Carbon Nanotubes in Environment Affect The Growth of Algae

With the rise of carbon nanotubes used in a range of emerging technologies, one question often surfaces: How will those particles affect the environment?

The problem of pollution and how nanoparticles such as carbon nanotubes will impact health of living things is something still being explored by researchers. But one study has shown that in elevated concentrations, carbon nanotubes can affect the growth of algae.

Science Daily reports, "Carbon nanotubes (CNTs) are up to 100,000 times thinner than a human hair and as light as plastic. Despite this they have a higher tensile strength than steel, are harder than diamond and conduct electricity better than copper. These properties make CNTs a raw material with a very promising future. All over the world possible applications are being investigated, including use in solar cells, plastics, batteries, medical technology and the purification of drinking water. With the increasing industrial production of CNTs now reaching the level of hundreds of tons per year, the quantity of these particles which could be released into the environment has also risen."

With particles able to escape into the air, water, and soil, a primary question is how they will affect simple but vitally important lifeforms, such as algae.

A study completed by scientists from Empa and the Agroscope Reckenholz-Taenikon (ART) Research Station looked specifically at what happens to algae when in the presence of carbon nanotubes. It turns out that algae is not directly affected by carbon nanotubes -- they don't absorb them or shut down normal processes around them. But what does happen is algae will clump up around the carbon nanotubes, which means there is not sufficient space and light for algae to grow. The organisms then grow more slowly.

"Our study shows how difficult is to understand in detail the effect of nanomaterials on organisms," says Empa and ART researcher Fabienne Schwab.

And of course, their take-away from the study is that "nanoparticles should not be released into our environment" until more comprehensive and long-term studies are completed.

Nanoparticles are, in effect, another case of moving fast in the direction of new technology, without giving equal consideration to the effects of that technology. It is an issue we discussed with the idea of electronic textiles that could be a considerable burden on the environment without proper recycling.

Nanoparticles seem to be a miracle of modern technology -- we've discussed their use in products from paper to clothing. And with each, we bring up the question of why risk assessment isn't keeping pace with the application of nanotechnology in products sold in the marketplace.

This study shows that carbon nanotubes, at some level of concentration, affect the growth of algae. Is that something to get all freaked out about? Not really, not yet. Nanoparticles could also potentially cause cancer. Is that something to get all freaked out about? Not yet. The answers are "not yet" because we don't have enough information to know how these particles are affecting us and the environment, though we're still producing several tons of this stuff every year and putting it in a wide range of products. Is that something to get all freaked out about? Absolutely.

If anything comes from this study, it is hopefully an awareness that we need to be very, very careful with nanoparticles, and invest more in studying their affects on the environment before we put them in everything.

Carbon Nanotubes in Environment Affect The Growth of Algae
It's still difficult to say how carbon nanotubes that make their way into the environment will affect flora and fauna, but some possibilities are already known

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