Particulate Plastics in Terrestrial and Aquatic Environments

Nanthi S. Bolan, M.B. Kirkham, Claudia Halsband, Dayanthi Nugegoda, Yong Sik Ok, Nanthi S. Bolan, M.B. Kirkham, Claudia Halsband, Dayanthi Nugegoda, Yong Sik Ok

• Publisher: CRC Press
• Year: 2020
• eBook ISBN: 9781000081497
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

The manufacture of plastic as well as its indiscriminate disposal and destruction by incineration pollutes atmospheric, terrestrial, and aquatic ecosystems. Synthetic plastics do not break down; they accumulate in the environment as macro-, micro-, and nanoplastics. These particulate plastics are a major source of pollutants in soil and marine ecosystems. Particulate Plastics in Terrestrial and Aquatic Environments provides a fundamental understanding of the sources of these plastics and the threats they pose to the environment. The book demonstrates the ecotoxicity of particulate plastics using case studies and offers management practices to mitigate particulate plastic contamination in the environment.

Features

· Describes physical and chemical properties of particulate plastics in terrestrial and aquatic ecosystems

· Presents information on characteristics of particulate plastics as impacted by weathering processes

· Provides numerous approaches for managing particulate plastic contamination

· Identifies sources of particulate plastics in the environment; distribution and characteristics of particulate plastics; and management strategies of particulate plastics

Written by a global team of scientists, this book is for researchers in the fields of environmental safety and waste management or individuals interested in the impact of particulate plastics on environmental health.

Section III

Ecotoxicity of Particulate Plastics

11	Environmentally Toxic Components of Particulate Plastics Sanchita Mandal, Nanthi S. Bolan, Binoy Sarkar, Hasintha Wijesekara, Lauren Bradney, and M. B. Kirkham

CONTENTS

11.1 Introduction

11.2 Manufacture of Plastics

11.2.1 Thermoplastics

11.2.2 Thermosets

11.3 Presence of Chemicals in Plastics and Their Toxicity

11.3.1 Hazardous Metals

11.3.2 Bisphenols

11.3.3 Phthalates

11.3.4 Per- and Polyfluoroalkyl Substances

11.3.5 Additives

11.4 Leaching of Chemicals from Plastics

11.5 Toxicity of the Chemical Components of Plastics

11.6 Conclusions

References

11.1 INTRODUCTION

The plastic revolution in our daily life enormously increased within the last few decades. It was estimated that around 348 million metric tons of plastics were produced globally in 2017, with around 40% used for packaging purposes (Statista 2018). This increasing amount of plastics ultimately get introduced to the terrestrial (i.e., soil) and aquatic (i.e., marine) ecosystems by generating a considerable amount of litter. About 10 million tons of plastic litter is migrating into the marine ecosystems each year and creating a “plastic footprint” in the environment (Boucher and Billard 2019). The concerns about plastic production and usages are multi-directional, such as: (a) accumulation of a huge amount of non-degradable plastics in the environment, (b) release of toxic chemicals during manufacturing and exposure of plastics to the environment, (c) generation of secondary micro- and nanoplastics during the production and usage of plastics, and (d) improper disposal of plastics into the soil and ocean (Jambeck et al. 2015; Thompson et al. 2009; Galloway 2015; Galloway and Lewis 2016; Biryol et al. 2017; Caporossi and Papaleo 2017; Gallo et al. 2018; Hahladakis et al. 2018). Table 11.1 summarizes information on selected synthetic polymers made of plastics, their origin, and characteristics.

Crude oil is the main source of synthetic plastics, whereas coal and natural gas are also used for plastic production. During the refining process of crude oil, several toxic by-products are produced, such as petrol, paraffin, lubricating oils, and petroleum gases. Plastics are diverse in nature and made of a range of different polymers and additives along with other components, such as adhesives and/or coatings. Furthermore, plastics can also contain the residues from the materials used for plastic production, such as solvents and additives. To understand and characterize the potential risks associated with the production, usage, disposal, and recycling of plastics and plastic packaging materials, comprehensive information of all the chemicals involved is needed. A study by Groh et al. (2018) compiled a list of chemicals associated with plastic manufacturing and those present in the final packaging materials. The identified most common hazardous chemicals from plastic productions are: monomers, intermediates, solvents, surfactants, plasticizers, stabilizers, biocides, flame retardants, accelerators, and colorants (Groh et al. 2018). However, achieving a completely comprehensive list of chemicals used in plastic manufacturing is not a straightforward task because plastics are made of a large variety of polymers and additives, and furthermore, the identity of the chemicals in finished plastic packaging is seldom measured. It was estimated that among 906 chemicals likely to be associated with plastic packaging, 63 rank the highest for human hazards, and 68 for environmental hazards, according to the harmonized hazardous classifications assigned by the European Chemicals Agency (Table 11.2) (EU 2018; European Commission 2018). Most of the recent studies have assessed the ultimate fate and impacts of plastics and their leachates or adsorbed contaminants without being able to separate the individual effects of hazardous chemicals, or, on the contrary, they examined only one specific substance/chemical without considering the integrated amount of chemicals/substances present in the plastic wastes (Auta et al. 2017; Anderson et al. 2016; Gallo et al. 2018). Therefore, this chapter aims to understand the manufacturing processes of plastics and to present an overview of environmentally hazardous components and chemicals in various plastics and their final states after manufacturing.

TABLE 11.1
Summarized Information on Selected Synthetic Polymers Made of Plastics, Their Origin, and Characteristics

Chemical Compound	Chemical Formula	Origin or Source to Environment	Characteristics	References
Low-density polyethylene (LDPE)	(C2H4)n	Squeeze bottles, toys, carrier bags, chemical tank linings, heavy duty sacks, general packaging, and gas and water pipes	Low density 0.91–0.94 g/cm^3, non-biodegradable, most common plastics	Lambert et al. (2014); Lassen et al. (2015)
High-density polyethylene (HDPE)	(C2H4)n	Chemical drums, toys, household and kitchenware, cable insulation, and carrier bags	High density 0.92–0.99 g/cm^3, non-biodegradable	Lambert et al. (2014); Lassen et al. (2015)
Acrylic	Acrylate polymers: based with acrylic acid: CH2=CHCOOH	Most used fibers in textiles: knitware and plastic flakes	High density 1.16 g/cm^3	Lassen et al. (2015)
Polyethylene terephthalate (PET)	(C10H8O4)n	Drinks bottles, oven-ready meal trays cable lining	High density 1.41 g/cm^3	Lambert et al. (2014); Lassen et al. (2015)
Polypropylene (PP)	(C3H6)n	Food containers and microwavable meal trays	Low density 0.90–0.91 g/cm^3	Lambert et al. (2014); Lassen et al. (2015)
Polystyrene (PS)	(C8H8)n	Food containers, stuffed animals, and protective packaging	High density 1.04–1.13 g/cm^3	Lassen et al. (2015)
Polyvinyl chloride (PVC)	(C2H3Cl)n	Water pipes, cable insulation, packaging, and healthcare applications	High density 1.39–1.43 g/cm^3, non-biodegradable	Lassen et al. (2015)

Source: Adapted from Wijesekara et al. (2018).

TABLE 11.2
List of Hazardous Chemicals Associated with Plastic Production and Packaging

Function	Chemical Group	Chemical Name
Colorants	Dye, azo	1.8-Dihydroxynaphthalene-3,6-disulfonic acid-[2-(4-Azo)]-N-(5-methyl-3-isoxazolyl) benzenesulfonamide
	Pigment	Cobalt (II) diacetate
Fire retardants	Boron	Sodium tetraborate, pentahydrate
		Boric acid
		Sodium tetraborate, anhydrous
		Sodium borate, decahydrate
	Organophosphate	Tris(2-chloroethyl) phosphate
		Triphenyl phosphate
		Trixylyl phosphate
	Others	Tetrachlorophthalic anhydride
		2,2′,6,6′-tetrabromobisphenol A
Foaming agents	Simple hydrocarbon	Isobutane
	Biopolymer	Azodicarbonamide
	Starch	Sodium bicarbonate
		Powdered sodium bicarbonate
Plasticizers	Chlorinated paraffin	Alkanes
		Medium-chain chlorinated paraffins, >17 carbon atoms
	Phthalate	DEHP (Di-ethylhexyl phthalates)
		DINP (Di-isononyl phthalate)
		Diallyl phthalate
		Dimethoxyethyl phthalate
		Diethyl phthalate
		Dioctyl phthalate
		Diundecyl phthalate
Lubricants	Perflourinated hydrocarbons	Polytetrafluoroethylene (PTFE)
	Synthetic hydrocarbon	Polyalpha-olefin (PAO) synthetic esters
Monomers	Acrylic	Isooctyl acrylate
		Acrylonitrile
	Amine	Aziridine
		m-Phenylenediamine
	Bisphenol	Bisphenol A
		Bisphenol F
		Bisphenol S
		Naphthalene
Antioxidants	Hydrocarbon polymers	Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphate and magnesium aluminum hydroxy carbonate hydrate
		2H-benzimidazole-2-thione, 1,3-di-hydro-4(or 5)-methyl
		Tris(mono-nonylphenyl) phosphite with up to 1% triisopropanol amine
		Benzenamine, N-phenyl, reaction products with 2,4,4-trimethylpentene
		1,3-Diethyl-2-thiourea
		Disodium 4,4′-bis(2-sulfonatostyryl) biphenyl
		1,2-Bis(2-methylphenyl) guanidine

11.2 MANUFACTURE OF PLASTICS

Plastics are commonly derived from various natural and organic materials, such as cellulose, coal, natural gas, and crude oil. Due to the complex nature of crude oil and the presence of thousands of components, it needs to be processed and refined before it can be used. The main production of plastic usually begins with the distillation of crude oil in the oil refineries. During the distillation process, heavy crude oil gets separated into lighter component groups, and they are termed as fractions (Gervet 2007). Each of these fractions is a mixture of hydrocarbon chains, which is made up of carbon and hydrogen atoms. According to the size and the structure of the molecules, the hydrocarbon chains are converted to fuels and other derivatives, such as lubricants, wax, petroleum products, and so on. One of the components of these hydrocarbon fractions is naphtha, which is considered as the most crucial raw material for plastic production. Figure 11.1 represents the production steps of plastics from crude oil in oil refineries.

The two main techniques for plastic production are polymerization and polycondensation, and these require specific catalysts. In the polymerization reactor, monomers, such as propylene and ethylene are combined in order to develop a long polymer chain. Therefore, each polymer has its own structure and size depending on the different varieties of basic monomers used to form the chains. Plastics have a wide range of types based on different base chemistries, additives and derivatives formulated to obtain desired functional properties. Thus, there may be thousands of different plastic types. To simplify their classification, plastics are mainly grouped into two polymer families, namely, thermoplastics and thermosets.

11.2.1 THERMOPLASTICS

Thermoplastics are the most common types of plastics used nowadays. The main feature is that it can undergo several melts and solidification processes without significant ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Foreword
• Preface
• Acknowledgments
• Editors
• Contributors
• SECTION I Sources of Particulate Plastics in the Environment
• SECTION II Distribution and Characteristics of Particulate Plastics
• SECTION III Ecotoxicity of Particulate Plastics
• SECTION IV Case Studies of Particulate Plastics in the Environment
• SECTION V Management of Particulate Plastics
• Index