{"id":88703,"date":"2023-08-13T10:30:56","date_gmt":"2023-08-13T14:30:56","guid":{"rendered":"https:\/\/newsroom.carleton.ca\/?post_type=cu_story&#038;p=88703"},"modified":"2025-08-19T09:37:05","modified_gmt":"2025-08-19T13:37:05","slug":"microplastics-pollution-farmland","status":"publish","type":"cu_story","link":"https:\/\/carleton.ca\/news\/story\/microplastics-pollution-farmland\/","title":{"rendered":"How microplastics are making their way into our farmland"},"content":{"rendered":"\n<section class=\"w-screen px-6 cu-section cu-section--white ml-offset-center md:px-8 lg:px-14\">\n    <div class=\"space-y-6 cu-max-w-child-max  md:space-y-10 cu-prose-first-last\">\n\n        \n                    \n                    \n            \n    <div class=\"cu-wideimage relative flex items-center justify-center mx-auto px-8 overflow-hidden md:px-16 rounded-xl not-prose  my-6 md:my-12 first:mt-0 bg-opacity-50 bg-cover bg-cu-black-50 pt-24 pb-32 md:pt-28 md:pb-44 lg:pt-36 lg:pb-60 xl:pt-48 xl:pb-72\" style=\"background-image: url(https:\/\/carleton.ca\/news\/wp-content\/uploads\/sites\/162\/microplastics-farmland-1200x900-1.jpg); background-position: 50% 50%;\">\n\n                    <div class=\"absolute top-0 w-full h-screen\" style=\"background-color:rgba(0,0,0,0.600);\"><\/div>\n        \n        <div class=\"relative z-[2] max-w-4xl w-full flex flex-col items-center gap-2 cu-wideimage-image cu-zero-first-last\">\n            <header class=\"mx-auto mb-6 text-center text-white cu-pageheader cu-component-updated cu-pageheader--center md:mb-12\">\n\n                                    <h1 class=\"cu-prose-first-last font-semibold mb-2 text-3xl md:text-4xl lg:text-5xl lg:leading-[3.5rem] cu-pageheader--center text-center mx-auto after:left-px\">\n                        How microplastics are making their way into our farmland\n                    <\/h1>\n                \n                            <\/header>\n        <\/div>\n\n                    <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"absolute bottom-0 w-full z-[1]\" fill=\"none\" viewbox=\"0 0 1280 312\">\n                <path fill=\"#fff\" d=\"M26.412 315.608c-.602-.268-6.655-2.412-13.524-4.769a1943.84 1943.84 0 0 1-14.682-5.144l-2.276-.858v-5.358c0-4.876.086-5.358.773-5.09 1.674.643 21.38 5.84 34.646 9.109 14.682 3.59 28.935 6.858 45.936 10.449l9.874 2.089H57.322c-16.4 0-30.31-.16-30.91-.428ZM460.019 315.233c42.974-10.074 75.602-19.88 132.443-39.867 76.16-26.791 152.063-57.709 222.385-90.663 16.7-7.823 21.336-10.074 44.262-21.273 85.004-41.688 134.719-64.193 195.291-88.413 66.55-26.577 145.2-53.584 194.27-66.765C1258.5 5.626 1281.34 0 1282.24 0c.17 0 .34 27.596.34 61.3v61.299l-2.23.375c-84.7 13.718-165.93 35.955-310.736 84.931-46.494 15.753-65.427 22.076-96.166 32.15-9.102 3-24.814 8.198-34.989 11.574-107.543 35.954-153.008 50.422-196.626 62.639l-6.74 1.876-89.126-.054c-78.135-.054-88.782-.161-85.948-.857ZM729.628 312.875c33.229-10.985 69.248-23.523 127.506-44.207 118.705-42.223 164.596-57.709 217.446-73.302 2.62-.75 8.29-2.465 12.67-3.751 56.19-16.772 126.94-33.597 184.17-43.671 5.07-.91 9.66-1.768 10.22-1.875l.94-.161v170.236l-281.28-.054H719.968l9.66-3.215ZM246.864 313.411c-65.041-2.251-143.047-12.11-208.432-26.256-18.375-3.965-41.73-9.538-42.202-10.074-.171-.214-.257-21.38-.214-47.046l.129-46.618 6.654 3.697c57.313 32.043 118.491 56.531 197.699 79.143 40.313 11.521 83.459 18.058 138.669 21.059 15.584.857 65.685.857 81.14 0 33.744-1.876 61.306-4.93 88.396-9.806 6.396-1.126 11.634-1.983 11.722-1.929.255.375-20.48 7.769-30.999 11.038-28.592 8.948-59.288 15.646-91.873 20.147-26.36 3.59-50.015 5.627-78.35 6.698-15.584.59-55.209.59-72.339-.053Z\"><\/path>\n                <path fill=\"#fff\" d=\"M-3.066 295.067 32.06 304.1v9.033H-3.066v-18.066Z\"><\/path>\n            <\/svg>\n            <\/div>\n\n    \n\n    <\/div>\n<\/section>\n\n<p>This article is <a href=\"https:\/\/theconversation.com\/do-smartphones-belong-in-classrooms-four-scholars-weigh-in-210099\" target=\"_blank\" rel=\"noopener noreferrer\">republished<\/a> from The Conversation under a Creative Commons licence. All photos provided by <a href=\"https:\/\/theconversation.com\" target=\"_blank\" rel=\"noopener noreferrer\">The Conversation<\/a> from various sources.<\/p>\n\n\n\n<p><a href=\"https:\/\/carleton.ca\/geography\/people\/jesse-c-vermaire\/\" target=\"_blank\" rel=\"noopener noreferrer\">Jesse Vermaire<\/a> is an associate professor of environmental science at Carleton University. <a href=\"https:\/\/theconversation.com\/profiles\/branaavan-sivarajah-1225906\" target=\"_blank\" rel=\"noopener noreferrer\">Branaavan Sivarajah<\/a> is a postdoctoral fellow of geography and environmental studies at Carleton University.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><\/p>\n\n\n\n<p><iframe loading=\"lazy\" style=\"width: 100%; height: 100px; border: none; position: relative; z-index: 1;\" height=\"400\" src=\"https:\/\/narrations.ad-auris.com\/widget\/the-conversation-canada\/how-microplastics-are-making-their-way-into-our-farmland\" width=\"100%\"><\/iframe><\/p>\n\n\n\n<p>Microplastic pollution is a global environmental problem that is ubiquitous in all environments, including <a href=\"https:\/\/doi.org\/10.1016\/j.scitotenv.2023.162193\" target=\"_blank\" rel=\"noopener noreferrer\">air<\/a>, <a href=\"https:\/\/doi.org\/10.1016\/j.scitotenv.2019.07.305\" target=\"_blank\" rel=\"noopener noreferrer\">water<\/a> and <a href=\"https:\/\/doi.org\/10.1016\/j.scitotenv.2020.138334\" target=\"_blank\" rel=\"noopener noreferrer\">soils<\/a>.<\/p>\n\n\n\n<p>Microplastics are readily found in treated wastewater sludge \u2014 also known as municipal biosolids \u2014 that eventually make their way to our agricultural soils.<\/p>\n\n\n\n<p><a href=\"https:\/\/doi.org\/10.1002\/jeq2.20497\" target=\"_blank\" rel=\"noopener noreferrer\">Our recent investigation<\/a> of microplastic levels in Canadian municipal biosolids found that a single gram of biosolids contains hundreds of microplastic particles. This is a much greater concentration of microplastics than is typically found in air, water or soil.<\/p>\n\n\n\n<p>Given that hundreds of thousands of tonnes of biosolids are produced every year in Canada, we need to pay close attention to the potential impacts such high levels of microplastics might have on the environment and find ways to reduce microplastic levels in Canada\u2019s wastewater stream.<\/p>\n\n\n\n<h2 id=\"municipal-biosolids\" class=\"wp-block-heading\">Municipal biosolids<\/h2>\n\n\n\n<p><a href=\"https:\/\/www.ontario.ca\/page\/sewage-biosolids-managing-urban-nutrients-responsibly-crop-production\" target=\"_blank\" rel=\"noopener noreferrer\">Municipal biosolids<\/a> are produced at wastewater treatment plants by settling and stabilizing the solid fraction of the municipal wastewater inflow.<\/p>\n\n\n\n<p>In Canada and around the world, municipal biosolids are used to improve agricultural farmland soil. This is because they are rich in nutrients needed for plant growth, such as phosphorus and nitrogen.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter align-center\"><img decoding=\"async\" src=\"https:\/\/images.theconversation.com\/files\/540502\/original\/file-20230801-17494-6okmwr.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip\" alt=\"A close-up photo of a dark substance lying on top of dry dirt\"\/><figcaption class=\"wp-element-caption\"><span class=\"caption\">Biosolids applied to an agricultural field.<\/span><br>\n<span class=\"attribution\"><span class=\"source\">(Branaavan Sivarajah)<\/span>, <span class=\"license\">Author provided<\/span><\/span><\/figcaption><\/figure>\n\n\n\n<p>Municipal biosolid applications are carefully <a href=\"https:\/\/publications.gc.ca\/site\/eng\/443732\/publication.html\" target=\"_blank\" rel=\"noopener noreferrer\">regulated in Canada<\/a> for heavy metals, nutrients and pathogens. However, guidelines for emerging contaminants, such as microplastics, are not currently available.<\/p>\n\n\n\n<p>While current wastewater treatment plants are not explicitly designed to remove microplastics, they are nevertheless efficient at <a href=\"https:\/\/doi.org\/10.1039\/D0EW00397B\" target=\"_blank\" rel=\"noopener noreferrer\">removing nearly 90 per cent of microplastic contaminants<\/a>. The removed microplastics are often concentrated in the settled sludge and eventually end up in the biosolids.<\/p>\n\n\n\n<h2 id=\"microplastics-in-municipal-biosolids\" class=\"wp-block-heading\">Microplastics in municipal biosolids<\/h2>\n\n\n\n<p>Previous studies have shown that municipal biosolid waste is an important pathway for microplastics to enter the broader <a href=\"https:\/\/doi.org\/10.1021\/acs.est.6b04140\" target=\"_blank\" rel=\"noopener noreferrer\">terrestrial ecosystems<\/a>, including agricultural fields.<\/p>\n\n\n\n<p>In collaboration with scientists from Environment and Climate Change Canada and Agriculture and Agri-Food Canada, we conducted the first pan-Canadian assessment of <a href=\"https:\/\/doi.org\/10.1002\/jeq2.20497\" target=\"_blank\" rel=\"noopener noreferrer\">microplastics in municipal biosolids<\/a>. We analyzed biosolid samples from 22 Canadian wastewater treatment plants across nine provinces and two biosolid-based fertilizer products.<\/p>\n\n\n\n<p>We found hundreds of microplastic particles in every gram of biosolids. The most common type of microplastic particles we observed were microfibres, followed by small fragments. We found small amounts of glitter and foam pieces too.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter align-center\"><img decoding=\"async\" src=\"https:\/\/images.theconversation.com\/files\/540499\/original\/file-20230801-19-x2ud2q.jpg?ixlib=rb-1.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip\" alt=\"Photos of microplastics seen through a miscroscope\"\/><figcaption class=\"wp-element-caption\"><span class=\"caption\">Microplastics in municipal biosolids. A-C: Processed biosolid samples; D-F: Assortment of microplastic particles in biosolids.<\/span><br>\n<span class=\"attribution\"><span class=\"source\">(Jesse Vermaire)<\/span>, <span class=\"license\">Author provided<\/span><\/span><\/figcaption><\/figure>\n\n\n\n<p>Microplastic concentrations in municipal biosolids are substantially higher than other environmental networks in Canada like <a href=\"https:\/\/doi.org\/10.1139\/facets-2016-0070\" target=\"_blank\" rel=\"noopener noreferrer\">water<\/a>, <a href=\"https:\/\/doi.org\/10.1016\/j.scitotenv.2020.138334\" target=\"_blank\" rel=\"noopener noreferrer\">soil<\/a> and <a href=\"https:\/\/doi.org\/10.1139\/cjfas-2021-0121\" target=\"_blank\" rel=\"noopener noreferrer\">river sediments<\/a>. This provides further evidence that microplastics are concentrated in biosolids produced at wastewater treatment plants.<\/p>\n\n\n\n<h2 id=\"reducing-microplastics\" class=\"wp-block-heading\">Reducing microplastics<\/h2>\n\n\n\n<p>Wastewater treatment plants are well-equipped to remove large plastics like bottle caps and plastic bags from municipal wastewater. However, microplastic particles are so small they can\u2019t be caught by current treatment infrastructure, so they end up concentrating in wastewater sludge.<\/p>\n\n\n\n<p>As wastewater streams concentrate microplastics, they also offer an opportunity to reduce the plastic pollution that is entering the environment. While researchers across Canada are working to find insights on the short- and long-term ecological consequences of microplastic pollution on soil ecosystems, one solution is already clear.<\/p>\n\n\n\n<p>Microplastics can be reduced at sources via systematic reductions in the use of single-use plastics, washing clothing with synthetic fibre less frequently and removing microfibres using <a href=\"https:\/\/doi.org\/10.3389\/fmars.2021.777865\" target=\"_blank\" rel=\"noopener noreferrer\">washing machine filters<\/a>. These approaches will help minimize the amount of microplastics that get into the wastewater stream and, ultimately, into the broader terrestrial and aquatic environments.<\/p>\n\n\n\n<p>Building new technologies at our wastewater treatment plants to remove microplastics through physical or chemical means should also be explored.<\/p>\n\n\n\n<p>We need to better understand the impact of high concentrations of microplastic on agro-ecosystems where biosolids are applied, including its impacts on <a href=\"https:\/\/doi.org\/10.1002\/jpln.202200136\" target=\"_blank\" rel=\"noopener noreferrer\">soil-dwelling organisms like earthworms and insects<\/a>. We also need to start building national guidelines for microplastic levels in biosolids and agricultural soils.<\/p>\n\n\n\n<p>__<br>\n<a href=\"https:\/\/newsroom.carleton.ca\">Carleton Newsroom<\/a><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"https:\/\/counter.theconversation.com\/content\/208346\/count.gif?distributor=republish-lightbox-basic\" alt=\"The Conversation\"\/><\/figure>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Microplastic pollution is a global environmental problem that is ubiquitous in all environments, including air, water and soils. Our recent investigation of microplastic levels in Canadian municipal biosolids found that a single gram of biosolids contains hundreds of microplastic particles.<\/p>\n","protected":false},"author":410,"featured_media":88714,"template":"","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"cu_story_type":[1623],"cu_story_tag":[],"class_list":["post-88703","cu_story","type-cu_story","status-publish","has-post-thumbnail","hentry","cu_story_type-expert-perspectives"],"acf":{"cu_post_thumbnail":"blueprint"},"_links":{"self":[{"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/cu_story\/88703","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/cu_story"}],"about":[{"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/types\/cu_story"}],"author":[{"embeddable":true,"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/users\/410"}],"version-history":[{"count":3,"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/cu_story\/88703\/revisions"}],"predecessor-version":[{"id":88712,"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/cu_story\/88703\/revisions\/88712"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/media\/88714"}],"wp:attachment":[{"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/media?parent=88703"}],"wp:term":[{"taxonomy":"cu_story_type","embeddable":true,"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/cu_story_type?post=88703"},{"taxonomy":"cu_story_tag","embeddable":true,"href":"https:\/\/carleton.ca\/news\/wp-json\/wp\/v2\/cu_story_tag?post=88703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}