microscopic

How much nanoplastic is in the oceans?

August 1, 2025 By EarthWise Leave a Comment

It is unfortunately well-known that microplastics are pretty much everywhere on Earth. They are also increasingly found in living things like birds and dolphins as well as in human brains and placentas. The oceans are polluted with plastic, and for the first time, there is now an estimate for the volume of nanoplastics – which are even smaller than microplastics and invisible to the human eye – found in the North Atlantic.

According to a study published in the journal Nature by the microplastics and nanoplastics research group at the Helmholtz Center for Environmental Research in Germany, there are at least 30 million tons of nanoplastics in the North Atlantic, which is more than the weight of all wild land mammals on Earth.

The same researchers have analyzed plastic in lakes, urban air, and even the air in very remote places, but the new study reveals a missing part of the plastics story.

Nanoplastics are microscopic fragments smaller than one micron, about the size of small bacteria. There has been ongoing concern about nanoplastics in ocean water, but there wasn’t the technology available to really investigate it. While nanoplastics were expected to be found in the ocean, the sheer amount of it was surprising.

The average concentration of nanoplastics near coastlines is about 25 milligrams per cubic meter of water, about the weight of a single large bird feather. Nanoplastics are tiny enough that they can easily infiltrate the bodies of living creatures. For fish and other ocean animals, that means constant exposure that builds up over time.

It is highly unlikely that plastic pollution is going to stop any time soon, but there is a United Nations meeting on the subject in August in Geneva.

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Tons of Invisible Plastic Pieces Lurk in Ocean Water

Photo, posted June 24, 2020, courtesy of G.P. Schmal / NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Colorful Solar Panels | Earth Wise

September 22, 2022 By EarthWise Leave a Comment

More and more buildings and public spaces are incorporating solar panels and not only just on rooftops. Some buildings are incorporating power-generating structures all over their facades.

Using solar panels in this way puts some design constraints on buildings because solar panels are typically a deep black color. This is because solar panels need to absorb light and making them any other color decreases their ability to do so and generate power. But the problem is that people don’t necessarily want a black building.

One alternative to traditional solar panel design is to use structural sources of color that include microscopic shapes that only reflect specific light frequencies, like the scales on butterfly wings. But this approach generally leads to iridescence – which might not be what is wanted – and is often quite expensive to implement.

A team of researchers at a university in Shanghai has now demonstrated a way to give solar panels color that is easy and inexpensive to apply and that does not reduce their ability to produce energy efficiently.

The technique involves spraying a thin layer of a material called a photonic glass onto the surface of solar cells. The photonic glass is made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres. Even though most light can pass through the photonic glass, certain colors are reflected back, depending on the sizes of the spheres. By varying that size, the researchers created solar panels that were blue, green, or purple with only a very small drop in solar panel efficiency.

The solar panels made this way maintained their color and performance under durability testing. With this new technology, there may soon be colorful solar panels on our buildings.

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Colorful solar panels could make the technology more attractive

Photo, posted December 15, 2021, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio