Microplastics: A Risk-Benefit Analysis
Olayinka Ajumobi-obe
Department of English, City College of New York
ENGL 21003: Writing for the Sciences
Prof. Katelyn Conroy
4/05/2022
Abstract
Plastic is a useful cost-effective lightweight durable material that’s very versatile but a large
amount of unrecycled plastic ends up in our oceans and fragments into microplastics. Plastic
pollution and microplastic contamination of the marine food chain can harm our ecosystem and
become a potential health crisis. This review was to answer the question of whether the benefits
that plastic provides outweigh the potentially harmful effects of plastic on our ecosystem and
health? A literature review was conducted with the thematic analysis regarding microplastic’s
effect on the marine food chain, individual organisms, its presence, and effect on humans as well
as the benefits of plastic to our society. Microplastic accumulation has been shown to lower fish
mortality and interfere with metabolism. Cell studies show implications that microplastics and
their additives have the potential to harm human reproductive health, cause disruption of
hormones and take part in the development of cancers. From our research, it appears that our
current use of plastic is a net negative to society. While plastic has an important role in a diverse
number of industries we need to recycle our plastic more efficiently while lowering our use of
consumer single-use plastic along with better waste management systems. We must also push for
technological innovations of biodegradable plastic-like materials and methods to dispose of
plastic without contributing to other forms of pollution or climate change.
Background
Plastic pollution has shown to be a persistent and growing topic as part of an ongoing
discussion of our negative impact on the environment. Researchers have recently been
investigating the effects of the disposal of plastic waste on the ecosystem and are now concerned
about a potential health crisis. Plastic pollution is the accumulation of plastic buildup in a natural
environment. From 1950 to 2015-2017 Bhuyan, Thompson, and Cverenkárová state the annual
production of plastic has grown from between 0.5 and 2 million tonnes in 1960 (Bhuyan, 2022;
Cverenkárová et al., 2021; Thompson et al., 2009) to 320 million tonnes in 2017 (Wright &
Kelly, 2017). Cverenkárová states over 79% of the 6300 million tonnes of plastic waste have not
been recycled or incinerated but instead placed in landfills or just left in the environment
(Cverenkárová et al., 2021). Plastic biodegradation takes hundreds to thousands of years to
complete leaving plenty of time for un-recycled waste to transfer from land to waterways with a
report of 8 million tonnes of plastics entering the seas and oceans every year (Cverenkárová et
al., 2021).
Marine plastic debris weathers and erodes into smaller fragments of pollutants called
microplastics. According to Wright and Bouwmeester, microplastics are defined as 0.1 um to
1000 um of plastic particles from larger fragments turned brittle from UV light then eroded by
wind and wave abrasion (Wright & Kelly, 2017; Bouwmeester et al., 2015); They both also
classified particles even smaller than 100 nm as nano plastics (Wright & Kelly, 2017;
Bouwmeester et al., 2015). Common sources of microplastic pollutants found near waterways,
beaches, and the ocean are fishing equipment, plastic bags, bottles, food, and drink containers
(Bhuyan, 2022; Cverenkárová et al., 2021). Microplastics are also purposefully manufactured for
various applications, such as exfoliants in personal care products such as facial cleansers,
toothpaste, cleaning agents, clothing fibers (Wright & Kelly, 2017), and used as drug vectors in
the field of medicine (Bhuyan, 2022). The presence of microplastic in the environment has raised
the concerns of researchers leading investigations to find the extent of microplastics’ reach into
the ecosystem.
Microplastic has been found to contaminate a wide range of marine life (Cverenkárová et al.,
2021; Wright & Kelly, 2017; Bouwmeester et al., 2015). Marine microplastic can share similar
characteristics to planktonic species leading to an accumulation of microplastics in the digestive
system of fish and the animals that prey upon them including humans (Bhuyan, 2022).
Researchers were able to disturbingly link the presence of microplastics discovered in nature and
the particles found in humans. There has been emerging research on the biological effects of
plastic on humans and wildlife.
While the prevailing reach of plastic pollution does give reason to worry, we must also consider
the risk of ending the use of plastic in society; one can say that plastic has provided numerous
benefits to our society to warrant its abundant use in most industries. The implications of
microplastic’s potential danger provides a call of action to do an investigation. The goal of this
writing is to review the current literature on plastic pollution in regard to microplastics and to
determine if the benefits that plastic provides outweigh the potentially harmful effects of plastic
on our ecosystem and health?
Methods
To find answers to our question of whether our current use of plastics is net positive for our
society we had to conduct a systematic literature review. We looked through multiple findings in
regards to microplastics, and their effect on the marine food chain and on human health; since
this literature review is presented as an analysis of the risk to benefits of plastic a search was also
conducted for its industrial utility. The studies were filtered through a thematic analysis of the
topics mentioned above.
Results
- Microplastics’ Presence in the Marine Food Chain
Microplastics’ major presence in marine environments gave researchers a good reason to look
into the extent of microplastic exposure to marine life and its effect on the food chain. According
to Bhuyan, Bouwmeester, and Cverenkárová microplastics have been found in a wide variety of
Marine life from animals at the base of the food chain such as zooplanktonic organisms to higher
trophic vertebrates and invertebrates like fish, marine mammals, and seabirds (Bhuyan, 2022;
Bouwmeester et al., 2015; Cverenkárová et al., 2021). Cverenkárová states that filter feeders are
particularly vulnerable to microplastic exposure (Cverenkárová et al., 2021) but Bouwmeester
claims that mussels, scallops, and other bivalves are able to select particles for uptake and thus
can potentially reject larger particles (Bouwmeester et al., 2015). Microplastics are capable of
“moving up” the food chain leading to the accumulation of plastic fragments and particles in the
gastrointestinal system of larger predatory fish causing intestinal obstructions, dietary, and
development changes leading to frequent death of fish before reaching maturity (Bhuyan, 2022).
The symptoms of microplastic exposure discussed here may be observable in marine wildlife but
to get a full scope of microplastic biochemical effect on organisms needs to be done in a
laboratory environment to isolate any interfering factors found in nature. - Research on Microplastic’s Effect on Organisms
Researchers were able to find the damaging effects of plastic on biological systems in a
laboratory setting. Bhuyan, Bouwmeester and Cverenkárová, report the negative impacts of
microplastics in animal and cell studies (Bhuyan, 2022; Bouwmeester et al., 2015; Cverenkárová
et al., 2021). Bhuyan states microplastic accumulation in zebrafish can cause “oxidative stress,
decreased mobility, gene expression disruption and damage of reproductive organs” and gilt-head
bream expressed signs of “Behavior changes and damage of immune system’s key
functions”(Bhuyan, 2022). Bouwmeester states that less than 1% of microplastics are absorbed in
rodent and in vitro studies and will hardly enter organs from blood circulation but nano plastics
may have a deeper reach based on studies following the effect of gold nanoparticles on rodents
(Bouwmeester et al., 2015). Cverenkárová states nanoplastics have a high risk of crossing the
blood-brain barrier (Cverenkárová et al., 2021). Most of the damage from microplastics is
localized and can be cytotoxic from oxidative stress as seen in vitro studies (Bhuyan, 2022;
Bouwmeester et al., 2015; Cverenkárová et al., 2021). Bhuyan states that microplastics can either
directly “influence metabolism by altering metabolic enzymes or circuitously by upsetting the
energy equilibrium” (Bhuyan, 2022, Pg.6). These studies show the biochemical effects of
microplastics centers around oxidative stress and inflammation of cells exposed to microplastics. - Human Exposure to Microplastics and Potential Effects
The effect of plastic on human health is of concern and interest to researchers focused on the
effect of microplastics. the effect of plastic on human health. According to Bhuyan,
Bouwmeester, Cverenkárová, and Wright a major part of humans’ exposure to microplastics is
through the consumption of seafood (Bhuyan, 2022; Bouwmeester et al., 2015; Cverenkárová et
al., 2021; Wright & Kelly, 2017) along with claims that plastic fibers were also found in honey
(Cverenkárová et al., 2021; Wright & Kelly, 2017) and found in bottled and tap water (Bhuyan,
2022; Cverenkárová et al., 2021), sugar, and beer (Bouwmeester et al., 2015; Cverenkárová et
al., 2021). Wright states, that while there was no direct link to lung cancers, can be made, nylon
manufacturing workers had a higher prevalence of lung irritation with interstitial lung disease a
condition where coughing, breathlessness, and reduced lung capacity were common was found in
4% of workers (Wright & Kelly, 2017). Bhuyan states that additive chemicals leached from
plastics such as ”persistent organic pollutants (POPs) and phthalates, bisphenol A (BPA),
bisphenone, triclosan, organotin, and brominated flame retardants” (Bhuyan, 2022, pg.8) are
associated with harmful effects like BPA ability to damage the endocrine system Possibly
explaining a negative correlation between an increase in BPA concentration in urine and
decreasing testosterone levels in adult men along with associated weight gain(Bhuyan, 2022).
Microplastics can possibly serve as vectors for diseases(Bhuyan, 2022; Cverenkárová et al.,
2021; Wright & Kelly, 2017) and heavy metals (Wright & Kelly, 2017). The localized oxidative
stress that microplastics produced in the body can possibly be linked to the impairment of
metabolic activity in the brain and also the creation and development of a variety of cancers
(Bhuyan, 2022). These studies show that our current handling of plastic waste comes with
potential a price on our health. - Societal Benefits of Plastic
After discussing all the harmful effects that plastic can do on biological organisms an apparent
solution that comes to mind is to simply cease our use of plastic immediately. We must look over
our current utility of plastic and the potential downsides of its removal before condemning the
material. Bhuyan, Cverenkárová, Thompson, and Wright can all agree that plastic is a useful
material to society(Bhuyan, 2022; Cverenkárová et al., 2021; Thompson et al., 2009; Wright &
Kelly, 2017). Bhuyan, Cverenkárová, Thompson details the benefits of plastic as being
inexpensive, light, and durable(Bhuyan, 2022; Cverenkárová et al., 2021; Thompson et al., 2009;
Wright & Kelly, 2017). Thompson also adds that plastic can be corrosion-resistant and have
“high thermal and electrical insulation properties”(Thompson et al., 2009, p1). Plastics as a
material is vast both in the diversity of its polymers and in their versatility of
applications(Thompson et al., 2009, p3). Plastics’ daily utility can be found “in transport,
telecommunications, clothing, footwear and as packaging materials that facilitate the transport of
a wide range of food, drink, and other goods” (Thompson et al., 2009, p3) and can have potential
utility in novel medical and scientific applications (Thompson et al., 2009). The immediate end
of the use of plastic could cause an increase in food waste due to a decrease in shelf life and
could contribute to climate change. Without plastics, many Industries will be found wanting
materials with similar properties and versatility and currently, researchers are looking for an
eco-friendly replacement for that need.
Discussion
Hence, it appears that plastics’ benefit to society may not outweigh their negative effect on the
environment and ecosystem. The looming threat that is the current contamination of
microplastics in our major food sources and drinking water requires immediate action alongside
intelligent planning. A large majority of marine life is affected by microplastics due to its vertical
transfer in the food chain and while some species like certain bivalves may be able to filter out
larger particles nanoparticles are still a danger to these organisms leaving room for ecological
disruption and potential shortages of certain species as well as leaving those who regularly
consume seafood particularly vulnerable to the exposure of microplastics. Recently most
researchers are currently using human cell models and animals to predict the long-term effect of
microplastics. While larger microplastics aren’t able to fully penetrate organs they are still able to
cause oxidative stress locally which can become cytotoxic and carcinogenic and especially
alongside plastic additives. Plastic can be seen as a cornerstone material to our society but we
must push for more responsible use and handling of plastic. Since it takes a long time to break
down we must reconsider if it needs to be used for single-use consumer goods like fast food
containers and shopping bags. Bhuyan stated that 79% of plastic is not recycled so we must push
for the number to be lower (Bhuyan, 2022). We must reevaluate our use of plastic from the top
down; corporations must responsibly manufacture plastics that have minimal impact on the
environment and push for waste management to have easier recycling systems for consumers.
Until we can have truly biodegradable plastic that’s able to replace our current use of single-use
we must develop technology that’s capable of disposing of unrecyclable plastic without
contributing to additional harm to our environment. We will be interested in future human studies
that take a deeper look into the correlation between a high concentration of micro/nano plastics
and additives in the body and their associated diseases.
References
● Bhuyan, M. S. (2022). Effects of microplastics on fish and in human health. Frontiers in
Environmental Science, 10. https://doi.org/10.3389/fenvs.2022.827289
● Bouwmeester, H., Hollman, P. C., & Peters, R. J. (2015). Potential health impact of
environmentally released micro- and Nanoplastics in the human food production chain:
Experiences from Nanotoxicology. Environmental Science & Technology, 49(15),
8932–8947. https://doi.org/10.1021/acs.est.5b01090
● Cverenkárová, K., Valachovičová, M., Mackuľak, T., Žemlička, L., & Bírošová, L.
(2021). Microplastics in the food chain. Life, 11(12), 1349.
https://doi.org/10.3390/life11121349
● Thompson, R. C., Moore, C. J., vom Saal, F. S., & Swan, S. H. (2009). Plastics, the
environment and human health: Current consensus and future trends. Philosophical
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https://doi.org/10.1098/rstb.2009.0053
● Wright, S. L., & Kelly, F. J. (2017). Plastic and human health: A micro issue?
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https://doi.org/10.1021/acs.est.7b00423
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