Nanotechnology: A new frontier?

Background

Historical nanotechnology

Current Uses: risks vs rewards

Regulating nanotechnology

US Regulates Nanoscale Silver as Pesticide

Occupational exposure to nano particles

ecospecifier's Position on Nanotechnology

 

Background

Nanotechnology is a term we are hearing more often each day, from invisible sunscreens, to makeup, self cleaning glass, VOC gobbling paints, water- and stain-resistant clothing and bacteria free fridges. Nanotechnology is also becoming a more common technology in everyday contact workplaces, at home and even at play. In Australia, as early as February 2006, the Therapeutic Goods Administration said that over 300 Australian sunscreens alone then contained nanoparticles[1] and Australian Consumer magazine Choice stated in March 2009 that nanotechnology was already used in around 800 products in Australia alone[2]. They are also often at the forefront of innovation with optical-nanomaterial-based solar cells created at Purdue University designed to self-repair using carbon nanotubes and DNA, an approach aimed at increasing service life and reducing cost[3]. Carbon Nanotubes are also being used in structures to increase strength and as superconductors and carbon 'Bucky Balls' to deliver medicines.

To begin to understand this technology, we need to define the term: Nanotechnology is the understanding and control of matter at dimensions of one to 100 nanometers.  A nanometer is one billionth of a meter[4] or the same as dividing a human hair by 100,000 times.

As opposed to materials at the sizes we have been used to dealing with to date where the physical properties remain relatively consistent, nano-sized materials or nanomaterials can have fundamentally different physical properties than their larger-sized counterparts.

These differences often enable nanoscale materials to be used in new and valuable way, but also to introduce other sometimes unexpected consequences.

While nanotechnology has the potential to change and improve many sectors of the global economy from consumer products to health care, transportation, energy, agriculture and the environment, the special properties that make nanoscale materials of potentially great benefit also present new challenges as their small size may allow them to pass through cell membranes or the blood-brain barrier, possibly resulting in unintended effects.

This introduces new challenges for risk assessment and decision-making in the assessment of health, environmental, social and occupational contexts.

Historical nanotechnology

nano1.pngThe Lycurgus Cup (British Museum; AD fourth century) as shown in Figures 1a and 1b is a Roman cup depicting  figures, carved in deep relief, showing the triumph of Dionysus over Lycurgus. He is seen being dragged into the underworld by the Greek nymph Ambrosia, who is disguised as a vine. However it is not only the cut-work design of the cup that shows the high levels of skill involved in its production. The glass of the cup is dichroic; in direct light it resembles jade with an opaque greenish-yellow tone, but when light shines through the glass (transmitted light) it turns to a translucent ruby colour. X-ray analysis has shown nanoparticles of silver-gold alloy, with a ratio of silver to gold of about 7:3, containing in addition about 10% copper. [5] These nano particles are responsible for the differential behaviour of the glass when the light shines from different directions.

Current Uses: risks vs rewards

As noted above, nanomaterials are being used in an increasingly diverse range of applications, many of which involve direct contact with human skin and involve risks not only to humans but also to organisms in the environment. Nanoscale silver has been shown to be toxic to some organisms in the marine environment, so when its use is proposed for water sanitation or as a pesticide (as it has) then serous concerns are raised as with conventional chemicals with similar impacts. However, because of their scale and consequent potential dispersal there are real difficulties in assessing the risk and potential damage.

Regulating nanotechnology

Nanotechnology has already been used to develop products that control pests, such as microorganisms on surfaces such as refrigerators, dishwashers and washing machines.  As early as 2004 the UK's Royal Society (one of the foremost scientific associations), and the Royal Academy of Engineering warned that nanoparticles should be treated as new chemicals and their release into the environment be avoided as far as possible until more is known about how they behave in the air, water and soil. It also recommended that ingredients in consumer products undergo a full safety assessment before they're permitted for use in products, and that manufacturers publish their methodologies publicly and identify the fact that manufactured nanoparticles have been added[6].

Europe is now poised for a moratorium on the technology's use in food, while The Australian Office of Nanotechnology (AON) that oversees the authority and develops nanotechnology policy thinks its current regulatory standards are sufficient[7].

However, according to the Friends of the Earth organisation:

'The review of Australia's regulatory capacity to manage new risks associated with the use of extremely tiny particles and technologies was conducted by a team of researchers at Monash University. This report finds truck-sized holes in Australia's regulation of the science of the small. Gaps this big mean that risky nanomaterials are effectively unregulated, leaving us vulnerable to a repeat of the asbestos tragedy. Less than two months ago a new study confirmed that carbon nanotubes cause the same disease and health harm that asbestos does. These nanomaterials are now used internationally, unlabelled, in sports equipment, specialty car parts, reinforced plastics and electronics. It is unknown if they are used commercially in Australia.'[8]

The AON used the Monash report to make its conclusion that regulations in Australia are sufficient, however  Associate Professor Thomas Faunce, from Australian National University's Medical School, found fault with the Monash University report and was quoted on the ABC as saying :

'All the research at the moment tends to indicate nanoparticles have unusual toxicities related to size and shape. 'In this sort of climate it's much better if regulatory authorities apply the precautionary principle and start developing nano-specific regulatory structures. If we don't we're going to have a catastrophe-driven approach to regulation, where we wait for a major public health crisis to arise because of nanoparticles causing toxicity in people.'

In the USA, the Environment Protection Authority (EPA) is responsible and has recently taken action to bring nanotechnology under more scrutiny.

US Regulates Nanoscale Silver as Pesticide

In the US, the EPA regulates products intended to control pests and producers of pesticide products must submit scientific and technical data for review by EPA to ensure that the use of a pesticide will not generally cause unreasonable adverse effects on human health or the environment.

The EPA has decided that one technology, nanosilver, is a pesticide and therefore needs to be regulated under the Federal Insecticide, Fungicide, and Rodenticide Act. Nanosilver uses the antimicrobial properties of silver. Small amounts of nanosilver are released to the environment when the material is used in air fresheners and washing machines, among other products.[9]

It is now implementing regulations to provide an effective framework for regulating all pesticide products that are a product of nanotechnology or that contain nanoscale materials and examining potential hazard, exposure, policy, regulatory, and international issues that may be associated with such nanoscale pesticides or particles.

Occupational exposure to nano particles

Workers handling nanomaterials may be exposed to them via inhalation, dermal exposure and ingestion, although workplace levels have not in general been adequately characterised. Of particular concern is that Instruments that can monitor the particle number, size distributions and surface areas of nanomaterials in the workplace are available but require a degree of expertise and are relatively expensive.

Moreover, workplace exposure standards are currently unavailable and appropriate methods that accurately characterise nanomaterial exposure have not been established. Due to the poorly characterised toxicity and other impacts of nanomaterials, measures taken to reduce the exposure of workers should apply the precautionary "as low as reasonably practicable" (ALARP) approach[10].

This is best achievable through risk management programs that broadly encompass all hierarchies of risk controls currently used for ultrafine particulates, especially the use of appropriate engineering controls, administrative controls, personal protective equipment, behavioural assessment and education.

ecospecifier's Position on Nanotechnology

ecospecifier considers that nanoscale materials have important benefits to offer society, but that these benefits should not overshadow the potential risks. As in all product assessments ecospecifier will draw on the latest information and research and will use the precautionary principle in assessing products where adequate research into health or environmental benefits does not exist. This includes transparent assessment of risks in reporting of Certified and Verified products. We also echo the call of eminent researchers for all governments to develop nano-specific regulatory structures.

 

Author: David Baggs

© Ecospecifier 2011



[1] Accessed 29/3/12 at http://nano.foe.org.au/node/241

[5] The Lycurgus Cup: A Roman Nanotechnology, accessed 29/3/12 at www.goldbulletin.org/assets/file/ goldbulletin/.../Lycurgus_4_40.pdf

[8] Accessed 29/3/12 at http://nano.foe.org.au/node/241

[10] NanoSafe Australia OHS Position Paper November 2007 acessed on 29/3/12 at http://mams.rmit.edu.au/72nuxiavskpg.pdf