Emerging Contaminants in the Terrestrial-Aquatic-Atmosphere Continuum: Occurrence, Health Risks and Mitigation

Front Cover
Emerging Contaminants in the Terrestrial-Aquatic-Atmosphere Continuum: Occurrence, Health Risks, and Mitigation
Copyright
Dedication
Contents
Contributors
Editor biography
Preface
	1. Motivation for the book
	2. Novelty of the book
	3. Layout/structure of the book
	4. Target audience
Acknowledgements
Section A: Introduction to emerging contaminants
	Chapter 1: Emerging contaminants: A handful of conceptual and organizing frameworks
		1. Introduction
		2. Nature, industrial applications, and sources of emerging contaminants
			2.1. Emerging contaminants
				2.1.1. Emerging organic contaminants
				2.1.2. Microplastics
				2.1.3. Antibiotic/antimicrobial resistance
				2.1.4. High-technology rare earth elements
			2.2. Novel entities/technologies
		3. Conceptual and organizing frameworks
			3.1. The terrestrial-aquatic-atmosphere continuum
			3.2. The SPRI/CM framework
			3.3. Eco-hierarchical or ecosystem cascade framework
			3.4. The human factor or dimension
			3.5. The concept of environmentally relevant conditions
			3.6. Emerging contaminants and their health risks in the COVID-19 era
		4. Conceptual frameworks as tools for framing and organizing the book
		5. Concluding remarks and outlook
		References
	Chapter 2: Emerging contaminants in the terrestrial-aquatic-atmosphere continuum: A global perspective
		1. Introduction
		2. Emerging contaminants
			2.1. Nature and sources
			2.2. Environmental occurrence and circulation
		3. Emerging contaminants: A global perspective
			3.1. Global industrial production and trade
			3.2. A life cycle perspective on emerging contaminants
			3.3. Regulatory, institutional, and policy frameworks
			3.4. Emerging contaminants as a global health concern
		4. Future perspectives and outlook
			4.1. Recommendations
			4.2. Research needs
		5. Conclusions
		References
Section B: Emerging contaminants in terrestrial systems
	Chapter 3: High-technology rare earth elements in the soil-plant system: Occurrence, behaviour, and fate
		1. Introduction
		2. Industrial applications and anthropogenic sources
			2.1. Industrial applications
			2.2. Natural and anthropogenic sources of rare earth elements in soils
			2.3. Anthropogenic sources
		3. Occurrence of REEs in the soil-plant system
			3.1. Soil matrix and pore water
			3.2. Soil organisms
			3.3. Plants and crops
		4. Biogeochemical controls and fate of REEs
			4.1. Biogeochemical controls
			4.2. Soil-root-microbial interactions
		5. Future directions and perspectives
			5.1. Increasing the research footprint of low-income countries in REEs
			5.2. Interactive effects of REEs and other essential plant elements
			5.3. Broadening the scope of soil organisms and REEs
			5.4. Biotransformation in soil trophic system
			5.5. REEs behaviour and fate in various soils
		6. Conclusions and outlook
		References
	Chapter 4: (Micro)plastics in the soil system: Occurrence, behaviour, fate, and future directions
		1. Introduction
		2. Nature and sources of (micro)plastics
		3. Occurrence of (micro)plastics in the soil system
			3.1. Soils
			3.2. Soil organisms
			3.3. Microplastics in plants
		4. Behaviour and fate processes
			4.1. Dissemination pathways
			4.2. Behaviour
				4.2.1. Effect on the physico-chemical properties of the soil
				4.2.2. Effect on microbial activity and soil biota
				4.2.3. Effect on other pollutants
			4.3. Fate processes
		5. Future research directions and perspectives
			5.1. Microplastic pollution: A perspective on low-income versus developed countries
			5.2. Future research directions
		6. Conclusions and outlook
		Acknowledgments
		Credit author contribution
		Declaration of conflict of interest
		References
Section C: Emerging contaminants in aquatic systems
	Chapter 5: Occurrence and behaviour of emerging organic contaminants in aquatic systems
		1. Introduction
		2. Emerging organic contaminants
			2.1. Nature and anthropogenic sources
			2.2. Overview of emerging contaminants
				2.2.1. Surfactants
				2.2.2. Pharmaceuticals
				2.2.3. Personal care products
				2.2.4. Flame retardants
				2.2.5. Gasoline additives
				2.2.6. Plasticizers
				2.2.7. Endocrine-disrupting chemicals
			2.3. Emerging contaminants detected in African aquatic systems
		3. Behaviour, fate, and human health risks
			3.1. Behaviour and fate
			3.2. Human exposure and health risks
		4. Removal of emerging contaminants: Opportunities and challenges
			4.1. Commonly used methods
			4.2. Advanced oxidation processes
			4.3. Emerging techniques
				4.3.1. Enhanced coagulation
				4.3.2. Membrane technologies
				4.3.3. Non-thermal plasma
			4.4. Economic considerations
		5. Knowledge gaps and future research
		6. Conclusions and outlook
		Author contributions
		References
	Chapter 6: Anthropogenic rare earth elements in aquatic environments: Occurrence, behaviour, and fate
		1. Introduction
		2. Sources and occurrence
			2.1. Overview of industrial applications
			2.2. Occurrence in aquatic systems
				2.2.1. Wastewaters
				2.2.2. Surface waters
				2.2.3. Groundwater
				2.2.4. Marine systems
		3. Behaviour and fate in aquatic systems
			3.1. Dissemination/transfer processes
			3.2. Biogeochemical behaviour and fate
			3.3. Behaviour and fate in wastewater and water treatment systems
		4. Future perspectives and knowledge gaps
		5. Conclusions and outlook
		References
	Chapter 7: (Micro)plastics in aquatic systems: Current research focal areas, under-studied matrices, and future directions
		1. Introduction
		2. (Micro)plastics in aquatic systems
			2.1. A summary of the evidence
				2.1.1. Marine aquatic systems
				2.1.2. Wastewater systems
				2.1.3. Surface water systems
				2.1.4. Groundwater systems
				2.1.5. Drinking water systems
			2.2. Current focal research areas
			2.3. Rationale for the research trends
			2.4. (Micro)plastic research and the `Matthew or bandwagon effect
		3. Future research directions: Ten (10) key knowledge gaps on (micro)plastics in aquatic systems
			3.1. (Micro)plastics in deep marine systems
			3.2. Stratification/depth variation of (micro)plastics in aquatic systems
			3.3. Standardization of research protocols
			3.4. Widening the bioassay organisms/species
			3.5. Trophic transfer and health risks in aquatic systems
			3.6. COVID-19 induced occurrence and ecological impacts of (micro)plastics
			3.7. Impacts of regulatory and policy interventions
			3.8. Comparative behaviour and fate of various (micro)plastics
			3.9. (Micro)plastic emission factors and loads at national, regional, and global scales
			3.10. Research needs in low-income regions
		4. Conclusions and outlook
		References
	Chapter 8: Antibiotic-resistant bacteria and antibiotic resistance genes in aquatic systems: Occurrence, behaviour, and fate
		1. Introduction
		2. Occurrence of antimicrobial resistance in aquatic systems
			2.1. Nature of antimicrobial resistance
			2.2. Hotspot sources and reservoirs
			2.3. Occurrence in aquatic systems
		3. Behaviour and fate of antimicrobial resistance in aquatic systems
			3.1. Abiotic factors
				3.1.1. Effect of temperature
				3.1.2. Nutrient availability
				3.1.3. Effect of sunlight ultraviolet light
				3.1.4. Effect of pH
				3.1.5. Effect of salinity
			3.2. Biotic factors
				3.2.1. Effect of predation and competition
				3.2.2. Role of biofilms in aquatic systems
			3.3. Antibiotic resistance in aquatic sediments
		4. Removal of antibiotic resistance in wastewater treatment systems
			4.1. Chlorination and UV irradiation
			4.2. Advanced processes
			4.3. Low-cost methods used in developing countries
		5. Future perspectives and conclusions
			5.1. Knowledge gaps
			5.2. Conclusions and outlook
		Author contributions
		References
Section D: Emerging contaminants in atmospheric systems
	Chapter 9: Air-borne emerging contaminants: An under-studied reservoir and a potential health risk?
		1. Introduction
		2. Air-borne emerging contaminants
			2.1. Why are air-borne emerging contaminants relatively under-studied?
			2.2. The mechanisms or (bio)physics of air-borne emerging contaminants
		3. Occurrence of air-borne emerging contaminants
			3.1. Microplastics
			3.2. Antimicrobial resistance
				3.2.1. Indoor environments
				3.2.2. Outdoor environments
			3.3. Emerging synthetic organic contaminants
			3.4. High-technology rare earth elements
			3.5. Summary and implications
		4. Future research directions
		5. Conclusions and outlook
		References
	Chapter 10: Occurrence, behaviour and fate of airborne microplastics
		1. Introduction
		2. Occurrence, nature and sources
			2.1. Occurrence of airborne microplastics
			2.2. Characteristics of airborne microplastics
			2.3. Sources of airborne microplastics
				2.3.1. Disposable masks as a new source of MPs in air
		3. Behaviour, transport and fate of airborne microplastics
			3.1. Degradation of plastics in the air
				3.1.1. Photo-oxidation/photo-degradation process
				3.1.2. Thermo-oxidative decomposition
				3.1.3. Mechanical degradation
			3.2. Transport and fate
				3.2.1. Factors influencing the abundance and distribution of atmospheric microplastics
					Precipitation
					Wind speed, wind direction and barometric pressure
					Particle size
					Altitude
					Proximity to human settlements/activity
					Level of economic development
		4. Future directions and perspectives
			4.1. Occurrence, nature and sources
			4.2. Behaviour and transport
			4.3. Sampling and analysis
		5. Conclusions and outlook
		References
Section E: Ecological health risks
	Chapter 11: Ecological health risks of high-technology rare earth elements
		1. Introduction
		2. Ecological health risks of REEs
			2.1. Overview of occurrence, and exposure and health risks
			2.2. Impacts of REEs on soil ecology
			2.3. Impacts of REEs on terrestrial plants and crops
			2.4. Impacts of REEs in experimental/laboratory animals
		3. Ecological health effects on aquatic organisms
			3.1. Aquatic and marine plants
			3.2. Aquatic and marine animals
			3.3. Ecological health risks of REE mixtures
		4. Future perspectives and research directions
			4.1. Ecological health risks of REEs in low-income countries
			4.2. Key knowledge gaps
		5. Conclusion and outlook
		References
	Chapter 12: Ecological health risks of antibiotic resistance: A perspective on the evidence, challenges, and research needs
		1. Introduction
		2. Materials and methods
		3. Occurrence and behaviour of antibiotic resistance
			3.1. Sources and occurrence
			3.2. Environmental behaviour and fate
			3.3. Antibiotic resistance mechanisms
				3.3.1. Antibiotics efflux pumps
				3.3.2. Inactivation of antibiotics
				3.3.3. Modification of antibiotic target sites
				3.3.4. Reduced uptake of antibiotics
		4. Environmental and ecological health risks
			4.1. Environmental exposure pathways
			4.2. Environmental and ecological health risks
				4.2.1. A summary and critique of the empirical and inferential evidence
				4.2.2. Why are the environmental and ecological impacts of antibiotic resistance under-studied?
					Antibiotic resistance as a complex and highly dynamic phenomenon
					Understanding health risks is constrained by methodological limitations
					Partitioning health risks between antibiotic resistance and other health stressors is a daunting task
					The bandwagon or Matthew effect accounts for limited research on environmental and ecological health risks of antibiotic re ...
					Research on human health risks as a research priority for the research community and decision and policy makers
		5. Future research directions and perspectives
			5.1. Key knowledge gaps
				5.1.1. Ecological health risks across levels or hierarchies of biological organization
				5.1.2. Ecological health burden of antibiotic resistances
				5.1.3. Environmental drivers of health risks and impacts of antibiotic resistance
				5.1.4. Partitioning ecological health risks amongst stressors
			5.2. The hierarchical or ecosystem cascade framework as a risk assessment tool
			5.3. Qualitative and quantitative health risk assessment
			5.4. Harnessing emerging and novel monitoring and analytical tools
		6. Conclusion and outlook
		References
	Chapter 13: Ecological health risks of emerging organic contaminants
		1. Introduction
		2. Overview of methodology
		3. Emerging organic contaminants
			3.1. Nature and sources
			3.2. Properties and occurrence
			3.3. Behaviour and fate
			3.4. Increased discharge of EOCs induced by COVID-19
		4. Ecological health risks on terrestrial systems
			4.1. Pharmaceuticals and personal care products
			4.2. Endocrine disrupting chemicals
			4.3. Surfactants
			4.4. Plasticizers and solvents
			4.5. Flame retardants
			4.6. Illicit drugs
			4.7. COVID-19 therapeutic drugs
		5. Ecological health risks of EOCs in aquatic systems
			5.1. Pharmaceuticals and personal care products
			5.2. Endocrine disrupting chemicals
			5.3. Surfactants
			5.4. Plastics and solvents
			5.5. Flame retardants
			5.6. Illicit drugs
			5.7. COVID-19 therapeutic drugs
			5.8. Ecological health risks of interaction of EOC mixtures and other health stressors
		6. Future perspectives and research directions
			6.1. Ecological health risks in low-income countries
			6.2. Key knowledge gaps
		7. Conclusion and outlook
		References
	Chapter 14: Occurrence and ecological health risks of microplastics
		1. Introduction
		2. Environmental and ecological health risks of microplastics
			2.1. Soil physico-chemical properties
			2.2. Soil microbial and biochemical processes
			2.3. Soil ecology
			2.4. Plants and crops
				2.4.1. Indirect effects: The role of chemical additives and their metabolites
		3. Ecological health risks in aquatic systems
			3.1. Direct impacts of microplastics
			3.2. Indirect impacts of microplastics: The role of chemical additives
		4. Interactive effects of microplastics and other health stressors
			4.1. Microplastics and inorganic/organic pollutants
			4.2. Microplastics and antimicrobial resistance
			4.3. Microplastics as a source of co-selection pressure for microbial evolution
		5. Looking ahead: Future perspectives and research directions
			5.1. A critique and limitations of current evidence on health risks
				5.1.1. Soil-plant system
				5.1.2. Aquatic systems
			5.2. Low-income versus developed countries: A comparison and handful of hypotheses
			5.3. Comparison among studies: The challenges and a call for standardized protocols
			5.4. Cross-cutting knowledge gaps
		6. Conclusion and outlook
		References
Section F: Human health risks
	Chapter 15: Rare earth elements: Human exposure, risk factors, and health risks
		1. Introduction
		2. Sources and occurrence
			2.1. Industrial applications
			2.2. Hotspot sources of REEs
		3. Human exposure risks
			3.1. REE occurrence in media relevant to human exposure
			3.2. Human exposure routes
				3.2.1. Risk factors and risky behaviours
				3.2.2. Human exposure routes
		4. Human health risks
			4.1. Evidence on human health risks
			4.2. A critical analysis of the evidence
		5. Future directions and perspectives
		6. Conclusions and outlook
		References
	Chapter 16: Occurrence, human exposure pathways, and health risks of (micro)plastics
		1. Introduction
		2. Occurrence and human exposure pathways
			2.1. Environmental occurrence
			2.2. Human exposure pathways
		3. Human health risks
			3.1. Behaviour and fate of (micro)plastics in the human body
			3.2. Evidence on the human health risks of (micro)plastics
			3.3. (Micro)plastics as reservoirs of toxic human contaminants
			3.4. A critique of the evidence
		4. A look ahead: Future perspectives and research directions
			4.1. Future research directions
			4.2. Future perspectives and challenges
				4.2.1. Increasing the evidence base in low-income countries
				4.2.2. COVID-19 PPE and human exposure and health risks
				4.2.3. The human factor: Knowledge, attitudes and practices
				4.2.4. On the limited evidence linking (micro)plastics to human health risks and possible solutions
			4.3. Future research directions
		5. Conclusions and outlook
		References
	Chapter 17: The environmental resistome: Human exposure, health risks, and research needs
		1. Introduction
		2. The environmental antibiotic resistome
			2.1. Nature
			2.2. Environmental occurrence
			2.3. The environmental resistome as a complex system
		3. Human exposure
			3.1. Risk factors
			3.2. Human exposure: A case of multiple sources, routes and receptors
		4. Human health risks
			4.1. A summary and critique of the evidence
			4.2. A call for empirical evidence and One-World-One-Health research
		5. Human health risk assessment: A handful of frameworks
			5.1. Qualitative risk assessment
			5.2. Quantitative microbial risk assessment
			5.3. Omics-based risk assessment
			5.4. A risk mitigation framework
		6. Future directions and perspectives
			6.1. Environmental and public health surveillance in low-income countries
			6.2. Estimating the human health burden of the environmental resistome
			6.3. The environmental resistome as a complex system
			6.4. Alternative antibiotic treatment
			6.5. Beyond antibiotics: The need to consider non-antibiotic antimicrobial resistance
			6.6. Quantifying the magnitude and extent of human exposure
			6.7. Building technical and research capacity in low-income countries
		7. Conclusions and outlook
		References
Section G: Risk assessment and mitigation
	Chapter 18: Health risk assessment and mitigation of emerging contaminants: A call for an integrated approach
		1. Introduction
		2. Health risk assessment
			2.1. Environmental and public surveillance systems
			2.2. Health risk assessment protocols
				2.2.1. Qualitative risk assessment
				2.2.2. Quantitative risk assessment
		3. The human factor, and regulatory and policy perspectives
			3.1. The human factor as a driver of the emerging contaminants industry
			3.2. Soft engineering approach
			3.3. Regulatory, institutional and policy frameworks
			3.4. Economic instruments to mitigate emerging contaminants and their health risks
		4. Hard engineering approach
			4.1. Substitution and removal technologies
				4.1.1. Emerging organic contaminants
				4.1.2. Microplastics
				4.1.3. High-technology rare earth elements
				4.1.4. Antimicrobial resistance
			4.2. Recycling, recovery, reduction and reuse technologies
		5. Future research directions and perspectives
			5.1. A call for an integrated approach
			5.2. Knowledge gaps
		6. Conclusion and outlook
		References
	Chapter 19: Emerging contaminants: Approaches for policy and regulatory responses in low-income countries
		1. Introduction
		2. The effects of emerging contaminants
			2.1. The health burden of emerging contaminants
			2.2. Healthcare investments and access in sub-Saharan Africa
			2.3. Potential impacts of emerging contaminants on economic growth
		3. Constraints affecting appropriate responses
			3.1. Lack of institutional capacity
			3.2. Framing
		4. Recommendations for action
			4.1. The precautionary principle
			4.2. Funding and capacity building
			4.3. Strengthening the research-policy interface in LICs
			4.4. New approaches to framing
		5. Conclusion
		References
	Chapter 20: Remediation technologies for contaminated soil systems
		1. Introduction
		2. Emerging organic contaminants
		3. Decontamination methods
			3.1. In situ and ex situ decontamination methods
			3.2. Bioremediation
			3.3. Chemical and physical methods
				3.3.1. Chemical oxidation
				3.3.2. Physical methods
					(1). Electrokinetic remediation
					(2). Soil vapour extraction
		4. High-technology elements
			4.1. Occurrence of high technology elements
			4.2. Removal techniques
			4.3. Extraction and recovery of high-technology elements
		5. Mitigation of microplastic pollution and its health risks in soil systems
		6. Antimicrobial resistance
		7. Conclusion and future outlook
		References
	Chapter 21: Bio- and chemical surfactants for remediation of emerging organic contaminants
		1. Introduction
		2. Overview of emerging organic contaminants
		3. Overview of surfactant-aided remediation technologies
		4. Surfactants for remediation of emerging contaminants
			4.1. Synthetic chemical surfactants
			4.2. Plant-derived surfactants
			4.3. Biosurfactants
		5. Conclusion and outlook
		References
Section H: The research agenda
	Chapter 22: Ten (10) key research questions on emerging contaminants and novel entities, and their health risks
		1. Introduction
		2. Emerging contaminants and novel entities
			2.1. Emerging contaminants
			2.2. Novel entities/technologies
		3. Cross-cutting research questions
			3.1. Global pools and fluxes in the terrestrial-aquatic-atmosphere continuum
			3.2. Health risk prioritization and ranking of emerging contaminants and novel entities
			3.3. A call for standardization of protocols to enable global synthesis of data
			3.4. Global ecological health burden and impacts on ecosystem goods, services, and benefits
			3.5. The human factor, and a call to social/behavioural scientists to actively participate in research on emerging contam ...
			3.6. Quantitative evidence on human health risks and global human health burden relative to other health stressors
			3.7. The need to shift from end-of-pipe approaches to life cycle assessment tools
			3.8. The health risks of mixtures, and their interactions with other stressors
			3.9. Ecological and human health risks: Putting low-income countries under the spotlight
			3.10. Risk communication and mitigation
		4. Moving ahead on emerging contaminants and novel entities
		5. Concluding remarks
		References
	Chapter 23: Epilogue: Summary, the next-frontier emerging contaminants/novel entities, and a look ahead
		1. Introduction
		2. A summary of the state-of-the-art
			2.1. Introduction
			2.2. Emerging contaminants in the terrestrial-aquatic-atmosphere continuum
			2.3. Ecological and health risks of emerging contaminants
			2.4. Risk assessment and mitigation
			2.5. Future research needs
		3. A look ahead: Future perspectives and challenges
			3.1. Novel entities: The next-frontier emerging contaminants
			3.2. Covid-19-induced complexities and emerging contaminants
			3.3. Grand challenges
		4. Concluding remarks and outlook
		References
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