- From whitegoods to textiles, cosmetics to electronics, nanotechnology-based products are everywhere around us, but you generally won’t know as there’s no national labelling requirement for them anywhere in the world.
- They’ve been allowed to flourish because of their potential benefits, but there are significant gaps in our knowledge about their potential side effects for health and the environment.
Nanotechnology is heralded as making products and processes smaller, smarter, cleaner and safer, but could also spell trouble for our health and the environment. We explain what it is, how it’s used, what the concerns are and what you can do.
Please note: this information was current as of June 2007 but is still a useful guide today.
What is nanotechnology?
Nanotechnology is a generic term for a wide range of technologies derived from physics, chemistry and biology and used in medicine, consumer goods and other applications. It involves the engineering of materials at atomic or molecular levels — at the nanoscale — measuring up to 100 nanometres (nm) in diameter, to create new materials or materials with substantially different properties.
One nanometre is a billionth of a metre (0.000001 mm); a human hair is about 80,000–100,000 nanometres wide. Without a microscope, we can’t see anything smaller than about 10,000 nm.
Nanomaterials aren't new. They occur naturally in sea spray or volcanic emissions, for example, or incidentally as by-products in diesel emissions or welding fumes. What's new now is that advanced tools are available that allow us to manipulate matter at the nanoscale, so we can expand and develop nanotechnologies in many different fields.
How nanotechnology is used
The number of products sold worldwide under the nanotechnology banner is growing at an amazing speed. In May 2007, the Washington-based Woodrow Wilson International Centre for Scholars listed 475 entries in its inventory of nanotechnology consumer products, though it’s estimated more than 700 are currently on the market.
Products that use nanotechnology are in our homes already, without most of us realising it. A few examples include:
- Clothing and household textiles made of wrinkle, stain and odour resistant fabric — like pants that don’t wrinkle, shirts that don’t stain, socks that fight fungal disease and sheets that keep you cool and comfy.
- Cosmetics and toiletries with nano-oxides of iron, aluminium, zirconium, silicon and manganese, and sunscreens with nanoparticles of titanium dioxide and/or zinc oxide for more transparent UV protection.
- Personal care items with nanosilver, such as teeth cleaners, toothpaste, condoms, wound dressings, dummies and other baby products. (Friends of the Earth Australia thinks several hundred cosmetics and personal care products with nanoparticles are currently on the market. It lists on its website 116 that contain nanoparticles, based on information in the public domain.)
- Sturdy and long-lasting coatings for buildings or furniture, and very thin coatings for self-cleaning surfaces.
- Germ-fighting whitegoods containing nanosilver claimed to keep your things fresher: your clothes in the wash, cups and plates in the dishwasher and food where it’s stored, in the fridge and in plastic containers.
- Smart foods and packaging including nutrient enriched and functional foods, nutrition supplements, and packaging infused with antibacterial nanosilver or sensors.
Outside the home
- In non-domestic situations, nanotechnology is being applied in the fields of environmental protection (for water and air purification, pollution detection and solar energy production) or in medicine.
- It has already led to the development of more effective drug delivery systems, and it’s hoped to lead to breakthroughs in cancer detection, diagnosis and treatment as well as enhanced tissue engineering procedures for nerve regeneration or replacement of body parts.
Environmental and health concerns
While it’s generally accepted that the characteristics of matter can be changed significantly at the nanoscale, there are concerns that the very properties that make nanomaterials so attractive — their small size and relatively larger surface area, which can make them more reactive — could also hold unforeseen health or environmental hazards.
Scientific studies suggest that some nanoparticles may cause harm to people and the environment, even if the material in bulk form is non-toxic.
Nanoparticles in consumer products may be present in clusters larger than 100 nm in size, in which case any toxic effects linked to their small size are no longer relevant. Even if they’re present in fixed form — enmeshed in a solid matrix or liquid suspension — there’s concern about how they behave in the environment during their disposal, destruction or recycling, when they may leach out of landfills, or how they affect workers during their manufacture.
Effects on human health
Free nanoparticles — those that aren’t embedded in a substance but which make up the substance themselves, like in some cosmetics — are of particular concern to human health, as they have the potential to enter the human body through the lungs, skin or intestinal tract.
- Once in the bloodstream, nanoparticles may be absorbed by organs and tissues. There’s simply not enough data available on human exposure to nanoparticles to know for how long they’ll remain there, how much damage they may cause and at what dose.
- The greatest risks may stem from inhalation of nanoparticles, as they can be deposited deep in the lungs where they may lead to lung disease and cancer.
- Whether and in what circumstances they can enter our bloodstream via the gastro-intestinal tract, or through the skin, is still unknown. However, it appears more likely that nanoparticles could penetrate broken skin that’s damaged by the sun, eczma, acne or wounds.
Nanoparticles could also have a significant ecological impact because of bioaccumulation — the increase in concentration of a pollutant from the environment to an organism through a food chain — especially if the nanoparticles absorb smaller pollutants such as pesticides, or if they persist in the environment because they’re too small to detect.
There may also be other problems. For example, silver is a powerful bactericide, so there’s concern that nanosilver particles could affect beneficial bacteria in the soil and water that are needed, for example, to help break down organic matter and keep waterways clean, or that they could lead to increased resistance to nanosilver among harmful bacteria.