Section I: Microplastics and Nanoplastics
Microplastics and Nanoplastics
Microplastics and Nanoplastics: Origin, Fate and Effects
Vividha Dhapte-Pawar, Piyush Mehta and Prathmesh Kenjale
- 1.1 Introduction 3
- 1.2 Micro/Nanoplastic Sources within the Environment 4
- 1.2.1 Micro/Nanoplastics on Land 5
- 1.2.2 Micro/Nanoplastics in the Freshwater Environment 5
- 1.2.3 Micro/Nanoplastics in the Marine Environment 5
- 1.2.4 Microplastics in the Atmosphere 5
- 1.3 Micro/Nanoplastics Effects on Plants 5
- 1.4 Micro/Nanoplastics Effects on the Food Chain 6
- 1.5 Separation and Analysis of Micro/Nanoplastics in Environmental Samples
- 1.6 Analytical Methodologies to Assess the Micro/Nanoplastics within the Environment
- 1.7 Threat of Micro/Nanoplastics to Human Beings 9
- 1.7.1 Oral Route 9
- 1.7.2 Dermal Route 10
- 1.7.3 Inhalation 10
- 1.8 Conclusion 11
Plastic is a synthetic or semi-synthetic material with a varied range of consumer and industrial applications . These synthetic materials are mostly fabricated from polymers built around chains of carbon atoms, mainly with hydrogen, oxygen, sulfur and nitrogen between the spaces . The term “plastic” is derived from the Greek word “plastikos,” meaning suitable for molding . Global production of plastics has increased over the past years and is still enduring (Figure 1.1). Because of poor waste management practices, plastic in the environment, as well as oceans, is also increasing rapidly . It is projected that around 60% of all plastics ever made have accumulated in landfills or the natural environment .
Nowadays, plastic items are being manufactured in all shapes and sizes, with the micron and submicron ranges considered to be “micro- or nanoplastics,” also termed as “primary micro- or nanoplastics.” While, on the other hand, in the environment, the breakdown of large plastic items into small micron or nano-sized fragments are termed as “secondary micro- or nanoplastics.” They appear in various micro, as well as in nano, forms, such as fragments,
FIGURE 1.1 Global plastic production over the past years (in metric tons).
FIGURE 1.2 Formation of micro/nanoplastics by breakdown mechanisms.
fibers or films. Various mechanisms by which this breakdown can occur are mechanical, chemical or biological degradation (Figure 1.2). Mechanical degradation involves tire abrasion, road wear, washing of synthetic textiles, physical weathering of large items [5-8]. Chemical degradation can occur by exposure to acids or alkalis while UV degradation occurs by exposure to non-ionizing, UV radiation. Biological degradation can also occur by the living organisms having capacity to ingest and degrade plastics like waxworms, mealworms and similar microorganisms [9-11]. Additionally, plasticizers added during plastic manufacturing improve durability and flexibility, along with enhancing degradation [12,13].