Nanoparticles: Can small really have it all?

By Sarah Jones

Nanoparticles. Depending on whom you listen to, these miniscule particles are either big news, or big trouble. They’re becoming common in a variety of products, and so have the potential to end up in the environment in huge quantities. But, is that a bad thing? Should it be stopped? What are the cold, hard, teeny tiny facts about these futuristic flecks?

Gold nanoparticles viewed using transmission electron microscopy.

Gold nanoparticles viewed using transmission electron microscopy.
Image from Microscopy Camp

Prepare yourself for excessive use of size-themed juxtapositions as we explore the exponentially expanding world of nanoparticles.

“Nanoparticles” just sounds so sci-fi, what are they? Will they mutate and kill us all?

Nanoparticles are any particles smaller than 100 nanometres (nm) in at least one dimension (500 times smaller than the width of a human hair). The term encompasses an extremely broad range of both metallic and non-metallic particles.

…And no, probably not (more on this later).

I’ve heard they’re all around us!

Yep, and they have been for a long time. Well, always in fact; nanoparticles occur naturally in the environment. However, engineered nanoparticles (particles which have been intentionally produced at nano-size) are increasingly being used in a wide variety of applications, from cosmetics to electronics1.

Some sunscreens and cosmetics contain nanoparticles.

Some sunscreens and cosmetics contain nanoparticles.
Photography by Sunny Ripert, CC-image from Flikr

Their small size and relatively large surface area give nanoparticles special properties (such as greater reactivity), allowing them to be used in ways that would not be possible for their micro-sized counterparts2. Nanoparticles are making our electronics smaller and smaller, are being used in sunscreens and soaps, and are even helping to improve the yield of our crops. Even more excitingly, pioneering medical research is developing nanoparticles to tackle a diverse range of human health problems, including detection and targeted treatment of cancer, prevention of infections associated with medical implants, and treatment for stroke victims.

They sound awesome, should I buy some nanoparticles and just sprinkle them on my food to ensure my on-going health?

No, that is ridiculous.

…but actually, they might already be in your food. A team of scientists at Arizona State University published a paper in 2012 that reported the presence of nanoparticles in a range of processed foods, including chewing gum, sweets and baked goods. Nanoparticles can be used to improve the colour, flavour, texture and even the nutritional value of foods. However, concerns have been raised about the safety of nanoparticles and their potential effects on human health.

Unfortunately, the thing that makes nanoparticles so appealing is also the reason they are cause for concern. As previously noted, nanoparticles can have very different properties compared to larger particles of the same material. As a result, their effects on humans and the environment is relatively unknown. Some studies have indicated that nanoparticles may have harmful effects on human health, such as increased cancer risk; but overall, not much is known either way and a great deal more research is needed3. We also know relatively little about the impact of nanoparticles on the environment, although research is now underway to investigate their ecological impact.

So, are nanoparticles good or bad? I’m confused.

So are the policymakers.

Back in the olden days, people released man-made substances into the environment indiscriminatingly. They seemed pretty safe, or at the very least they weren’t instantly and obviously unsafe; their harmful long-term effects weren’t discovered until much later (see: asbestos and DDT).

Nowadays, this still happens (see: other pesticides). Unless, of course, what you are trying to release has a science-y sounding name that can be easily portrayed as a terrifying franken-product by the tabloids. In which case people will loudly and angrily call for a ban, regardless of whether or not the body of scientific evidence supports one (see: GM).

In an attempt to avoid negative press campaigns and any “bit awkward…but you know that thing we’ve been saturating the environment with for 50 years, well actually it turns out it causes cancer” incidents, some countries have taken an extremely cautionary approach towards nanoparticles. For example, intentional release of nanoparticles into the environment is currently prohibited in both Germany and the UK.

However, this might be a missed opportunity, as nanoparticles have shown potential as effective environmental clean-up agents. For example, one EU research project, called NanoRem, is currently investigating the potential for nanoremediation (treatment of environmental pollutants using nanoparticles) of contaminated environments.

I couldn’t be bothered to read most of this article, can you hit me up with a summarising conclusion?

Of course.

Nanoparticles are really small particles (<100nm), which can have big benefits in many applications. However, not a lot is currently known about the risks (either to the environment or to human heath) associated with them. More research is required to both further refine nanoparticle engineering for specific uses, and to determine the safety and impact of nanoparticles on the environment, wildlife and humans.

One thing’s for sure though, these tiny particles have a big future ahead of them.


1. A to Z of Nanotechnology
2. Understanding Nano
3. The Royal Society (2004) Nanoscience and nanotechnologies: opportunities and uncertainties

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