**2. Plastics in the environment**

Easily observed plastic pollution is often referred to as macroplastics which have dimensions greater than 1 mm. Smaller plastic particles are referred as micro- or nanoparticle. The aspects of long-term pollution and human health effects have been issues of social concern in recent times [9]. The wanton dispersal of plastic film bags and drink bottles mar our global landscape, waterways, and oceans/seas. Plastics apparent resistance to degradation elongates their residence time in the environment. Environmental processes can contribute to the debris by activating degradation pathways which lead to the conversion of macroplastics to smaller dimension plastic materials [10]. Plastics can carry with them pollutants such as plasticizers, antioxidants, and other persistent organic pollutants **Table 1** [11–15]. Human health concerns have been focused on the monomeric components, additives, and certain combinations of the chemical employed in the synthesis of a plastic [16].


**Table 1.**

*Characteristics influencing microplastic behavior.*

### **3. Microplastics**

The chemical composition of the major plastics provides some basic understanding of their environmental behavior (**Table 2**) [17]. The physical dimensions of plastic particles are classified by size class which refers to the particle's largest dimension that is important to the design of analytical collection protocols used in sampling microplastics sensitive to particle shape [18, 19]. The term microplastics refers to anthropogenic polymer materials having the dimensions of less than 5 mm (0.2 inch) occurring as

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**3.2 Composition**

**3.1 Definition**

**Table 2.**

*The Importance of Biofilms to the Fate and Effects of Microplastics*

**Polyethylene (PE)** 0.91–0.94 Float

**Polypropylene (PP)** 0.90–0.92 "

**Polystyrene (expanded) (PS)** 0.01–1.05 "

**Polystyrene** 1.04–1.09 Sink **Polyvinyl chloride (PVC)** 1.16–1.30 "

**Polyester resin + glass fibers** >1.35 " **Cellulose acetate** 1.22–1.24 "

*Plastic properties important to the fate and effects of microplastics.*

**gravity**

Low density LDPE " " 45–55 High density HDPE " " 70–80

Atactic PP " " ~0 Isotactic PP " " 70–80

**Polyamide** 1.13–1.15 " 35–45 **Polyethylene terephthalate (PET)** 1.34–1.39 " 30–40

**Water column movement**

**Degree of crystallinity %**

plastic pollution in the environment [20]. Smaller particles referred to as nanoplastics are becoming an issue of growing concern that falls into the size range of 10–1,000 nm

achieved. Uneven size classes are employed for sampling for microplastics to represent random size classes, and even material composition is a matter of debate [22, 23].

Microplastic specifications can be found in two broad categories, primary and secondary [24]. Primary microplastics are manufactured particles that are characterized as microbeads, nurdles, and fibers in size dimensions of 5 mm or smaller. Any interception technology must be equipped with appropriately sized filters to remove the particles from contaminated environmental media. Secondary microplastics are formed from larger plastics or macroplastics through the effects of weathering and physical deterioration in the environment. Weathering by photochemical oxidation, UV rays, and wind and wave action leads to the fragmentation of macroplastics to form microplastics. Aquatic plastic debris can be organized by size as mega (>1 m)-, macro (<1 m)-, meso (<2.5 cm)-, micro (<5 mm)-, and nano (<1 μm)-dimensions [25]. A recently proposed size schema separates microplastics in marine environments into the following categories: nano (1–1000 nm)-, micro (1–1000 μm)-, meso (1–10 mm)-, and macroplastics (≥1 cm). Size schemes are proposed to address the sampling problems encountered in the field, but these schemes are lacking since it is difficult to provide a microplastic sample that is spatially

Chemical composition and environmental impacts of microplastic samples differ broadly (**Table 2**). Microplastic composition reflects the use and disposal of

representative of a specific environmental space [26–29].

[21]. The consensus definition and categorization of plastic debris are yet to be

*DOI: http://dx.doi.org/10.5772/intechopen.92816*

**Polymer category Specific** 

Seawater ~1.02


*The Importance of Biofilms to the Fate and Effects of Microplastics DOI: http://dx.doi.org/10.5772/intechopen.92816*

**Table 2.**

*Bacterial Biofilms*

management trends continue unabated [2].

**2. Plastics in the environment**

may exceed 12,000 Mt. of plastic waste by 2050 if current production and waste

Macroplastics or the polymers from which they are constructed have been recognized as valuable materials composed of repeating units and applicable to many material design requirements [6]. Each repeating unit of a polymer is referred to as the "-mer" with "polymer" denoting a chemical composed of many repeating units. Plastics are unique materials having the benefits of being light weight, versatile, having reasonably long service lives, and attractive cost. Across the land and seas, the accumulation of plastic litter found in natural environments looms as a global issue [7]. Potential negative impacts to wildlife, human health, and the economy offer strong incentives to thoroughly explore our approach to the sustainable use of plastics [8].

Easily observed plastic pollution is often referred to as macroplastics which have dimensions greater than 1 mm. Smaller plastic particles are referred as micro- or nanoparticle. The aspects of long-term pollution and human health effects have been issues of social concern in recent times [9]. The wanton dispersal of plastic film bags and drink bottles mar our global landscape, waterways, and oceans/seas. Plastics apparent resistance to degradation elongates their residence time in the environment. Environmental processes can contribute to the debris by activating degradation pathways which lead to the conversion of macroplastics to smaller dimension plastic materials [10]. Plastics can carry with them pollutants such as plasticizers, antioxidants, and other persistent organic pollutants **Table 1** [11–15]. Human health concerns have been focused on the monomeric components, additives, and certain

The chemical composition of the major plastics provides some basic understanding of their environmental behavior (**Table 2**) [17]. The physical dimensions of plastic particles are classified by size class which refers to the particle's largest dimension that is important to the design of analytical collection protocols used in sampling microplastics sensitive to particle shape [18, 19]. The term microplastics refers to anthropogenic polymer materials having the dimensions of less than 5 mm (0.2 inch) occurring as

Polymer additives Highly variable depending on polymer composition and application of polymer

combinations of the chemical employed in the synthesis of a plastic [16].

Extent of oxidation Chemical composition determines the ease of oxidation and weathering Biodegradability Contributes to the general structural deterioration of microplastics through

**Characteristic Behavior** Density Determines the vertical water column position Crystallinity Controls susceptibility to photochemical oxidation

biological means

Transport properties Affinity for hydrophobic chemicals and metals

Surface properties Important to aggregate formation and biofouling

Monomer residual Potential source of toxicity and small molecule pollutants

**304**

**3. Microplastics**

*Characteristics influencing microplastic behavior.*

**Table 1.**

*Plastic properties important to the fate and effects of microplastics.*

plastic pollution in the environment [20]. Smaller particles referred to as nanoplastics are becoming an issue of growing concern that falls into the size range of 10–1,000 nm [21]. The consensus definition and categorization of plastic debris are yet to be achieved. Uneven size classes are employed for sampling for microplastics to represent random size classes, and even material composition is a matter of debate [22, 23].
