Nanoparticles Affect Health

Did you know that you might be among millions of unwilling users of nanotechnology: a global industry worth an estimated $11.7 billion in 2009 alone? More than 1,000 products containing nanomaterials are commercially available. Knowledge on the risks posed by these products to humans and the environment is limited.

What is nanotechnology?

Nanotechnology broadly refers to many diverse technologies aimed at the development of new materials and products with structures containing nanoparticles; that is, particulate materials with at least one dimension of less than 100 nanometres (nm). A nanometre is one-billionth of a metre.

To give you a rough idea of such an extremely small measurement, consider that an average sheet of paper is about 100,000 nanometres thick. If you were 1 nm tall, the thickness of that sheet of paper would be 100,000 times taller than you.

Ancient materials, new technology

Naturally occurring nanoparticles are probably as old as our planet. They exist in the smoke from forest fires and volcanoes, and in the ocean air.

Nanomaterials (nanoparticle-containing materials) unintentionally created by humans have also been around for thousands of years. Artists used nanoparticles of silver and gold to create the colour in the stained glass windows of medieval cathedrals. By grinding gold particles into ever smaller pieces, artists changed their colour: from its original yellow to blue, then to green, and finally to red.

However, the ability to “see” and intentionally manipulate matter atom by atom is a very recent human achievement. In 1959 the renowned physicist Richard Feynman was the first to envision man-made molecular machines built with atomic precision; but his vision took more than 20 yearsof advances in technology and microscopy to realize.

What is all the fuss about?

At the nanoscale the physical, chemical, and biological properties of most materials differ from the same materials at larger scales. As a result, nanomaterials could produce new colours, make metals stronger and harder, enable normally insulating materials to conduct heat or electricity, and make protective coatings transparent.

The new properties could lead to unique applications, but also to possible harmful consequences. Given their small particle sizes and increased reactivity, nanomaterials might cross body membranes, and scatter in the environment.

The technology is also used in car paints that resist scratching and to enhance the safety of cars by increasing tire adhesion to the road, improving the stiffness of the car body, or preventing glare or condensation on displays and panes. Atom-sized transistors and semiconductors have been made for computers, memory devices, and sensors.

Only a few inventories of nanotechnology on consumer products exist. Their reliability and validity is questionable due to the lack of mandatory labelling of nanoproducts and the unregulated nature of this industry. Therefore, be cautious when consulting any inventory.

The Project on Emerging Nanotechnologies maintains a commonly cited electronic inventory (nanotechproject.org). It lists more than 1,000 consumer products that are available globally, and in Canada.

The number of consumer products registered has more than doubled in just over 18 months. The European Union consumer bodies also maintain an inventory (nanowerk.com).

Risks to human health

To date there is no conclusive scientific evidence to support any harmful effect of nanomaterials on human health. This is partly due to the absence of tests and instruments to identify and assess these new materials.

Regardless of the lack of data, the potential risks related to newly engineered nanomaterials are compelling. Considering the well-documented health effects associated with existing larger particles, there is no reason to be complacent.

To understand what happens when living organisms are exposed to nanomaterials, ongoing scientific studies are looking at:

• the reactivity of nanoparticles with biological systems
• the nanomaterial lifecycle; this information will be beneficial for the medical sector, including implantable medical devices or materials to rebuild bones and nerves
• the ability of our immune system to fight particles not previously encountered
• the nanoparticle path inside the body: researchers speculate that inhaled nanoparticles may deposit in the region of the lungs where gas exchange takes place; then, the small size of the particles may facilitate their translocation into the blood and allow access to potentially sensitive target sites such as bone marrow, spleen, liver, kidney, heart, and brain.

Revealing the potential risks posed by nanomaterials will take time, but our encounter with them is imminent. In addition to inhalation, exposure could occur through ingestion, injection for therapeutic purposes, and at cuts or abraded skin.

The levels of exposure may also vary depending on the product and its use. For instance, fixed nanomaterials are embedded in stable matrices (present in sports equipment and textiles), therefore posing low risk to consumers.

In contrast, freely engineered nanomaterials are not immobilized in a matrix, and can unintentionally escape into the air or water during production, use, or disposal. Obviously, the groups at the greatest risk include the nanotech researchers and those involved in the manufacturing process.

Also risky is the use of nanoproducts such as cosmetics and sunscreens that could penetrate the skin. Unlike drugs and natural health products regulated by Health Canada, cosmetics are not subject to health assessment.

Intentionally ingesting nanotechnologically modified food, drugs, and oral hygiene products, or unintentionally ingesting nanomaterials used in food packaging could also be potentially dangerous.

Impact on the environment

Nanotechnology holds promise for cleaning up contaminated sites, yet little research has been done on the potential toxicological effects nanomaterials might pose. The available research data indicates that silver and copper nanoparticles are harmful to aquatic life.

Likewise, direct exposure to carbon nanoproducts can cause brain damage in largemouth bass, be toxic to micro-organisms that digest bacteria in water, and have a negative impact on marine ecosystems.

In addition, research in mice showed that inhalation of particles from carbon nanotubes (strong, flexible, powerful electrical conductors) may result in asbestos-like health effects.

Researchers have also found that the process of nanotube manufacturing releases toxic substances similar to those found in cigarette smoke and automobile tailpipe emissions. Moreover, different carbon nanotubes have diverse chemical compositions, making it difficult to trace their impact in the environment.

Notably, carbon nanotubes are not biodegradable. Hence, they will persist in our environment and may build up in the food chain. Furthermore, studies on the impact of nanoparticles on soil ecosystems, vertebrates, or invertebrates are missing almost completely.

Consumer awareness

The promises of nanotechnology to address many of the problems facing today’s society are limitless, yet the potential environmental and human health impacts of nanomaterials remain unknown.

Moreover, the majority of Canadian consumers are not aware of the use of nanotechnology in a number of products on the market, as determined by various surveys and studies assessing the public’s knowledge of these materials.

Seventy percent of those surveyed in Canada were not aware of nanotechnology, according to a study commissioned by the Consumers Council of Canada. Governments have a unique opportunity to develop policies tailored to this emerging technology, and we must ask for them.

Application in consumer products

Nanomaterials are now being used in the manufacture of several consumer products:

• toothpaste
• skin creme
• transparent sunscreen for adults and children
• textiles (clothes that repel stains)
• scratchproof eyeglasses
• vitamins
• food additives and packaging
• medical products (bandages, heart valves, MRI contrast agents)

Protect yourself from unwelcome nanoproducts

Demand government action

The federal government should formulate and enforce regulatory policies and establish mandatory safety testing and product labelling for drugs, cosmetics, foods, and dietary supplements. Lack of labels and reliable regulations keep us unaware about the presence of nanomaterials in consumer goods.

Buy organic

The Canadian government banned nanotechnology in organic food production in 2010.

Avoid at-risk products

If in doubt, do not buy products that you think may contain nanomaterials. While manufacturers, processors, and dealers do not have to reveal the presence of nanomaterials, you can check for the words “nano,” “ultrafine,” and “micronized.” Avoid wrinkle-free or stain-proof clothing, clear sunscreens, and some cosmetic and personal care products.

Be informed

Learn about the technology and its applications (read press and media releases, consumer reports, attend seminars, ask questions).

Current state of nanotechnology

• Nanotechnology is under active development or already in practical use in several areas including materials science, medicine, and electronics.
• There is almost no comprehensive research data on the effects of nanoparticles on human health, other species, and the environment. The few studies available have indicated some negative effects to the aquatic ecosystem.
• No governmental regulations currently exist regarding the occupational hazards of nanotechnology.
• Labelling of products with regard to the presence and quantities of nanoparticles is not required by law.
• The manufacture, use, transport, and disposal of engineered nanomaterials is unregulated globally.