{"id":2268,"date":"2023-01-19T11:05:49","date_gmt":"2023-01-19T11:05:49","guid":{"rendered":"https:\/\/horizon.peachpuff-wolverine-566518.hostingersite.com\/?p=2268"},"modified":"2023-01-19T11:05:49","modified_gmt":"2023-01-19T11:05:49","slug":"soil-and-freshwater-come-under-the-spotlight-in-plastics-pollution-fight","status":"publish","type":"post","link":"https:\/\/scienceblog.com\/horizon\/2268\/soil-and-freshwater-come-under-the-spotlight-in-plastics-pollution-fight\/","title":{"rendered":"Soil and freshwater come under the spotlight in plastics-pollution fight"},"content":{"rendered":"

Growing awareness of microplastics in the ground and in freshwater highlights the need to tackle an environmental threat generally associated with oceans.<\/p>\n

By<\/em><\/strong>\u00a0\u00a0GARETH WILLMER<\/p>\n

On a recent stroll to his local supermarket in the southern German town of Bayreuth, Christian Laforsch decided to count how much plastic trash he passed.<\/p>\n

\u2018It was 52 pieces on only a normal walk,\u2019 said Professor Laforsch, an ecologist at the University of Bayreuth. \u2018The problem starts indoors before moving outside. If you open your door and look out onto the street, you will see plastics.\u2019<\/p>\n

Spotlight shift<\/strong><\/p>\n

Over time, plastic waste is weathered and breaks down into minute fragments \u2013 with those measuring less than 5 millimetres in diameter defined as microplastics. Much about their threat to the environment and human health remains unknown.<\/p>\n

The lack of knowledge is particularly pronounced when it comes to soils and freshwater, with research to date tending to focus on microplastics in oceans. Yet\u00a0terrestrial microplastics pollution may be four to 23 times higher than it is in seas.<\/a><\/p>\n

\u2018We started as researchers in the marine system, then we went on to the freshwater system and terrestrial ecosystems,\u2019 said Laforsch.<\/p>\n

Interest in microplastics pollution in soils has grown over the past few years.<\/p>\n

For example, a quick search on\u00a0Science Direct<\/em>\u00a0for papers in 2018 on the subject brings up just over 150 results compared with around 450 for oceans. But for 2022, the figures are 2 300 to 2 400 for both soils and oceans.<\/p>\n

\u2018People who work in environmental sciences found that microplastics are everywhere,\u2019 said Dr Nasrollah Sepehrnia, a soil physicist at the University of Aberdeen in the UK.<\/p>\n

However, investigating their effects in ecosystems such as soils is challenging.<\/p>\n

\u2018Monitoring and tracing such materials is complex, and their fate in soil is not clear,\u2019 said Sepehrnia. \u2018But very likely they find a way to go into our food chain \u2013 and may impact our climate and the environment.\u2019<\/p>\n

Progress on the research front could help pinpoint ways to reduce microplastics and any effect they have on human health. With the\u00a0EU recently proposing to limit the use of microplastics in industry<\/a>\u00a0and the United Nations calling last month for countries to work towards eliminating plastics pollution, research could also help determine the most important areas for further regulatory action.<\/p>\n

Soiled soils<\/strong><\/p>\n

The\u00a0EU-funded TRAMPAS<\/a>\u00a0project that Sepehrnia works on is investigating microplastics pollution in soils. The focus is on the biological, chemical and physical impacts, including the potential effects on pathogens.<\/p>\n

The surface or pores of microplastics can create artificial habitats for disease-causing organisms and protect them against harsh external environments, according to Sepehrnia.<\/p>\n

\u2018Microplastics in soil could be a good harbour or shelter for other contaminants, potentially increasing the life of pathogens,\u2019 he said.<\/p>\n

The project will use a new approach to monitor the movement of bacteria, harnessing synthesised DNA to track how organisms are transported through the soil on microplastics and where they end up.<\/p>\n

Studying microplastic particles measuring 1.5, 3 and 5 mm, Sepehrnia\u2019s team noticed that the smaller the particle, the longer the contaminants such as bacteria appear to stay in soil.<\/p>\n

\u2018When we have such information, it helps trace the contaminants\u2019 fate,\u2019 he said. \u2018We can then use it to define management practices and regulations.\u2019<\/p>\n

Microplastics in soil may even play a role in global warming.<\/p>\n

Plastics release greenhouse gases as they break down in soil. In addition, bacteria that hitch a lift on microplastics might contribute to increasing the amount of carbon dioxide released.<\/p>\n

On top of this, work by TRAMPAS indicates that changes in the surface of degraded microplastics can make soils hydrophobic and, as a result, harder for water to permeate.<\/p>\n

Troubled waters<\/strong><\/p>\n

After microplastics move through the soil or arrive from other sources such as sewage treatment plants and runoff from streets, they often end up in streams and rivers before flowing into the sea.<\/p>\n

The\u00a0EU-funded LimnoPlast<\/a>\u00a0project led by Laforsch is focusing on microplastics in freshwater bodies. The team is investigating the sources, impact, removal options and possible policy responses of this invisible invader.<\/p>\n

So far, LimnoPlast has discovered that some biodegradable plastics are potentially as harmful as traditional plastics. As a result, analysing the whole mix of constituents in finished plastic products is important, according to Laforsch.<\/p>\n

A challenge is that microplastics are a diverse set of contaminants of varying polymer types, sizes and shapes rather than a single material \u2013 so it\u2019s important to investigate these differences. Knowing more about them will help to inform manufacturing practices and EU regulation of the most harmful microplastics.<\/p>\n

\u2018It might be that only some of those properties are responsible for the effects we see,\u2019 said Laforsch. \u2018If we know which properties do most harm, we can be more focused on these when it comes to the design of new polymers.\u2019<\/p>\n

Promising possibilities<\/strong><\/p>\n

LimnoPlast is testing a removal method that uses an electric field to isolate microplastic particles in wastewater.<\/p>\n

The researchers are also developing new biodegradable polymers made from orange peels.<\/p>\n

\u2018It\u2019s hard to say when we will be successful in having a new material, but at the moment things look promising,\u2019 Laforsch said.<\/p>\n

Beyond hoping to lay the ground for an improved European legal framework for microplastics, LimnoPlast is training a new generation of interdisciplinary scientists in the field who have an understanding of the wider societal context of microplastics.<\/p>\n

The project brings together experts with backgrounds in environmental, technical and social sciences from 14 research institutions and organisations across Europe \u2013 including Denmark, France, Germany, Slovenia and the UK.<\/p>\n

\u2018You cannot tackle an environmental issue only by looking the natural-science part,\u2019 said Laforsch. \u2018You have to include social sciences and all the legal aspects.\u2019<\/p>\n

Expanding on that idea, he highlighted a need to think in a joined-up way across ecosystems too.<\/p>\n

\u2018We should stop talking about it being a problem of the marine or the freshwater or the terrestrial system because it\u2019s all interconnected,\u2019 Laforsch said.<\/p>\n

Research in this article was funded via the EU’s Marie Sk\u0142odowska-Curie Actions (MSCA). This article was originally published\u202fin <\/em>Horizon<\/em><\/a>, the EU Research and Innovation Magazine.<\/em><\/p>\n

XXX<\/p>\n

EU MISSION: A SOIL DEAL FOR EUROPE<\/strong><\/p>\n

\u201cA Soil Deal for Europe\u201d seeks, among other goals, to reduce pollution in the ground and protect the numerous species that live in it. Today, an estimated 60-70% of EU soils are unhealthy.<\/p>\n

The Mission reflects soil\u2019s role as a foundation for food production, fresh water, biodiversity and cultural heritage. 100 test sites, including on individual farms, will spearhead the Mission\u2019s aim to transition to healthier soils by 2030.<\/p>\n

Read more about the EU’s Soil Mission,\u00a0here<\/a>.<\/p>\n

EU MISSION: RESTORE OUR OCEANS AND WATERS<\/strong><\/p>\n

\u201cRestore our Oceans and Waters\u201d aims to reduce pollution in European seas, rivers and lakes through research, innovation and \u2013 not least \u2013 public engagement.<\/p>\n

The Mission fosters regional cooperation in affected areas in Europe through \u201clighthouses\u201d in major sea and river basins: Atlantic-Arctic, Mediterranean Sea, Baltic-North Sea and Danube-Black Sea.<\/p>\n

In the push for broad interest and impact, the mission includes a charter that the European Commission is urging a wide range of actors to support. They include public authorities, philanthropists, investors, businesses, non-governmental organisations and academic institutions.<\/p>\n

Read more about the EU’s Ocean and Waters Mission,\u00a0here<\/a>.<\/p>\n

More info<\/p>\n