Distribution and Impact of Microplastics in the Aquatic …
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leads to a reduction in body size and the overall quantity of neonates. In addition,
abnormal swimming behavior was only observed in C. dubia exposed to polyester
fibers, with their movement often inhibited as a result of entanglement in twisted
fibers. Particularly, reduced reproduction and growth are associated with the inability
to tolerate fibers in the environment, loss of energy to physical contact with fibers
during chronic exposure to fibers [74].
Further study was also carried out to examine the toxicity of MPs ingestion
by amphipod, exposed to polyethylene (PE) particle and polypropylene (PP)
microfibers of 0–20,000 d/mL for 10 and 42 days of exposure. The 10-days toxicity
of PP MPs fibers was significant than PE MPs particles. In addition, chronic
exposure (42-days) of PE particle and PP fibers in the same concentration had
shown decreased growth and reproduction at the low and intermediate exposure
concentrations. But, MPs fibers had higher toxicity than MPs particles due to the
longer residence time accumulation of fibers in the gut. Consequently, the variance
in residence time could affect the capability to process food, ensuing in an energetic
effect revealed in sublethal endpoints [75]. Likewise, the effect of PE MPs ingestion
on the freshwater cnidarian, Hydra attenuata at different concentrations (0.01, 0.02,
0.04, and 0.08 g/mL) were evaluated. The results of the study [76] demonstrated that
Hydra attenuata ingest exposed MP. Accordingly, a significant decline in feeding
rates was observed after half an hour and 1 h MPs exposures. Therefore, the exposure
to the MPs produced remarkable alterations to the morphology of Hydra attenuata,
however, these alterations were non-lethal [76]. In other investigations, physical
adsorption of PS was studied on freshwater primary producers such as Chlorella sp.
and Scenedesmus sp. The adsorption was found diligently to favor positive charges
over negatively charged plastic beads as a result of the electrostatic attraction
among the beads and the cellulose component of the living systems. As a result,
photosynthesis Nano-MPs adsorbed on Chlorella and Scenedesmus from physical
blockages on light, air, and CO 2 depletion. Furthermore, adsorbed PS beads on
algae hinder photosynthesis and promote the generation of reactive oxygen species
[77]. Correspondingly, the toxicity of Nano-polystyrene (nano-PS) was evaluated
for the green alga Scenedesmus obliquus and the zooplankton, Daphnia magna.
Evidence has shown that nano-PS reduced growth and chlorophyll concentrations
in the algae [78]. Similarly, nano-PS triggered a reduction in body size and severe
modifications in the reproduction systems of Daphnia sp. The quantities and body
size of neonates rose to 68% of the entities. Furthermore, the survival of Daphnia
was reduced with an average of 27% mortality and 11% reduction in Daphnia body
size upon exposure to MP concentration in a range of 0.22 to 103 mg nano-PS/L.
The presence of such a concentration of nano-PS leads to life-history changes in
aquatic organisms such as algae and Daphnia [78].
89
leads to a reduction in body size and the overall quantity of neonates. In addition,
abnormal swimming behavior was only observed in C. dubia exposed to polyester
fibers, with their movement often inhibited as a result of entanglement in twisted
fibers. Particularly, reduced reproduction and growth are associated with the inability
to tolerate fibers in the environment, loss of energy to physical contact with fibers
during chronic exposure to fibers [74].
Further study was also carried out to examine the toxicity of MPs ingestion
by amphipod, exposed to polyethylene (PE) particle and polypropylene (PP)
microfibers of 0–20,000 d/mL for 10 and 42 days of exposure. The 10-days toxicity
of PP MPs fibers was significant than PE MPs particles. In addition, chronic
exposure (42-days) of PE particle and PP fibers in the same concentration had
shown decreased growth and reproduction at the low and intermediate exposure
concentrations. But, MPs fibers had higher toxicity than MPs particles due to the
longer residence time accumulation of fibers in the gut. Consequently, the variance
in residence time could affect the capability to process food, ensuing in an energetic
effect revealed in sublethal endpoints [75]. Likewise, the effect of PE MPs ingestion
on the freshwater cnidarian, Hydra attenuata at different concentrations (0.01, 0.02,
0.04, and 0.08 g/mL) were evaluated. The results of the study [76] demonstrated that
Hydra attenuata ingest exposed MP. Accordingly, a significant decline in feeding
rates was observed after half an hour and 1 h MPs exposures. Therefore, the exposure
to the MPs produced remarkable alterations to the morphology of Hydra attenuata,
however, these alterations were non-lethal [76]. In other investigations, physical
adsorption of PS was studied on freshwater primary producers such as Chlorella sp.
and Scenedesmus sp. The adsorption was found diligently to favor positive charges
over negatively charged plastic beads as a result of the electrostatic attraction
among the beads and the cellulose component of the living systems. As a result,
photosynthesis Nano-MPs adsorbed on Chlorella and Scenedesmus from physical
blockages on light, air, and CO 2 depletion. Furthermore, adsorbed PS beads on
algae hinder photosynthesis and promote the generation of reactive oxygen species
[77]. Correspondingly, the toxicity of Nano-polystyrene (nano-PS) was evaluated
for the green alga Scenedesmus obliquus and the zooplankton, Daphnia magna.
Evidence has shown that nano-PS reduced growth and chlorophyll concentrations
in the algae [78]. Similarly, nano-PS triggered a reduction in body size and severe
modifications in the reproduction systems of Daphnia sp. The quantities and body
size of neonates rose to 68% of the entities. Furthermore, the survival of Daphnia
was reduced with an average of 27% mortality and 11% reduction in Daphnia body
size upon exposure to MP concentration in a range of 0.22 to 103 mg nano-PS/L.
The presence of such a concentration of nano-PS leads to life-history changes in
aquatic organisms such as algae and Daphnia [78].