Microplastics are tiny fragments of plastic measuring less than 5 millimetres in diameter. Some are deliberately manufactured at this size for use in products such as cosmetics, personal care items and clothing. Others result from the breakdown of larger plastic objects, including packaging, bottles and fishing nets.
These microscopic particles are now found across a wide range of ecosystems, contaminating humans, plants and wildlife alike. In this article, we explore the effects of microplastics on human and animal health, and share practical steps you can take to reduce your personal exposure.
How do microplastics end up in the environment?
Today, microplastics contaminate virtually every environment, from the depths of the oceans to mountain peaks, with harmful consequences for the planet and its inhabitants.
What are the main sources of microplastics?
The primary sources of microplastics include synthetic textiles, plastic waste and cosmetic products.
Synthetic textiles
Commonly found in our wardrobes (polyester, elastane, rayon, and similar fibres), synthetic fabrics can release microfibres during washing and everyday wear.
Breakdown of plastic waste
When plastic waste is discarded into the environment or improperly managed, it gradually breaks down under the influence of several factors.
These include:
- UV radiation, which breaks down the long molecular chains of plastic polymers.
- Water (fresh or salt), which promotes the hydrolysis of plastics.
- Physical abrasion against rocks, waves or other debris.
- Micro-organisms, such as fungi and bacteria, capable of degrading certain plastics.
Cosmetics and personal care products
Microplastics enter cosmetics through two main routes: packaging and ingredients.
In many cases, microplastics are intentionally added to cosmetic formulations as:
- Exfoliating agents: polyethylene or polypropylene microbeads used to scrub the skin.
- Texture agents: synthetic polymers that improve product feel and consistency.
- Absorbent agents: synthetic silicates that absorb moisture and control oil.
In total, more than 500 different polymer types are used in cosmetics and personal care products.
How do microplastics spread through water, soil and air?
During machine washing, synthetic fibres such as polyester, nylon and acrylic detach from clothing. These microfibres are flushed away with wastewater and can end up in rivers, lakes and eventually the ocean. A significant proportion of microplastics from cosmetic products also enter wastewater systems when products such as shower gels, exfoliants and toothpaste are rinsed away.
Microplastics are also present in the air we breathe. While evaporation from contaminated water is one pathway, other less obvious mechanisms contribute to airborne pollution. For example, as vehicle tyres wear down on the road, tiny fragments of rubber and plastic are released into the atmosphere.
Similarly, friction between clothing — even when dry — can release microfibres into indoor air. Some cosmetic products, such as perfumes and deodorants, may also contribute by dispersing microscopic plastic particles into the air.
Finally, the improper disposal of items such as makeup wipes, cotton buds and other personal care products can lead to soil contamination.
How are microplastics detected and measured in the environment?
Two spectroscopic techniques are commonly used to identify and analyse microplastics: Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. When combined with microscopy, these methods can detect particles as small as 1 micrometre.
However, a major challenge remains: effectively separating microplastics from surrounding organic matter. Breaking down this organic material is a crucial step in the extraction process, but it is often time-consuming and costly, limiting the speed and efficiency of analysis.
Researchers at the University of Portsmouth have developed a promising method for detecting microplastics in wastewater. This technique, published in the journal Analytical and Bioanalytical Chemistry, uses a chemical solution known as Fenton’s reagent to remove organic matter, one of the main sources of interference during analysis.
The method was tested on samples of raw wastewater, sewage sludge and treated effluent, with two types of microplastics added (polystyrene and polymethyl methacrylate). The results were encouraging, with recovery rates between 60% and 80%, demonstrating the effectiveness of the approach.
What are the effects of microplastics on animal health?
The ingestion of large plastic debris is known to cause serious physical harm to animals, including entanglement, internal injuries and exposure to toxic substances.
When animals ingest microplastic particles, smaller species such as birds and fish may experience blockages of the digestive tract. This can lead to digestive disorders, a false sense of fullness and a decline in physical condition, increasing the risk of disease and mortality.
Once present in soil, microplastics can also be ingested by terrestrial animals in several ways:
- Herbivores consume microplastics while grazing on contaminated plants.
- Carnivores and omnivores are exposed through prey that has already ingested microplastics.
- Earthworms ingest microplastics in soil and pass them on to animals that feed on them.
Although research into the effects of microplastics on terrestrial animals is ongoing, early findings are concerning. Observed impacts range from reduced food intake and choking risks to behavioural changes and genetic alterations.
Exposure to microplastics may also disrupt reproduction and alter animal population dynamics.
How are microplastics transmitted to humans?
While microplastics have been detected in a wide range of foods and drinks, most research has focused on seafood and drinking water. Studies analysing fish, squid and shrimp commonly consumed by humans have found microplastics in all sampled organisms.
In addition, a recent report by the United Nations Environment Programme (UNEP), along with other studies, has identified microplastics in products such as:
- salt,
- sugar,
- seafood,
- fish,
- honey,
- beer,
- tap water,
- bottled water,
- meat,
- dairy products,
- fruit and vegetables,
- other edible plants.
Microplastics also enter our daily lives through less obvious routes, including the air we breathe, the water we drink and even through skin contact. Some particles may be absorbed by intestinal cells and transported to other organs, such as the liver, kidneys and lymph nodes.
What are the health risks of microplastics for humans?
According to international environmental health research, once inside the human body, microplastics may cause harm through several mechanisms, including:
- Inflammation: exposure may trigger chronic inflammatory responses, increasing the risk of inflammatory and autoimmune conditions.
- Oxidative stress: microplastics can generate free radicals, which are linked to chronic diseases such as cardiovascular conditions and certain cancers.
- Genotoxicity: some particles may damage DNA, raising the risk of mutations.
- Cell death: microplastics may induce apoptosis or necrosis, disrupting normal tissue and organ function.
Further research is still needed to determine how much microplastic is actually absorbed by the human body. Scientists also highlight the technical challenges involved in detecting these particles within biological tissues, underlining the need for unbiased, high-quality studies that assess health risks based on particle size and type.
Recent international research has also shown that microplastics can negatively affect the human gut microbiome. These disruptions may increase the risk of inflammatory bowel conditions, allergies and other chronic health issues.
Microplastics and public health
The ingestion of microplastics raises growing concerns for public health and food safety. As a result, health authorities and regulators are increasingly addressing this issue.
In the UK, this includes investment in improved monitoring and measurement techniques. For example, researchers at the University of Portsmouth have developed advanced methods to better detect microplastics in wastewater, helping authorities gain a clearer picture of environmental exposure and inform future regulatory decisions.
More broadly, regulatory frameworks such as UK REACH and wider environmental policies are beginning to restrict the intentional use of microplastics in products, while also seeking to reduce plastic pellet losses across the supply chain.
At an individual level, it is also possible to reduce both personal and collective exposure to microplastics through simple actions, such as:
- Ventilating your home regularly and vacuuming frequently, particularly if you have plastic-based flooring.
- Airing your car interior and opening windows when driving, where possible.
- Carefully reading cosmetic ingredient lists and avoiding products containing plastic microbeads.
- Limiting purchases of synthetic clothing that sheds microfibres during washing.
- Washing clothes only when necessary and keeping wash temperatures at around 30°C.
- Avoiding ready meals packaged in plastic trays, especially those designed for microwave heating.
- Using water filters to reduce exposure to microparticles and persistent pollutants such as PFAS..
In this context, activated carbon block filters are particularly effective, retaining contaminants down to 2 microns. This is the technology used in Weeplow gravity-fed water filtration systems, which can remove up to 99.999% of harmful contaminants.
Why reducing everyday exposure to microplastics matters
The widespread presence of microplastics in our environment — and therefore in our bodies — represents a growing challenge for both human health and the planet. While scientific research is still ongoing, existing uncertainties highlight the importance of a cautious, informed approach.
Addressing this issue requires both large-scale action from public health authorities and responsible individual choices.
Simple solutions, such as water filtration systems, can help reduce daily exposure to microplastics. Explore the model that best suits your needs in our shop and start reducing the number of microparticles your household consumes each day.
