Distribution and Impact of Microplastics in the Aquatic …
87
egested and displayed more toxicity effects on growth to rotifers. Similar to the effects
on growth, the rotifer fertility rate was affected by different sizes of microbeads. Similarly, the smallest particles (0.05-μm) microbeads exerted the most toxic effects on
the fertility rate. Therefore, the findings have shown microbeads toxicity is sizedependent and lesser size microbeads were more toxic. Consequently, the 0.05μm microbeads increase reactive oxygen species (ROS) levels in the monogonont
rotifer Brachionus koreanus [64].
Likewise, the effect of PS-MPs (20-μm, and 1 mg/L) exposure on clam Scrobicularia plana were assessed for 14 days, followed by seven days of depuration. The
results revealed that PS-MP induces effects on antioxidant capacity, DNA damage,
and the nervous system [24]. In other investigations, reproductive toxicity of the
chronic exposure of 1–5 μm MP and 1–10 μm MP was assessed on Cladoceran
species (Daphnia magna, Daphnia pulex, andCeriodaphnia dubia). The results have
shown that the fertility of species dropped due to the ingestion of both size ranges of
MP. In particular, chronic exposure to concentration 10
2 –10
5 p/mL of MP impaired
reproductive output of the number of neonates by influencing brood sizes. The study
also disclosed that 1–5 μm MP particles are more toxic to the studied organisms
compared to 1–10 μm MP [65].
Similarly, the toxic effects of 0.1 μm PS beads were investigated using oceanic
planktonic crustaceans. The experimented Crustaceans species showed the accumulation of MP without causing mortality of larval stages of the species. However,
swimming activity was significantly affected in crustaceans exposed to high MP
concentrations (>1 mg/L) after 48 h. In addition, enzyme activities were meaningfully affected by all marine crustaceans due to the presence of MPs, indicating the
introduction of neurotoxic effects and induction of oxidative stress in organisms [66,
67]. Correspondingly, the toxicity of the exposure to PVC fragments concentration
of 0.2, 0.5, and 1.0 mg/L for 96 h was evaluated for fry fish. According to the whole
body histological assessment and examination of the digestive enzymes trypsin and
chymotrypsin, the activities of the enzymes increased considerably in fish exposed to
higher concentrations of PVC (0.5 and 1.0 mg/L). But no tissue damage was apparent
in other interior body parts or gills. Henceforth, The mean thickness of the fish distal
and proximal intestine increased by 73.4% and 29.1%, respectively [68].
Another impact study of phenanthrene (Phe)- loaded LDPE fragments were
conducted using juvenile African catfish (Clarias gariepinus). The virgin LDPE
concentration of 500 mg/L and 100 mg/L were exposed to the fish for 96 h. The
study showed the phenanthrene usages ominously increased the extent of tissue
alteration in the liver while reduced the transcription levels of forkhead box and
tryptophan hydroxylase in the brain of C. gariepinus. Consequently, the exposure
to either concentration of the stated MPs increased the degree of tissue change in
the liver and plasma albumin while reduced the transcription extent of tryptophan
hydroxylase. Moreover, due to the widespread of MPs and other associated pollutants in marine environments, virgin LDPE fragments can able to trigger toxicity and
modulate the harmful effects of Phe in C. gariepinus [69].
In the same manner, Yin et al. [70] also were examined the effects of PS-MPs
(1 × 10
6 microspheres/L) on the intrinsic behavior, energy reserve, and nutritional
87
egested and displayed more toxicity effects on growth to rotifers. Similar to the effects
on growth, the rotifer fertility rate was affected by different sizes of microbeads. Similarly, the smallest particles (0.05-μm) microbeads exerted the most toxic effects on
the fertility rate. Therefore, the findings have shown microbeads toxicity is sizedependent and lesser size microbeads were more toxic. Consequently, the 0.05μm microbeads increase reactive oxygen species (ROS) levels in the monogonont
rotifer Brachionus koreanus [64].
Likewise, the effect of PS-MPs (20-μm, and 1 mg/L) exposure on clam Scrobicularia plana were assessed for 14 days, followed by seven days of depuration. The
results revealed that PS-MP induces effects on antioxidant capacity, DNA damage,
and the nervous system [24]. In other investigations, reproductive toxicity of the
chronic exposure of 1–5 μm MP and 1–10 μm MP was assessed on Cladoceran
species (Daphnia magna, Daphnia pulex, andCeriodaphnia dubia). The results have
shown that the fertility of species dropped due to the ingestion of both size ranges of
MP. In particular, chronic exposure to concentration 10
2 –10
5 p/mL of MP impaired
reproductive output of the number of neonates by influencing brood sizes. The study
also disclosed that 1–5 μm MP particles are more toxic to the studied organisms
compared to 1–10 μm MP [65].
Similarly, the toxic effects of 0.1 μm PS beads were investigated using oceanic
planktonic crustaceans. The experimented Crustaceans species showed the accumulation of MP without causing mortality of larval stages of the species. However,
swimming activity was significantly affected in crustaceans exposed to high MP
concentrations (>1 mg/L) after 48 h. In addition, enzyme activities were meaningfully affected by all marine crustaceans due to the presence of MPs, indicating the
introduction of neurotoxic effects and induction of oxidative stress in organisms [66,
67]. Correspondingly, the toxicity of the exposure to PVC fragments concentration
of 0.2, 0.5, and 1.0 mg/L for 96 h was evaluated for fry fish. According to the whole
body histological assessment and examination of the digestive enzymes trypsin and
chymotrypsin, the activities of the enzymes increased considerably in fish exposed to
higher concentrations of PVC (0.5 and 1.0 mg/L). But no tissue damage was apparent
in other interior body parts or gills. Henceforth, The mean thickness of the fish distal
and proximal intestine increased by 73.4% and 29.1%, respectively [68].
Another impact study of phenanthrene (Phe)- loaded LDPE fragments were
conducted using juvenile African catfish (Clarias gariepinus). The virgin LDPE
concentration of 500 mg/L and 100 mg/L were exposed to the fish for 96 h. The
study showed the phenanthrene usages ominously increased the extent of tissue
alteration in the liver while reduced the transcription levels of forkhead box and
tryptophan hydroxylase in the brain of C. gariepinus. Consequently, the exposure
to either concentration of the stated MPs increased the degree of tissue change in
the liver and plasma albumin while reduced the transcription extent of tryptophan
hydroxylase. Moreover, due to the widespread of MPs and other associated pollutants in marine environments, virgin LDPE fragments can able to trigger toxicity and
modulate the harmful effects of Phe in C. gariepinus [69].
In the same manner, Yin et al. [70] also were examined the effects of PS-MPs
(1 × 10
6 microspheres/L) on the intrinsic behavior, energy reserve, and nutritional