- Adam Levy<\/li><\/ul>\n\n\n\n
Read when you\u2019ve got time to spare.
![\"Hirondellea_gigas.jpg\"](\"https:\/\/pocket-syndicated-images.s3.amazonaws.com\/5ec6a4a83197a.jpg\")
<\/p>\n\n\n\nCredit: Daiju Azuma Wikimedia<\/a> (CC BY-SA 2.5).<\/p>\n\n\n\n
The Mariana Trench, in the western Pacific Ocean between Japan and Papua New Guinea, plunges nearly seven miles below the surface at its deepest point. It is one of the most inaccessible environments on Earth, but it has not escaped the impact of humanity\u2019s violence.<\/p>\n\n\n\n
A group of scientists have now found radioactive carbon-14\u2014at levels high enough to indicate it originated from the detonation of nuclear bombs\u2014in the flesh of shrimplike crustaceans living in the trench. \u201cTypically, we say the trenches are far away from us; they\u2019re very deep and they\u2019re pristine. But actually, they\u2019re not,\u201d says earth scientist Jiasong Fang of Shanghai Ocean University, who worked on the new study. \u201cEverything can get into the trenches.\u201d<\/p>\n\n\n\n
Scientists can trace the reach of above ground nuclear detonations, the first of which was conducted in 1945, by measuring levels of carbon-14\u2014a radioactive isotope of carbon produced when neutrons from nuclear reactions collide with nitrogen atoms in the atmosphere. (It is also produced naturally, at lower levels, by cosmic rays bombarding the atmosphere.) Atmospheric carbon-14 levels doubled in the 1950s and 1960s as scores of hydrogen bombs were tested. A very small amount of the \u201cbomb carbon\u201d from these gigantic explosions has decayed, but the rest has spread around the world and been taken up via carbon dioxide by plants, which are then eaten by animals\u2014including humans.<\/p>\n\n\n\n
Until now, it has been unclear whether bomb carbon has managed to spread into the farthest crevices of the world, especially the deepest seas. It would have taken natural oceanic circulation about 1,000 years to carry it to the depths of the Mariana Trench. And in fact, testing for the new study showed that the waters of the trench did have low levels of carbon-14\u2014which is what the researchers expected, given the long travel time from atmosphere to deep ocean.<\/p>\n\n\n\n
But when they used traps to catch and test crustaceans living at these depths, they detected much higher levels of the isotope in these animals\u2019 tissues and gut contents than in the surrounding waters. The bomb carbon had to be arriving another way that brought it there faster, and the researchers surmised it was taking a shortcut via the food chain. Organic matter\u2014including the poop and carcasses of surface-dwelling life\u2014falls through the water column in just weeks or months. When crustaceans on the seabed munch these morsels, they absorb the signature of nuclear tests into their bodies, the researchers say in their study, published online in April 2019 in Geophysical Research Letters [pdf<\/a>].<\/p>\n\n\n\n
Other studies conducted around the world have also recently identified the residue of the weapons tests of the mid-20th century\u2014as well as the Chernobyl and Fukushima nuclear disasters\u2014in mountain glaciers, another landscape often considered pristine and remote. Together with the results from the Mariana Trench, these findings \u201cprove that atmospheric and oceanic circulation distribute bomb-derived radioactivity globally, even to the most remote sites,\u201d says Edyta Lokas of the Institute of Nuclear Physics PAS in Krakow, Poland, who worked on the glacier research<\/a>, which was presented at a meeting of the European Geoscience Union (EGU) in April. Worse still, the fallout locked in glaciers includes more worrisome radioactive elements (such as americium-241, a product of the decay of plutonium)\u2014and could be released as the world warms and the ice thaws. \u201cThe legacy of radioactive contamination will be felt by many generations ahead,\u201d Lokas says.<\/p>\n\n\n\n
Such clear, long-lasting imprints of nuclear testing are among the markers proposed by scientists who suggest humans have changed the planet so much that we are now living in a distinct geological epoch, often called the \u201cAnthropocene<\/a>.\u201d Proponents of this idea say the fact that remnants of these tests are reaching glaciers and deep oceans indicates humans have begun fundamentally altering the geology of the entire planet. \u201cIt just shows that the human signal is getting even to places that were thought to be distant or remote from human influence,\u201d says Jan Zalasiewicz, a paleobiologist at the University of Leicester in the U.K. who researches the Anthropocene.<\/p>\n\n\n\n
But it is not just relatively rare impacts, like nuclear tests, that have reached these remote environments; more mundane human contamination can be found there too. Researchers recently announced they had found microplastics\u2014degraded pieces of larger plastics, as well as microbeads and synthetic fibers\u2014in every crustacean they tested from the Mariana Trench. \u201cIt was disheartening but not unexpected,\u201d says William Reid, an ecologist at Newcastle University who worked on the study, published in Royal Society Open Science<\/em><\/a> in February. \u201cIt is probably the saddest piece of research I have ever been involved with.\u201d Microplastics have also been detected in glaciers<\/a>, according to results presented at the April EGU meeting.<\/p>\n\n\n\n
In fact, humanity\u2019s actions are so far-reaching that a 2018 study in<\/a> Current Biology<\/em><\/a> suggested just 13 percent of Earth\u2019s oceans can still be classed as wilderness<\/a>. \u201cI very much doubt,\u201d Reid says, \u201cthere are many places left on the surface or seafloor of this planet that we have not impacted.\u201d<\/p>\n\n\n\n
\n\n\n\nThis post originally appeared on Scientific American and was published May 15, 2019. <\/p>\n","protected":false},"excerpt":{"rendered":"
The detection of this radioactive relic of nuclear weapons tests in a remote environment shows humanity\u2019s far-reaching environmental impact. Scientific American Adam Levy Read when you\u2019ve got time to spare. Credit: Daiju Azuma Wikimedia (CC BY-SA 2.5). The Mariana Trench, in the western Pacific Ocean between Japan and Papua New Guinea, plunges nearly seven miles<\/p>\n
![Daiju Azuma Wikimedia<\/a> (CC BY-SA 2.5).<\/p>\n\n\n\nThe Mariana Trench, in the western Pacific Ocean between Japan and Papua New Guinea, plunges nearly seven miles below the surface at its deepest point. It is one of the most inaccessible environments on Earth, but it has not escaped the impact of humanity\u2019s violence.<\/p>\n\n\n\nA group of scientists have now found radioactive carbon-14\u2014at levels high enough to indicate it originated from the detonation of nuclear bombs\u2014in the flesh of shrimplike crustaceans living in the trench. \u201cTypically, we say the trenches are far away from us; they\u2019re very deep and they\u2019re pristine. But actually, they\u2019re not,\u201d says earth scientist Jiasong Fang of Shanghai Ocean University, who worked on the new study. \u201cEverything can get into the trenches.\u201d<\/p>\n\n\n\nScientists can trace the reach of above ground nuclear detonations, the first of which was conducted in 1945, by measuring levels of carbon-14\u2014a radioactive isotope of carbon produced when neutrons from nuclear reactions collide with nitrogen atoms in the atmosphere. (It is also produced naturally, at lower levels, by cosmic rays bombarding the atmosphere.) Atmospheric carbon-14 levels doubled in the 1950s and 1960s as scores of hydrogen bombs were tested. A very small amount of the \u201cbomb carbon\u201d from these gigantic explosions has decayed, but the rest has spread around the world and been taken up via carbon dioxide by plants, which are then eaten by animals\u2014including humans.<\/p>\n\n\n\nUntil now, it has been unclear whether bomb carbon has managed to spread into the farthest crevices of the world, especially the deepest seas. It would have taken natural oceanic circulation about 1,000 years to carry it to the depths of the Mariana Trench. And in fact, testing for the new study showed that the waters of the trench did have low levels of carbon-14\u2014which is what the researchers expected, given the long travel time from atmosphere to deep ocean.<\/p>\n\n\n\nBut when they used traps to catch and test crustaceans living at these depths, they detected much higher levels of the isotope in these animals\u2019 tissues and gut contents than in the surrounding waters. The bomb carbon had to be arriving another way that brought it there faster, and the researchers surmised it was taking a shortcut via the food chain. Organic matter\u2014including the poop and carcasses of surface-dwelling life\u2014falls through the water column in just weeks or months. When crustaceans on the seabed munch these morsels, they absorb the signature of nuclear tests into their bodies, the researchers say in their study, published online in April 2019 in Geophysical Research Letters [pdf<\/a>].<\/p>\n\n\n\nOther studies conducted around the world have also recently identified the residue of the weapons tests of the mid-20th century\u2014as well as the Chernobyl and Fukushima nuclear disasters\u2014in mountain glaciers, another landscape often considered pristine and remote. Together with the results from the Mariana Trench, these findings \u201cprove that atmospheric and oceanic circulation distribute bomb-derived radioactivity globally, even to the most remote sites,\u201d says Edyta Lokas of the Institute of Nuclear Physics PAS in Krakow, Poland, who worked on the glacier research<\/a>, which was presented at a meeting of the European Geoscience Union (EGU) in April. Worse still, the fallout locked in glaciers includes more worrisome radioactive elements (such as americium-241, a product of the decay of plutonium)\u2014and could be released as the world warms and the ice thaws. \u201cThe legacy of radioactive contamination will be felt by many generations ahead,\u201d Lokas says.<\/p>\n\n\n\nSuch clear, long-lasting imprints of nuclear testing are among the markers proposed by scientists who suggest humans have changed the planet so much that we are now living in a distinct geological epoch, often called the \u201cAnthropocene<\/a>.\u201d Proponents of this idea say the fact that remnants of these tests are reaching glaciers and deep oceans indicates humans have begun fundamentally altering the geology of the entire planet. \u201cIt just shows that the human signal is getting even to places that were thought to be distant or remote from human influence,\u201d says Jan Zalasiewicz, a paleobiologist at the University of Leicester in the U.K. who researches the Anthropocene.<\/p>\n\n\n\nBut it is not just relatively rare impacts, like nuclear tests, that have reached these remote environments; more mundane human contamination can be found there too. Researchers recently announced they had found microplastics\u2014degraded pieces of larger plastics, as well as microbeads and synthetic fibers\u2014in every crustacean they tested from the Mariana Trench. \u201cIt was disheartening but not unexpected,\u201d says William Reid, an ecologist at Newcastle University who worked on the study, published in Royal Society Open Science<\/em><\/a> in February. \u201cIt is probably the saddest piece of research I have ever been involved with.\u201d Microplastics have also been detected in glaciers<\/a>, according to results presented at the April EGU meeting.<\/p>\n\n\n\nIn fact, humanity\u2019s actions are so far-reaching that a 2018 study in<\/a> Current Biology<\/em><\/a> suggested just 13 percent of Earth\u2019s oceans can still be classed as wilderness<\/a>. \u201cI very much doubt,\u201d Reid says, \u201cthere are many places left on the surface or seafloor of this planet that we have not impacted.\u201d<\/p>\n\n\n\n\n\n\n\nThis post originally appeared on Scientific American and was published May 15, 2019. <\/p>\n","protected":false},"excerpt":{"rendered":"The detection of this radioactive relic of nuclear weapons tests in a remote environment shows humanity\u2019s far-reaching environmental impact. Scientific American Adam Levy Read when you\u2019ve got time to spare. Credit: Daiju Azuma Wikimedia (CC BY-SA 2.5). The Mariana Trench, in the western Pacific Ocean between Japan and Papua New Guinea, plunges nearly seven miles<\/p>\n\n\t\t\t\t Read more<\/a>\n\t\t\t<\/div>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[118],"tags":[266,265,267,14],"class_list":["post-2605","post","type-post","status-publish","format-standard","hentry","category-environment","tag-fish-life","tag-nuclear-waste","tag-ocean-life","tag-pollution"],"_links":{"self":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts\/2605","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/comments?post=2605"}],"version-history":[{"count":1,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts\/2605\/revisions"}],"predecessor-version":[{"id":2606,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/posts\/2605\/revisions\/2606"}],"wp:attachment":[{"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/media?parent=2605"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/categories?post=2605"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fitadelphia.com\/index.php\/wp-json\/wp\/v2\/tags?post=2605"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}](\"https:\/\/commons.wikimedia.org\/wiki\/File:Hirondellea_gigas.jpg\"){kind=link}