{"id":26701,"date":"2025-06-23T12:42:40","date_gmt":"2025-06-23T06:57:40","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=26701"},"modified":"2025-06-23T12:44:04","modified_gmt":"2025-06-23T06:59:04","slug":"recycled-plastics-can-affect-hormone-systems-and-metabolism","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/recycled-plastics-can-affect-hormone-systems-and-metabolism\/","title":{"rendered":"Recycled plastics can affect hormone systems and metabolism"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full is-resized\"><img data-dominant-color=\"aba091\" data-has-transparency=\"false\" loading=\"lazy\" decoding=\"async\" width=\"700\" height=\"525\" sizes=\"auto, (max-width: 700px) 100vw, 700px\" src=\"https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp\" alt=\"\" class=\"wp-image-26702 not-transparent\" style=\"--dominant-color: #aba091; width:840px;height:auto\" title=\"\" srcset=\"https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp 700w, https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-675x506.webp 675w, https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-150x113.webp 150w\" \/><figcaption class=\"wp-element-caption\"><em><sup>Recycled plastic pellets from polyethylene (PE) can be used when making a water bottle for instance. But we can never have full knowledge of what chemicals will end up in an item made of recycled plastic. Therefore the item could contain toxic chemicals that can leach out. IMAGE: Olof L\u00f6nnehed<\/sup><\/em><\/figcaption><\/figure>\n\n\n\n<p>A single pellet of recycled plastic can contain over 80 different chemicals. A new study with researchers from the University of Gothenburg and Leipzig shows that recycled polyethylene plastic can leach chemicals into water, causing impacts on the hormone systems and lipid metabolism of zebrafish larvae.<\/p>\n\n\n\n<p>The plastic pollution crisis has reached global levels, threatening both planetary and human health, and recycling is proposed as one of the solutions to the plastic pollution crisis. However, as plastics contain thousands of chemical additives and other substances that can be toxic, and these are almost never declared, hazardous chemicals can indiscriminately end up in recycled products.<\/p>\n\n\n\n<p><strong>Increasing gene expression<\/strong><\/p>\n\n\n\n<p>In a new study, researchers bought plastic pellets recycled from polyethylene plastic from different parts of the world and let the pellets soak in water for 48 hours. After which, zebrafish larvae were exposed to the water for five days. The experimental results show increases in gene expression relating to lipid metabolism, adipogenesis, and endocrine regulation in the larvae.<\/p>\n\n\n\n<p>\u201cThese short leaching times and exposure times are yet another indicator of the risks that chemicals in plastics pose to living organisms. The impacts that we measured show that these exposures have the potential to change the physiology and health of the fish,\u201d says Azora K\u00f6nig Kardgar, lead author and researcher in ecotoxicology at the University of Gothenburg.<\/p>\n\n\n\n<p><strong>\u201cNever full knowledge\u201d<\/strong><\/p>\n\n\n\n<p>Previous research has shown similar effects on humans, including threats to reproductive health and obesity, from exposure to toxic chemicals in plastics. Some chemicals used as additives in plastics and substances that contaminate plastics are known to disturb hormones, with potential impacts on fertility, child development, links to certain cancers, and metabolic disorders, including obesity and diabetes.<\/p>\n\n\n\n<p>\u201cThis is the main obstacle to the idea of recycling plastic. We never have full knowledge of what chemicals will end up in an item made of recycled plastic. And there is also a significant risk of chemical mixing events occurring, which render the recycled plastic toxic,\u201d says Bethanie Carney Almroth, professor at the University of Gothenburg and principal investigator on the project.<\/p>\n\n\n\n<p><strong>Different chemicals<\/strong><\/p>\n\n\n\n<p>Apart from the study on the impact that recycled plastics have on zebrafish fish larvae, the researcher also conducted a chemical analysis of the chemicals leaching from the plastic pellets into the water. And they found a lot of different chemical compounds, but the mixture varied between different samples of pellets.<\/p>\n\n\n\n<p>\u201cWe identified common plastic chemicals, including UV stabilizers and plasticizers, as well as chemicals that are not used as plastic additives, including pesticides, pharmaceuticals, and biocides. These may have contaminated the plastics during their first use phase, prior to becoming waste and being recycled. This is further evidence of the complicated issue of plastic waste flows and of toxic chemicals contaminating recycled plastics,\u201d says Eric Carmona, researcher at the Department of Exposure Science, Helmholtz Centre for Environmental Research in Leipzig.<\/p>\n\n\n\n<p><strong>\u201cBan hazardous chemicals\u201d<\/strong><\/p>\n\n\n\n<p>Representatives from the nations of the world are preparing to head to Geneva, Switzerland, in August, for what is planned to be the final negotiating meeting for a Global Plastics Treaty at the Intergovernmental Negotiating Committee under the United Nations Environmental Program. <\/p>\n\n\n\n<p>The authors of the work stress that negotiators and decision-makers must include provisions to ban or reduce hazardous chemicals in plastics and to increase transparency and reporting along plastics value chains. Plastics cannot be recycled in a safe and sustainable manner if hazardous chemicals are not addressed.<\/p>\n\n\n\n<p>\u201cThis work clearly demonstrates the need to address toxic chemicals in plastics materials and products, across their life cycle,\u201d says Professor Bethanie Carney Almroth. \u201cWe cannot safely produce and use recycled plastics if we cannot trace chemicals throughout production, use, and waste phases.\u201d<\/p>\n\n\n\n<p><strong>Facts of\u00a0Polyethylene (PE)<\/strong><\/p>\n\n\n\n<p>Polyethylene, abbreviated PE, is a type of plastic used in a lot of packaging materials like bottle caps, plastic bags, agricultural mulch films, insulation for wiring and cables, pipes, ropes, toys, and household items. It is the most widely produced and used polymer. On plastic products made of polyethylene, the number in the recycling code is either 2 or 4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A single pellet of recycled plastic can contain over 80 different chemicals.<\/p>\n","protected":false},"author":2,"featured_media":26702,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-26701","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-health"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-200x200.webp",200,200,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-675x506.webp",675,506,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed.webp",700,525,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-600x525.webp",600,525,true],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-600x525.webp",600,525,true],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-700x490.webp",700,490,true],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-550x360.webp",550,360,true],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-95x65.webp",95,65,true],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-640x525.webp",640,525,true],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-96x96.webp",96,96,true],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2025\/06\/Plastpellets-och-flaska-av-polyetylen-foto-Olof-Lonnehed-150x113.webp",150,113,true]},"author_info":{"info":["RevoScience"]},"category_info":"<a href=\"https:\/\/www.revoscience.com\/en\/category\/health\/\" rel=\"category tag\">Health<\/a>","tag_info":"Health","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/26701","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=26701"}],"version-history":[{"count":2,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/26701\/revisions"}],"predecessor-version":[{"id":26705,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/26701\/revisions\/26705"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/26702"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=26701"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=26701"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=26701"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}