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Much More Microplastics In The Ocean | Earth Wise

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We’ve been hearing more and more about plastic contamination (microplastics) in the ocean.  It is pulled from the nostrils of sea turtles, found in Antarctic waters, and tracked in increasing quantities in sedimentary layers dating back to the 1940s.  A new study by researchers from the Scripps Institution of Oceanography suggests that there could be a million times more pieces of plastic in the ocean than previously estimated.

Oceanographers found that some of the tiniest countable microplastic particles in seawater occur at much higher concentrations than previously measured.  Apparently, the traditional way of counting marine microplastics most likely misses the smallest particles, and therefore underestimates the number of particles by a factor of anywhere from 10,000 to a million.

The new measurements estimate that the oceans may be contaminated by 8 million pieces of so-called mini-microplastics per cubic meter of water.  Earlier studies that only looked at larger pieces of plastic found only 10 pieces per cubic meter. 

Microplastic studies typically trawl or pull a fine net behind a ship to collect samples.  But the meshes previously used could only capture plastics as small as 333 microns.  The new study found plastic particles as small as 10 microns, which is less than the width of a human hair.

Plastics keep breaking down into smaller and smaller particles, but they are so chemically strong that their chemical bonds don’t break down. They remain bits of plastic.  Scientists are concerned that these particles can get small enough to enter the human bloodstream.  The potential effects on human health are not well known and not extensively studied.

The problem of plastics just keeps getting bigger.

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Microplastics a million times more abundant in the ocean than previously thought

Photo courtesy of UC San Diego.

Earth Wise is a production of WAMC Northeast Public Radio.

Road Salt Pollution

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Mirror Lake is a popular recreational lake located in the Village of Lake Placid.  It is the most developed lake within the Adirondack Park, which is a publicly protected area that is actually larger than Yellowstone, Yosemite, Glacier, and Grand Canyon National Parks combined.

New research has revealed that road salt runoff into Mirror Lake is preventing natural water turnover which poses a risk to the balance of its ecology.  The study, which was published in Lake and Reservoir Management, found that road salt runoff is preventing spring mixing of the water column.    This creates more anoxic water conditions, meaning there is less oxygen in the water, and limits the ability of the habitat to support the native lake trout. 

Mirror Lake is the first lake in the Adirondack Park to show an interruption in lake turnover due to road salt.  Many lakes in northern climes experience so-called “dimictic turnover”, which is a natural process where wind and less stratified water conditions of spring and fall allow mixing of the water column that redistribute oxygen and nutrients throughout the lake.  High levels of surface-water chloride introduced into the lake from road salt runoff inhibit the mixing of the water column.

The lack of mixing and oxygenation is bad news for fish species such as lake trout, which require cold, oxygenated water to survive.  It may also put the lake at a greater risk of algal blooms.

Mirror Lake is small, surrounded by concentrated development, and receives the direct discharge of stormwater.  So, it is particularly vulnerable to road salt contamination.  Other lakes elsewhere in New York may experience similar conditions.  The researchers are confident that natural turnover conditions could be restored to the lake if road salt application in the watershed is reduced.

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Road salt pollutes lake in one of the largest US protected areas, new study shows

Photo, posted January 5, 2018, courtesy of MTA of the State of NY via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

China And Rare Earth Mining

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Rare earth elements are a crucial part of much of modern technology.  Everything from computers to X-ray machines and aircraft engines needs one or more rare earth elements for magnets, lenses, and other functions.  The world’s tech giants such as Apple, Huawei, and Tesla depend on suppliers of rare earths.

Rare earth elements are not actually rare, but they are very expensive to extract in ways that are not extremely harmful to the environment.  China has been a major source of these elements since its rare earth mining industry took off in the 1990s.  The removal of rare earths from the earth’s crust, using a mix of water and chemicals, has caused extensive water and soil pollution.

Today, concrete leaching ponds and plastic-lined wastewater pools dot the hills of Southeast China.  Large wastewater ponds sit uncovered and open to the elements in many places.  Landslides or barrier failures can spill contaminated contents into waterways or groundwater.

Local and federal officials in China have started to shut down illegal and small-scale rare earth mining operations and have embarked on a cleanup of polluted sites.  The rare earth mining cleanup operation is part of wider efforts across China to address severe problems of water, air and soil pollution.

China’s Ministry of Industry and Information Technology estimated that the cleanup bill for southern Jiangxi Province could amount to more than $5 billion.  Many environmental experts and local officials say that the cost of the cleanup should not be shouldered by the Chinese government alone, but also by the rare earth industry and the global companies and consumers that benefit from rare earth technology.  As rare earth mining efforts start up elsewhere around the world, it is important not to repeat the mistakes made in China.

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China Wrestles with the Toxic Aftermath of Rare Earth Mining

Photo, posted April 21, 2019, courtesy of John Beans via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Antibiotics In The Environment

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Antibiotics make their way into the environment in many ways.  Sources of antibiotic pollution include the waste from large-scale animal farms and the wastewater from hospitals, municipalities, and antibiotic manufacturing.

A new study has discovered concentrations of antibiotics in some of the world’s rivers exceed safe levels by up to 300 times.  In the project, researchers looked for 14 commonly used antibiotics in rivers in 72 countries across six continents.  They found antibiotics at 65% of all the sites they examined. 

The antibiotic ciproflaxacin was the compound that most frequently exceeded safe levels, surpassing that threshold in 51 places. The antibiotic metronidazole exceeded safe levels by the biggest margin.  Concentrations of this antibiotic at one site in Bangladesh was 300 times greater than the safe level.  The most prevalent antibiotic was trimethoprim.  It was detected at 307 of the 711 sites. 

Some of the world’s most iconic rivers were sampled as a part of this study, including the Danube, Mekong, Seine, Thames, Tiber and Tigris. 

The project, which was led by the University of York, found that high-risk sites were often located near wastewater treatment systems, waste or sewage dumps, and in some areas of political unrest. 

Safe levels for antibiotics, which were recently established by the AMR Industry Alliance, range from 20,000 to 32,000 nanograms per liter depending on the compound. 

According to the research team, solutions to the problem of antibiotic contamination should include infrastructure investment, tighter regulation, and the remediation of already contaminated sites. 

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Antibiotics found in some of the world’s rivers exceed ‘safe’ levels, global study finds

Photo, posted October 7, 2013, courtesy of Nicola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Problem Of Microplastics

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In recent years, there have been multiple reports of microplastic contamination seemingly everywhere:  in the ocean, in lakes and rivers, in beverages and foods, and in the bodies of birds, fish, and even people.  As the world tries to come to grips with this growing problem, there are many things that we simply don’t know.

Microplastics are usually formed by the breakdown of larger pieces of plastic.  Shopping bags and cups degrade into microplastics.  Microfiber clothing generates microplastics in washing machines.  And some manufacturers still intentionally add microplastics to personal care products like toothpaste and facial scrubs.

Technically, a microplastic is any piece of plastic measuring five millimeters in size down to one micron – which is one thousandth of a millimeter.  But there can be even smaller plastic particles classified as sub-microplastics and even nanoplastics.

A real concern is that it is not actually clear how dangerous microplastics are for living organisms.  We know that aquatic and terrestrial species – including humans – can and do absorb microplastic particles, but whether there is actual toxicity and the nature of any detrimental effects is not yet well understood.

Another real problem is that it is actually not easy to distinguish microplastics from other particles in a given sample.   When you are looking at a particle that is smaller than a millimeter in size, it is not easy to tell whether it is a grain of sand, a bit of cellulose from a plant, or a microplastic.  There are reliable and definitive ways to analyze samples for microplastics, but they are not as simple and commonplace as just looking through a microscope.

Microplastics are a rapidly growing problem and we don’t even really know how big and how bad the problem is.

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How dangerous is microplastic?

Photo, posted January 10, 2015, courtesy of Daria Nepriakhina via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

An Accidental Plastic Eater

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A couple of years ago, scientists in Japan discovered bacteria at a recycling plant that were breaking down a type of plastic called polyethylene terephthalate, or PET.  With the world facing a growing plastic pollution problem, British and American researchers began to study the enzyme that the bacteria were using to try to understand how it works.

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Are We Drinking Plastic?

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Almost everyone everywhere comes into contact with plastic everyday.  Its use has increased 20-fold in the past half-century, and production is expected to double again in the next 20 years.  But is plastic so ubiquitous that we are unwittingly drinking the stuff?

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A Ton Of Plastic Per Person

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A study by the American Association for the Advancement of Science has produced an estimate of the total amount of plastic manufactured worldwide since the 1950s.  The researchers then measured that data against statistics on recycling, incineration and discard rates.  The results are sobering.

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Dioxane And Drinking Water

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A byproduct of plastics production, dioxane is a clear, synthetic, liquid solvent that easily mixes with water.  It’s frequently used in paint strippers, dyes, and varnishes, as well as shampoos and body washes – particularly those that are sudsy.  Dioxane doesn’t really biodegrade and is widely regarded as a contaminant.    

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