Exposure to nanoparticles can have serious health impacts

Louise Sales

Chain Reaction #115, August 2012, www.foe.org.au/chain-reaction/editions/115

Groundbreaking research by scientists from Trinity College Dublin has found that exposure to nanoparticles can have a serious health impacts, potentially causing rheumatoid arthritis and other serious autoimmune diseases.1

The research raises serious concerns about the widespread use of nanoparticles in consumer products and the way these substances are currently manufactured, handled and disposed of. It also illustrates the need for a mandatory register of nanomaterials, so that these substances can be tracked and appropriately handled throughout the supply chain.

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What are nanoparticles?

Nanoparticles are tiny particles 200 nanometres or less in size – with one nanometre being one billionth of a metre. The properties of matter change at the nano-scale, as the laws of classical physics give way to quantum effects. The physical properties of nano-sized particles can therefore be quite different from those of larger particles of the same substance. Altered properties can include colour, solubility, material strength, electrical conductivity and magnetic behaviour. Nano-sized particles also have a greater surface area relative to mass. This makes them much more chemically reactive.

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Nanoparticles are able to penetrate deeply into the lungs and are an important factor in the development of various diseases. Exposure to car exhaust fumes and cigarette smoke have long been recognised as risk factors causing chronic inflammation in the lungs. It has also been established that smoking can also trigger undesirable immune reactions. This can lead to the development of autoimmune diseases, such as rheumatoid arthritis, which incapacitates millions of people worldwide.

Recently, new concerns have been raised regarding the emerging products of nanotechnology which, if not handled appropriately, may contribute to the generation of new types of airborne pollutants. Therefore, the importance of identifying risks and hazards involved in the manufacturing, handling, use, and disposal of nanomaterials cannot be overestimated.

In their research, the Nanomedicine and Molecular Imaging team at Trinity College Dublin's School of Medicine, led by Prof. Yuri Volkov, investigated whether there was a common underlying mechanism contributing to the development of autoimmune diseases in human cells following exposure to a wide range of nanoparticles containing different physical and chemical properties.

The scientists applied a wide range of nanomaterials including ultrafine carbon black, carbon nanotubes and silicon dioxide particles of different sizes, ranging from 20 to 400 nanometres, to human white blood cells and cells derived from the lining of the airway passages.

At the same time, collaborating researchers from the Health Effects Laboratory Division, National Institute for Occupational Safety & Health (Morgantown, WV, USA) exposed mice to chronic inhalation of air contaminated with single walled carbon nanotubes.

The result was clear: all types of nanoparticles in the Irish and US studies caused an identical response in human cells and in the lungs of mice. Essentially, the nanoparticles caused a chemical to change in one of the common building blocks of our proteins (an amino acid). Proteins which incorporate this modified amino acid as building blocks can no longer function properly and are subject to destruction and elimination by the body's defence system.

Furthermore, once programmed to get rid of citrullinated proteins, the immune system can start attacking its own tissues and organs, thereby causing the autoimmune processes which may result in rheumatoid arthritis.

Commenting on the significance of the findings, Prof. Volkov says that the research establishes a clear link between autoimmune diseases and nanoparticles.

Government inaction

So what is the Australian government doing to protect us from exposure to nanoparticles?

Despite the growing body of evidence that nanoparticles behave differently to bulk forms of the same chemicals and may be cause serious health effects, in Australia nano versions of existing chemicals do not require separate safety assessments. This means that there are literally hundreds of consumer products out there containing unregulated and untested nanoparticles.

Furthermore, while other countries such as France and the Netherlands are in the process of introducing mandatory notification and registration for commercial use of manufactured nanomaterials, the Australian Federal government is still sitting on its hands.

Recently the federal government made public a report it commissioned on the feasibility of implementing a mandatory nanotechnology product registry.2 The report concluded that "the feasibility of a nano-product registry is questionable". This is despite the fact that France has already adopted a mandatory register for nanomaterials, with the first reporting year to be 2013.

The government commissioned the report following pressure from the Greens to introduce a national, publicly accessible, mandatory register for all manufactured nanoparticles in commercial use. The Greens argued that this register should include "companies who import, manufacture, use, supply, and/ or dispose of manufactured nanoparticles, including products that contain them" and that it should "treat manufactured nanoparticles as new chemicals, and require information on the size, shape, physicochemical properties and quantities of nanoparticles used."

Australian regulators currently have very limited information about the actual commercial use of nanomaterials. Responses to calls for voluntary information have been very low. A 2008 call from the chemical regulator NICNAS for information from industry on the use of nanomaterials resulted in just seven responses.

A register is required to enable accurate supply chain tracking of nanomaterials. This is vital to enable effective risk identification and risk management by workers, employers and the public.

Calls for a publicly accessible national mandatory register of companies dealing with manufactured nanoparticles, and of nanoparticles in commercial use have been made by the Australian Council of Trade Unions (ACTU) and the Australian Nano Business Forum (ANBF).3

The 2008 NSW Parliamentary Inquiry into Nanotechnology also recommended that a national mandatory labelling scheme be put in place for all manufactured nanomaterials used in the workplace. This is in contrast to the federal government, which recently announced it will not be introducing new regulations.

What can you do?

Get active in our campaign for the proper regulation of nanoparticles. You can find out more about the campaign and sign up for monthly updates via our website: nano.foe.org.au

Louise Sales is the Nanotechnology Campaign coordinator with Friends of the Earth, Australia.

References:

(1) Mohamed B. M. et al. (2012) Citrullination of proteins: a common post-translational modification pathway induced by different nanoparticles in vitro and in vivo, Nanomedicine (2012), www.futuremedicine.com/doi/full/10.2217/nnm.11.177; Laboratory Journal (2012) Exposure to Nanoparticles can have Serious Impact on Health, www.laboratory-journal.com/news/scientific-news/exposure-nanoparticles-c... Nanowerk (2012) Study shows how nanometer size tiny substances present in polluted-air or smoke can trigger human diseases, www.nanowerk.com/news/newsid=25406.php

(2) CIE (2011) Feasibility of Implementing a Mandatory Nanotechnology Product Registry, www.innovation.gov.au/Industry/Nanotechnology/NationalEnablingTechnologi...

(3) Salleh, A. (2009) Calls to protect workers from nano risks, www.abc.net.au/science/articles/2009/03/24/2524875.htm