![\"Microplastic](\"https:\/\/nilu.com\/wp-content\/uploads\/2023\/03\/microplasticsampler-zeppelin-annecathrinenilsennilu.jpg\")
The microplastic sampler is based on a similar sampler NILU previously developed for taking samples of other substances in the air. The principle is the same, but in the new microplastic version, all the plastic sampler components have been replaced with metal.<\/p>\n
\u201cWe can\u2019t take microplastic samples with plastic equipment,\u201d says Dorte Herzke. \u201cIf we did, we\u2019d contaminate our samples. Therefore, our first air sampler for microplastics was made from stainless steel. Later we switched to aluminium.\u201d<\/p>\n
Svalbard influenced by microplastics<\/h2>\n
In autumn 2021, NILU mounted two different microplastic samplers at the Zeppelin observatory. The observatory is located 474 metres above sea level, near the top of Zeppelin Mountain on Svalbard. The nearest settlement is the \u201cresearch village\u201d Ny-\u00c5lesund. In winter, only around 30 people live there; during summer, up to 200.<\/p>\n
Even there, the filters in the samplers picked up tiny plastic pieces, down to a hundredth of a millimetre.<\/p>\n
\u201cUnfortunately, I was not surprised,\u201d says Herzke. \u201cWe think of Svalbard as untouched and desolate, but microplastics find their way to this remote area too.\u201d<\/p>\n
The six microplastic air samples NILU took during autumn 2021 were part of the Norwegian Environment Agency\u2019s monitoring project for microplastics, MIKRONOR. In 2022, NILU financed its own tests. According to Herzke, the goal is to determine if the results from 2021 can be repeated, and also whether the results look different during the summer period.<\/p>\n
\u201cWe now have samples from both the winter and summer seasons at the Zeppelin observatory,\u201d she says. \u201cIn addition, we are taking corresponding microplastic samples at the Birkenes observatory in the south of Norway.\u201d<\/p>\n
Smart solutions are needed!<\/h2>\n
Two kinds of microplastic samplers have been developed by NILU. One is a \u201cpassive\u201d sampler, in practice a large metal bucket that collects everything that falls from the sky.<\/p>\n
The other air sampler for microplastics \u2013 the one Dorte Herzke used on the Plastic Cruise \u2013 is an \u201cactive\u201d sampler. It uses a pump to draw air through filters, capturing all particles larger than a hundredth of a millimetre.<\/p>\n Every 14 days, the filters in the active samplers at Zeppelin and Birkenes observatories are replaced. Herzke is particularly pleased that they were able to design the filter holder so that it closes immediately when it is removed. In this way, they avoid contaminating the filter inside with plastic from sources other than the air. In addition, the entire filter holder can be packed and sent to NILU\u2019s laboratory in Troms\u00f8, where Herzke and her colleagues are ready to do the analysis.<\/p>\n The microplastics on the filters are too small to be seen with the naked eye. So how does Dorte Herzke know that there is microplastic on the filter?<\/p>\n \u201cWe don\u2019t know, and we can\u2019t even use a microscope to look for it,\u201d she explains. \u201cInstead, we use an instrument called a mass spectrometer (GC\/MS) and connect it to a pyrolysis unit.\u201d<\/p>\n Although \u201cpyrolysis\u201d makes it sound like they are burning the samples, that is not what is happening. The filter samples must be exposed to 600-degree heat to reveal the microplastic. But without oxygen present, combustion does not occur. Instead, a process called pyrolysis takes place, where the polymer structure, i.e. the repetitive bond between each molecule in the plastic, is destroyed. Since different types of plastic break down into different polymer structures, scientists can measure and classify the different structures into different types of plastic and determine how much there is of each kind.<\/p>\n When Dorte Herzke began to take an interest in plastic pollution, and later microplastics, most measurements were done on samples from animals and fish. Eventually, she became more interested in what happens to the microplastics in the environment, and which transport routes they take to the Arctic. With funding from the Fram Centre, NILU, and the Norwegian Environment Agency, she was able to start looking for answers.<\/p>\n \u201cAfter all, air is NILU\u2019s home ground,\u201d she says. \u201cAs soon as we started looking at microplastics in the context of air, collaborating with other NILU departments was initiated. Together, we can both determine that there is microplastic in the Arctic and calculate how it was transported through the atmosphere to get there.\u201d<\/p>\n Filters from microplastic sampling at the observatories in Svalbard and at Agder are still coming in. Analysis and further studies of these will fill a lot of Herzke’s time in the future, but she can already say that this time, too, plastics are in the air.<\/p>\n![\"Microplastic](\"https:\/\/nilu.com\/wp-content\/uploads\/2023\/03\/microplasticsampler-ship-dorteherzkenilu.jpg\")
600\u00b0C reveals the microplastic<\/h2>\n
Tracking microplastics through the air<\/h2>\n
![\"Microplastic](\"https:\/\/nilu.com\/wp-content\/uploads\/2023\/03\/microplasticsampler-polarbear-louisekieljensennpi.jpg\")