Freshwater Microplastic Pollution and Management PDF

Freshwater Microplastic Pollution and Management  MODULE ONE SESSION 1 Introduction to Microplastics  MODULE 1: SESSION A This course will bring you: The Definition and Classification of Microplastics The Origins of Microplastics Global Distribut...

Freshwater Microplastic Pollution and Management  MODULE ONE SESSION 1 Introduction to Microplastics  MODULE 1: SESSION A This course will bring you: The Definition and Classification of Microplastics The Origins of Microplastics Global Distribution of Microplastics  LEARNING OUTCOMES At the end of the course, you should be able to: 1. Define and classify microplastics 2. Identify the origins of microplastics 3. Understand the global distribution of microplastics  Introduction to Microplastics Understanding Microplastics: Definition and Classification Courtesy Alexander Kunz  Shape of microplastics Classification by Introduction to Microplastics GESAMP (2019) Introduction to Microplastics The Origins of Microplastics Household Use of personal care products or cosmetics (4,594 and 94,500 microbeads per single use) Use of washing machines and tumble driers (12,500 t of plastic fibres/Year) Opening of plastic packaging (0.46 to 250 microplastic particles per cm per opening) The Origins of Microplastics Tyre abrasion Road traffic produces tiny rubber particles from tires which are then washed into rivers and from there into the oceans. Top emitting nations/economic groups (Wagner et al., 2018) are: The European Union: 1,327,000 t/a The USA: 1,120,000 t/a The Origins of Microplastics Industry Cutting or grinding of plastic Styrofoam is released into the environment by the fishing industry Preproduction pellets are often released due to improper handling during packing and shipping Plastic pellet production sites can release between 3 – 36 million particles annually (Karlsson et al., 2018)  The Origins of Microplastics Degradation of plastic Breakdown of larger plastic into small particles via UV radiation, mechanical or chemical agents. The largest source for microplastic fragments 4.8 – 12.7 million t of plastic waste is released into the environment yearly (Jambeck et al., 2015). Source: IUCN (2022)  Global Distribution of Freshwater Microplastics Source: Cera et al. (2020)  Global Distribution of Microplastics Most microplastics result from land-based human activities, entering freshwater via runoff (Horton et al., 2017). During dry periods, plastics linger in rivers, degrading (Li et al., 2020a). Wet seasons, with intense flows, worsen microplastic pollution, resuspending particles from sediment (Hurley et al., 2018).  Global Distribution of Microplastics Spatial distribution – land cover – proximity to anthropogenic activities Temporal distribution – timing and volume of precipitation and runoff  Global Distribution of Microplastics Factors affecting the spatial distribution of microplastics – Anthropogenic activities – Urban land cover – Wastewater treatment plants – Agricultural land cover – Microplastics in remote regions – Population density  Global Distribution of Microplastics Physical watershed/stream characteristics – Increased slope of the riparian zone – Less dense polymers (polypropylene, polyethylene) float near the water surface in calm conditions – Denser polymers (polyethylene terephthalate, polyvinyl chloride) sink and settle at the channel bottom  Global Distribution of Microplastics Factors affecting the temporal distribution of microplastics – Precipitation seasonality – Storm runoff – Flow velocity/discharg e  Global Distribution of Microplastics The prevalent 'species' of microplastics include PVC and polyester either in pellet or fiber form Fibrous microplastics were of particular concern from 2018 to 2022 High fibrous microplastic levels in lab laundry simulations and from wool textiles in home washing  Global Distribution of Microplastics Studies from Africa, Asia and Europe revealed that microplastic concentrations in the freshwater range from 0.01 to 3 g/L  Global Distribution of Microplastics The final distribution of microplastics in the water column is also influenced by – Degree of weathering – Sorption and – Rate of aging Denser microplastics may cause more lasting damage to the environment.  Global Distribution of Microplastics Tourism contributes to microplastic generation ( Retama et al., 2016). Presence rises during the tourist season at Wastewater Treatment Plants (WWTP). Fibers dominate, followed by fragments, attributed to laundry effluent influx.  MODULE ONE SESSION 2 The Environmental and Health Impacts of Microplastics  MODULE 1: SESSION 2 This course will bring you: Aquatic Microplastics and Human Exposure Human Health Risks of Aquatic Microplastics Ecological Risks of Microplastics in Aquatic ecosystems  LEARNING OUTCOMES At the end of the course, you should be able to: 1. Understand human exposure to aquatic microplastics 2. Appreciate the human health risks from aquatic microplastics 3. Appreciate the ecological risks of microplastics in aquatic ecosystems Aquatic Microplastics and Human Exposure: Occurrence and Risk Besides environmental exposure, humans are also directly exposed to microplastics via domestic products Microfibers, plastic foams, and microbeads are widely used in clothing, food containers, and toiletries, enhancing the risks of personal exposure to microplastics.  Aquatic Microplastics and Human Exposure: Occurrence and Risk The content of Alconox (2018) microplastics in tap water can be as high as 4.2 pieces/L Source: In bottled water it can be 20 times higher: 94 pieces/L Due to their small sizes, microplastics are readily accumulated in both aquatic and terrestrial organisms MPs are transferred via the food chain and finally end Source: up in human consumers Hongtek (2021) Aquatic Microplastics and Human Exposure: Occurrence and Risk Domestic food with additives is another origin of microplastics ( Source: Facciolà et al., 2021 0.10–1.48 pieces/g) Annual individual consumption of MP reaches 52,000 microplastic pieces from food and drink Adding the inhalable MPs takes the figure to 121,000 items per year. The ubiquitous presence of microplastics around humans thus results in inevitable exposure to humans  Aquatic Microplastics and Human Exposure: Human Exposure Routes Exposure routes of microplastics to humans include – ingestion – inhalation, and – dermal penetration The ingestion of microplastics is the primary route Seafood is considered one main source of microplastics by the ingestion route Yearly microplastics uptake per family consuming: Source: Pironti et al., 2021 – Mollusks: 27,825 items – Crustaceans: 17,716 items – Fish: 8,323 items  Aquatic Microplastics and Human Exposure: Human Exposure Routes The content of microplastics in various sources of salt: – Sea salt: 550 items/kg – Lake salt: 43 items/kg – Rock/well salt: 7 items/kg The size of MPs in tap water from groundwater sources (50– 150 μm: Mintenig et al., 2019) is larger than the sizes of water packaged in bottles (6.5–20 Source: Newhart (2019) μm: Kankanige and Babel 2020 ) The size of MPs in soft drinks, cold teas, and energy drinks is larger: 0.1–3 mm. ( Shruti et al., 2020)  Aquatic Microplastics and Human Exposure: Human Exposure Routes MP ingestion predisposing factors include: – Direct release of microplastics from food packaging – Migration of chemical plasticizers from food packaging to food For instance: – Size of MPs directly derived from seafood is 38.2–820 μm ( Leung et al., 2021) – Size of MPs in canned seafood was bigger and reached 3800 μm (Karami et al., 2018)  Applied Microplastics and Human Exposure: Human Exposure Routes MP particles that enter via the transdermal route pass sublayers of epidermis They reach microcirculation of the dermis and are transported through the human body via the circulatory system  Applied Microplastics and Human Exposure: Human Exposure Routes Dermal absorption occurred mostly when people used personal care products: – Hand cleanser – Facial/body scrubs – Face masks and – Toothpaste Consequence: local toxicity and possible absorption The human skin (Largest Organ: surface area of 1.5–2 m2) provides an interface with ubiquitous MPs in the environment  Human Health Risks of Aquatic Microplastics Toxic chemical additives in plastic that are known to affect human health include: – Bisphenol A (BPA) – Phthalates – Triclosan – Bisphenone – Organotins and – Brominated flame retardants (BFR)  Human Health Risks of Aquatic Microplastics Four (4) morphological and chemical characteristics of microplastics influence their Source: Wang (2023) potential hazards: – Physical – Chemical composition – Metabolism or Source: degradation to form Kang et al., 2 monomers or other 019 derivatives – The presence of biofilms  Human Health Risks of Aquatic Microplastics Toxic effects strongly depend on the: – dose – dose rate, and – duration of exposure Uptake across the gastrointestinal Source: Anderson and Li 2020 tract (particles