Microplastic Distribution Across the Environment Module 2 PDF

MODULE TWO SESSION 1 Microplastic distribution across the environment  Course overview This course will bring you: Microplastic entry into water, soil and sediment Microplastic transit and transport mechanisms in water and atmosphere...

MODULE TWO SESSION 1 Microplastic distribution across the environment  Course overview This course will bring you: Microplastic entry into water, soil and sediment Microplastic transit and transport mechanisms in water and atmosphere Microplastic distribution in soil, sediment and biota Ecological impact assessment of aquatic microplastics  LEARNING OUTCOMES At the end of the course, you should be able to: 1. Understand how microplastic enter into water, soil and sediment 2. Understand the transport mechanisms microplastics in water and atmosphere 3. Comprehend the distribution of microplastics in soil, sediment and biota 4. Evaluate the ecological consequences of microplastic pollution on aquatic organisms, communities, and ecosystem.  Microplastic Entry into the Environment: Rivers Microplastic influx and deposition in rivers can be linked to: – upstream land use (Mani et al. 2016) – urban runoff (Nizzetto et al. 2016) – relative effluent discharge volumes (Moore et al. 2011) – river hydraulics and river morphology (Besseling et al. 2017) – population density – urbanization and industrialization surrounding a river (Yonkos et al. 2014).  Microplastic Entry into the Environment: Rivers Barriers such as dams and weirs also influence the concentration, composition, and transport of microplastics in freshwater ecosystems (Zhang et al. 2015). Other important factors to consider are related to the polymer itself: – size Yu and Singh 2 023 – shape, – density – presence of organic and/or inorganic materials, including biofouling  Microplastic Entry into the Environment: Rivers Environmental factors that could affect microplastic distribution in rivers include: – Winds – Currents – Waves – Water density (Prata et al. 2019) Microplastic concentration in river systems can be highly variable both spatially and temporally (e.g. high flows vs low flows).  Microplastic Entry into the Environment: Lakes According to Fischer et al. (2016), lakes are a "semi-closed" system for microplastics, as they can be found in: – Sediments – Circulated in open water, and – Depart through tributaries.  Microplastic Entry into the Environment: Lakes Microplastics' movement in lakes is influenced by factors such as: wind strength wind direction lake morphology prevailing currents storm events  Microplastic Entry into the Environment: Soil and Sediment Microplastics enter the soil: – Landfill dumping, – Plastic mulching, – Recycling operations of wastewater sludge (Rillig, 2012) – Organic fertilizer (Zhang et al., 2022)  Microplastic Entry into the Environment: Soil and Sediment Vegetated sediments are more effective at retaining pollutants than bare soil. The presence of dense roots and rhizomes Reduced water flow/turbulence Retention/ accumulation of MP’s  Microplastic Entry into the Environment: Soil and Sediment Transport, deposition in sediments, or availability to Rummel et al., 2017 organisms is affected by: – Aggregation to biofilms – Encapsulation in sewage Sooriyakumar et al., 2022  Microplastic Entry into the Environment: Soil and Sediment Sediments are suggested to be a long-term sink for microplastics High-density plastics sink and accumulate in sediment Low-density particles float on Yan et al., 2021 the water surface or in water columns  Microplastic Transit and Transport Mechanisms: Water Transport Rivers, being essential carriers in nature, are crucial for transporting microplastics (MPs) across landmasses. Freshwater systems, often close to terrestrial sources and heavily affected by human activities, are significant in this regard. Rivers, serving as vital sources of drinking water and food, support millions Gettyimages Credit: D EA/SIOEN of people and diverse aquatic life.  Microplastic Transit and Transport Mechanisms: Water Transport In the river ecosystems, the transport and deposition of MPs are governed by – Hydrologic characteristics – Storm events – Hydraulic conditions Credit: – Physical properties International Rivers  Microplastic Transit and Transport Mechanisms: Water Transport Suspension and deposition of MPs is via: River hydrological characteristics – Discharge – Flow velocity – Water level  Microplastic Transit and Transport Mechanisms: Water Transport Microplastics are transported into Lakes by: – Movement of water – The propagation of waves – The drifting of water – Surface discharge – Seasonal shifts  Microplastic Transit and Transport Mechanisms: Atmospheric Transport Sources – Vehicle tires, brakes, and road surfaces – Smoke emissions from factories – Agriculture activities Microplastics enter the atmosphere through various mechanical processes: – Wind waves – Water spray – Lake waves – They can also rise via gas bubbles  Environmental Distribution of Microplastics The concentration of microplastics in water can vary spatially and temporarily Higher concentrations occur downstream in the rainy season The concentration of microplastic increases from upstream to downstream metropolitan areas MP abundance positively correlates with clay and silt fractions but negatively with sand fraction in sediment. Environmental Distribution of Microplastics Microplastic abundance in sediments rises downstream alongside increasing population density. Microplastic in sediments is related to the complex: – Geographical – Climate – Elevation – Grassland – Per capita GDP, and – Anthropogenic factors.  Environmental Distribution of Microplastics MP ingestion by aquatic species occurs either through direct consumption and/or Source: Abin secondary ingestion (i.e., trophic transfer). (2023) Microplastic ingestion by fish is influenced by anthropogenic disturbance and point source The concentration of microplastic in fish correlates with the microplastic concentration in water High MP concentration in sediment elicits high concentrations in larvae of Chironomus sp., a benthic inhabitant Chironomus sp (  Environmental Distribution of Microplastics MPs have been found in molluscs from River Osun Larger molluscs show higher concentrations per individual and smaller ones show higher concentrations per gram of body weight. Microbial colonization is abundant in oligo- mesotrophic and dystrophic lakes: >oxygen consumption than in eutrophic lakes. Microplastics: Ecological Impacts Toxic effects on aquatic life due to MPs; Environmental impacts from additives released during MPs degradation; and "Microplastic carrier effect" caused by the hydrophobic nature and large surface area of MPs.  Microplastics: Ecological Impacts Exposure of Daphnia magna to MPs causes reduced feeding and reproductive capacity Daphnia accumulates MPs in the digestive tract with increasing intestinal transit time MPs inhibit nematode: Daphnia magna (Water flea) – survival – body length – reproduction were significantly inhibited Affect nematode metabolism via elevated Glutathione S- transferase (GST) enzyme levels Nematode  Microplastics: Ecological Impacts Postmortem examination of zebrafish with ingested MPs indicated different degrees of damage to the intestinal Intestinal Villi: tissues: Balbi and Ciarletta (2013) – villus rupture – intestinal epithelial cell division Zebrafish: Reardon (2023)  Microplastics: Ecological Impacts Bisphenol-A (BPA), a plastic additive, can interact with estrogen receptors, causing several endocrine diseases MPs have a strong adsorption capacity for hydrophobic organic pollutants MPs can act as common carriers of heavy metals and antibiotics Human pathogenic bacteria will form biofilms on the surface of MPs Heavy metal-mediated multi-drug Source: Pebody (2021) resistance can develop in the pathogens  MODULE TWO SESSION 2 International Microplastic and Macroplastic Regulations  Course overview This course will bring you:  International Regulatory Frameworks for Microplastics  International Regulatory Frameworks for Macroplastics  Stakeholder Roles and Enforcement  LEARNING OUTCOMES At the end of the course, you should be able to: 1. Understand international regulations on microplastics 2. Understand international regulations on macroplastics 3. Fathom stakeholder roles and enforcement of regulations International Regulatory Frameworks for Microplastics In March 2022, the United Nations Environment Assembly (UNEA) adopted a historic resolution to initiate intergovernmental negotiations for an international legally binding instrument aimed at ending plastic pollution.  International Regulatory Frameworks for Microplastics Tenets of the resolution: 1. The full-life-cycle approach is crucial for addressing plastic pollution, as it has a significant impact on ecosystems and human activities. 2. The future instrument outlines sustainable plastic production, waste management, country- Source: driven action plans, Alhazmi et al., 2021 reporting mechanisms,  International Regulatory Frameworks for Microplastics Tenets of the resolution: 3. It recognizes the role of the future instrument in cooperation and coordination with relevant regional and international conventions, instruments and organizations 4. The Intergovernmental Negotiating Committee (INC) shall complete its Source: Danida 2023 work by 2024  International Regulatory Frameworks for Microplastics Microplastic regulations are developing internationally and domestically with two main approaches. The EU focuses on removing intentionally produced microplastics from consumer use and production chains The US and Canada prioritize monitoring programs and regulations to comprehend microplastics issues better.  International Regulatory Frameworks for Microplastics Australia The Australian Government's National Plastics Plan 2021 states it will collaborate with industry to implement microfiber filters on new residential and commercial washing machines by July 1, 2030.  International Regulatory Frameworks for Microplastics European Union The 2018 Plastics Strategy urged the exploration of policy options to decrease unintentional microplastic releases from tyres and textiles. – Developing methods to measure emissions – Allocating targeted R&D funding, and – Establish minimum design and information Source requirements. : Jono Design 2024  International Regulatory Frameworks for Microplastics France France's 2020 anti-waste law mandates that all new professional and household washing machines must include a microfiber filter by January 1, 2025. Source: texfash 2023  International Regulatory Frameworks for Macroplastics The European Union Green Deal The EU's Plastics Strategy, introduced in 2018, is a component of the Circular Economy Plan within the EU Green Deal. The Plastics Strategy comprises directives and policies aimed at Credit: safeguarding CarbonEmit 2023 environmental and human health while supporting the SDGs.  International Regulatory Frameworks for Macroplastics The European Union Plastic Strategy of 2018 Transforming the way that plastic products are: – produced – designed – used, and recycled within the EU – initiating change at a global level Credit: Through this, less plastics Plastic Europe 2021 and microplastics should ultimately end up in the aquatic environment.  International Regulatory Frameworks for Macroplastics The EU Single-Use Plastics and Fishing Gear Directive 2019 From 2025 PET bottles must be made of 25% recycled material, and by 2030 this should increase to 30% The Packaging Act (developed in 2019) stipulates that 63% of Credit: plastic packaging must be Antos 2022 recycled by 2023.  International Regulatory Frameworks for Macroplastics Africa 37 countries have some form of regulation on plastic bags in 2018 Enforcement is a challenge due to: – illegal trade and – the exploitation of loopholes in regulations The South African government in 2023 mandated a minimum of 50% recycled content in plastic carrier bags, aiming for 100% recycled content by 2027.  International Regulatory Frameworks for Macroplastics Africa Rwanda's success with plastic bag and single- use plastic bans is largely attributed to rigorous enforcement measures. The South African government in 2023 mandated a minimum of Credit: 50% recycled content in Practical Action 2023 plastic carrier bags, aiming for 100% recycled content by 2027. Plastic Regulations: Stakeholder Roles and Enforcement The current national and international legislation and management approaches are: – Typically fragmented – Insufficient, and – Often focus on plastic disposal Globally, we need a coordinated transboundary approach that addresses plastic across its entire lifecycle: – resource extraction – consumption – distribution – disposal  Plastic Regulations: Stakeholder Roles and Enforcement Legislation must take a holistic approach. This requires: – Improvements in plastic recycling and waste export – The continued reduction in plastic packaging and single use plastic waste – An enhanced circular economy approach. Enforcement must consider the full lifecycle of plastic: – its production Source: – design and The Conservation 2014 – disposal. Plastic Regulations: Stakeholder Roles and Enforcement Plastic Regulations: Stakeholder Roles and Enforcement  Plastic Regulations: Stakeholder Roles and Enforcement An Intergovernmental Negotiating Committee (INC) was formed to develop a binding instrument addressing plastic pollution by the end of 2024. As part of this effort, the "High Ambition Coalition to End Plastic Pollution" was launched in August 2022. Senegal is the only African nation in the 18-nation coalition.  Plastic Regulations: Stakeholder Roles and Enforcement AFRIPAC: Effective Plastic Treaty Capacity Building for Africa To empower five African nations´ negotiating skills for a strong Global Treaty on plastic pollution – Cabo Verde – Guinea Bissau – São Tomé and Príncipe – Senegal, and – Sierra Leone  Plastic Regulations: Stakeholder Roles and Enforcement AFRIPAC Aims – Ensure global commitments to end plastic pollution are strengthened, – Improve National action plans and policies, and – Align global policy to the national and regional instruments to prevent marine litter  Plastic Regulations: Stakeholder Roles and Enforcement AFRIPAC Expected Outcomes – Target States and stakeholders, including women, will actively participate in the Intergovernmental Negotiating Committee (INC) Source: Igamba 2023 processes, including INC-2 in Paris. – Target States' plastic pollution mitigation efforts will incorporate Circular Economy principles into waste management practices. 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