surprising that the main composition of microplastics is polystyrene, because
expanded polystyrene is widely used in cork boxes for the transport of food in
southern China and Hong Kong (Fok and Cheung 2015). When this waste is not
managed properly, these boxes can be transported to the oceans, seas, and beaches
by means of rivers and stormwater drainage systems. The fragments are usually
microplastics resulting from the physical-chemical degradation of larger plastics
exposed to the action of heat, wind, and waves (Andrady 2015). On the other
hand, polyethylene terephthalate is also a fiber very common in textile industry, as
polyamide (nylon).
All particle sizes were in the range of 0.1–5 mm. In some areas the smallest
microplastics (between 0.5 and 1 mm) were more abundant, as is the case in the
northwest Pacific (Pan et al. 2019). In other locations, such as beaches in southern
India, larger microplastics between 1.2 and 4.5 mm were more abundant (Karthik
et al. 2018). On the other hand, equal abundance of fragments and fibers was found
in studies carried out in both North and South America, and the preferred composition is polyethylene, followed by polyethylene terephthalate and polypropylene in
equal proportions (Fig. 1.18).
In some areas of North America, the presence of rayon fibers was also detected
(Yu et al. 2018), as was the case on the beaches of the Algarve (Portugal). As
mentioned above, polyethylene terephthalate is a synthetic fiber widely used in the
textile industry. The release of textile fibers into the environment is frequent and
abundant, due to the large number of household and industrial washes carried out
every day. A standard wash of 5 kg of synthetic clothing can release 6,000,000 fibers
into the environment, although it depends on the type of washing machine and
detergents used, making it a very difficult source to quantify (De Falco et al. 2018).
Other authors suggested that microplastics in North American waters may also
come from fishing, recreational boating, and wastewater effluent (Desforges et al.
2014). On the other hand, in Guanabara Bay, microplastics are mainly fragments,
which come from the degradation and breakage of larger plastics on the coast
(Gomes de Carvalho and Baptista 2016). Most of the small plastic debris found on
beaches from Guanabara Bay possibly come from fishing, rivers, harbor activities,
and other local sources. The predominant particle size in these studies is lower than
1 mm, although larger microplastics can be found, especially fragments, with sizes
exceeding 2–3 mm (Wessel et al. 2016).
In Africa, the few available studies show a dominance of fibers over other
morphologies. The predominant composition in the area of Morocco and Namibia
is EPS and PA, probably coming from the detachment of synthetic textile garments
(Kanhai et al. 2017).
In sum, the most frequent polymer found in the studies reviewed was polyethylene, which corresponded approximately to 60% of those studies. Polystyrene was
the second representative in Europe and Asia, with 14.3% and 28.6%, respectively.
It is important to take into account that polypropylene was the second polymer found
28
V. Godoy et al.
expanded polystyrene is widely used in cork boxes for the transport of food in
southern China and Hong Kong (Fok and Cheung 2015). When this waste is not
managed properly, these boxes can be transported to the oceans, seas, and beaches
by means of rivers and stormwater drainage systems. The fragments are usually
microplastics resulting from the physical-chemical degradation of larger plastics
exposed to the action of heat, wind, and waves (Andrady 2015). On the other
hand, polyethylene terephthalate is also a fiber very common in textile industry, as
polyamide (nylon).
All particle sizes were in the range of 0.1–5 mm. In some areas the smallest
microplastics (between 0.5 and 1 mm) were more abundant, as is the case in the
northwest Pacific (Pan et al. 2019). In other locations, such as beaches in southern
India, larger microplastics between 1.2 and 4.5 mm were more abundant (Karthik
et al. 2018). On the other hand, equal abundance of fragments and fibers was found
in studies carried out in both North and South America, and the preferred composition is polyethylene, followed by polyethylene terephthalate and polypropylene in
equal proportions (Fig. 1.18).
In some areas of North America, the presence of rayon fibers was also detected
(Yu et al. 2018), as was the case on the beaches of the Algarve (Portugal). As
mentioned above, polyethylene terephthalate is a synthetic fiber widely used in the
textile industry. The release of textile fibers into the environment is frequent and
abundant, due to the large number of household and industrial washes carried out
every day. A standard wash of 5 kg of synthetic clothing can release 6,000,000 fibers
into the environment, although it depends on the type of washing machine and
detergents used, making it a very difficult source to quantify (De Falco et al. 2018).
Other authors suggested that microplastics in North American waters may also
come from fishing, recreational boating, and wastewater effluent (Desforges et al.
2014). On the other hand, in Guanabara Bay, microplastics are mainly fragments,
which come from the degradation and breakage of larger plastics on the coast
(Gomes de Carvalho and Baptista 2016). Most of the small plastic debris found on
beaches from Guanabara Bay possibly come from fishing, rivers, harbor activities,
and other local sources. The predominant particle size in these studies is lower than
1 mm, although larger microplastics can be found, especially fragments, with sizes
exceeding 2–3 mm (Wessel et al. 2016).
In Africa, the few available studies show a dominance of fibers over other
morphologies. The predominant composition in the area of Morocco and Namibia
is EPS and PA, probably coming from the detachment of synthetic textile garments
(Kanhai et al. 2017).
In sum, the most frequent polymer found in the studies reviewed was polyethylene, which corresponded approximately to 60% of those studies. Polystyrene was
the second representative in Europe and Asia, with 14.3% and 28.6%, respectively.
It is important to take into account that polypropylene was the second polymer found
28
V. Godoy et al.