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V. Singh and S. Chakraborty
1 Introduction
Plastic pollution is one of the most critical and challenging issues globally. The global
production of plastics is increasing day by day due to its durability, lightweight,
economical and can be easily processed [1]. According to World Economic Forum,
plastic production in 1950 was 1.5 million tons per year, and in the year 2018, it
becomes 400 million tons per year, in which 50% of the plastics produced were singleuse plastics. Improper plastic waste disposal has now become an environmental
concern across the globe [2].
Microplastics (MPs), an emerging contaminant, are defined as the plastic particles
of size less than 5 mm with no definite lower size [3–5]. Plastic particles primarily
manufactured of size less than 5 mm are termed as primary microplastics, whereas
plastic particles which are the consequence of physical, chemical or biological interaction are termed as secondary microplastics [6]. These tiny particles are detected in
various shapes such as pellets, fragments, films, fibers, microbeads and foams, and
size ranges between 1 mm to 5 mm are termed as large MPs whereas size less than
1 mm are termed as small MPs [1]. The persistent nature of MPs makes them more
vulnerable to the environment, especially freshwater systems. In India, many cities
utilize freshwater lakes as the primary source of water consumption. If these MPs
reach the human body through water consumption, it can cause serious problems
to human health. These MPs may act as carrier of many toxic chemicals and heavy
metals, can be carcinogenic and ultimately contaminate the food web [3, 6, 7]. Some
studies reported the accumulation of pesticides, organic pollutants and biofilms on
these tiny particles [6, 7]. As far as freshwater systems are concerned, the primary
source of occurrence of MPs is the direct littering of plastic waste into these lakes
and fishing activities carried out inside these lakes. The secondary sources of these
MPs are the treated wastewater discharge, stormwater runoff or wind advection [8].
Freshwater systems are most vulnerable to the microplastic contaminants as these
tiny particles cannot be removed easily with conventional treatment from water and
the vulnerability and risks associated with microplastics are its persistent and toxic
to living beings which ultimately leads to water quality degradation. Several studies
show that these microplastic particles are detected in salt, packaged drinking water
bottles and even in tea bags. These tiny particles can act as a carrier of many harmful
chemicals which can be toxic or sometimes carcinogenic to humans. Freshwater
systems are given less emphasis when it comes to the investigation of occurrence of
MPs. Till date, very few studies are done on the quantification of MPs on freshwater
systems, especially in India [7]. Most of the studies are carried out on oceans and
estuaries, and the protocols have been standardized accordingly [9–13]. However,
there is a lack of information about the standard protocols for the quantification and
identification of MPs in freshwater systems. Various studies confirmed the presence
of MPs in drinking water and bottled water, which is a major public health concern,
globally [14–16]. The presence of these microplastic particles ultimately degrades
the quality of drinking water. These freshwater systems are efficient to accumulate
a lot of MPs, however. Biomonitoring of these particles is given less attention when
V. Singh and S. Chakraborty
1 Introduction
Plastic pollution is one of the most critical and challenging issues globally. The global
production of plastics is increasing day by day due to its durability, lightweight,
economical and can be easily processed [1]. According to World Economic Forum,
plastic production in 1950 was 1.5 million tons per year, and in the year 2018, it
becomes 400 million tons per year, in which 50% of the plastics produced were singleuse plastics. Improper plastic waste disposal has now become an environmental
concern across the globe [2].
Microplastics (MPs), an emerging contaminant, are defined as the plastic particles
of size less than 5 mm with no definite lower size [3–5]. Plastic particles primarily
manufactured of size less than 5 mm are termed as primary microplastics, whereas
plastic particles which are the consequence of physical, chemical or biological interaction are termed as secondary microplastics [6]. These tiny particles are detected in
various shapes such as pellets, fragments, films, fibers, microbeads and foams, and
size ranges between 1 mm to 5 mm are termed as large MPs whereas size less than
1 mm are termed as small MPs [1]. The persistent nature of MPs makes them more
vulnerable to the environment, especially freshwater systems. In India, many cities
utilize freshwater lakes as the primary source of water consumption. If these MPs
reach the human body through water consumption, it can cause serious problems
to human health. These MPs may act as carrier of many toxic chemicals and heavy
metals, can be carcinogenic and ultimately contaminate the food web [3, 6, 7]. Some
studies reported the accumulation of pesticides, organic pollutants and biofilms on
these tiny particles [6, 7]. As far as freshwater systems are concerned, the primary
source of occurrence of MPs is the direct littering of plastic waste into these lakes
and fishing activities carried out inside these lakes. The secondary sources of these
MPs are the treated wastewater discharge, stormwater runoff or wind advection [8].
Freshwater systems are most vulnerable to the microplastic contaminants as these
tiny particles cannot be removed easily with conventional treatment from water and
the vulnerability and risks associated with microplastics are its persistent and toxic
to living beings which ultimately leads to water quality degradation. Several studies
show that these microplastic particles are detected in salt, packaged drinking water
bottles and even in tea bags. These tiny particles can act as a carrier of many harmful
chemicals which can be toxic or sometimes carcinogenic to humans. Freshwater
systems are given less emphasis when it comes to the investigation of occurrence of
MPs. Till date, very few studies are done on the quantification of MPs on freshwater
systems, especially in India [7]. Most of the studies are carried out on oceans and
estuaries, and the protocols have been standardized accordingly [9–13]. However,
there is a lack of information about the standard protocols for the quantification and
identification of MPs in freshwater systems. Various studies confirmed the presence
of MPs in drinking water and bottled water, which is a major public health concern,
globally [14–16]. The presence of these microplastic particles ultimately degrades
the quality of drinking water. These freshwater systems are efficient to accumulate
a lot of MPs, however. Biomonitoring of these particles is given less attention when