Unveiling the Hidden World of Microplastics and Nanoplastics

Unveiling the Hidden World of Microplastics and Nanoplastics

Breaking down the tools scientists and engineers are using to fight this crisis

Our Plastic Dilemma

The modern world is heavily reliant on plastics to meet consumer demands. Derived from fossil fuels, plastics are the major contributor to our global waste crisis, with nearly 9.2 billion tons disposed of since 1950. While environmental damage occurs through the production of this substance, we are focusing on the aftereffects of plastics once they are thrown away. Today, only between 6-14% of all plastics are recycled, the rest of the waste ends up in landfills or the natural environment. Every biome on Earth contains small plastic fragments. These microscopic particles are referred to as microplastics if they are less than 5mm in size, and nanoplastics if they are smaller than 100 nanometers (a strand of hair is about 90,000 nanometers wide.) (1). Microplastics have been found in most marine organisms, in the depths of the oceans, and unsurprisingly in our bodies. In this review, we will discuss a few of the many ways scientists and engineers are studying the composition and decomposition of plastics to handle this ever-expanding crisis.

So, What Are We Dealing With?

Uncovering the Scope of the Issue

Since discovering the presence of microplastics across all environments, scientists first had to uncover what the composition of these microplastic molecules was. Fourier transform infrared spectroscopy (FTIR) is an ever-advancing technique consisting of scanning microplastics to determine their composition based on how they absorb light. While this method first emerged in the early 2000s, it continues to be a cornerstone in understanding the type of plastics scientists are aiming to eradicate in specific environments (3).

Turning to Other Species for Solutions

In recent years, scientists have made exciting discoveries about the power of other species in breaking down plastics. It has been uncovered that wax worms, mealworms, and beetle larvae can all break down plastic molecules. In the last year, scientists have also uncovered a microbe that can break down plastics in a matter of hours instead of centuries. Originating from the Swiss Alps and Antarctica, these microbes can turn plastics into compost without the addition of heat, required by their microbe predecessors. While this is an exciting development, it cannot be our sole solution. These microbes can break down two forms of biodegradable plastics and polyester-polyurethane but do not break down polyethylene, the most commonly used plastic (4).

Plastic-Fighting Membranes

Many scientists are working with wastewater treatment plants to mitigate the amount of microplastics that are flushed into natural waterways. Membranes are being tested and implemented in the final stages of wastewater treatment to remove over 95% of plastic from the water. Depending on the membrane’s composition, they can effectively remove a wide variety of plastics of varying sizes (5).

Uncovering the Invisible Threat in Our Water Bottles

Using a new Raman Scattering (SRS) microscopy technique, scientists have recently uncovered that there are more nanoplastics in plastic water bottles than previously thought. Unlike traditional methods, SRS microscopy offers unparalleled sensitivity and specificity, enabling the detection of nanoplastics as small as 100 nm, useful in distinguishing various plastic polymers. A tailored spectral matching algorithm also enhances the ability to identify different plastic polymers, turning this method into a potent tool for environmental analysis. Recent findings using SRS microscopy to analyze bottled water revealed unsettling findings. Every liter of bottled water tested contained an estimated 105 nanoplastic particles, predominantly from polymers like polyamide (PA) and polystyrene (PS). This discovery is concerning, suggesting a significant, unseen ingestion of nanoplastics through daily water consumption which can more easily enter the bloodstream than their microplastic counterparts (6).

These developments in the fight against plastic pollution are a beacon of hope. With ever-evolving technology and tools, scientists and engineers are becoming more knowledgeable of the scope of the plastic crisis and the actions that we must take to counteract the damage.

Engage with Us!

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Resources

(1) Kundu, Aayushi., et. al. “Identification and removal of micro- and nano-plastics: Efficient and cost-effective methods.” Chemical Engineering Journal, Volume 421, Part 1, 1 October 2021. https://doi.org/10.1016/j.cej.2021.129816. Accessed 27 January 2024.

(2) National Geographic. “Plastics 101.” YouTube, uploaded by National Geographic, 19 May 2018, https://www.youtube.com/watch?v=ggh0Ptk3VGE. Accessed 27 January 2024.

(3) Veerasingam, S., et al. “Contributions of Fourier transform infrared spectroscopy in microplastic pollution research: A review.” Critical Reviews in Environmental Science and Technology, Volume 51, Issue 22, 2021. https://doi.org/10.1080/10643389.2020.1807450. Accessed 27 January 2024.

(4) Enking, Molly. “Scientists Discover Microbes That Could Revolutionize Plastic Recycling.” Smithsonian Magazine. https://www.smithsonianmag.com/smart-news/scientists-discover-microbes-that-could- revolutionize-plastic-recycling-180982185/. Accessed 27 January 2024.

(5) Talvitie, Julia. “Solutions to microplastic pollution – Removal of microplastics from wastewater effluent with advanced wastewater treatment technologies.” Water Research, Volume 123, 15 October 2017, Pages 401-407. https://doi.org/10.1016/j.watres.2017.07.005. Accessed 27 January 2024.

(6) Qian, Naixin. “Rapid single-particle chemical imaging of nanoplastics by SRS microscopy.” Proc NatlAcad Sci USA, Volume 121 Issue 3, 16 Jan 2024, DOI: 10.1073/pnas.2300582121. Accessed 27 January 2024.