Step outside, breathe in the air, or take a sip of water, and you are likely to encounter something hidden, something insidious—microplastics. These near-invisible invaders are so small they evade even the keenest of eyes, infiltrating the earth so deeply that they lurk in almost every corner of the environment. Microplastics float through the air, swim in our seas, rest in our soil, and, alarmingly, even flow within our bodies. They are not just in the city streets or oceans—they are in our food and our drink.[1] This nearly omnipresent plastic pollution is one of humanity’s most pressing environmental concerns, yet we go about our daily lives unaware of this microscopic menace that accompanies us everywhere.
Synthetic polymers first emerged in the late 19th century, around the 1860s, but it wasn’t until after World War II that the “plastics boom” truly took off. Since its early days as a phenol-formaldehyde resin (known as Bakelite), plastic has become one of the most widely used materials worldwide.[2] Originally intended to enhance human living conditions, plastic has, over time, transformed into a significant threat to the environment and the planet’s safety.
Microplastics are defined as tiny plastic particles measuring less than five millimetres in diameter—smaller than a grain of rice, categorised into primary microplastics and secondary microplastics. Primary microplastics are particles that are intentionally manufactured at a small scale and released directly into the environment, accounting for an estimated 15–31% of microplastics in the oceans. Key sources include the laundering of synthetic fabrics, which sheds microfibres (making up 35% of primary microplastics), the abrasion of vehicle tyres through driving (28%), and micro-beads added to certain personal care products, such as facial scrubs (2%).[3]
In contrast, secondary microplastics result from the breakdown of larger plastic items like bags, bottles, and fishing nets, a process driven by UV radiation, physical wear, and microbial activity. These particles make up the remaining 69–81% of microplastics in the ocean. Their durable design means that they continue breaking down into smaller fragments without fully decomposing, evading natural processes that would otherwise transform them into harmless substances. This durability makes microplastics a persistent and far-reaching environmental threat.[4]
The scale of microplastic pollution is staggering: around 51 trillion particles are now scattered throughout the oceans, a quantity 500 times greater than the stars in our galaxy. Every year, over eight million metric tonnes of plastic are dumped into the seas, disrupting marine life, impacting fisheries, and costing the global economy at least $8 billion in damages to marine ecosystems.[5] If current trends continue unchecked, it’s projected that by 2050, our oceans could contain more plastic than fish by mass, underscoring the urgent need for action.
The impact of microplastics on human health is an area of increasing concern, though definitive answers are yet to be found. Microplastics enter the human body primarily through ingestion and inhalation. Research has found particles in places where they were previously undetected, such as the lungs and bloodstream. For example, a 2022 study[6] found microplastics deep within the lungs of surgical patients and in the blood of anonymous donors, revealing how easily these particles can enter the body and subsequently spread throughout.
Airborne microplastics, often originating from household materials like clothing, upholstery, and carpets, may pose an even greater risk than food sources. Studies show that humans inhale and ingest thousands of microplastic particles annually, with some small enough to penetrate deep lung tissues and even cross into the bloodstream6. Once inside, these particles can move through the bloodstream to various organs, potentially accumulating in tissues over time.
Laboratory tests indicate that microplastics can cause cell damage, inflammation, and disrupt hormone function, with certain types shown to produce toxic effects depending on their size, chemical composition, and the additives they contain. With over 10,000 chemicals used in plastics—2,400 of which are potentially harmful—the chemical complexity adds another layer of risk.
The respiratory system’s response to inhaled particles includes inflammation, which, over prolonged exposure, could lead to conditions such as asthma, chronic obstructive pulmonary disease (COPD), or even cancer. However, establishing a direct causal relationship between microplastics and specific diseases is challenging, in part because microplastics are only a fraction of the particles we breathe daily, alongside dust, pollen, and other pollutants.
Preventing microplastic pollution relies on reducing plastic use, enhancing waste management, and advancing filtration technology. Simple changes, such as opting for reusable over single-use plastics and choosing biodegradable products, can significantly cut down microplastic sources. Improved recycling and advanced filtration in wastewater plants help capture microplastics before they reach natural waterways. Additionally, stronger legislation, such as bans on micro-beads and stricter pollution controls, can curb plastic production and environmental impact. Combined, these measures reduce microplastic spread and mitigate risks to ecosystems and human health.
In conclusion, microplastics have become an under-explored but serious issue, impacting the air, oceans, soil, and even our bodies. While we don’t fully understand all the health risks yet, it is clear that reducing plastic use, improving recycling, and enforcing stricter regulations can help limit microplastic pollution. Taking these steps now can protect both the environment and our health for a cleaner, safer future.
[1] siani K, Ioniță-Mîndrican CB, Mititelu M, Neacșu SM, Negrei C, Moroșan E, Drăgănescu D, Preda OT. Microplastics: A Real Global Threat for Environment and Food Safety: A State of the Art Review. Nutrients. 2023 Jan 25;15(3):617. doi: 10.3390/nu15030617. PMID: 36771324; PMCID: PMC9920460.
[2] Patterson G.D. Materia Polymerica: Bakelite. ACS Symp. Ser. 2011;1080:21–29. doi: 10.1021/bk-2011-1080.ch003.
[3] Microplastics: Sources, effects and solutions: Topics: European parliament (no date) Topics | European Parliament. Available at: https://www.europarl.europa.eu/topics/en/article/20181116STO19217/microplastics-sources-effects-and-solutions (Accessed: 28 October 2024).
[4] Microplastics: Sources, effects and solutions: Topics: European parliament (no date) Topics | European Parliament. Available at: https://www.europarl.europa.eu/topics/en/article/20181116STO19217/microplastics-sources-effects-and-solutions (Accessed: 28 October 2024).
[5] ‘turn the tide on plastic’ urges Un, as microplastics in the seas now outnumber stars in Our galaxy | un news (no date) United Nations. Available at: https://news.un.org/en/story/2017/02/552052-turn-tide-plastic-urges-un-microplastics-seas-now-outnumber-stars-our-galaxy (Accessed: 27 October 2024).
[6] Parker, L. (2023) Microplastics are invading our bodies. how severe is the damage?, Environment. Available at: https://www.nationalgeographic.com/environment/article/microplastics-are-in-our-bodies-how-much-do-they-harm-us (Accessed: 28 October 2024).
