Microplastics have infiltrated daily life and now pose a potential risk to human health. A research team in Spain detected microplastics in drinking water across multiple sites. The findings, published in Water Research, were led by the Autonomous University of Madrid (UAM) and involved more than a dozen centers within the EnviroPlaNet Network, in collaboration with the University of Alcalá (UAH). The study highlights the persistent presence of plastic-derived particles in the water system and underscores the importance of effective waste management to keep these pollutants from returning to households through the water supply.
Plastics have permeated nearly every ecosystem on the planet due to shortcomings in waste handling. They travel to beaches and rivers and, once in the environment, break down into smaller fragments known as microplastics. These tiny particles are described by researchers as ubiquitous pollutants because they appear in almost every environmental compartment.
For the study, researchers sampled tap water after it passed through steel filters connected to household lines at 24 points in eight locations across mainland Spain and the Canary Islands. Microplastics were detected in all samples, though the quantities were generally small.
Microplastics are particles smaller than five millimeters that can move through natural systems with relative ease. They are increasingly considered one of the most widespread contaminants, found in air, water, soil, and even biota, including human environments.
The study’s methodology involved spectroscopic identification and characterization of all collected particles. In addition to microplastics, some particles consisted of natural materials that bore signs of industrial processing, such as dyed natural fibers from textiles that may carry trace additives like dyes and paints.
The predominant plastics identified were polyamides, polyesters, and polyolefins, materials commonly used in everyday products and textiles alike.
Comparable values with antibiotics
Across all samples, researchers found a total of 570 particles of potential anthropogenic origin. Of these, 84 particles were positively identified as microplastics (synthetic polymers) and 132 particles were characterized as artificial materials that are not plastics. The remaining 360 particles were natural materials. A detailed mass assessment indicated an average microplastic concentration of about 45.5 nanograms per liter in the processed samples.
Although the detected levels are small, the researchers note that they are within the range observed for other surface-water pollutants that can reach drinking water. They estimated that consuming about 1.5 liters of water per day would require roughly 40 years to accumulate a milligram, a threshold considered unlikely to pose a direct health risk. Still, the presence of microplastics in tap water is a concern that warrants ongoing monitoring.
In the Madrid area, which has high population density, tap water contained the highest concentration of microplastics, yet a similar pattern emerged across other sites, suggesting a widespread distribution of these particles in the municipal water networks.
Most likely sources point to wastewater discharges entering drinking-water catchment channels via upstream treatment facilities. Even when treatment processes meet published parameters, residual microplastics can still enter water supplies, indicating a need for improved upstream controls and better waste management practices.
Plastic waste in human blood
The researchers conclude with a sobering reminder: the waste generated in households can eventually reappear in human systems if not properly managed. This perspective emphasizes the need for robust waste handling at the source to reduce environmental and potential health impacts.
Microplastics have already spread widely, from remote polar regions to ocean depths, and they have been detected in human and animal blood, plant tissues, and even airborne particles. Possible sources include drinking water, air, toothpaste, lipstick, and tattoo inks, highlighting the broad exposure pathways that exist in daily life. About a year ago, a study by Dutch scientists first reported microplastics in human blood, suggesting these particles may reach various organs over time. In that study, roughly half of the blood samples from 22 volunteers contained traces of PET plastic, commonly used in beverage bottles, while more than a third showed polystyrene, used in disposable food containers and many other products.
Researchers have also observed microplastics on plant leaves and in other natural settings, with fragments and fibers found in small puddles on leaf axils. The prevailing hypothesis is that atmospheric transport and movement via soil and plant surfaces contribute to their distribution.
For further reading, the original findings and related methodology are discussed in a study published in a reputable scientific outlet, with citation details available in the literature attribution section of the report.
Citation note: Tap water microplastics study conducted by the EnviroPlaNet Network and colleagues, with additional input from UAM and UAH, as summarized in Water Research. Attribution: researchers and institutions involved in the study.