National Oceanic and Atmospheric Administration (NOAA)
That fancy iced coffee you downed this morning might give you more than a jolt. A common accessory - the plastic straw - is contributing to a type of contaminant affecting our ecosystems, not to mention the human food chain.
The pollutants are called microplastics, tiny bits of plastic that break down from larger pieces and are ingested by sea life. And eventually by humans. Microbeads are also part of the problem. These are extremely small pieces of plastic, used especially in cleansing products as exfoliating agents. The detection of microplastics has become an important research goal.
But why straws? It’s small and often bypasses recycling automation. If it doesn’t go to landfill, it can end up in our oceans and lakes.
While some cities have taken to banning straws, others have considered banning other single-use plastic products, such as plastic water bottles, cutlery, and bags. It’s the life cycle of these materials that can make them harmful.
According to various estimates, by 2016, microplastics detection efforts reported there were between 15 and 51 trillion pieces of microplastics in the world’s oceans.
About one million plastic water bottles were bought every minute across the globe in 2017, according to Forbes Magazine. Yet only nine percent was recycled.
The rest end up in landfills, or on our beaches and in our parks. Some of those materials can wash away into our oceans, lakes, or rivers.
Sand samples containing microplastics are prepared for analysis
When plastics are subjected to the sun, air and sea, the larger pieces fragment or degrade into smaller pieces. The smallest pieces, with a size of smaller than 5 millimeters, are called microplastics. Some are microscopic and pass through filters meant to remove impurities from our drinking water.
Researchers ran tests on 259 bottles of water from 11 brands bought in nine countries, according to Time Magazine. More than 90 percent of the examined bottles contained microplastics.
Different plastic types have different toxicities, according to Ashok Deshpande, Ph.D., a research chemist with the Northeast Fisheries Science Center of National Oceanic and Atmospheric Administration (NOAA) in Sandy Hook, New Jersey.
And different polymers accumulate various contaminants to different extents. Plastics also accumulate bacteria, viruses, chemicals and harmful algae.
“The plastics act as a conduit for the transport of the algae and colonizing bacteria,” Deshpande said.
Microplastics can be mistaken for prey by fish. Fish think it’s their food – the aquatic life can’t distinguish between microplastics and food. The microplastics affect the fish when they are ingesting it, mostly choking up the fish’s digestive system. The fish thinks it’s not hungry. So it starves to death. Since plastics are the conduits for chemical contamination, the fish can be subject to all those agents too.
And people, of course, eat fish.
Northeast Fisheries Science Center of National Oceanic and Atmospheric Administration poster
According to a study Deshpande was involved in 15 years ago, the contaminants in the fish off Sandy Hook tested within U.S. Food and Drug Administration’s acceptable levels. But that was 15 years ago.
“We are just beginning to do the research on the fish,” he said. “Different studies have shown how the plastics affect the fish and shellfish. These are ongoing and there are no conclusions now. But if they eat microplastics, it’s definitely not good for them.“
The World Economic Forum warns that there will be more plastics in the ocean by 2050 than fish.
Ashok Despande Ph.D., a research chemist with the Northeast Fisheries Science Center of National Oceanic and Atmospheric Administration (NOAA) in Sandy Hook, New Jersey
To characterize the microplastics found in fish, multiple technologies can be applied such as gas chromatography (GC) pyrolysis, mass spectrometry, infrared (IR) spectroscopy, or Raman spectroscopy, according to Deshpande. Raman microscopy combines Raman spectroscopy and optical microscopy, and is one of the most efficient and effective ways to identify polymers. It allows the researcher to analyze microscopic pieces of plastics by focusing the laser beam to a very small spot, and obtaining Raman spectra from it. Raman spectra are characteristic to each polymer, and can be identified by searching the library of known polymer spectra.
Chelsea Rochman, Ph.D., Professor at University of Toronto’s Department of Ecology and Evolutionary Biology uses a Raman microscope to study microplastics. She said she’s tried to understand how much is there, what it is, and what size it is. There are so many different types of plastics out there, she pointed out, that analytical tools (like Raman) are necessary to characterize these materials, which helps gauge their impact on animals.
Her group is pursuing faster and more accurate ways to analyze microplastic samples. The goal is to increase the efficiency of the analytical methods to answer relevant questions more effectively. It’s important to identify the type of polymers (or microplastics) because it can lead to identifying the source of the pollutants to the environment. This will, in turn, help to reduce contamination in the environment via social campaigns, consumer movements or regulatory actions. Rochman’s group uses HORIBA Scientific’s XploRA™ PLUS Raman microscope, and is developing sample characterization methods that are fast, easy, robust and accurate.
Deshpande said one of the next challenges is to identify the small fibers in shellfish and other small organisms. He said shellfish “ingest microplastics, and fish eat thousands of them, as well as zooplankton. Imagine how much fish are ingesting. The bigger fish have double exposure because they can eat smaller sea life and bigger pieces of plastics.”
A 2018 study estimated that the average adult consumes approximately 2,000 microplastics per year through salt.
Researchers found microplastics in 90 percent of the table salt brands sampled worldwide, according to a 2018 report by National Geographic. The study was part of an effort to look at the geographical spread of microplastics in table salt, and their correlation to where researchers found plastic pollution in the environment.
The findings of the study suggest that human ingestion of microplastics via marine products is strongly related to emissions in a given region.
Different brands showed a dramatic variation in the density of microplastics among different brands. However, the density of those from Asian brands were especially high, the study found. The journal cited Asia as a hot spot for plastic pollution.
Microplastics levels were highest in sea salt, followed by lake salt and then rock salt. That provided another indicator of the geographic density of plastic pollution.
The study replicated earlier ones done in the United States, Spain, China, and by a group from France, Britain, and Malaysia.
The 2018 study estimated that the average adult consumes approximately 2,000 microplastics per year through salt. The health effects of that phenomenon was unclear at the time of the research.
Rochman warns the mismanagement of our waste means it has come back to haunt us in our seafood and drinking water. We may not know the exact impact it has on human health, but it is a fact that our trash is coming back into our food, and we should manage it properly.
It is clear there is so much yet to learn about microplastics, and researchers agree that we must and as soon as possible.
In 2019, researchers published a microplastics study in the Environmental Science & Technology journal from the American Chemistry Society. It estimated how many microplastic particles are entering our body through our food supply.
The team reviewed 26 published studies that looked at microplastic quantities in fish, shellfish, added sugars, salts, alcohol, tap or bottled water, and air. They calculated the food and drink intake using recommendations from the 2015-2020 Dietary Guidelines for Americans.
The researchers estimated we consume microplastics in the range of 39,000 to 52,000 particles per year. When they added inhalation to this estimate, it increased to 74,000 to 121,000 microplastic particles per year. The results varied depending on sex and age.
The researchers encouraged more studies on the topic.
Researchers with the U.S. Geological Survey in 2019 found that about 90 percent of rainwater samples collected from the Denver-Boulder area of Colorado contained microplastics.
The researchers weren’t sure how the microplastics ended up in the rainwater.
They found the microplastics in samples from six sites in the areas.
Fibers were found in a variety of colors. The most common colors were blue, followed by red, silver, purple, green, and yellow.
In Microplastics explained part I, Dr. Chelsea Rochman breaks down what we know, what we don’t, and what we want to know. Alterra Sanchez describes the big risks and factors involved. Part II gives us a look into the Rochman Lab and the work being done there. Alterra Sanchez tells us the importance of her research as well.
Watch this video for more information on microplastics and the environment.
Microplastics a Big Problem For The Environment
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Discover 50 years of Raman innovation by HORIBA. Click here to read more about Raman Spectroscopy history and HORIBA's contribution.
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