Share:
Microplastics in the sea Studies partly falsified by lab coat material
In recent years, numerous studies have been published that showed how polluted our oceans are. Researchers now point out that some examinations could be falsified by fibers from the laboratory shells of the scientists involved. This does not mean, however, that the pollution of the oceans by plastic is harmless.
Plastics in oceans
The pollution of our environment is progressing day by day. Also in the oceans lands more and more waste. For example, plastic is constantly being released into the sea - from ships, from unsecured landfills, through the sewage. According to scientific research, plastic waste is now found in all marine regions. Even in arctic waters, plastic waste has already been discovered. Researchers from Austria now report that previous studies were often dirty.
The pollution of the oceans with plastic garbage has, according to studies, sometimes dramatic proportions. However, some of these scientific studies were apparently falsified by the fibers of the lab coat. (Image: kranidi / fotolia.com) Contamination by natural fibers of laboratory mantles
For years it has been claimed again and again that a large part of the marine plastic consists of tiny synthetic fibers - are called polyester or viscose. Even at great depth these particles should have been detected.
In such studies, however, one must pay close attention to choose the right detection method, and this rule was often not observed in previous studies, as an analysis of the Technical University (TU) Vienna now shows.
According to the experts, it has been found that some measurement techniques can not distinguish between natural and artificial microparticles.
What was considered to be plastic from the environmental sample may in many cases merely have been contamination by natural fibers of the lab coat.
The Austrian researchers recently published their new findings in the journal "Applied Spectroscopy".
Anyone who measures measures crap
"If you look for plastics in water samples, there is always the danger that the detected substances do not originate from the sample itself, but from the laboratory environment," explained Prof. Bernhard Lendl from the Institute for Chemical Technologies and Analytics of the Vienna University of Technology Message.
This problem was already known, so some research groups also made great efforts to avoid synthetic fibers in the laboratory when detecting plastic in environmental samples.
According to the information, the experiments were carried out in special clean rooms, clothing made of synthetic fibers was prohibited. Otherwise, tiny fibers of clothing would inevitably have found their way into the sample and falsified the result.
But what you did not think about it: viscose is a wood-based cellulose fiber that can not be equated with plastic. Unlike synthetic plastic, viscose is made of natural cellulose and is therefore biodegradable.
Synthetic fibers and natural cellulose fibers (e.g., viscose and cotton) are difficult to distinguish from each other. Failure to use the right analysis methods can also result in cotton fiber fiber contamination resulting in a result that can be misinterpreted as evidence of plastic.
Similar distortions in the laboratory had previously existed with beer and honey samples - microplastic had also been detected there, but later it was noticed that the results were probably due to unclean laboratory conditions.
Synthetic fibers at great sea depth?
The common method for detecting plastic traces in water samples is infrared spectroscopy. If you illuminate the sample with infrared radiation, a part of the radiation is absorbed.
Different chemical substances absorb different regions of the infrared spectrum to varying degrees, thereby allowing individual chemicals to be assigned individual infrared fingerprints.
"We studied different samples with well-known content, using several different infrared spectroscopy methods," Lendl explained. It showed how easily errors can occur in such tests.
"Choosing the right method and setting the measurement parameters carefully will give you some reliable results, but with the technology that has been used so far, it is simply not possible to distinguish between synthetic fibers and natural substances," says the expert.
"According to our results, the artificial fibers that are supposed to be found in great depths of the sea are simply a measurement error."
Dramatic pollution of the oceans
This does not mean, however, that the pollution of the oceans by plastic is harmless. In fact, large quantities of plastic are floating around in our oceans - from the plastic bottle to the lost fishing net - there is no doubt about that.
"But when it comes to detecting micro-plastic traces, one must choose the appropriate scientific methods," emphasized Lendl. "Everything else is dubious and does not help the ocean or science."
It should also be noted that not only in water samples but also in marine fish plastic parts were detected.
For example, scientists from the Alfred Wegener Institute (AWI) in Bremerhaven have detected plastic residues in food fish from the North and Baltic Seas.
And researchers from the East China Normal University in Shanghai reported in the Journal of the American Chemical Society that they also found microplastics in sea salt. (Ad)