Detect microplastics in drinking water in some Spanish cities

Plastics have been found in nearly every ecosystem on Earth. Most end up in the natural environment due to poor management of our waste. Plastics pollute our rivers and reach our beaches, where they slowly degrade, giving rise to smaller and smaller particles, which we call microplastics.

Microplastics measure less than 5 millimeters, which makes them move easily in nature. Currently, we can consider them ubiquitous pollutants, since they are present in all environmental compartments (in water, soil, plants and air).

Now, a study published in Water Research by the EnviroPlaNet network —which coordinates the efforts of more than a dozen Spanish research groups— has revealed the presence of microplastics in drinking water in several cities in the autonomous communities of Galicia, Madrid, Catalonia, Murcia and the Canary Islands. These are samples collected in the cities of A Coruña, Vigo, Madrid, Barcelona, ​​​​​​San Cristóbal de la Laguna, Las Palmas de Gran Canaria, Cartagena and Murcia.

The research, conducted by the Autonomous University of Madrid (UAM) in conjunction with the University of Alcalá (UAH), was based on these water samples, which were collected in 24 locations, during the months of May and July 2022. , specifically steel filters fixed on the faucets of the residences and public places of those who eight cities in mainland Spain and the Canary Islands.

The results showed that microplastics are present in all samples collected.

In addition to microplastics, researchers also found artificial materials such as dyed cotton fibers from clothing, which are a potential source of additives such as dyes.

diffuse pollution

O average concentration plastics was 12.5 ± 4.9 microplastics per cubic meter of water, while that of artificial materials was 32.2 ± 12.5 particles per cubic meter of water.

The main plastics detected were polyamides, polyesters and polyolefinsmaterials of general use in countless objects of common use and in textile clothing.

The careful characterization of all particles under study allowed estimating the mass of microplastics contained in the processed samples, whose average was 45.5 nanograms per liter.

“It’s a small value and comparable to other contaminants that appear in surface water and then reach the mains water, such as antibiotics. Consuming 1.5 L of water per day, it would take 40 years to ingest 1 milligram, which probably indicates that the risk to human health is negligible. This is good news,” the authors detail.

“Now, as small as it is, you don’t expect plastic to come out of the faucet. In our study it was demonstrated that although the water from the public network in the most populated area, Madridwas the one that contained the most microplastics, plastic residues appeared in all samples with a very similar concentration”.

Sampling points and concentrations of microplastics (PMs) in the water network of eight Spanish cities. / Roberto Rosal

The most likely origin is in the diffuse pollution that reaches the channels from which drinking water treatment plants drink, which generally receive wastewater from treatment plants located upstream.

O waste water dischargeseven if they are properly purified, according to current parameters, they are a major source of microplastic discharges into the environment.

“As a final reflection, it is worth mentioning that what we discard in our homes ends up coming back to them; hence the importance of correctly managing the waste we generate”, conclude the authors.