 The EU and the International Organization for Standardization

(ISO) are the only jurisdictions to currently define NMs by a number size distribution

What are the risks?

 Evidence suggest that NM properties differ considerably from the bulk

material

 The phenomena of NMs are derived from size and specific surface

area: electronic spatial constraints and increased chemical reactivity

 Smaller particles (>30 nm) are thermodynamically unstable and the

confinement of electrons cause changes in the surface atoms leading to interfacial reactivity

 These properties are exploited for consumer uses.

What are the risks? Toxicology issues

 Depending on surface chemistry and

reactivity, NPs have been demonstrated to interact with biological tissues

 bioaccumulation leading to internalized

toxicity

What are the risks? Increased use of Nanomaterials

worldwide

http://www.nanotechproject.org/cpi

What are the risks? Nano-Enabled Products

From the 1628 nano-enabled products in 2013, 383 products that claim to contain nano- silver and 179 products contained titanium dioxide particles.

Nano-Silver (Ag) Nano-Titanium Dioxide (TiO2)

 Measurements of environmental concentrations of NPs, and

releases of NPs from consumer products are mostly absent in the available literature (Gottschalk et al, 2009).

 The lack of information is mainly because funded research

has concentrated its efforts on human health implications that NPs directly may impose, rather than environmental (Nowack and

Bucheli, 2007).



The potential implications for exposure will be to a number of aquatic and terrestrial organisms, including bacteria (Wigginton et

al, 2010).



Silver can be released either as a nanoparticle, colloidal aggregate or as a silver ion. How these transform in the environment is still uncertain…

Why is this a problem?

What are the risks: Source-Pathway-Receptor =Risk/Hazard?

Batley et al, 2013

Sources and flow of nanomaterials in the environment

Sources and impacts from environmental releases of nanomaterials: risk assessment frame works

Nowack et al, (2012)

Provide Environmental Health Risk Assessments

Handy and Shaw (2007)

Prevent and Develop Response Strategies: Establish the problem



Measurements of environmental concentrations of NPs, and releases of NPs from consumer products are mostly absent in the available literature (Gottschalk et al, 2009).



The lack of information is mainly because funded research has concentrated its efforts on human health implications that NPs directly may impose, rather than environmental (Nowack

and Bucheli, 2007).



The potential implications for exposure will be to a number of aquatic and terrestrial

• rganisms, including bacteria , finally humans(Wigginton et al, 2010).



Silver can be released either as a nanoparticle, colloidal aggregate or as a silver ion. How these transform in the environment is still uncertain…



Increased use/releases of titanium dioxide- particularly from sunscreens.



Develop models

Research at the University of Birmingham

 Provide a facility for environmental nanoscience analysis

and characterisation (FENAC)

 Public health impacts of environmental hazards of

nanomaterial releases

 Research: source-pathway-receptor =Risk/Hazard?  Provide public, environmental health and eco-toxicology

risk assessments

 Prevent and develop response strategies  Research provides information for regulators

 FENAC underpins research on nanomaterial properties &

behaviour, along with investigations of other types of nano-

• bjects including incidental (combustion, industry etc) & natural

(microbial, weathering etc).

 FENAC provides access & sample analysis, acting in a fully

collaborative manner with users, providing support through the whole process from experimental design to data analysis.

 FENAC also provides training for DRs & PDRs during the

sample and data analysis period and, more formally through summer schools.

Our research Facility: FENAC

 Funded by the Natural Environment Research Council (NERC) in the UK  Research access by competitive applications  Commercial access charged for time and usage  Supports researcher work to help Understand the biological and

environmental impacts of nanomaterials within the UK

 Multi-method characterisation of nanoparticles  Support with experiment design

Our research Facility: FENAC

DLS Zeta poten al FFF TEM

• (+

EDS, EELS) SEM,

• ESEM

AFM NTA XRD

University

• f

Birmingham

ICP-MS

Mul -method characterisa on at

• FENAC

Publications & citations

Reference materials: Labelled nanoparticles

 Environmental sampling can be challenging,

particularly when identifying inorganic nanomaterials from background concentrations.

 Increase method robustness and traceability of

characterisation/quantification

 Serve as internal standards to track the

extraction efficiency from complex matrices

Examples of labelled materials

1 0 0 n m 1 0 0 n m 1 0 0 n m 1 0 0 n m

Commercial TiO2 used in Sunscreens

Synthesised labelled materials

Acknowledgements

 Professor Eva Valsami-Jones  Professor Iseult Lynch  Dr Christine Elgy FENAC Manager