Over the millennia, humanity bathed in natural waters, simply because there was no other. The lower population density living in the landscapes of yore and the absence of contamination allowed this, in some parts of the world until today. Thus, one took a bath without concern.

The first “pools” were invented 3,000 years before Christ, that is, artificial baths, filled with natural water from rivers or springs, by peoples of present-day Pakistan.

Water quality was guaranteed by running water or by water renewal. For this reason, they needed a connection to the existing resources in the environment. In this context, it is not surprising that the Romans perfected bathing. As masters of architecture and engineering, they built pipelines and aqueducts to bring water from long distances to the desired places where they installed the baths, even heated. Two thousand years ago in Rome, there was a spa with the capacity to serve two hundred bathers simultaneously, with a public Olympic-sized pool. That is, over millennia there was no water treatment technology. Only the water available at the site was used, or brought from afar, but always in its natural form.

The reasons of human beings for taking baths were several and have not lost validity until today. Whether for pure pleasure, washing, health and hygienic reasons, for physical exercises or religious rites. Swimming as a sport was also appreciated, it was part of the elementary education of boys in ancient Greece, Rome, Persia, Assyria and Egypt  4,500 years ago.

Only from the 19th century, with the advance of industrialization in Europe and the subsequent growth of the population, the problems of diseases associated with contaminated water were recognized.

At the beginning of the sec. XX water treatment systems by chemicals were invented, a technology that spread quickly across the globe. In historical terms, it means a relatively short stage compared to bathing in naturalized waters over millennia. Only in the 8th decade of the last century there was a return to the origins, the search for biological treatment systems began, with the aim of producing natural or naturalized water as of yore, based on innovative and very modern tecnology.  At this time, the first biological pools in the world were born, in Central Europe, in Germany and Austria in parallel. The first biological swimming pool in Portugal was constructed in 1995, located at Costa Vicentina, it is our authorship and its biological treatment system works until today.
However, this new applied biotechnology is nowadays part of the bioeconomy and its products, today, are considered bio-based solutions.

Source of historical data: Vitorino de Matos Beleza, “A história das piscinas e das suas condições sanitárias”, 2014
Photo: National Archaeological Museum of Paestum, Public domain, via Wikimedia Commons