Physical and chemical effects of conventional microplastic glitter versus alternative glitter particles on a freshwater plant (Lemnaceae: Lemna minor).

Glitters are primary microplastics which are directly littered into the environment, yet the ecological effects have seldom been tested. When microplastics enter the environment, their physical presence and chemical leachate may alter the physiology of primary producers. Glitter can be composed of plastic or natural and/or biodegradable materials, often with additives. Three experiments were run for 14 days to separate chemical and physical effects of different types of glitter: polyethylene terephthalate (PET), biodegradable modified regenerated cellulose (MRC), synthetic mica, and a natural particle control (kaolinite) on several physical characteristics of Lemna minor (common duckweed). L. minor was exposed to either fresh (chemical and physical effects), leachate from glitter (chemical) or aged glitter (physical). Overall, there was little effect of PET, synthetic mica, kaolinite or of any aged glitter. High concentrations of fresh MRC glitters, however, decreased root length, biomass and chlorophyll content of L. minor. Some of these effects were also present when exposed to leachate from MRC glitters, but were less pronounced. Elemental analysis revealed the presence of metals in MRC glitters which may explain these responses. Short-term ecotoxicity of biodegradable glitters can arise due to their physical and chemical properties, but may lessen over time as their surface coating degrades.

Effects of Microplastics in Soil Ecosystems: Above and Below Ground.

Environmental contamination by microplastics is now considered an emerging threat to biodiversity and ecosystem functioning. Soil ecosystems, particularly agricultural land, have been recognized as a major sink of microplastics, but the impacts of microplastics on soil ecosystems (e.g., above and below ground) remain largely unknown. In this study, different types of microplastics [biodegradable polylactic acid (PLA)], conventional high-density polyethylene (HDPE), and microplastic clothing fibers were added to soil containing the endogeic Aporrectodea rosea (rosy-tipped earthworm) and planted with Lolium perenne (perennial ryegrass) to assess the biophysical soil response in a mesocosm experiment. When exposed to fibers or PLA microplastics, fewer seeds germinated. There was also a reduction in shoot height with PLA. The biomass of A. rosea exposed to HDPE was significantly reduced compared to control samples. Furthermore, with HDPE present there was a decrease in soil pH. The size distribution of water-stable soil aggregates was altered when microplastics were present, suggesting potential alterations of soil stability. This study provides evidence that microplastics manufactured of HDPE and PLA, and synthetic fibers can affect the development of L. perenne, health of A. rosea and basic, but crucial soil properties, with potential further impacts on soil ecosystem functioning.

Cigarette butts have adverse effects on initial growth of perennial ryegrass (gramineae: Lolium perenne L.) and white clover (leguminosae: Trifolium repens L.).

Cigarette filters (butts) are currently the most abundant form of anthropogenic litter on the planet, yet we know very little about their environmental impacts on terrestrial ecosystems, including plant germination and primary production. When discarded, filters contain a myriad of chemicals resulting from smoking tobacco and some still contain unsmoked remnants. A greenhouse experiment was used to assess the impacts of discarded filters of regular or menthol cigarette, either from unsmoked, smoked, or smoked cigarettes with remnant tobacco, on the growth and development of Lolium perenne (perennial ryegrass) and Trifolium repens (white clover). After 21 days, shoot length and germination success were significantly reduced by exposure to any type of cigarette filter for the grass and clover. Although total grass biomass was not measurably affected, the root biomass and root:shoot ratio were less in the clover when exposed to filters from smoked regular cigarettes and those with remnant tobacco. Cigarette filters caused an increase in chlorophyll-a in clover shoots and an increase in chlorophyll-b in grass shoots. Accordingly, whilst the chlorophyll a:b ratio was increased in the clover exposed to cigarette filters, it was decreased in grass. This study indicates the potential for littered cigarette filters to reduce growth and alter short-term primary productivity of terrestrial plants.

Microplastics Affect the Ecological Functioning of an Important Biogenic Habitat.

Biological effects of microplastics on the health of bivalves have been demonstrated elsewhere, but ecological impacts on the biodiversity and ecosystem functioning of bivalve-dominated habitats are unknown. Thus, we exposed intact sediment cores containing European flat oysters (Ostrea edulis) or blue mussels (Mytilus edulis) in seawater to two different densities (2.5 or 25 µg L-1) of biodegradable or conventional microplastics in outdoor mesocosms. We hypothesized that filtration rates of the bivalves, inorganic nitrogen cycling, primary productivity of sediment dwelling microphytobenthos, and the structure of invertebrate benthic assemblages would be influenced by microplastics. After 50 days, filtration by M. edulis was significantly less when exposed to 25 µg L-1 of either type of microplastics, but there were no effects on ecosystem functioning or the associated invertebrate assemblages. Contrastingly, filtration by O. edulis significantly increased when exposed to 2.5 or 25 µg L-1 of microplastics, and porewater ammonium and biomass of benthic cyanobacteria decreased. Additionally the associated infaunal invertebrate assemblages differed, with significantly less polychaetes and more oligochaetes in treatments exposed to microplastics. These findings highlight the potential of microplastics to impact the functioning and structure of sedimentary habitats and show that such effects may depend on the dominant bivalve present.

Impacts of discarded plastic bags on marine assemblages and ecosystem functioning.

The accumulation of plastic debris is a global environmental problem due to its durability, persistence, and abundance. Although effects of plastic debris on individual marine organisms, particularly mammals and birds, have been extensively documented (e.g., entanglement and choking), very little is known about effects on assemblages and consequences for ecosystem functioning. In Europe, around 40% of the plastic items produced are utilized as single-use packaging, which rapidly accumulate in waste management facilities and as litter in the environment. A range of biodegradable plastics have been developed with the aspiration of reducing the persistence of litter; however, their impacts on marine assemblages or ecosystem functioning have never been evaluated. A field experiment was conducted to assess the impact of conventional and biodegradable plastic carrier bags as litter on benthic macro- and meio-faunal assemblages and biogeochemical processes (primary productivity, redox condition, organic matter content, and pore-water nutrients) on an intertidal shore near Dublin, Ireland. After 9 weeks, the presence of either type of bag created anoxic conditions within the sediment along with reduced primary productivity and organic matter and significantly lower abundances of infaunal invertebrates. This indicates that both conventional and biodegradable bags can rapidly alter marine assemblages and the ecosystem services they provide.

Impacts of pristine, aged and leachate of conventional and biodegradable plastics on plant growth and soil organic carbon.

Plastic is an essential component of agriculture globally, becoming a concerning form of pollution. Biodegradable alternatives are gaining attention as a potential replacement for commonly used, non-degradable plastics, but there is little known about the impacts of biodegradable plastics as they age and potential leachates are released. In this study, different types (conventional: polyethylene and polypropylene and biodegradable: polyhydroxybutyrate and polylactic acid) of micro- and meso-films were added to soil at 0.1% (w/w) prior to being planted with Lolium perenne (perennial ryegrass) to evaluate the plant and soil biophysical responses in a pot experiment. Root and shoot biomass and chlorophyll content were reduced when soil was exposed to plastics, whether conventional or biodegradable, pristine, aged or when just their leachate was present. The pH and organic matter content of soil exposed to these plastics and their leachates was significantly reduced compared to control samples; furthermore, there was an increase in CO2 respiration rate from soil. In general, meso (> 5 mm) and micro (< 5 mm) plastic films did not differ in the impact on plants or soil. This study provides evidence that conventional and biodegradable plastics have both physical and chemical impacts on essential soil characteristics and the growth of L. perenne, potentially leading to wider effects on soil carbon cycling.

Above- and below-ground field study on the impacts of conventional and alternative mesoplastics on Hordeum vulgare growth and soil invertebrate communities.

Plastic plays an important role in agriculture, but its use has become a concerning source of pollution. While new (bio)degradable, alternative plastics are being developed and used as mulching films, their ecological impacts, in particular under field conditions, are not well understood. Furthermore, there is a notable lack of knowledge on how plastic pollution affects soil invertebrate communities. Most existing studies primarily focus on microplastics, often neglecting the impacts of mesoplastics. This study therefore compared the separate effects of two conventional (polyethylene and polypropylene) and two alternative (polyethylene containing biodegradable additives and compostable polylactic acid) mesoplastic films on plant performance (biomass, seed yield) and soil mesofaunal assemblages in a field experiment. The mesoplastics were applied at 0.1% (w/w), prior to soil being planted with Hordeum vulgare (spring barley), which was grown to maturity, for 11 weeks. Generally, there were no measurable differences between the conventional and alternative plastic treatments, however, barley exposed to mesoplastics showed reduced biomass, seed yield, and chlorophyll content, along with increased oxidative stress. Soil fauna, particularly Collembola, had lower richness and abundance when exposed to both plastic types, but assemblage structure and composition remained unchanged after 11 weeks. This study is pivotal in highlighting that both conventional and alternative plastics can similarly affect plant health and soil ecosystems. The evidence provided is essential for refining future risk assessments of agricultural plastic pollution and underscores the urgent need for more sustainable practices and materials in agriculture.

Ecotoxicological effects of leachate from e-cigarettes and e-liquid on the performance of perennial ryegrass (Loliumperenne).

Once littered, disposable e-cigarettes present a complex type of waste in the environment. They typically contain a lithium battery, electronics to produce vapour and remnant e-liquid, all of which could leach into the environment. The effects of littered e-cigarettes are not well understood, and they have not been tested in terrestrial ecosystems. To address this, an experiment was set up to assess how leachate from e-cigarettes with or without a battery, but also e-liquid on its own can alter fundamental physical characteristics of Lolium perenne (perennial ryegrass) when irrigated with contaminated water. After 31 days, shoot length of L. perenne was not measurably affected, but the biomass was significantly reduced by 30% when e-liquid, and 24% when leachate from intact e-cigarettes was present compared to control plants. Plants grown with leachate or e-liquid displayed a significant level of early senescence of leaf apices, and the chlorophyll content was increased. Furthermore, root biomass was significantly less (29-46%) compared to the control. Leachate from used disposable e-cigarettes can affect the performance of plants when entering the soil ecosystem, therefore stricter regulations are needed to prevent this new type of electronic litter from becoming more widespread.

Disposable e-cigarettes and cigarette butts alter the physiology of an aquatic plant Lemna minor (Lemnaceae).

Cigarette butts are one of the most littered single-use plastic items worldwide and can have ecotoxicological effects. e-Cigarettes (or 'vapes') have gained popularity globally as an alternative to tobacco-based cigarettes in recent years. The increased availability of disposable e-cigarettes has resulted in a rise in their littering, presenting a complex form of e-waste in the environment, yet the environmental impacts of littered e-cigarettes are largely unknown. Here Lemna minor (common duckweed) was used as a model organism to understand the effects of smoked cigarettes, vaped e-cigarettes or e-liquid. Growth-related physiological responses were measured (biomass, root development and frond chlorophyll content). After 14 days of exposure to cigarette butts there was an increase of all measured growth variables. On the contrary, exposure to e-cigarettes or e-liquid caused a decrease in root length, biomass and frond number relative to controls. The significant deviations from control conditions suggest that the presence of either cigarette butts, e-cigarettes or e-liquid caused stress to the model plant which could indicate disruption of aquatic ecosystems at the primary producer level. Disposable vapes pose a novel threat to aquatic ecosystems and it would be prudent to prevent them from becoming the next top litter item.

Time to kick the butt of the most common litter item in the world: Ban cigarette filters.

Cigarette filters offer no public health benefits, are single-use plastics (cellulose acetate) and are routinely littered. Filters account for a significant proportion of plastic litter worldwide, requiring considerable public funds to remove, and are a source of microplastics. Used cigarette filters can leech toxic chemicals and pose an ecological risk to both terrestrial and aquatic ecosystems. Bottom-up measures, such as focusing on consumer behaviour, are ineffective and we need to impose top-down solutions (i.e., bans) if we are to reduce the prevalence of this number one litter item. Banning filters offers numerous ecological, socioeconomic, and public health benefits.

Implication of microplastics on soil faunal communities - identifying gaps of knowledge.

There is mounting evidence that plastic and microplastic contamination of soils can affect physico-chemical processes and soil fauna, as has been excellently summarised in many recently published meta-analyses and systematic reviews elsewhere. It has become clear that impacts are highly context dependent on, e.g. polymer type, shape, dose and the soil itself. Most published studies are based on experimental approaches using (semi-)controlled laboratory conditions. They typically focus on one or several representative animal species and their behaviour and/or physiological response - for example, earthworms, but rarely on whole communities of animals. Nevertheless, soil animals are rarely found in isolation and form part of intricate foodwebs. Soil faunal biodiversity is complex, and species diversity and interactions within the soil are very challenging to unravel, which may explain why there is still a dearth of information on this. Research needs to focus on soil animals from a holistic viewpoint, moving away from studies on animals in isolation and consider different trophic levels including their interactions. Furthermore, as evidence obtained from laboratory studies is complemented by relatively few studies done in field conditions, more research is needed to fully understand the mechanisms by which plastic pollution affects soil animals under realistic field conditions. However, field-based studies are typically more challenging logistically, requiring relatively large research teams, ideally of an interdisciplinary nature to maintain long-term field experiments. Lastly, with more alternative, (bio)degradable and/or compostable plastics being developed and used, their effects on soil animals will need to be further researched.

The ecological impacts of discarded cigarette butts.

Cigarette butts, one of the most littered items globally, present a unique challenge to ecosystems due to their ubiquity, persistence, and potential for harm. Over 35 studies have examined the toxicity of cigarette butts in biota from aquatic and terrestrial habitats from microbes to mice, but many organisms and habitats have not been tested. Two-thirds of studies are on aquatic organisms, and lethal effects were common. Research on the impacts on terrestrial life is lagging behind. Cigarette butts can affect the growth, behaviour, and reproductive output of individual organisms in all three habitats, but research on wider effects on biodiversity and ecosystem functioning is lacking. Here, we summarise the ecotoxicological concerns and identify important knowledge gaps for future research.

Effects of cigarette butts on marine keystone species (Ulva lactuca L. and Mytilus edulis L.) and sediment microphytobenthos.

Outdoor mesocosms with constantly flowing natural seawater were used to test the effects of littered cigarette butts on the filter feeder Mytilus edulis (blue mussel), the macroalga, Ulva lactuca (sea lettuce) and sediment microphytobenthos in a semi-natural marine setting. Either conventional, cellulose acetate, or biodegradable, cellulose, smoked cigarette butts were added at densities of 0.25 or 1 butt L-1. The clearance rates of mussels exposed to 1 butt L-1 of cellulose acetate butts were three times less than the controls. The growth of U. lactuca was not measurably affected by cigarette butts, however the sediment chlorophyll content was significantly less in mesocosms exposed to 0.25 and 1 butt L-1 of cellulose acetate butts. These effects occurred despite constant replacement of seawater indicating how hazardous conventional cigarette butts are to marine life. Biodegradable cellulose cigarette butts had minimal effects on the measured variables but should still not be discarded as litter.

All that glitters is litter? Ecological impacts of conventional versus biodegradable glitter in a freshwater habitat.

Biodegradable plastics are becoming increasingly popular due to global concerns about plastic pollution. In this study, the impacts of glitter manufactured of conventional, non-biodegradable polyethylene terephthalate (PET) versus glitter of alternative materials (modified regenerated cellulose (MRC), mica or synthetic mica) on the biodiversity and ecosystem functioning of freshwater, lotic habitats were compared using a semi-natural mesocosm experiment. After 36 days, there was no effect of glitter on overall assemblage structure or diversity indices, however there was a two-fold increase in the abundance of New Zealand mud snails (Potamopyrgus antipodarum) in response to MRC glitter. In addition, the root length of common duckweed (Lemna minor) and phytoplankton biomass (based on chlorophyll content) were significantly reduced by exposure to any type of glitter. On the contrary, the chlorophyll content in the sediment (indicating microphytobenthos biomass) was significantly greater in those exposed to synthetic mica glitter. Organic matter content of sediment did not differ amongst any of the treatments. However initially, on days 8 and 15, NO32- concentration in the control treatment were significantly greater than in all glitter treatments, but this observation disappeared over time. Overall, results indicate that both conventional and alternative glitters can cause ecological impacts in aquatic ecosystems.

Smoked cigarette butt leachate impacts survival and behaviour of freshwater invertebrates.

Smoked cigarette filters a. k.a. "butts", composed of plastic (e.g. cellulose acetate) are one of the world's most common litter items. In response to concerns about plastic pollution, biodegradable cellulose filters are being promoted as an environmentally safe alternative, however, once smoked, both contain toxins which can leach once discarded. The impacts of biodegradable butts as littered items on the receiving environment, in comparison with conventional butts has not yet been assessed. A freshwater mesocosm experiment was used to test the effects of leachate from smoked cellulose acetate versus smoked cellulose filters at a range of concentrations (0, 0.2, 1 and 5 butts L-1) on the mortality and behaviour of four freshwater invertebrates (Dreissena polymorpha, Polycelis nigra, Planorbis planorbis and Bithynia tentaculata). Leachate derived from 5 butts L-1 of either type of filter caused 60-100% mortality to all species within 5 days. Leachate derived from 1 butt L-1 of either type resulted in adults being less active than those exposed to no or 0.2 butts L-1 leachate. Cigarette butts, therefore, regardless of their perceived degradability can cause mortality and decreased activity of key freshwater invertebrates and should always be disposed of responsibly.

A comparison of sampling methods for seawater microplastics and a first report of the microplastic litter in coastal waters of Ascension and Falkland Islands.

To date there is no gold standard for sampling microplastics. Zooplankton sampling methods, such as plankton and Neuston nets, are commonly used to estimate the concentrations of microplastics in seawater, but their ability to detect microplastics is limited by their mesh size. We compared different net-based sampling methods with different mesh sizes including bongo nets (>500 µm), manta nets (>300 µm) and plankton nets (>200 µm and >400 µm) to 1 litre bottle grabbed, filtered (0.45 µm) samples. Concentrations of microplastics estimated using net-based methods were ~3 orders of magnitude less than those estimated by 1 litre grab samples. Some parts of the world with low human populations, such as Ascension Island and the Falkland Islands, lack baseline data on microplastics. Using the bottle grab sampling method we found that microplastic litter was present at these remote locations and was comparable to levels of contamination in more populated coastal regions, such as the United Kingdom.

Detection of Coxiella burnetii in Urban River Water.

Previous molecular-based studies have identified microorganisms of zoonotic and human nature in surface waters. Contaminated water can lead to human health issues, and the detection of pathogenic microorganisms is a valuable tool for the prevention of their spread. Water samples were taken from the River Tiber in and out of the city of Rome. Genetic analysis of the sequences obtained showed the presence of Coxiella burnetii in both the analyzed sites. Blast analysis showed that two sequences were identical to each other. Sequences from the polluted site showed high homology with different strains of C. burnetii. In this article, we report for the first time the presence of C. burnetii in environmental waters.

Monitoring of freshwater toxins in European environmental waters by using novel multi-detection methods.

Monitoring the quality of freshwater is an important issue for public health. In the context of the European project µAqua, 150 samples were collected from several waters in France, Germany, Ireland, Italy, and Turkey for 2 yr. These samples were analyzed using 2 multitoxin detection methods previously developed: a microsphere-based method coupled to flow-cytometry, and an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The presence of microcystins, nodularin, domoic acid, cylindrospermopsin, and several analogues of anatoxin-a (ATX-a) was monitored. No traces of cylindrospermopsin or domoic acid were found in any of the environmental samples. Microcystin-LR and microcystin-RR were detected in 2 samples from Turkey and Germany. In the case of ATX-a derivatives, 75% of samples contained mainly H2 -ATX-a and small amounts of H2 -homoanatoxin-a, whereas ATX-a and homoanatoxin-a were found in only 1 sample. These results confirm the presence and wide distribution of dihydro derivatives of ATX-a toxins in European freshwaters. Environ Toxicol Chem 2017;36:645-654. © 2016 SETAC.

Effects of conventional and biodegradable microplastics on a marine ecosystem engineer (Arenicola marina) and sediment nutrient cycling.

Effects of microplastic pollution on benthic organisms and ecosystem services provided by sedimentary habitats are largely unknown. An outdoor mesocosm experiment was done to realistically assess the effects of three different types of microplastic pollution (one biodegradable type; polylactic acid and two conventional types; polyethylene and polyvinylchloride) at increasing concentrations (0.02, 0.2 and 2% of wet sediment weight) on the health and biological activity of lugworms, Arenicola marina (Linnaeus, 1758), and on nitrogen cycling and primary productivity of the sediment they inhabit. After 31 days, A. marina produced less casts in sediments containing microplastics. Metabolic rates of A. marina increased, while microalgal biomass decreased at high concentrations, compared to sediments with low concentrations or without microplastics. Responses were strongest to polyvinylchloride, emphasising that different materials may have differential effects. Each material needs to be carefully evaluated in order to assess their risks as microplastic pollution. Overall, both conventional and biodegradable microplastics in sandy sediments can affect the health and behaviour of lugworms and directly or indirectly reduce primary productivity of these habitats.

Detection of Human Enteric Viruses in Freshwater from European Countries.

The transmission of water-borne pathogens typically occurs by a faecal-oral route, through inhalation of aerosols, or by direct or indirect contact with contaminated water. Previous molecular-based studies have identified viral particles of zoonotic and human nature in surface waters. Contaminated water can lead to human health issues, and the development of rapid methods for the detection of pathogenic microorganisms is a valuable tool for the prevention of their spread. The aims of this work were to determine the presence and identity of representative human pathogenic enteric viruses in water samples from six European countries by quantitative polymerase chain reaction (q-PCR) and to develop two quantitative PCR methods for Adenovirus 41 and Mammalian Orthoreoviruses. A 2-year survey showed that Norovirus, Mammalian Orthoreovirus and Adenoviruses were the most frequently identified enteric viruses in the sampled surface waters. Although it was not possible to establish viability and infectivity of the viruses considered, the detectable presence of pathogenic viruses may represent a potential risk for human health. The methodology developed may aid in rapid detection of these pathogens for monitoring quality of surface waters.