Insight

Plastic is no longer merely an environmental pollution problem. Its smallest particles are found in drinking water, seafood, salt, and other food products. Scientists are actively investigating how microplastics may affect human health and how we can reduce our daily exposure to them.

What Are Microplastics and How Do They Enter Our Food?

Plastic packaging, single-use bottles, food containers, and synthetic fabrics are part of everyday life. Over time, exposure to ultraviolet radiation from sunlight, heat, mechanical stress, and wear causes plastic to break down into smaller particles. These particles are known as microplastics.

Microplastics are generally defined as plastic particles smaller than 5 millimetres. Even smaller particles are called nanoplastics. They are often impossible to see with the naked eye, while detecting and accurately measuring the smallest particles requires specialized laboratory methods.

Microplastics enter water and soil from the environment and may subsequently make their way into the food production and supply chain. Their sources may include environmental pollution, wear and deterioration of plastic packaging materials, production and transportation processes, and certain food-contact materials.

It is important to understand that the presence of microplastics in a product does not automatically mean that it is dangerous to human health. Assessing the risk requires information about the number, size, and chemical composition of the particles, the route by which they enter the body, and the effects of a particular dose on human health.

Which Products Contain Microplastics?

Scientific studies have detected microplastics in various foods and beverages. However, comparing the findings of different studies is difficult because laboratories use different methods, and not all of them can detect the smallest particles with the same degree of accuracy.

Drinking water is one of the most frequently studied potential sources of microplastics. Particles have been found in samples of both bottled water and tap water. Some studies have reported higher concentrations in bottled water, although the results depend on factors such as the bottle material, water source, cap, storage conditions, and analytical method used. It would therefore be incorrect to claim that all bottled water is more contaminated than tap water.

Salt, honey, and other products are also being studied. Their contamination may be associated with the environment, production processes, processing, or packaging. However, comparisons of the quantities of particles detected in different products are not always reliable.

Plastic food-contact materials are also considered a possible source of microplastics. Wear and deterioration of containers, lids, and packaging may contribute to the release of particles. Food contamination may, however, arise not only from packaging but also from dust and other sources within the production environment.

How Might Microplastics Affect Human Health?

This is the issue that raises the most questions among consumers. Scientists are investigating whether microplastics can pass through the digestive system into body tissues, trigger inflammatory processes, or alter the effects of chemicals already present in the body.

Laboratory and animal studies have identified changes associated with certain types of plastic particles, including inflammatory responses and signs of cellular damage. However, the size, type, and dose of the particles used in experiments often differ from the quantities and forms to which people are exposed through an ordinary diet. These findings must therefore be applied to humans with caution.

Studying the potential effects of microplastics in humans is considerably more difficult. Several studies have detected plastic particles or related materials in human biological samples, but their presence alone does not prove that they cause a particular disease. Establishing such a link requires larger, longer-term, and methodologically robust studies.

In 2019, the World Health Organization published an assessment of microplastics in drinking water. It concluded that the evidence available at the time was insufficient to establish a clear threat to human health from the levels of microplastics detected in water. The organization also emphasized the need for additional, higher-quality research. This conclusion does not mean that every quantity of microplastics is harmless; rather, it reflects the uncertainty that remains in the scientific evidence.

How Can We Reduce the Likelihood of Microplastics Entering Food and Drinking Water?

At present, completely avoiding daily exposure to microplastics is virtually impossible. However, consumers can reduce certain potential sources by adopting a few simple habits.

First, where drinking-water quality allows, tap water from a reliable source may be preferred. This choice is often beneficial for the environment as well because it reduces the use of single-use plastic bottles. Water safety, however, depends on the local water supply, the condition of the pipes, and water-quality monitoring. If the safety of the water is uncertain, efforts to reduce exposure to microplastics should not take priority over microbiological safety requirements.

It is also important to avoid excessive scrubbing of plastic containers or cleaning them with abrasive sponges, as wear may contribute to the release of particles from the material. Reusing single-use packaging is also poor practice, particularly when it was not designed for repeated use.

Food manufacturers and public authorities have an equally important role to play. Reducing contamination requires improvements in production processes, assessment of packaging safety, reduction of environmental pollution, and development of reliable laboratory methods. Changing consumer behaviour alone is not sufficient to solve the problem completely.

What Should We Watch for in the Future?

Scientific knowledge about microplastics is developing rapidly. One of the main challenges for researchers is accurately identifying and measuring these particles. Standardized methods are needed so that findings from studies conducted in different countries can be compared reliably.

Future research should determine how much microplastic enters the human body, how much is naturally excreted, which particles are most relevant to health, and whether there is a particular level of exposure that increases the risk of disease.

Until then, the best approach for consumers is reasonable caution. There is no need to immediately discard every plastic product or stop drinking water. It is more important to choose safe drinking water, use food-contact materials correctly, replace damaged containers and utensils, and rely on trustworthy scientific information.

The issue of microplastics reminds us that food safety concerns more than what we can see or sense in our food. It encompasses the entire chain-from the environment and production to packaging, storage, and final consumption. The better we understand these processes, the better equipped we will be to make informed decisions that protect our health and the health of our families.
 

Scientific Sources

• WHO (2019). Microplastics in Drinking-water. See source.

• Leslie et al. (2022). “Discovery and Quantification of Plastic Particle Pollution in Human Blood.” Environment International. DOI.

• Cox et al. (2019). “Human Consumption of Microplastics.” Environmental Science & Technology. DOI.

• EFSA (2016). Presence of Microplastics and Nanoplastics in Food, with Particular Focus on Seafood. EFSA.