Microplastics: An Invisible Air Pollutant?

Microplastics are small plastic pieces less than five millimeters long that are polluting the air we breathe. They are formed from the degradation of larger pieces of plastic and are light enough to be transported by wind over large distances. Studies have found microplastics in the air in urban areas like London, Beijing, and Paris, with the highest concentrations measured at sites in London and Beijing. Research on airborne microplastics is still in its early stages, but it is known that they can have an impact on climate change and human health. As plastic waste is projected to double over the next few decades, addressing plastic pollution and reducing microplastic emissions are crucial to mitigate their potential harmful effects.

Microplastics in the atmosphere

Microplastics are indeed considered ambient air pollution. They are present in the air we breathe and in Earth's atmosphere, and they can affect the climate. The current concentration of microplastics in the atmosphere is low, and they have a very small influence on the global climate. However, given the projections for a doubling of plastic waste over the next few decades, it is expected that microplastics could have a more significant impact on Earth's climate system unless we take action to address plastic pollution.

Microplastics are tiny fragments or fibres shed during the degradation of larger pieces of plastic. They are light enough to be transported by wind over large distances and have been found in remote mountain catchments, Arctic snow, and conservation areas. The highest reported concentrations of airborne microplastics (thousands of fragments per cubic metre of air) were measured at urban sampling sites in London and Beijing. An aircraft-based study found microplastics at altitudes of up to 3.5 kilometres.

The presence of microplastics in the atmosphere raises concerns about their potential impact on human health and the environment. Microplastics can be inhaled, and their small size allows them to penetrate deep into the respiratory system, potentially causing respiratory issues and other health problems. Additionally, microplastics can act as ice-nucleating particles (INPs) and cloud condensation nuclei (CCN), affecting cloud formation processes, sunlight reflection, precipitation, and cloud lifetime. This could ultimately alter the Earth's radiation balance and contribute to climate change.

To address the issue of microplastics in the atmosphere, it is crucial to reduce plastic waste and promote sustainable alternatives. Proper waste management, recycling, and the reduction of single-use plastics can help decrease the amount of plastic pollution that ends up in the environment. Additionally, further research and collaboration are needed to fully understand the sources, prevalence, and behaviour of microplastics in the atmosphere, as well as their potential health and environmental impacts.

Microplastics in snow and water

Microplastics are tiny plastic fragments or fibres shed during the degradation of larger pieces of plastic. They are light enough to be transported by wind over large distances and have been found in the air, snow, water, and soil. While the current concentration of microplastics in the atmosphere is low, with studies reporting between <1 to >1000 microplastics/m3 (outdoor) and <1 microplastic/m3 to 1583 ± 1181 (mean) microplastics/m3 (indoor), the impact of microplastics on the climate is an area of ongoing research.

Microplastics in Snow

Recent studies have detected the presence of microplastics in snow samples from remote regions, including the Arctic, the Alps, and Antarctica. Snow samples from the Arctic ice floes in the Fram Strait, for example, had an average of 1,800 particles per 34 ounces, with one spot reaching 14,000 particles. Similarly, snow samples from the Ross Island region of Antarctica showed an average concentration of 29 particles per litre, with fibres being the most common form. These findings indicate significant atmospheric contamination, as snow captures particles from the air as it falls.

Microplastics in Water

Microplastics have been detected in various water bodies, including the ocean, rivers, and tap water worldwide. Studies have found microplastics in the deep-sea sediments of the Weddell Sea, the Ross Sea, and the Southern Ocean, as well as in the surface waters of the Antarctic Peninsula and the Fram Strait. The presence of microplastics in these remote areas suggests that they are being transported by atmospheric winds and ocean currents, highlighting the global extent of plastic pollution.

The potential health impacts of microplastics on humans and wildlife are a significant concern. While the science on the health effects of microplastics is still evolving, it is known that microplastics can enter the human body through inhalation and the consumption of contaminated water or food. In aquatic ecosystems, microplastics have been found to enter every level of the food chain, and their small size allows them to be taken up by a wide range of organisms, potentially affecting their health and ecosystems.

Microplastics in food and drink

Microplastics are tiny plastic particles that are considered a form of ambient air pollution. They are found in the air, water, and food we consume. While the current concentration of microplastics in the atmosphere is low, with a small influence on the global climate, projections indicate that plastic waste will double in the coming decades, increasing the abundance of airborne microplastics and their impact on the climate.

Now, moving on to the topic of "Microplastics in Food and Drink," it is important to note that microplastics and nanoplastics are prevalent in our food and water sources. They have been detected in various food products, including salt, seafood, sugar, honey, milk, tea, chicken nuggets, apples, and broccoli. Drinking water, both tap and bottled, has also been found to contain microplastics. The scientific evidence, including studies by the FDA, currently suggests that the levels of microplastics in food and drink do not pose a significant risk to human health. However, the FDA continues to monitor the research and will take regulatory action if necessary.

The primary source of microplastics in food is environmental contamination, where plastics degrade and contaminate the soil, water, or air, eventually making their way into the food chain. Single-use plastics and plastic food packaging have also been implicated as potential sources of microplastics in food and drinks. It is important to note that the effects of ingesting microplastics are still being studied, and there is limited understanding of the long-term health implications.

To reduce exposure to microplastics in food and drink, experts recommend limiting the use of single-use plastics, avoiding microwaving or heating food in plastic containers, and switching from bottled water to tap water. It is also advisable to prioritize fresh, whole foods and reduce the consumption of processed or packaged foods to minimize potential exposure to microplastics.

While it is challenging to completely avoid microplastics in our food and drink, maintaining a healthy lifestyle, including proper sleep, exercise, a balanced diet, and stress management, can help lower the potential health risks associated with microplastic exposure.

Health impacts of microplastics

Microplastics are a major emerging pollutant of concern as the chemical compounds within them can pose a threat to human health. Humans are constantly inhaling and ingesting microplastics through contaminated seafood, including fish and shellfish, tap water, bottled water, and even commonly consumed beverages such as beer and salt. A new study estimates that the average adult consumes approximately 2,000 microplastics per year through salt alone.

Different chemicals can leach from plastic products, such as water bottles, knives, and dermatological products, and enter our bodies. These compounds are linked to serious health issues such as endocrine disruption, weight gain, insulin resistance, and decreased reproductive health. In addition, the bioaccumulation of plastics in the human body can potentially lead to respiratory disorders like lung cancer, asthma, and hypersensitivity pneumonitis, neurological symptoms such as fatigue and dizziness, inflammatory bowel disease, and even disturbances in gut microbiota.

Most studies to date have confirmed that microplastics can induce apoptosis in cells and have genotoxic and cytotoxic effects. The smallest microplastics, termed nanoplastics (1 nm up to 1 μm), can enter the human body through the respiratory system via inhalation, the digestive tract via consumption of contaminated food and water, or penetration through the skin via cosmetics and clothes contact.

While the existing knowledge on toxicity is too preliminary to evaluate the environmental risks of microplastics, research has linked microplastic exposure to adverse health impacts in humans. The scientific evidence indicates a need for policies to mitigate current and future risks to ecosystems and human health. The European Commission has initiated regulatory actions, such as restrictions on the sale of non-degradable and non-soluble synthetic polymer microparticles and products containing them.

Several projects in the EU are studying the relationship between hazardous chemicals, including certain microplastics, and their health impacts. These projects, set to finish in 2025, aim to investigate the impact and consequences of micro- and nanoplastics on different aspects of human health.

Sources of microplastics

Microplastics are tiny plastic particles smaller than 5 millimetres in size. They are formed by the disintegration of larger plastic debris into smaller pieces.

Land-based sources

• Synthetic clothing: Synthetic textiles are the single greatest contributor to microplastics in the ocean. When synthetic clothing is washed, microplastics are released through the abrasion and shedding of fibres. These fibres are too small to be filtered by wastewater treatment plants and eventually find their way into the oceans.
• City dust: City dust accounts for 24% of microplastics in the oceans. It is created by the weathering, abrasion, and detergents used on man-made products. This includes the abrasion of synthetic soles of footwear, synthetic cooking utensils, artificial turfs, household dust, harbour and marina building coatings, and the blasting of abrasives.
• Tires: Car tires contain synthetic rubber, a plastic polymer, which can break down into microplastics.
• Road markings: Road markings can be made of plastic, which can degrade and become a source of microplastics.
• Marine coatings: Coatings on boats and other marine infrastructure can contain plastics that break down into microplastics.
• Personal care products: Microbeads, which are commonly used in personal care products for their abrasive and exfoliating properties, are a source of microplastics.
• Packaging: Packaging is the largest use of plastics worldwide and a significant source of plastic waste. Plastic packaging can break down into microplastics that contaminate food and drinks.
• Solid waste application to agricultural fields: Microplastics can enter the soil and be absorbed by crops.
• Emissions from vehicles and braking: Vehicle emissions and brake linings can contain microplastics that are released into the air.
• Landfill erosion: Landfills are a significant source of plastic waste, which can break down into microplastics and be transported by wind.

Ocean-based sources

• Marine waste: Microplastics comprise 75% of marine waste and can be ingested by marine animals, leading to toxic effects and alterations in their gastrointestinal tract physiology.
• Sea spray: Once microplastics enter the ocean, they can be lifted by wind currents and return to the atmosphere through sea spray.

It is important to note that microplastics have been detected in various biological samples, including human blood, saliva, liver, kidneys, lungs, and placenta, indicating potential health risks.

Frequently asked questions