Plastics and Polymers Harmfulness Assignment Sample

• Subject Name : Environmental Science

Criminal Investigation Process

Table of Contents

Claim..

Research and planning.

Rationale.

Research question.

Analysis and interpretation.

Background.

Evidence.

Limitations of evidence.

Conclusion and evaluation.

Quality of evidence.

Evaluation of the claim..

Improvements/extensions.

Bibliography.

Claim

Plastics are bad for the environment.

Research and Planning on Plastics and Polymers Harmfulness 

Rationale

The plastic waste crisis has gained a significant amount of attention in the past few decades, especially in the wake of other negative impacts of human activities on the global environment such as deforestation and climate change. While the oceans have arguably been the subject to the majority of the plastic in terms of waste, other environmental facets including the land and its subsets comprised of the flora, the fauna and human life. Micro plastics have also been a key area of contention within recent discussion in the context of how they permeate into the foods and the agricultural system over time (Rochman, 2018). Poor measures to dispose plastic by products and waste materials have also managed to create a stir, especially due to the impact of large scale industries like clothing and cosmetics on the environment in the context of plastic waste.

Statistical figures have estimated that polymers like polyethylene may take well over 1,000 years to decompose and could potentially entail a leaching effect, whereby dangerous toxins are gradually released in to the soil and water that we consume (UN Environment Programme, 2018). While the overall impact of plastic and polymers are fundamentally detrimental for the environment, the true extent of its impact can be relatively difficult to gauge in terms of quantitative data. Any attempt at establishing the objective impact that plastic waste has upon the environment would fundamentally need to break down the characteristics of polymers that lead to the harmful impacts on the environment.

Research question

The research question for the investigation has been presented below and is as follows:

1. To what extent are plastics and polymers harmful for the environment?

The review would rely upon four papers from Wright & Kelly (2017), Liu et al. (2017), Hahladakis et al. (2018) and van Emmerik and Schwarz (2019) that delve into the varying degrees of negative impacts polymers and plastics have upon the environment. The conclusions drawn within the studies along with their final outcomes would be consolidated within the current investigation to determine the extent to which plastic harms the environment. Additional references would also be incorporated into the investigation to support any arguments made in alignment with the findings and the outcomes of the aforementioned studies.

Analysis and Interpretation of Plastics and Polymers Harmfulness 

Background

Plastic as a polluter and environmental waste largely boils down to the chemical components and characteristics. While polymers such as polyethylene, polystyrene, and polypropylene are easily mouldable, there area certain group of polymers called thermosets that become immensely hard, and often in an irreversible manner. This phenomena takes place due to the covalent cross linkers within the molecular features, that go on to bridge the various polymer strands. Decomposition essentially translates into breaking the bonds into the singular atoms. However, several attempts by scientists across the world have achieved limited results in this context, especially in the commercial perspective. While some progress has been made using ZnCl₂-ethanol catalysts at 250 ºC, the large scale commercialization of the process is far from a reality (Lemonick, 2018). The cross linkers within plastics contribute towards the inability of environmental factors to decompose the polymers, which then go on to act as leaches that push out dangerous toxins into the air and water. Similarly, a number of alternatives have also been in development, with the most prominent being the vitrimers and lignins based on eugenols.

Evidence

Authors van Emmerik & Schwarz (2020) take on a quantitative approach to assess the impact of plastic waste materials on riverine bodies through relatively accurate modelling systems. They tabulate the data from a number of journals and peer reviewed publications and depict the major harms of plastic debris as a waste material with an emphasis on water bodies. The harmful impacts were primarily categorized into five categories comprising ingestion of the plastics entanglement, release of toxic additives and compounds, the breakdown of the fibres into micro plastics and the cumulative impact on human livelihood. Based on the density of the plastic, ingestion and entanglement were found to impact a large number of animals, both on the land as well as water. Gut obstruction was the primary impact in terms of how it impacted these animals and fishes, where the prevalence was primarily established within low trophic species. The rates of ingestion cumulatively exceeded beyond 33%.

The data on chemical leaching was also largely aligned with the agricultural impacts of plastics, while microfibers and the breaking down of the bonds into the micro plastics were stated as suffering from limited data sets (van Emmerik & Schwarz, 2020). In terms of the impacts on human livelihood, an increase in flood risks was identified. Accumulation in plastic levels was linked to rapid growth ofthe water levels along with the risks of drainage systems and canals. 

The impact of polymers on human health was extensively discussed in the publication authored by Wright & Kelly (2017). Based on primary research measures as well as a substantial amount of secondary data collection, the article mentioned that the key risk that humans suffered from in terms of plastic waste was the threat of accumulation. Lungs and the gastro intestinal tracts were identified as the regions that were the most prone to plastic accumulation. Studies also showed that the average human consumption was roughly 40 mg/person/day (Wright & Kelly, 2017).

Several factors were also determine by the authors in terms of establishing the rate of uptake, with the most prominent being the surface functionalisation and surface charge. The protein corona and the hydrophobicity were also identified as key drivers in higher rate of uptakes along with the size and scale of the micro plastic.

The breaking down of plastic was also studied extensively within one of the publications. Authors Liu et al. (2017) took on a experimental approach where different epoxies were tried to be broken down using different catalysts including ZnCl2/water, Phosphotungstic acid (HPW)/water, Phosphotungstic acid (HPW)/ethanol, Tungstosilicic acid/water and Phosphomolybdic acid/water. The results showed that the general break down temperate was roughly 190 °C and would have to be maintained constantly for a minimum of 5 hours in the presence of the catalysts.

While epoxies are not generally found in the environment, the recycling approach that the authors took depict that the temperatures and the catalysts that are required for the breaking down are certainly aligned with the difficulty in decomposition for polymers. Moreover, epoxies are considered as one of the weaker polymer bonds that exist within plastics. Typical polymers that are found in the environment including thermo plastics would therefore require higher temperatures and durations of exposure in terms of the decomposition.

Lastly, the authors Hahladakis et al. (2018) tested the disposition of plastic compounds and micro plastics from the environment into common elements consumed by humans. The key areas of tests included the migration of Phthalate esters comprised of DMP, DEP, BBP, DBP, DEHP, DINP, DOP, and DIDP and how the bonds managed to remain associated with cooking oil and mineral water. The storage times that were tested for the purposes of the experiment roughly went up to 2 months and included static as well as dynamic conditions. In terms of the results, the PAE content was consistently found to be higher in the oil as compared to the mineral water. The highest levels of disposition and migration was depicted by DEHP and DBP, which was found to remain within the oil at 20 °C even after a period of 2 months (Hahladakis et al. 2018). The conclusions showed that a dynamic process was far more favourable for the migration of the plastic compounds into common human consumption liquids as opposed to a static process.

Limitations of evidence

The limitations of the evidence were primarily related to the limited area of testing in terms of the common polymers that are found within the environment. Furthermore, the consumption aspect and how the polymers manifested within different environmental settings in different conditions were also overlooked in some of the publications. Water bodies and human consumption were the key areas of the studies, albeit certain alignments were present where the drainage into agricultural systems was discussed to some extent.

Conclusion and Evaluation on Plastics and Polymers Harmfulness 

Quality of evidence

The four papers chosen comprehensively show varying impacts that polymers and plastic compounds have on the environment from a varying degree of perspectives. All the publications were peer reviewed and published in reputed journals, which enhances the credibility of their findings. In terms of the quality of the findings, the fact that plastic is hard to break down was distinctly quantified by Liu et al. (2017). The negative impacts of polymers and how they continue to remain within water bodies over prolonged period was established by van Emmerik & Schwarz (2020). Human consumption of plastic is also a pressing issue faced in the modern near, especially since the polymers break down into micro fibres and micro plastics. Authors Wright & Kelly (2017) depict how the lungs and the gastro intestinal tracts suffer from plastic accumulation over time. However, the paper does not study the accumulation percentages and the levels of disposition on other organs and parts ofthe body, which does limit the conclusiveness of the findings to some extent. Authors Hadlakis et al. (2018) state how the drainage of plastic compounds occurs into the major human consumption elements such as mineral water and cooking oil. However, the study limits its approach to these two substances, and the study could have included a variety of other elements to progressively improve the assertion of the findings.

Evaluation of the claim

Based on the presentation of evidence in the aforementioned papers and the discussion included therein, the claim that plastics and polymers are bad for the environment could be firmly be asserted. The study includes a range of different aspects ranging from the impact of polymers on water systems and human consumption along with the difficulties faced in breaking down and decomposing the bonds within polymers found in the environment.

Improvements/extensions

The questions to what extent are plastics and polymers bad for the environment could certainly be improved upon in future studies with a seamless integration of the various elements of the environment that range beyond water systems and human consumption. Statistical methods could also be relied upon in this regard to clearly present the correlation between the presences of different polymers within different environmental settings, while the variables could include the time required for decomposition and degradation under normal circumstances. The aspect of human consumption could also be expanded into how polymers accumulate over time and what is the manner of disposition.

Bibliography for Plastics and Polymers Harmfulness 

Hahladakis, J, N, Velis, C, A, Weber, R, Iacovidou, E, & Purnell, P, 2018, ‘An overview of chemical additives present in plastics: migration, release, fate and environmental impact during their use, disposal and recycling’, Journal of hazardous materials, 344, pp.179-199, <https://www.sciencedirect.com/science/article/pii/S030438941730763X>

Lemonick, S, 2018, ‘Chemistry may have solutions to our plastic trash problem’, <https://cen.acs.org/environment/pollution/Chemistry-solutions-plastic-trash-problem/96/i25>

Liu, T, Guo, X, Liu, W, Hao, C, Wang, L, Hiscox, W, C, Liu, C, Jin, C, Xin, J, & Zhang, J, 2017, ‘Selective cleavage of ester linkages of anhydride-cured epoxy using a benign method and reuse of the decomposed polymer in new epoxy preparation’, Green Chemistry, 19(18), pp.4364-4372, < https://www.researchgate.net/profile/Cheng_Hao12/publication/318854424_Selective_cleavage_of_ester_linkages_of_anhydride-cured_epoxy_using_a_benign_method_and_reuse_of_the_decomposed_polymer_in_new_epoxy_preparation/links/59e53107aca272390ed64616/Selective-cleavage-of-ester-linkages-of-anhydride-cured-epoxy-using-a-benign-method-and-reuse-of-the-decomposed-polymer-in-new-epoxy-preparation.pdf>

Rochman, C, M, 2018, ‘Microplastics research—from sink to source’, Science, 360(6384), pp.28-29, <https://waterguardianexperts.thewaternetwork.com/storage/TFX%5CDocumentBundle%5CEntity%5CDocument-GcYotvrfjs-4KO0iKt5EmA/aLs4p-6kP-DYBqA1GLGQeQ/file/Microplastics%20research%E2%80%94from%20sink%20to%20source.pdf>

UN Environment Programme, 2018, ‘Plastic planet: How tiny plastic particles are polluting our soil’, <https://www.unenvironment.org/news-and-stories/story/plastic-planet-how-tiny-plastic-particles-are-polluting-our-soil>

van Emmerik, T, & Schwarz, A, 2020, ‘Plastic debris in rivers’, Wiley Interdisciplinary Reviews: Water, 7(1), p.e1398, https://onlinelibrary.wiley.com/doi/pdf/10.1002/wat2.1398

Wright, S, L, & Kelly, F,J, 2017, ‘Plastic and human health: a micro issue?’, Environmental science & technology, 51(12), pp.6634-6647, < https://www.researchgate.net/profile/Stephanie_Wright6/publication/317078116_Plastic_and_Human_Health_A_Micro_Issue/links/59c138d40f7e9b21a8265428/Plastic-and-Human-Health-A-Micro-Issue.pdf>

Remember, at the center of any academic work, lies clarity and evidence. Should you need further assistance, do look up to our Environmental Science Assignment Help