Microplastics React With Water: A New Threat to Living Organisms

Plastic has long been considered one of the most durable and stable materials in human history. Due to its chemical inertness, it was deemed safe for food packaging and water bottles. However, a new team of scientists from Columbia University and the University of California, Berkeley (UC Berkeley), is challenging this long-held assumption. According to a study published in the journal Nature, microplastics—now ubiquitous in the environment—behave quite differently when they come into contact with water.

Why are microplastics more dangerous?

Large plastic items are typically stable, but the situation changes radically with microplastics. The primary reason is surface area. As Wei Min, a professor of chemistry and biomedical engineering at Columbia University, explains, when plastic breaks down, its surface area increases colossally. This allows it to react with water and generate high-energy reactive radicals.

This process produces reactive oxygen species, among which hydroxyl radicals are particularly dangerous. These molecules are destructive to living organisms because they can "steal" electrons from the proteins and fats that make up cell membranes. As a result, the cell's structure is damaged, and its functionality is disrupted.

Oxidative stress and cellular damage

Our bodies possess natural defense mechanisms called antioxidants, which neutralize such harmful molecules. However, if the amount of reactive substances exceeds the capacity of these antioxidants, oxidative stress develops. This process leads to mass cellular damage.

Scientists conducted an experiment on mouse erythrocytes (red blood cells). The results showed hemolysis—the deformation and rupturing of cells. The more reactive the plastic particle was toward water, the more severe the damage. This confirms that microplastics are not merely passive "pollutants" that enter the body; they actively interfere with biological processes.

What threat does this pose?

Traditionally, research on microplastics has focused either on the toxic substances they contain or their physical impact. This new discovery shows that the surface of the plastic itself can be a source of danger, especially in the circulatory system, which is composed primarily of water.

Although the extent of microplastics' impact on the human body is still a subject of debate, this study raises significant questions. If microplastics are present in our tissues, they are potentially in constant reaction with our bodies. In the future, scientists will need to determine the extent of these chemical processes' influence on long-term health, but one thing is already clear: microscopic plastic particles are far more active than we previously thought.