Abstract
In an industrialized world, it seems impossible to live without plastics. From food storage to aircrafts, plastics provide benefits that make them an irreplaceable material. However, a consistent increase in plastic production and use has led to a massive plastic pollution crisis. Plastics are produced from non-renewable resources and can never fully decompose. They end up in our oceans, our environment, and even our stomachs (a credit card’s worth per week). Additionally, the massive amount of plastic waste has created a global plastic trade that unfairly places the burden of waste processing on less developed countries that may not be able to support even their own waste. The effects of plastic pollution are reaching a critical stage, and engineers must find solutions to relieve the growing pressure.
Introduction
By 2050, our oceans may contain more plastic than fish by weight. This estimate from the Ellen MacArthur Foundation is based on the current rate of 8 million metric tons of plastic that leak into the ocean each year [1]. These plastics continue to accumulate because they never truly decompose, even over hundreds of years, making the act of plastic production a formidable environmental threat [2]. Yet everywhere you turn, there is some kind of plastic product in use. This is ultimately because of the wide range of material benefits unique to plastics. From food packaging to spacecraft, plastics have been integrated into daily life because they are versatile, lightweight, and durable. Nevertheless, engineers must investigate our global use of plastic to determine the ethicality of the plastic industry.
From raw material to disposal, every stage in the lifespan of plastic has an environmental effect. Even outside of the environmental scope, current plastic engineering practices violate ethical principles like fairness and the common good. While plastic is a major pollutant that impacts the environment and disproportionally affects poorer areas, it is unrealistic to expect a world completely without plastics. To address these ethical issues, engineers must seriously consider solutions such as recycling and utilizing sustainable raw materials, as well as new systems that benefit the environment and the global population.
Relevant Ethical Approaches
In the field of engineering, several ethical frameworks can be harnessed to evaluate the ethicality of our work. The engineering of plastic is no different: the lenses of the common good, fairness, and the environment are all significantly applicable.
The driving force in many ethical frameworks is consequentialism, in which the ethical value of an action is determined by the consequences of that action. The most popular application of this theory is utilitarianism, where the most ethical decision is one which results in the greatest good for the greatest number of people [3]. In essence, this method of ethical analysis dissects the pros and cons of a decision and quantifies its impact. Before applying this framework, though, the definition of utilitarianism requires a definition of what “good” is, as well as who is considered equal in the overall pro-con sum. Such questions are addressed in the common good and the justice and fairness approaches.
The “common good” is a well-known but broad concept. In the most general sense, common good refers to “facilities” that a few members of a community supply to serve the needs of the entire community [4]. Popular examples are services such as universal healthcare or public transportation. Decisions that align with the common good are inherently aligned with the utilitarian approach, as they both attempt to benefit the most people. However, common good reasoning is more particular; in the common good, a decision that hurts few at the benefit of many is not ethical, while utilitarianism may reason that the same decision is ethical given the larger number of beneficiaries.
While the common good approach defines “good,” the justice and fairness approach defines equality among all people as an ethical truth. The ultimate goal of the justice and fairness approach is to ensure that all people are treated equitably and that there are systems in place that reinforce this principle. This extends to the equitable distribution of “benefits and burdens.” For justice and fairness, equitable systems are more effective than equal systems, as equitable practices take into account the existing inequalities between people, such as socioeconomic class [5]. These ethical principles are usually applied to human-human interaction, but they are also relevant to the ethical standing of plastic.
Environmental ethics considers the relationship humans should have with the environment, emphasizing the protection and sustainable use of natural resources. Within environmental ethics, there are two competing schools of thought: anthropocentrism and physiocentrism. Anthropocentrism focuses on the ethical rights of humans, while physiocentrism also considers the rights of natural entities beyond human beings [6]. Ultimately, who and what deserves rights is subjective, but the physiocentric view of environmental ethics is the most general, placing importance on Earth as a whole, with all living things considered valuable and deserving of rights. Environmental ethics is perhaps the most significant concern when discussing the ethics of plastic production and consumption, as it affects greenhouse gas balance, marine environments, and human health. To truly understand the impact plastics can have on all these areas, we must track plastic over its lengthy lifetime.
The Current State of Plastic
Commercial plastics have seen an exponential increase in production since their development as a military resource in the 1950s. Between 1950 and 2015, it is estimated that 7.8 billion metric tons of plastic were produced, with half of that number from just the last thirteen years of the period [7]. The extreme popularity of plastic is no surprise; it is cost-effective, easily moldable, waterproof, and chemically inert. The coronavirus pandemic in particular has emphasized the importance of single-use plastics to eliminate the need for sterilization and prevent cross-contamination [8]. Commercially, plastics do provide several environmental benefits as well. In transportation, plastic is used in place of metals to decrease weight and subsequently decrease fuel costs and emissions. Plastic packaging adds relatively little mass to a product while maintaining durability, and plastic is extremely effective in preserving perishable items, preventing product waste [9]. These positive aspects contribute to plastic’s commercial longevity. Unfortunately, while plastics have a multitude of benefits, their production and disposal can lead to environmental harm.
Plastic: Raw Materials and Disposal
Even in the raw material stage, plastics contribute to significant environmental damage. A majority of plastics are produced using ethane, one of several hydrocarbons included under the general definition of natural gas [10]. Fracking has provided an effective method to extract natural gas from the earth, and as natural gas becomes cheaper to extract and refine, so do the plastic products derived from it. Natural gas is seen as a “cleaner” alternative to crude oil and coal and is an abundant resource that could encourage economic growth. However, several studies have shown that fracking may contaminate groundwater and release methane into the atmosphere, possibly affecting drinking water reservoirs and increasing global warming [11]. While there may not be a definitive answer on whether fracking is an ethically sound practice, the potential environmental risks alone should prompt research into alternative raw materials. In its current state, the plastics industry helps fuel the high demand for natural gas, a non-renewable resource.
The environmental harm of plastic does not end after production. Once plastic enters landfills, a multitude of environmental issues arise. In the U.S. alone, 35.7 million tons of plastic were produced in 2018, and 75.6% of that plastic was landfilled [12]. The sheer amount of plastic that is created and disposed of each year results in large parts of Earth being covered in plastic waste. Perhaps the most notorious example is the Great Pacific Garbage Patch, a shifting mass of trash located in the Northern Pacific Ocean. This “patch” is actually closer to an island – it weighs approximately 79 thousand metric tons, 90% of which is plastic [13, 14].
Plastic debris disrupts every level of our marine environment. Macroplastics such as plastic bags are consumed by larger animals, or entangle and suffocate marine life. Subsequently, since plastics never truly degrade, they simply break down into smaller pieces, resulting in micro and even nanoplastics [7]. Because these plastics are so small (<5mm), they are easily consumed by marine life as minuscule as plankton, the backbone of many complex marine food chains. If animals aren’t killed by the poisonous chemical additives in the plastic they consume, it fills up their digestive systems with indigestible material, creating a false feeling of satiation. This leads to a nutritional deficit and eventually death for animals up and down the food chain [13].
The drastic effect human plastic waste has on the environment raises questions about environmental rights: what are the rights of environmental entities, and what is our obligation to protect those rights? From a physiocentric perspective, the answer is clear. While the scope of living organisms ranges dramatically, there is inherent value in all living things, even if they do not benefit human beings. The value of the environment for its own sake is reason enough to take action against the ever-growing problem of plastic waste, especially when the only clear benefit to the current waste system is economic savings.
From a physiocentric perspective, plastic pollution in the ocean is a deep violation of marine rights. But even from an anthropocentric view, humans are not shielded from plastic pollution. Many microplastics end up in the fish we eat, the sea salt we use, and most significantly in the water we drink. A study commissioned by the World Wide Fund for Nature (WWF) found that, on average, a person ingests a credit card’s worth of plastic in one week [16]. This does not include the multitude of microplastics inhaled from the atmosphere, such as synthetic rubber tire particles released from vehicle wear and tear. This constant intake of microplastics may result in gastrointestinal damage, respiratory impairments, neurotoxicity, and even cancer [17]. While there are geographical variations in the amount of plastic consumed per person, pollution has grown to such an extent that contaminated water systems are nearly unavoidable. Ignoring the destruction of marine environments is not only environmentally unethical, but also detrimental to the common good.
The environmental strain and sheer volume of plastic waste have led to the worldwide plastic waste trade. The distribution of plastic waste raises questions of fairness, especially for those who live in areas that house waste from more than just their own country. One nation with many of those areas is China. For nearly 30 years, China was the largest importer of plastic waste, taking in 8.88 million tons annually [18]. However, in 2017, China implemented a ban on plastic waste imports due to massive waste mismanagement. Many wealthy countries then diverted their exports to other poorer countries. The United Kingdom, for example, now exports much of its waste to Malaysia, Turkey, and Indonesia [19]. Plastic waste disproportionately affects poorer countries with less sophisticated infrastructure that may not be able to handle their own waste. On top of the aforementioned health effects of plastic pollution, residents of these nations are subjected to harmful disposal practices outside of their control. In Malaysia, the overwhelming amount of plastic taking up land leads some companies to resort to illegal incineration practices, which in turn results in a higher rate of respiratory issues for locals [20, 21].
The United States is by far the largest producer of plastic waste, but it bears very little of the waste burden compared to countries like Malaysia. Waste-importing countries are protected from contaminated waste imports but have otherwise limited ways to deny plastic imports if they wish to maintain trade income [21]. The economic reality is that many recycling operations in Malaysia can turn a profit by using cheap labor to produce recycled pellets, then reselling the recycled plastic to other countries [22]. However, the amount of plastic recycled this way is tiny compared to the amount left to languish in landfills. This unfair distribution of the burden of plastic is in direct violation of ethical principles of justice and fairness and has negatively affected the health and wellbeing of hundreds of thousands of people for the sake of those living in developed countries. Although the global plastic trade benefits more people than it harms in terms of population, we must also consider the severity of the consequences. Convenience for many does not outweigh the health of one. If engineers are not able to find more efficient and safe ways to process plastic waste, those living in less wealthy countries are unfairly saddled with millions of tons of plastic from around the world.
The Problem of Recycling
Plastic provides essential material advantages as long as it is used properly. Furthermore, engineers can improve and implement processes that decrease plastic waste and increase safe disposal. In theory, the reuse and recycling of plastic reduce the need for virgin plastic production, subverting the use of natural gas as a resource altogether, and keeping plastic out of landfills where it would not be able to decompose. While these concepts are well established, they have not been effectively put into practice, and their environmental benefits are not as straightforward as they may seem.
According to the Environmental Protection Agency, the overall percentage of plastic being recycled has increased over time, but in 2018 the amount of plastic recycled in the U.S. was only 8.7% of the amount produced. The remaining plastic, over 90% of the total amount produced, ends up incinerated or in landfills [12]. This low rate of recycling can be attributed to several factors. Some are due to consumer practices: plastic that is contaminated by non-recyclable materials such as food residue is rejected from recycling plants, as there is no efficient way to decontaminate the materials. However, a majority of recycling resistance comes from plastic industries; while all types of plastic can theoretically be recycled, it is usually only industrially practical to recycle certain kinds [23]. Polyethylene terephthalate (PETE) and high-density polyethylene (HDPE), labeled as 1 and 2 respectively in the “chasing arrows” triangle commonly seen on consumer plastics, are usually the only plastics that recycling plants process. However, their recycling rates are still low: 29.1% for PET and 29.8% for HDPE [12]. Even if these numbers were increased, it is unclear whether there would be a net benefit to the environment. While recycling takes plastic out of the waste cycle, current recycling processes require large amounts of energy, most times with little economic return. The energy required to produce virgin plastic is typically much lower than the energy required to create recycled products [23]. The high economic and energy costs of present recycling processes make it unclear whether an increased amount of recycling is at all viable.
The Engineer’s Obligation
From a materials standpoint, plastic is a fantastic product. But engineers cannot focus solely on the positive chemical or material properties of plastic. As much benefit as plastic brings, its environmental impact is destructive. Many engineering fields hold environmental conservation paramount: the American Institute of Chemical Engineers Code of Ethics includes “protect[ion] of the environment” in the first statement, and the American Society of Civil Engineers Code of Ethics contains an entire section emphasizing the importance of conservation of the environment and its resources [24, 25]. To fulfill our obligation to the environment, engineers must constantly analyze industry practices and find viable alternatives to processes that may be harmful. Additionally, ethically sound engineers must work to improve the quality of life for all of humanity, not just select groups. If we are to fully address the problems of plastic pollution, we must also efficiently process waste.
One way engineers may be able to lessen environmental damage is through the replacement of the raw material for plastics. Bioplastics researchers seek to produce polymers chemically similar or identical to conventional plastics by using renewable materials such as cellulose and starch from plants or even bacterially synthesized polymers instead of natural gas [26]. The mere existence of an alternative polymer source warrants analysis of its viability. Engineers must investigate the wider implementation of these processes, and should advocate for change in the status quo, especially if it lowers the environmental burden of producing plastic. Unfortunately, these methods have only been tested on a small scale, and have yet to be integrated into production to a fraction of the extent of traditional plastics. Additionally, while these materials are sourced from renewable resources, the final product is usually only biodegradable in specific conditions and does not address the problem of plastic waste management.
Ultimately, bioplastics are just one possible solution in the struggle against plastic pollution. A multitude of solutions are required to fully address the impact plastics have on marine environments, human health, and the global waste disparity. These would have to be changes implemented across the lifecycle of plastic, from production to disposal. Engineers are not merely privileged but obligated to create new methods that benefit the entire planet.
Conclusion
For better or worse, plastic has become ubiquitous, especially in places where more expensive alternatives are impossible to find. Its accessibility as a cheap, lightweight material has made it necessary for large-scale industrialization. However, the current production cycle of plastic creates several areas of environmental concern. Plastics are mainly synthesized from non-renewable sources, and only a fraction of plastics can be recycled in public recycling programs. The improper disposal of plastic results in the most harmful impact, leaving millions of tons of plastic floating in our oceans. Additionally, the distribution of plastic waste is unjust, as poorer countries must trade plastic waste to maintain economic stability. The consequences of plastic have been revealed and cannot be ignored. To improve the common good, restore fairness, and salvage our environment, engineers can and must consider effective solutions to the problems of plastics, both in production and in consumption.
By Kaylee Tseng, Viterbi School of Engineering, University of Southern California
About the Author
At the time of writing, Kaylee Tseng was a second-year majoring in chemical engineering with a biochemical emphasis. Outside of research and tutoring, she spends her time knitting, cooking, and singing.
References
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Links for Further Reading
EPA Guide to Recycling (also check your local guidelines!):
https://www.epa.gov/recycle
Article about the effectiveness of popular plastic alternatives:
https://www.globalcitizen.org/en/content/plastic-alternatives-doing-harm/
Peer-reviewed paper about current bioplastic development using tapioca (2021):
https://doi.org/10.1016/j.molstruc.2021.129954