 Well, thank you all for joining us today for Hydrotera's webinar. We've got a fantastic turnout today. That's over 400 registrants. So congratulations to Susie for drawing such a big crowd. Today's topic is about microplastics in soil. Need more attention, but why? Our presenter today is Susie Reichman, and she's director of CAPM. And I've got some more details about Susie shortly. All right, there's a picture of Susie for you. So Susie is associate professor at the University of Melbourne, and she's director of the Center for Anthropogenic Pollution Impact and Management, better known as CAPM. Her role is really to reinvigorate CAPM to include water, soil, air, and waste-related pollution. From 2010 to 2020, she was a senior lecturer and associate professor in the School of Engineering at RMIT University. Susie has also worked for the Environment Protection Authority in Victoria, the University of California, and Lincoln University in New Zealand and graduated in 2002 with her PhD in Mining Remediation from the University of Queensland. Susie is an expert in soil chemistry and ecotoxicology, and her research aims to reduce the risk of contaminated land to humans and the environment. Her research has been incorporated into government guidelines for deriving background concentrations in soil and for legacy contamination in urban veggie gardens. Susie is currently undertaking research on the impacts of microplastics and PFAS in soil and ecotoxicology research that is helping to establish soil quality guidelines for contamination assessment and remediation in Antarctica. There's a picture of Susie on the right there. We're about, say, there, Susie. So that was Richard when we were starting our Antarctic research and we went down to Antarctica to gather samples. And I think I'm there looking at a tardigrade under the microscope. Very good. It's a bit sad to hear that we've polluted Antarctica already. All right, moving along. So a few administrative matters. So if you would like to raise a question and we do love you to raise questions. So that is one of the big things that this is about. Please use the Q&A button. That allows us to keep a record of the questions that have been asked. All right. Why does Hydrotera undertake these webinars? Well, we've become increasingly passionate about them. We're seeking to educate the community on the impacts of pollution on the environment and how with better management and monitoring, this can be improved. And so today's presenter is obviously very much aligned with that. We'd like to share knowledge. We'd like to facilitate education. And we'd like to be a bit of an industry leader making people aware of how things can be done better. Today's presenter is someone who has a huge amount of knowledge in the particular topic. And I feel very lucky to have Susie to present today. So thanks very much, Susie, for doing this. We got to know Susie during lockdown through about 4,000 teams meetings. So we're used to doing this. But today's topic is really in the presentation itself is broken up into sources of microplastics in soil and their impacts on the environment. Obviously, there's a lot of detail to get through between those two headings. But further ado, over to you, Susie. Thank you, Richard. Oh, sorry. I forgot one of my slides. So in terms of just a little bit of background of how we ended up in the mess that we are in, I just thought I'd have a little squeeze at what the history of plastics were. So plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. So it's a pretty broad definition, right? The first synthetic polymer was invented back in 1869 as a substitute for ivory. So it was produced with good intentions, which is somewhat of an irony given the topic today. At the time, the discovery was seen as a saviour of the elephant and the tortoise and that plastics could protect the natural world from the destructive forces of human need. In 2021, global plastics production was estimated to be over 400 million metric tons. Humans began producing plastic on the onset of the 20th century and since then, there have been five billion tons of plastic waste. And that graph over there sort of shows where we're headed with plastic. Obviously, it's all built up. And where is it going? Well, we hear quite a bit about it ending up in the ocean. So I thought I'd have a quick peek at that. And there are approximately 269,000 tons of plastic in our ocean, which is a disgrace, isn't it? The Great Pacific garbage patch is approximately 1.6 million square kilometres in area. So you can sort of see the scale of that relative to the US there on that picture. What we haven't really discussed much as a community is what about in the land? What's it like in the soil? And that's what Susie's topic is about today. So now, Susie, I feel some confidence I can pass over to you. Thank you very much, Richard. It's great to be here talking to everyone today. So let's move on to the next slide. So I did a bit of an activity in preparation for this. I took a picture. Well, I aimed to take a picture of every single piece of plastic I touched in one day. But actually, I think in retrospect, this is only about 80%, because I know there were some things that I missed and it was too late to go back. But I've got it here because every single piece of this plastic at some point will end up as waste. And I'm relatively typical. In fact, I'm someone who's trying to reduce my plastic usage. So I'm probably down the low end. And so if you think of my plastic use and what I interact with every day and multiplying that by every day of my life and then multiply that by every person on the planet, I think it gives quite a good visual understanding of how big our plastic issue is and how much we're creating on a daily basis. So next slide, please. So as we all know, we've all heard about this sort of plastic, the plastic that's ending up in the ocean. And it really is having a big impact there. We've seen and heard about pictures of birds being opened up with their guts filled with plastics and all sorts of horrible images. And there's quite a big effort on understanding the extent of it and doing something about it. But what we haven't heard as much about, and if we could have the next slide, please, is microplastic and soil. And so today I want to talk through the situation of what we do know and why it's just as big a problem. It's not that the issue in the ocean isn't big. It is really big. It's that soil, the problems with microplastics and soil, really I think need to be raised up to a similar level to what's going on in the oceans. So I wanted to give you a bit of an idea of the size of our problem with a bit of data too. So we've got 368 million metric tons of plastics have been produced annually and it's expected to double by 2040, which really isn't that far away. Very little of our plastics are recycled or incinerated and so therefore they're no longer with us. Most of them have accumulated in the landfills or somewhere in the environment. And the thing with plastics is we know that they're persistent in the environment. So once they're there, they're going to stay there. They might break down into smaller and smaller pieces but they're going to stay in the environment and stay potentially having an impact. So next slide please. So this is just to give you an idea of where the plastic is coming from and you'll see the numbers on the other side, on the left-hand side are a little bit different to the previous slide and that's because this slide includes the plastics that are still in use and you can see that the majority of our plastic has been discarded. But I think it's interesting that definitely packaging which is where we're putting quite a lot of emphasis on reducing the amount of packaging is our biggest source of plastics. It's almost half of the plastics that get out into the environment. I'm also going to talk a little bit about agriculture and water and wastewater treatment at different times throughout today and they do fit in those other sectors but even though that's quite small I think you'll see as I go through why they are important beyond their total volume that they're producing. So to give you an idea of the total annual emissions so in aquatic environments, rivers, lakes and the ocean various different estimates are between 9 to 23 million tonnes entering into our rivers, lakes and the ocean every year and when we look at the terrestrial environment it's actually on par or a little bit bigger and normally when I see these values being talked about people go well the terrestrial environment is really important because it starts in the terrestrial environment and it ends up in the ocean and that is true, that is an important issue but a lot of it stays in the terrestrial environment or stays in the terrestrial environment long enough to have an impact in the terrestrial environment so what I want to do today is talk about that direct impact that microplastics are having in the terrestrial environment and why we need to be paying more attention to it. Next slide please. So this is just quickly looking at some of the main sources so we've got microplastics coming from tyre abrasion ending up in the environment City is a big source with coming from waste packaging, clothing there's a whole lot around agriculture that put plastic mulching in here but I'll talk about some different ones later sewage treatment is a big source and is one of the sources into agriculture and composting too is a big potential source and they're drawing on a lot of that urban waste is ending up in our compost. Next slide please. So firstly I thought I should actually go back and talk a little bit about what are microplastics so there's a little bit it's not 100% defined but we seem to be coming to a consensus around microplastics pieces of plastic particles of plastic that are smaller than 5000 micrometre which is half sorry five millimetres also there are nanoplastics which again the definition of that's not exactly defined here it's 0.1 micrometre I've seen it defined a number of ranges around there but they're basically the very very small plastics and when I use the word microplastic today I'm actually going to be including nanoplastics in it but nanoplastics because they're so small they're right at the edge of what we can measure and so we're only just starting to get information down at that size range of less than 0.1 of a micrometre or less than 100 nanometres next slide please so the other thing to really consider when we're talking about microplastics is that there's two main types there's the primary microplastics so they're microplastics that have been created as a microplastic and so the example here is like a little microplastic beads in a personal care product and then there we also have secondary microplastics and that's when the plastic started as something bigger like here a plastic bottle or a plastic bag and either before it gets into the environment or when it's pieces of plastic that are smaller than that 5mm upper bound of what we consider microplastics different to why we're really gross sized plastics because once they're in the environment they will break down next slide please so I do not expect you to really take in all this slide but I have it there to show you that microplastics are actually quite complicated so in some ways they're like PFAS we've all been talking about PFAS for a few years now there's thousands of PFAS chemicals how can we come up with overall consensus about them and manage them in a really easy way now microplastics there are many types of microplastics like polyethylene polystyrene, polypropylene etc but the thing about microplastics too is that there's a whole lot of other characteristics that can impact the impact that can affect the impacts that they have on the environment so things like the shape of the microplastics the size of the microplastics their chemical composition whether they're solvable or not and so all of this ends up meaning that we have a diversity of impacts and it's harder to work out how we're going to manage them and how to set thresholds in the environment and here next slide okay so let's talk now about microplastics in soil so what are the main sources so this was a study that was done came out in 2020 and they looked at all the studies that have been done that had measured the concentration of microplastics in soil and the two different slides are studies that had measured them in particles per kilo and then studies that had measured them in milligrams per kilo on the right hand side and basically the big takeaway from this is that there's a big range in every different we have like plastic mulching, sewage road and tyre wear straight directly from litter, fonding and then multiple different sources and also ones where they hadn't stead where the source was and what you can see is that we've got multiple orders of magnitude in each different source and up to around the sort of 1 million particles or even up to 100 million particles per kilo of soil which if you think about it as kind of mind boggling how much that can be in some heavily microplastic contaminated soils but we're not really seeing differences too much between the different types, they all have the potential to be high and there's all the potential to be low. I also just wanted to mention we've had a big study actually led by the now Chief Environmental Scientist of EPA Victoria on microplastics in Australian house dust and so a lot of that also ends up in soil and so I just wanted to mention it because they found that almost 40% of the dust particles in our houses are actually microplastics, they're coming off our clothing if you look at all the different plastics that we have in our house are releasing these microplastics over time they found that it varied a lot between 22 up to over 6,000 microfibres per meter squared per day deposited as dust and this is really important because people spend up to 90% of their time indoors and if you do the calculations I do it with a class to look at exposure when I'm teaching and even people who consider themselves to be outside people often end up at close to that 90% because we are spending so much time sleeping and things inside as well so it's a really high exposure for us. Next slide please Okay, so how much microplastics are we finding in soil globally in different land uses again are we seeing different concentrations depending on what the land use is and you can see here it's a similar sort of thing there's not as many studies when you take it down and aggregate it up by the different land uses but the first three are related to agriculture we've got agriculture, horticulture and then grasslands pastures we've got multiple orders of magnitude up to sort of 100,000 particles it's a little bit lower in pastures they probably don't have as many they're not as intensely managed and then when it's when it's fellow agricultural land you might think that it would be lower but the few studies have tended to find it as higher numbers of particles forestry is quite high and this may be because of biosolids in a number of countries the other thing I think should realise too is often these soils were studied because they were potentially microplastic contaminated they wanted to find out what the extent was so it is a little bit biased it does show us the range but it's not necessarily representative of the proportion of soils that are that high and then we also have a lot of studies where they couldn't tell what the land use was okay so I wanted to just say a little bit about microplastics in agricultural soils and why I think they're important so if we go back to the sectors it's actually included in that it's quite a low source but the thing is a lot of the microplastic waste from agricultural soils stays in agricultural soils also we have these external sources coming in so biosolids and compost are both two and also treated wastewater are also two sources that aggregate up microplastic waste from the environment and then when it's added to agricultural soils and potentially forestry soils as well it then tends to be a sink for them so we have a high exposure even though they're relatively low production and it tends to stay there and then the other thing of course is that agricultural soils is there's a direct line to exposure to humans because it's where most of our food comes from and so there's the potential for it to be entering the food chain and impacting on us there and you can see I've just written down a few of the different sources there for microplastics in agricultural soils thanks Richard okay so let's look at the impacts that microplastics have on the environment so this is I thought it was quite a good summary I'm mainly going to talk about the soil physical properties and soil chemical properties here and then later we'll talk about the animals and the plants and microorganisms and just a note that I got this out of a paper and they've actually got their soil physical properties and soil chemistry back to front I realised after I'd sent the slides into hydraterra so our soil physical properties on the right microplastics can have an impact on things a lot to do with how water moves through soil they can clog up pores and so reduce water movement they can depending on the size and the poor structure in the soil they might even increase water movement it's quite a you know it depends on the soil one of those it depends on the soil ones and then for soil chemical properties they can they've been shown to impact soil pH soil nutrients and bioavailability overall soil fertility and then soil enzymes which is actually really a measure of microbial processes happening in soils okay so let's move on and look at I think I've got plants first we can go to them okay so I'm doing a little bit of a faux pas here with a slide with a lot of information on it but I think as I'm going to talk through it and I think you'll be able to see how it really illustrates the issues we have so each one of these slides measuring the effect of the particular parameter that's been measured which is up the top so for plants it's got the length of the roots that got up the top going from left to right the length of the roots the biomass of the roots the length of the shoots the biomass of the shoots chlorophyll so that's photosynthesis germination then antioxidant stress and oxidative stress filling out down the bottom now the effect all you need to know is that the effect is is roughly about the average of what the studies are and then it's showing a 95% confidence for the range and if that if it's on the red dotted line that you can see going down that means that there's no effect of microplastics you don't get any difference to in a situation where you didn't have microplastics if it's to the left it means it's a negative effect and if it's to the right it means it's a positive effect and so this is a meta-analysis that looked at all the research that was published in 2022 so it's pretty up to date and I think you can see that we've got a pretty consistent effect where even though there's quite a lot of variation where in most things we're picking up negative impacts of microplastics on plants whether it's their growth or various physiological ones now you might look at the antioxidant oxidative stress right down in the bottom right and be like most of them are over in the positive but in this case the positive means an increase in stress so it's also bad as well you can see though that there's variation it's not all situations like for example the below ground biomass if when plastics are small it's not having as big an impact but when they're big it is and that's maybe to do with the impacts it's having on soil physical characteristics like water retention in soil you can also see with the green ones that they're having the ones in the middle we've got polystyrene, polyethylene and others so different types of plastics and for some of those characteristics there's definitely a microplastic type effect okay next slide so this is the same way of presenting it it's from the same paper again they looked at all the research out there and it's on fauna and microbes I think we can see then the impact in general is probably bigger on soil fauna so this is mostly earthworms and springtails that the research has been done on and across the top we've got pretty clear negative impacts on survival on growth on reproduction on a locomotion so on their ability to move around down the bottom we've got the antioxidive stress and the oxidative stress and again even though that's on the right that's because it's becoming more stressful to them and they're showing more of that stress now microbes are the last two G and H down the bottom and I think microbes are interesting because they're showing less effects overall than plants and soil fauna and you can see that this particularly for microbial diversity which is number two if you look right down the bottom the blue microplastic size is having quite a big effect and so it's again it's when bigger that it's having more effects on microbes for their diversity and this again may be due to a soil physical effect although if we move over to the richness in the number of microbes we're not really seeing massive big differences because of the plastic size but it is we are sort of starting seeing in some ways the plastic type is having an effect so these are all factors we need to take into account and there's a pretty clear impacts on plants soil fauna and to some extent microbes next slide please so talking about the environment what about on us so it's been pretty clearly we're starting to get quite a lot of evidence now that microplastics they can get exposure by inhaling them into our lungs by ingesting them eating them in our food or water and also sometimes if they're small enough through our skin and it's having a number of effects we can get inflammatory responses autoimmune responses they can interfere with our immune system neurotoxicity we can have they can affect our gastrointestinal tract and we can get this oxidative stress again we're seeing the same we're seeing in the soil fauna and we're seeing in the plants as well and it's just really an indication of stress in all of these different organisms thanks Richard so what are the modes of action well we get direct toxicity some plastics they're just toxic to us or animals plants like polystyrene is one that's often quite toxic we can also get physical damage so there's been research that's shown microplastics and nanoplastics can create physical damage in our lungs and in earthworms they've been shown to tear holes in their gastrointestinal tract so we can get that sort of physical impact they can also be absorbed chemicals so we can have completely different non-plastic related chemicals that at some stage in the plastics movement either through its use or as it's moved through the environment they've become bound onto the plastic and then they can be released like for example when an organism or us eats them and it's going through our digestive tracts they can be released and then be toxic to us and then another one which is not so much an issue for humans but definitely has been shown in soil fauna is starvation and this has been shown in oceans as well where small enough little critters mistake microplastics for food they eat them they feel full they're not getting the energy and the nutrients and if it's bad enough they can end up starving if not they just have poorer health so what are some of the challenges we face with making decisions around how we manage microplastics so the first one is a lack of data this is pulled from a publication in 2020 and it shows the number of studies that have been published just looking at the concentration of plastics in soils around the world you can see it wasn't until up until 2016 we only had one study published in the entire world on how what the concentration of microplastics were in soil but you can now see it's going exponentially and it stops at 2020 we're now in the like tens of studies every year and climbing so we're fast fixing that data gap we also have it to do with like in soils there's only been about five years worth of data on organisms in soils and impacts on them and we only really know for earthworms and springtails there's not many other species that we know anything and of course there's this same issue that I said like with PFAS because we've got so many different types of microplastics and different sizes and different shapes and different you know and how do we put that all together to come out with an overall view of what's going on and how to manage them and you know what the risk is ok measuring microplastics so measuring microplastics is just a bit of an issue in general especially as we get down to smaller and smaller sizes it's an issue for measuring them in the ocean particularly down in that nano plastics range it's an issue in the ocean it's an issue in soils but in soils we have an even bigger issue because basically you've got to get rid of the soil to be able to see the microplastics and measure them you've also got to get rid of the organic matter also organic matter is carbon and plastic is carbon and so a lot of techniques have trouble differentiating between the plastic and the carbon and the organic matter and then the other thing you can see is there's very few methods that can measure all across the full range those ones down the bottom PyGCMS and the TEDGCMS they're really expensive and not many places have one we are very lucky to have a PyGCMS and Melbourne Uni that we have access that was purchased in part with CAPM support before I joined CAPM so we do have that ability at CAPM to measure right across but not very many places do and it's expensive when you're getting into those well all the time but when you're getting into particularly those ones that can do the full range okay next slide please Richard now another issue we have which is another one of these not having enough data is that almost all the studies on the impacts of microplastics have been done on spherical microplastics and the reason for that is because you can buy them you can buy different spheres of known sizes and test them in a controlled laboratory setting but we know that spheres aren't really what we see out in the environment we see far more fibres we see far more irregularly weathered microplastics and so we have we're building up this data but most of it we're not sure how applicable it is out in the real world and so we need to get more real world real types of microplastics that we're seeing out in the world both the shapes the sizes and also that they're weathered often out in the world okay next slide please the other one is I keep talking about it it's one of these complex situations different sorts of microplastics different compositions different sizes different shapes different colours some of them are composites of different microplastics now how do we come up with an overall risk based approach and this is actually an interesting paper because it's starting to look at how do we do that for microplastics and I would love to talk about it more but we don't have time today so we're going to go into the next little bit so so mostly today my aim was to bring awareness to that microplastics are an issue in soil we need to be doing something about it but I thought I'd finish up with a bit of like what can we actually do with the issue of microplastics in soil so for us we can you know of course reduce reuse and recycle our plastic use and Richard can you just hit the little forward one time because this is my only animation I've got a little grumpy there and I've got recycling red because as we all know over the last few years we've been discovering in multiple different ways that the plastics we thought were being recycled aren't being recycled they're being stored various places and so while we can technically put it in our recycle bins it's probably not being that effective and then the other one vacuum endorsement frequently this is one of the studies that came out of um this is one of the outcomes that came out of the microplastics in dust study that was done that people who vacuumed at least once a week have fewer microplastic particles depositing on surfaces and so therefore also in the air in their house so they were probably inhaling less microplastics and that is quite an important exposure pathway for us okay next slide so I think there I'm guessing quite strongly that there are multiple people here today in government and industry who are probably far better placed than me to suggest how from a government approach and from an industry approach we are best to approach dealing with microplastics and so on my main aim today is to get it on the agenda and get it being looked at as much as microplastics in our oceans currently are but I did think I'd put up just a few sort of ideas so like us in the other side in the other slide there's this issue with the economics of recycling like is it doesn't seem to be economically viable and companies are stockpiling them rather than actually recycling it there's been ideas put around about like a circular you know moving more towards circular economies and there is starting to be some research coming out on soil remediation including things like using bacteria that have the ability we've found some bacteria that have the ability to eat plastics which is great and then just globally what we're seeing with government policies is it's mostly around levees bans and voluntary efforts so voluntary efforts like in Australia the phasing out of microplastics in personal care products voluntary efforts like us putting our recycling in the recycling bin it tends globally to be emphasising more macro sized particles like bans on plastic bags and things it tends to be emphasising oceans and we're also there's starting to see some policies globally around microplastics in drinking water in particular California at the moment is looking at having some policies around microplastics in drinking water and I'd like to say we also need to look at some risk-based policies so most of them is about reducing it and reusing plastics and that's super important but it's not keeping up with the use and the amount of plastics that are ending up in the environment both in the oceans and in soils so I think we also need some risk-based policies to protect human and environmental health and in particular are brought out like by solids soils, composts and our food so that's it for me and I hand over to Richard now to give his webinar takeaways. Well Susie that was fantastic very comprehensive and done in great time too very interesting and a bit concerning I suppose definitely is a few takeaways from today's session I think microplastics are just as big an issue in soil as in our oceans we know microplastics are harmful to humans animals, plants and microbes and soil, physical, chemical properties so that's pretty strong statement right there okay so we know they're having a detrimental effect agricultural soils need our attention because they are a microplastic source sink and exposure root and microplastic solutions need to consider terrestrial environments and be risk-based I think one of the challenges with this whole you know what is the risk of plastic is the plastic in itself is made up of multiple compounds and a lot of the time we do risk-based studies it's compound specific we use doses and look at responses whereas plastics are a bit of a different beast also you know that physical aspect to it you're sort of leaning into how we deal with something like asbestos or that sort of thing it's more of a physical problem so it doesn't fit nicely with the way we normally measure things with a sensor or with a laboratory it's requiring a different approach to that monitoring I think there's a bit of work around that too so look we have heaps of questions today so we're going to charge into that and thanks so much for raising those questions we have about 17 that came in in the early bird question format so well done to you early birders you may well get the last laugh today so here we go question number one how transferable are the human health issues to wildlife so very in part because we can't we're not going in there and dosing up humans with microplastics and seeing the impact we're actually measuring it on animal models so a lot of the information we have is coming from lab animals there's also been an interest in information there's also been some studies done around agricultural animals so things like cows and sheep because of course again it's the potential exposure route for us so even though I mainly talked about it from a human perspective definitely like the vertebrate animals that we've looked at are having similar impacts they're often used for the models for how we're working out what's happened in humans and so I think going from like you know rats and mice and rabbits and cows and sheep and even I think there's been some studies in chickens across to wildlife is you know not too far a jump so probably the issues are similar okay next question local governments management of Fogo Waste that's kind of more of a statement it's a question what's your view of I know I'm just laughing that's an academic thing this is more of a statement than a question we say sometimes in academic presentations so I think it's an issue and I think they know that it's an issue and I think they're trying to work out what to do about it is my understanding of where they're at and they're struggling with the sort of issues that I talked about today and I think the good thing though is that they're struggling with it actually I don't think that it's so much the local governments directly who are struggling with it it's the companies that then take the waste and compost it and they're the ones who are dealing with it I think more than the could be wrong on that I don't really know the detail but I know that there are things going on and that people want they want to deal with it and they're trying to work out how to deal with it Susie look is it possible that we're too late like your numbers are showing a lot of plastic out there in the soil so if we start stopping right what are we going to do about that yeah so I think that's a great question I think it's never too late because because there's so much going in it's getting worse and worse and worse and anything we can do to reduce that is beneficial and that's both in soil environments and in aquatic environments as well it doesn't you know it's the same but yeah it would have been nice if we'd done something 10 or 20 you know done what we're doing now 10 or 20 years ago and now being at a much better place but we're not so let's just do what we can now last sneaky question before we go to the next one so all this plastic in the soil and it's degrading so it's getting smaller in particle sizes and presumably releasing more compounds as it degrades are we sort of at a wave of highest toxicity now or do you think with degradation you know like sometimes a contaminant bath gets worse for that that's a good question I I don't actually have a good direct feel for that but I would say because of this exponential increase in plastics that it doesn't matter where along that weathering and degradation process so partly we know that smaller gets the more toxic it is in general you know as I showed you there's some differences in that whether it's to do with physical or biological impacts but in general the smaller it gets the more toxic it is so in big part of weathering is it breaking down smaller and smaller so from that point of view no but from the point of view with chemicals leaching out and things like that presumably there would be some level at which we reach peak that but we're continuing to add more and more fresh more and more and more fresh plastics so I don't think that we'll see the peak of that for a long time either okay thanks for that so question number three potential role of microplastics to act as carriers for microbial pathogens viruses implications for their persistence yeah now this is a great question and this I have to admit has me a little bit stumped I mean I think we do know that microbial and viruses as mentioned there as an example too we do know that they do like hitch rides on particles through the air and so I can't see why microplastics would be any different and we know that they bind chemicals and so I can't see I mean I think particularly with like viruses they're not when they're outside of their host they're not sentient so it's more the size and the shape and the physical properties of it that means that they can hitch a ride rather than that they're choosing where they want to go so I would imagine that I would imagine and I don't know that that this could definitely happen and it could either I don't know what impacts it would have on persistence but it could definitely maybe is part of could help with dispersal maybe maybe I'm not it would definitely not quote me on any of that I'm really just guessing educated yes too late it's recorded Susie next question effects of microplastics on the soil microbiome is there an interruption to function yeah so this is a good question and it's very hard to keep up with the microplastic research they're starting to be so much now and I can't recall a paper that's directly been on the soil microbiome but you did see those that data that I had for like microbial diversity and for what they were able to look at in the meta-analysis there definitely are impacts but it doesn't seem to be as big as on you know more like earthworms and things earthworms spring tails those more soil invertebrates but there are impacts yeah so on those earthworms you mentioned that the plastics tearing up their gut is that widespread like are we actually seeing that in obviously worms are an important part of productivity with the soil seeing mass extinctions of worms or is it a minor component well this is one of the things so we are seeing less and less like I think people have heard about things like insect darmageddon and again this is one of the things we're mainly paying attention to the insects that are in the air but the invertebrates some of them are insects and some of them are other types of little critters that are in the soil we're getting reducing numbers and reducing diversity of them and it's not been looked at in the same way and yeah I think there's a decent chance that micro plastics could be part of that there's also you know habitat destruction loss of organic matter climate change you know we've got a whole host other contaminants a whole host of things but definitely micro plastics could be playing a part you know okay that's a bit dark there Susie are you going to ask dark questions? Is there international consensus on the analytical method for micro plastic analysis and the answer is no we don't even we don't have it's we're still especially so it's in general whether you're doing it in water or soil but particularly in soil there's this slurry of trying to get better and better methods because of this issue that we have to get rid of the organic matter and rid of the rest of the solid matrix as well to be able to have like robust methods and because we're down at the edges of where a lot of the equipment that people have access to can measure and it's expensive like people are literally going through and like finding each particle and measuring it like doing software on it but measuring it and finding out they might have put into two pieces of equipment to measure the size versus the composition and it's we're not at a time we're not at a stage where we've got robust and quick and cheap methods for it it's sort of a common problem right we try to measure impacts on the environment and it might take us 10 years to work it out meanwhile you know damage keeps going on managing and it's not a good thing to say but he's up on the measurement just get on with it next this is a good one should we be doing incineration rather than landfill and can this be a way that is not harmful to the environment yeah I think this is a good really good question and again I'm not sure I think this would be something you'd have to do like a life cycle analysis on because yeah you can have scrubbers and things but then there's all these impacts like I mean depending on the landfill like is it properly lined is it there's all these issues so I think it's a good question and I think it's something we should look at like we shouldn't be accepting the status quo and we should be going like right what are all the solutions the potential solutions and then we should be working out like quantitatively what are the best possible solutions and you know maybe in some circumstances we should be looking at incineration or maybe not I'm not sure it's a good trigger to answer when we're still working out what the impacts of all those plastics are right so yeah and they do relate like they're releasing chemicals like potentially toxic chemicals like final chloride and things like that when they get incinerated so it's yeah we have to be careful be careful okay question number seven are there any proposed health investigation levels for plastics in soil sorry my understanding is so talking about in Australia is more that our EPAs are at the level of working out how to develop health investigation levels more rather than that they have health investigation levels like that they're on the case but they're not at the point of like you know putting out draft ones or something like that that's my understanding I'm not necessarily up on every single EPA around Australia though and can EnviroLabs quantitatively analyse or report concerns there are a few in Australia like commercial laboratories that can measure microplastics it's very labour intensive and then there are like research labs like ours that do it and I know that there have been circumstances where people would have normally just gone to a commercial lab but where they've come to us because it really is in its infancy of being worked out how to do it is it actually possible to develop a health investigation level with such a broad category as microplastic and when you look at all the other health criteria you know we might grip it and say heavy metals underneath that the actual health criteria isn't based on heavy metals total it's based on arsenic or whatever why do we think we can do it for plastic that is a good question so I think part of it is just like part of what might come out of this is new ways of developing risk the same as we've been doing with things like carbon pollution from climate change there's a whole lot of different types of greenhouse gases that can have an impact and then they worked out a way like carbon equivalence and we're doing that a little bit with PFAS so maybe it'll be something like that maybe it's about working out what are the sizes that are really the issue or what are the types of plastic the same as we've done with PFAS we're really concentrating on PFOS and PFOA and they're the ones that were discovered first and there's lots of them out in the environment and we're moving into some of the other types of PFAS now and so there might be a similar approach maybe with microplastics where we start with the ones that there's lots of or the ones that we know are having and then build up some sort of matrix way of dealing with it it's not easy though question number eight remediation of microplastics from the soil environment I did briefly mention that there are some methods that are starting to be developed they're looking at like bioremediation there are some microbes that it's been discovered they can eat microplastics I think there are also like depending on the size if you're not looking for microplastics if it's bigger you can do or the big end of microplastics you can do sieving and things to get rid of it and then there's like some thermal techniques but like with other thermal techniques they didn't have a pretty big impact on your soil so it depends what you're what you would do with the soil afterwards if you're starting to go down those thermal techniques it takes out a lot of good stuff doesn't it yeah it's a sterile solution yeah number nine would you please also discuss microplastics in air and lungs I think we've touched on it yeah so we have touched a little bit so definitely finding microplastics in air this is not my area of expertise I'll probably speak a little bit more generally than someone who was their expertise we're definitely finding microplastics in air we know they're travelling distances through the air again they're particles so similar to you know a standard like PM10 and that sort of situation and with lungs we know that I can't remember the exact size but if microplastics are small enough they will travel through the lining of the lungs and they can do physical damage to the lungs and they can then also get into the bloodstream so yeah definitely there's impacts we don't want to be breathing in microplastics if we can help it but like from that microplastic in house dust study we all are you sort of makes you wonder about carpet doesn't what it's made of oh your carpet is definitely one of the fibres yeah number ten sediment fencing eco options so I guess other options rather than plastic based ones yeah so that's what that means too again this is more a statement than a question so I have a go so I guess yeah you mean like other options than using plastic to do the fencing and that is a great question I guess again it would depend I'm coming up with this off the top of my head I would think I mean we are starting to come out with some biodegradable plastics and so depending on how long you need the sediment fencing for but the issues we're finding is that some of the biodegradable plastics the way they biodegrade is by becoming microplastics rather than actually degrading so we don't want to be switching across like that we want ones that actually do break down but within a time frame that's okay for that sediment fencing yeah and then other options again I guess depending on the length of time you need it you might be able to use some organic methods maybe yeah depending on what it is that you're trying to do there okay I think there are some already in existence question number 11 interested in migration of microplastics in different sorts of soils particularly those on river banks and former waste so this is the physical impacts so like physical movement of microplastics through soil is only it's in more infancy than looking at the impacts on soil and microbes is even less but what we do know is there's been a few studies that are showing it ending up in groundwater and so it's going it's traveling down through the soil and getting into the groundwater so I can imagine I guess the question about river banks is does it end up in the river and so it could again by sort of traveling through the soil but also it's on a river bank you can just get erosion of that river bank in it directly ending up and get overland flow in it ending up in the river and former waste disposal I'm not aware of direct studies there's starting to be so much literature it's hard to keep up if you're in the ocean space there's been so much literature for years that it's hard to keep up but in soil I'm glad the research is really starting to take off so waste disposal again I think it depends on things like the liners both above at the top like how like if the clay liners and things get broken over time or not and I mean the same sort of issues that we have with all sorts of contaminants and in in our landfill basically well landfills are made of plastic membranes these days yeah then as the membrane breaks down it's part of the issue yeah alright next question how can microplastics enter plants yeah so part of the impacts on plants they don't even need to enter the plants it's these physical impacts chemical impacts that it's having on soils indirectly impacting them and then they can go with this small enough they just go in through the plant roots and that's been demonstrated to happen and something that I actually thought of as I was writing this that I should go and have a look is if there's been any research to see if microplastics can come in through plant leaves too if they deposit on the leaves from the atmosphere and again I think that would be size dependent definitely we know that various metals and things can enter through plant leaves and and particles they just need to be small enough to get in through I think there's a question I think one of the new ones was around stomata it's all about the size depending on the size of the stomata openings in plants and the microplastic if it's big enough they can go in there and they could potentially block it if they then don't move further into the plant it's interesting the impact on that conductive tissue like whether it can just actually block the water up the plants too yeah exactly through their roots question number 13 what do the causes of microplastics differ between soil and aquatic environments yeah so I guess the answer I guess the broad answer is yes like in aquatic environments we've got a lot of these aquatic sourced microplastics so things like that come from shipping and fishing nets and all of this sort of thing which is I mean you might have it along the shoreline but that's not really an issue on land the other thing is that microplastics from land there's quite a few studies now that have come out and shown that microplastics from land are moving into our rivers and then into our oceans and depending on how close they are also just directly into the oceans so it might take longer to get there but there's similar sources from that point of view and then I mean litter a lot of our plastic is packaging and a lot of that is not being disposed of properly and not being disposed of in a secure way in land full or incinerated and so then it can get out and get anywhere and then of course we've also got plastics moving through the atmosphere like I said and so they can come from land and end up in the ocean too so there are some that are different but there's a lot that are similar and there might be different proportions as well it's interesting and the Yarra River Keeper Association did this study on sources of plastics in the Yarra River and they found that 50% of the of the plastic was polystyrene and it was actually coming from the construction sector predominantly so it was actually when you carry around glass and other building products it's wrapped in reasonably substantial polystyrene sheets so it's interesting like they've actually gone out and quantified it and said 50% of the problem in the Yarra is that one source so a clear way to manage that one wouldn't be too hard that's part of the going back to like how do we manage it part of it is working out like what are the biggest sources, what are the biggest exposures and dealing with them yeah alright good answer says Susie we've got heaps of questions coming in it's sort of like we're not going to keep up how do you remove microplastics in soil that's a bit like the one about remediating them that's the answer to that one alright here's one way to keep it up number 15 what can we expect in terms of regulation of microplastics I can't read that last bit but going forward going forward yeah so I think at the moment the emphasis really is on that reduce reuse like you know the Victorian governments just banned a new suite of single use plastics at the moment I think we're at that stage then I think we will probably see I'm hoping I mean I'm not in our EPA's so I mean this is probably a better question for them in a way but I know that they have microplastics as priorities and they're trying to work it out so I think what I can say is that in that beyond we are going to get regulations around the environmental risk of them when I don't you know I don't know but I can see that it's hitting in that direction okay the next one's an interesting one it's sort of caught you know how that different particle sizes are bracketed and I think your slides might have touched on this what is the percentage of nanoparticles out from micro particles and are any of these releasing nanoplastics into the air so the second one is yes we like there's been a few studies in air and we know that there are micro and nano more down the nanoplastic and the smaller microplastic range the sort of proportion that they make up excuse me I would want to say there's probably there's be a few studies that have quantified both but like I said it's down the edge of what we can quantify at the moment and I think we're just discovering it and what we're discovering is every time we get better at measuring it we find more and more nanoplastics and so I wouldn't I wouldn't want to say and I think it's also a moving sort of line because again the longer we've had plastics in the environment the more of them kind of weathered and broken down into that nanoplastic range so it's a bit of a moving line I suppose there's potential that the nano is more dangerous than you know the micro and that's the that is the issue yeah so in that context do you have a view on biodegradable plastics yeah so I don't know particularly about biodegradable mulch per se what I know is there have been issues with biodegradable plastics that they're not really biodegradable like the standards are actually that they break down into microplastics not that they actually degrade away and so if that's the case you know in some ways maybe they're worse I do know though that there are not just talking about mulches like we're collaborating with the Cambridge University and there's some engineers there who for glitter have developed these micro the micro crystalline cellulose glitter that they can heat treat and it will you know for as long as you need your glitter it'll be fine but then when it goes out into the environment it's just made out of cellulose so it breaks down and so I think there's a lot of potential in general for biodegradable plastics more moving into those treated micro celluloses or depending on how big you need it so that they really they actually are breaking down chemically not just physically it's really hard for the standards to keep up with the knowledge isn't it and that's a classic case of you know fast-track that one yeah alright so do you feel you've answered 17 does biodegradable mulch pose a risk to human health yeah I think as much as I guess what other alternatives are like you know organic mulches you know organic mulches and there's been a few studies that are showing out that coming out now that they're showing that while plastic mulch in the short term can have benefits in the long term it actually can start to decrease yield so it's maybe not the panacea that it was thought to be in some types of agriculture it's interesting in another life I did quite a few studies on mulch agriculture there's a lot of other benefits beyond you know just the moisture retention you're getting a reservoir of good organics to come down into the soil profile so nutritional mulch is probably a better go well right goodness we got through the early bird questions well done everybody now Susie I need to let you know we're about 7 minutes over time and we have 23 questions left to answer so are you willing to stay a little bit longer yeah let's have a go at it Richard just for Friday I'd just like to formally thank Gordon Carter for preparing the slides we've looked at so far really appreciate it and would like to welcome Mary Carter Gordon's mother to the webinar today now let's move right along so Q&A William Gordon hi Susie slide 29 what is the scale on the bottom of the charts okay that's a good question I can't even remember what slide 29 was well I'm sorry but maybe on the recording you'll be able to interrogate that slide and yeah and if you want to email me I think my email's right at the end if you want to email me I can tell you what the slide was and I'm sorry that I wouldn't give that info okay now I think you referred to this before so Andrew Dougal wants to know do microplastics block stomata in defamable respiration answered that one so the answer was you weren't sure I wasn't sure but I could see that if they're the right size they could yeah okay Jackie Dailey any estimates on the proportion of microplastics originating from biodegradable plastics so I don't know the answer but just as a like citizen I'm not seeing that much in shops and things that are claiming to be biodegradable so I'd imagine it's relatively small but that's you know it's just a guess okay so you're saying just as much coming from well it's probably because there's so much front of the other well that's yeah if you were to look at conventional plastic versus biodegradable what you'd expect a lot more of the sort of nano sized to come out of the biodegradable or you don't really know um yeah well if they're biodegradable because they break down faster that means we're going to get to that nano sized faster yeah depending you know depending on the time frame it may or may not be more like if it's long enough for the other plastics to break down to that size then you know but yeah we might be we might be getting to it faster and then we'll see what they do all right next question running a what's a HEPA stand for yeah HEPA filter would reduce the inhalable micro plastics would be interesting to compare vacuuming which often resuspends aerosols and HEPA HEPA should win I think um Robyn I think yeah that's a great point so Robyn is one of my colleagues at the University of Melbourne and she's a Kappa member as well so she's thinking as she's listening which I think um I think that's a great point and it would be interesting now that um you know there's enough like in schools and things they've got all the HEPA filters um because of COVID it would be interesting to see if they now have less micro plastic fibres in the air like if there's a dual benefit of having um those HEPA so it's different Robyn's talking about vacuums and now I'm bringing out across to like actual HEPA filters that you can have in a room that and again it's all based on particle size they're just removing particles of that in that small size um so it removes viruses it removes um it'll it'll remove plastics that are down there yeah so given um you mentioned earlier there's plastics coming off tyres and um those sorts of sources as well should it becoming part of the suite of things that the HEPA is looking at in our air quality you know that typically look at vehicle emissions that's a good yeah that's a good question I mean I think um I think this is part of this thing around risk assessment that we really need to be doing working out what the risk is and is it is like is it inside our homes that the risk is is it outside is it is it high enough risk that we do need to be measuring it or is it just in certain situations and so I don't think we know the answers yet to be able to say yeah you should be going out and measuring it do we know if everyone is out there measuring it and that's the question this one from next one from Robyn um so I can't there are people measuring microplastics in air um whether or not there's anyone in Australia I can't remember whether I because again Robyn's our air expert and I'm our soil expert and so I'm not looking at the air as much but there may not have been one in Australia good chance there hasn't been in Melbourne for sure I'd say um but I know there are some other groups in New South Wales and Queensland and um doing quite a lot of microplastics research so there might have been studies up there I'm not sure and it sounds like you've put Susie on the spot there Robyn so maybe uh you can come back to the job a bit of information for us both um William Gordon you can ignore that question above now that's alright thanks okay um Rachel Lancaster if bacteria eat the plastics what is the end product just carbon that is a good question and I think that's part of what the research is around making sure um that yeah you don't end up with a bigger problem than what you had before um again this is not my direct area of expertise so I know the research is going on um but I'm I don't know whether they know that answer yet but we'd be aiming for um yeah kind of neutral carbon um compounds yeah I know history sort of seems to show you know most of these biological degradation paths produce a few uh hiccups don't they in terms of toxicity of the next thing down the chain and exactly yeah so many different compounds it's going to be a big study to work that out um but a good question ah so Russell Schindler from sample serve hello from Michigan ah great presentation very informative so we've got people listening on the other side of the world there you go Susie that's fantastic international superstar now um Juan Montoya I've got that right beyond bans and policy change reuse and reduce action should we also be pursuing more waste to energy options in Australia yeah so um Juan I think I think like I said before I think we should be sort of putting everything on the table and then working out what is the most sustainable options and so we need to look at it both from the point of view of microplastics and you know we don't want these unintended consequences where we solve it but then we're creating a big climate change impact or something is as the unintended consequence so um I definitely think it should be something that we're looking at and and assessing all right next question ah from Sadiq Bala I think what is the magnitude of microplastic contamination through irrigation compared to other sources like biosolids lettering, textile and others okay um so I can't remember reading one that's directly in irrigation and I'm assuming this is not wastewater irrigation because there's definitely issues with wastewater irrigation but this is just water that's come from a river and I think it depends on or from groundwater potentially or you know like fresh water irrigation sort of um I'm so it depends on the source um I've got a little like factoid about biosolids though because I'm pretty sure biosolids are going to be higher um so there's an author and I can't remember who the author was but they compared some two different sets of modelling that had worked out the total amount of biosolids the total amount of plastics added in biosolids globally every year is more than the total amount of plastics that are on the surface of the ocean in any given year so it's like staggering how much is in biosolids and that was I was going to give that little factoid and forgot so it's great that you asked that question so I think um you know biosolids are going to win over um definitely over irrigation there and then um composting too has got the potential to be really high especially when it's like this Fogo waste and things where you know we're not necessarily so good at like oh there's the rubber band that's around the shallots that are all wilted and people just chuck that in and you know whatever else it is that they they just chuck the whole plastic bag in with the the shallots that are wilted or I don't know what people are doing but there's lots of plastic getting in there or they just don't care that it's Fogo waste like so you know we've got a real issue with our Fogo waste as well do we know how much plastics in the sort of human body on average right now oh yeah I don't know that they're founded though they're founded in breast milk they're founded in our blood like it's we've got microplastics you know I can pretty much guarantee you and I and everyone watching have you know measurable quantities of microplastics in us at the moment okay interesting alright so Sadiq or Sadiq is also interested in can we use phyto remediation as a method to plastics from soils so this is a good question so I think there's you know when you're talking about phyto remediation broadly there's a whole lot of different approaches so if it's phyto extraction that you mean plants in general can be pretty small before they're going to absorb them so you might it depends on the situation but they're going to be leaving those bigger ones which will then break down but maybe you know if it's like sipping combined there may be a potential there so you know I think it's something that should be looked at but then there's all sorts of phyto remediation so maybe you're talking more about that like there's phyto remediation where the plants are used to stimulate the microbes and to have substrates so that you get more microbes that are then degrading, bioremediating the plastics and so again that's another potential area that would be good to look at Greg Hamcock great talk where does plastic coatings on surfaces and in particular paints fit into this issue yeah so definitely and I think in urban environments we've documented that there's high like from house paints we've got high concentrations of lead say in our back garden soils and a lot of that lead's coming off paint so it's going to be you know little fragments of paint that are the lead that's in the soil often there so I think you know it is there it's not this is another thing with how we work out that it's paint rather than it's in the scale of relatively easy it's easier to go in and go it's these compounds it's harder to go in and go oh that means it's plastic oh plastic coatings oh no in particular paints yeah it's paints or it's not that many studies that have gone to that level where they're really looking at like not just what is the composition but what is the origin of these plastics particularly in terrestrial environments there's a bit of it happening now in marine environments so we'll be bringing that into the soil environment doing more research there will be good Andrew Dougal do we know if it eventually stratifies in the soil as a high concentration layer don't think we do know but like I said we're finding it in groundwater so we do know that it's moving through but whether we get like bulges moving through like we get with nitrogen moving through soil and down I don't know and again it's going to depend on your soil type and the pore size and the types of micro plastics and yeah so that is I think that's a really good question though I like this next question you said how do you reduce cross-contamination during analysis look like they're everywhere so a lot of sampling containers this is yeah so sampling containers we've got to be careful what we're wearing like you don't want fibers coming off your clothes so we're wearing cotton lab coats and and our gloves you know they're plastics so we make sure that they're like a really distinctive colour and that we're consistently using the same colour so if it is a particle from them we can identify it easily depending on what we do it like we do we make sure things are covered all the time except when we really need them to not be where we'll often do it in fume cupboards so that it's not you know the air has been blown off or or biosecurity cabinets too where it's keeping you know the whole aim of them is to keep the air off the of our samples so that we're not getting contamination coming in yeah but it's a it's a and we do a whole lot of quality control so that if it is coming in we can pick it up all right so Scott Carroll's giving us a bit of wisdom here about incineration versus other I think it should be you know what EFW is I don't know what EFW is this is and I think this is great that we're getting people with more expertise on the these issues coming in on the bits that they know more about as opposed to incineration various options available with positive outcomes like gasification and pyrolysis can be much better than incineration and I guess this is this waste to energy that I can't remember who it was but someone else brought up is the gasification I'm assuming yeah that's right so looking at incineration versus recycling I think the other one was Cathy Phillips have there been any studies on the economics of not recycling plastics e.g. costs of investigation remediation the human health impacts to the environment etc would this be likely to make us reconsider economic barriers to recycling I think look there's so many great questions that is a great question Cathy and I the answer is I don't know and I think we need more of this sort of life cycle whole life cycle what are the impacts of plastic and the benefits you know that's what you do in life cycle assessment and then working out like where are the situations where we still have plastics and where are the situations where we don't because the cost outweighs the benefit right that was a good question and Robyn Schofields back again. PM2.5 is an aggregate pollutant um yeah so I guess you're saying Robyn I think that it's pretty big in the that that's even pretty big compared to some of the microplastics that we're seeing and so oh oh no I know what Robyn's saying there I think is that you're saying it's an aggregate of all particle pollutants so it's not we can't use PM2.5 to measure microplastics if we want to measure microplastics in air we have to measure microplastics in air I think which is a good that's a good point all right now it's 5 to 2 I think we'll give it 5 more minutes this is fantastic to have all those questions thank you Andrew Doogle there is a global trend to monetize the natural capital of soil it seems that microplastics would reduce this potential capital value is this a liability for someone eg waste collector household polluter or plastic manufacturer yeah um I think I mean it depends where we lay the liability but in general in our society it's whoever owns the land that the soils in like that's how we do the audit system it's whoever owns that property so I would think that the potential risk is there for property owners and I'm worried I'm worried about agriculture farmers and that you know then you know they think they've been doing the right thing they've been doing and that it may end up that there are some issues down the line there potentially when assessing industrial sites for reuse microplastics in the future might come up as an issue and this is the thing at the moment there's this uncertainty around what is a soil that's unacceptably contaminated with microplastics we just don't we don't have values at the moment to be able to say that so yeah there's potential in the future for it and there's the potential just like with other contaminants for it to reduce value what would be interesting to look at is from the EU perspective you know they're coming in with all these new effectively they're not tariff barriers but essentially they're going to stop the selling into their markets based on how sustainable our agriculture is so they look at I'm wondering if this one's going to appear in that area that it could be outside forces that drive before we get into the policy space on it yeah it's true is there any movement in the EU on regulating this general there is I don't think they have like besides this kind of like let's reduce it reuse at levees that's more at that end still but there's definitely there's movement there and like as a California's getting really close to having concentrations in drinking water it is amazing how the EU policy is driving quite rapid change right yeah they do I mean it's a good thing right yeah yeah I agree I think it's a it's a good you know in general it's a good thing yeah especially for the industries very that's true to be you know slightly biased people in the audience next one do you think the positive impacts on microbial diversity and richness shown in some cases in the graphs you showed relate to increases in plastic degrading microbes yeah very well could be and this is part of the issue of measuring microbes in that way and so I think there was the question on the microbial biome I think there's good case for going in there and looking at like what are the pros like even though the diversity overall is the same are we seeing differences in different groups with different functions so yeah is it like plastic degrading microbes are increasing but maybe the nitrogen cycling ones are decreasing we we don't know when we're measuring it in those aggregated ways alright Toby Montgomery thanks very much for your presentation he's had to leave us well thanks so much to everyone who's hanging around we've still got over a hundred people here impressive you're holding a big audience yeah Jasmine Paget thank you for this talk I am part of the waterkeepers alliance and so interested in the problems on land that affect riverways so I am on the border in terms of my workers riverkeeper and the local land coordinator are you connected to land care in Victoria be great to have your presentation at the land care conference as well as our waterkeepers alliance meetings what's the best way for people to get in touch with you Susie so I think at the end my email is going to be shown but you can Google Susie Reikman and I come up I come up top and so you can get my email that way that's probably best I'm on LinkedIn I'm on Twitter I'm on Facebook and I tend to with LinkedIn especially after an event like this if people who I can see are in the field even if I don't know them if you connect with me I'll connect back with you so yeah LinkedIn or direct email I'm Susie dot Reikman at unimel.edu.au and yeah it's easy to Google me there's not many Susie Reikmans these contact details are at the end of the presentation which is saved on our website so you can pick up that as well and you can Google Capem as well because there's contact details for Capem on the Capem website alright back to questions Susie you're not quite off the hook yet sort of are do microplastics bioaccumulate in guts or lungs um so I think they both they're both pathways by how they get into our body um as to whether they definitely I know they sort of can accumulate in the lung lining and the gut lining a lot of what's going on in the gut though is passing through and so there's um a lot of it will move through and it can have those physical potentially have those same sort of physical impacts on us that it's been trying to have on earthworks. I think I think there's been some studies on humans showing similar impacts in our gut linings as well in our gastrointestinal linings don't quote me on that so yeah both just wondering Susie like I'm a little bit partial to cheese and it's typically wrapped in plastic is that a problem with the direct pathway uh yeah potentially and then the other thing is I know that they've shown there are micro plastics in human milk and so presumably it's in cow milk as well so you could be just directly getting it from the cheese but don't stop eating cheese because you're also getting it from your drinking water and maybe in your celery and your beef and you know although I think it's not mainly in muscles it's not too bad in muscles muscle issues okay look we might have to stop it there I'm sorry we've still got 13 questions to answer and we're over 2 o'clock but thank you very much everyone for your questions that's been fantastic and we'll do our best to answer them by email I would like to say thank you very much to Susie it's been fantastic presentation and obviously there's a huge amount of interest and I guess concern out there about this and congratulations to CAPM for sort of identifying this as a key issue to be sorted out so well done and anyone who's interested in further research in this area or partnering with CAPM should contact Susie they do have industry partnerships program and they're going very well as a research organization but clearly it's an area that needs a lot more study so thanks very much Susie that's been fantastic and really appreciate your time today thank you Richard and thank you to the audience for such great questions it's been lots of fun