Microplastics

Microplastics: Invisible Pollutants with a Big Impact

Imagine a world where tiny plastic particles, invisible to the naked eye, are silently infiltrating our ecosystems. These microplastics, less than 5 mm in length, have become an insidious form of pollution, affecting everything from our oceans to our air and even our food.

The Two Faces of Microplastics

Microplastics come in two forms: primary and secondary. Primary microplastics are manufactured for specific uses like exfoliating scrubs or industrial processes, while secondary microplastics result from the degradation of larger plastic products over time.

The Persistent Presence

These tiny particles persist in environments, particularly aquatic ones, causing water pollution. They can also accumulate in air and terrestrial ecosystems, making their impact far-reaching and complex. In medicine, microplastics are used as vectors for drugs, but they pose significant risks when released into the environment.

The Hidden Dangers of Microplastics

Primary microplastics become contaminated with heavy metals over time, while bioplastic microbeads have a long degradation life cycle. Secondary microplastics form from the physical breakdown of larger plastic debris through fragmentation and photo-oxidation.

The Environmental Threat

Fiber shedding from clothing and tire erosion contribute to microplastic pollution. Microplastic fibers are found in air, water, and soil, with small plastic pellets used in other products entering ecosystems due to spills and accidents. Nanoplastics, defined as particles less than 1 μm in size, pose an environmental and health threat by crossing cellular membranes and affecting cell functioning.

Microplastics in Everyday Life

Research has identified various sources of microplastic pollution, including textiles, tires, city dust, paint, and clothing. Synthetic fibers shed from clothing can persist in the environment, with studies showing that 1,900 fibers per garment are released during laundry. Microplastics have been found to contribute up to 30% of the Great Pacific Garbage Patch.

The Indoor Environment

Indoor concentrations of textile fibers can be high, ranging from 1-60 fibers/m³, while outdoor concentrations are much lower at 0.3-1.5 fibers/m³. The deposition rate indoors is significant, with an average loss of over 100 fibers per liter of water during washing.

Microplastics in Food and Beverages

Plastic containers can shed microplastics and nanoparticles into foods and beverages, with bottled water showing high levels of contamination. Baby bottles also release microplastics, with polypropylene infant feeding bottles causing exposure ranging from 14,600 to 4,550,000 particles per capita per day.

Single-Use Plastics and Beyond

Single-use plastic products like plastic cups and paper coffee cups lined with a thin plastic film release trillions of microplastic-nanoparticles per liter into water during normal use. Local and statewide policies to reduce single-use plastics are effective in addressing plastic pollution.

The Role of Transportation

Car tires contribute significantly to microplastic emissions, with estimates ranging from 0.23 to 4.7 kg/year per capita. The relative contribution of tire wear and tear to the total global amount of plastics ending up in oceans is estimated to be 5-10%. In air, 3-7% of particulate matter (PM2.5) consists of tire wear and tear.

Shipping and Marine Pollution

Shipping has significantly contributed to marine pollution, with around 6.5 million tons of plastic in the early 1990s. Research shows that approximately 10% of the plastic found on beaches in Hawaii are nurdles. In one incident, 150 tonnes of nurdles and other raw plastic material spilled from a shipping vessel off the coast near Hong Kong after a major storm.

The Airborne Threat

Airborne microplastics have been detected in the atmosphere, indoors, outdoors, and even in snow samples. Microplastics were found in Antarctic sea ice for the first time in 2009 with 96 microplastic particles from 14 different types of polymers.

Microplastics in Soil and Food

A substantial portion of microplastics are expected to end up in soil, but little research has been conducted on microplastics in soil outside of aquatic environments. Microplastics have been linked to the use of organic waste materials and geophagous soil fauna contributing to their presence in soil.

The Human Impact

Microplastics are inconspicuous particles less than 5 mm that enter the food chain at the bottom and become embedded in animal tissue through ingestion or respiration. Marine and freshwater organisms ingest microplastics inadvertently, leading to bioaccumulation. Fish may mistake plastic particles for food, blocking their digestive tracts and sending incorrect feeding signals.

Health Implications

The consequences of plastic degradation and pollution release over long term had mostly been overlooked, referred to as ‘toxicity debt.’ Microplastics affect soil ecosystems by reducing earthworm weights and stunting plant growth due to increased uptake of toxic metals like cadmium. Microbe live on microplastics forming biofilms that spread pathogens and antibiotic-resistant genes through horizontal gene transfer.

Human Health Risks

The International Research Workshop concluded that microplastics were a problem in the marine environment, and a comprehensive review found that microplastics were present in every part of the environment. Microplastics have been detected in freshwater systems, high mountains, and deep layer ocean sediment surveys, leading to suspected underestimation of microplastics in surface sample ocean surveys.

Prevention and Solutions

The consequences of microplastic pollution are far-reaching, affecting everything from the health of our oceans to the air we breathe. Prevention measures include dust control, treatment through incineration or biodegradation, efficient removal of microplastics from wastewater treatment plants, collection devices near coasts, and education and recycling campaigns.

Global Initiatives

The Garbage Patch State initiative and the EPA’s ‘Trash-Free Waters’ program were launched in 2013 to raise awareness about plastic waste and its impact on waterways. The Florida Microplastic Awareness Project searches for microplastics in coastal waters and advocates for action against microplastic pollution.

Conclusion

The fight against microplastic pollution is a global effort that requires collective action. By understanding the sources, impacts, and prevention methods of microplastics, we can work towards cleaner, healthier environments for ourselves and future generations. The journey to reduce microplastic pollution starts with awareness and ends with action.