Bianca Villegas*
Traduçao: Ligia Payao Chizolini
Recently, there was news about the Ypê case in Brazil, where batches of detergent were baned due to biological contamination of the products. Although it was a relatively simple issue, affecting only the color and smell of the product, it prompts us to think indirectly about how such cleaning products can affect the environment, especially rivers and oceans.
In our daily lives, we cook, clean the house, wash clothes and dishes, and engage in self-care activities like bathing. We often don't consider where this water goes, much less our environmental impact when we relax with our favorite fragrance after a stressful day. This seemingly innocuous act, if the wastewater is not properly treated, can lead to the extinction of marine species.
The impact of soap and detergents on water bodies occurs because these products contain surfactant substances. These substances are divided into four groups: anionic, non-ionic, cationic, and amphoteric. A surfactant has the ability to break the separation between polar and non-polar substances, such as water and dirt. This capability leads to a reduction of oxygen in the ecosystem, and affects local birds by impacting the natural oils in their feathers. Additionally, the foam reduces sunlight penetration, hindering the process of photosynthesis.
The lack of oxygen, known as hypoxia, caused by contamination, affects the fauna since many fish species cannot survive in low-oxygen environments. This effect creates so-called "dead zones," where ecosystems cannot exist due to hypoxia. Although dead zones can occur naturally, they are exacerbated and more frequent due to water pollution.
An example is the "dead zone" in the Gulf of Mexico, caused by contamination from agricultural fertilizers and urban sewage. In this case, the fertilizers cause algae to grow excessively, consuming much of the area's oxygen. This, combined with the effects of surfactant substances, creates an imbalance in the area. In Brazil, there are dead zones along the country's coast, such as the Pino Basin in Pernambuco, Vitória Bay in Espírito Santo, and Patos Lagoon in Rio Grande do Sul, among others (according to a study conducted this year, Brazil has 11 dead zones).
Another human action that could expand dead zones is global warming. As water temperatures rise, fish and other species need to breathe more rapidly, leading to oxygen scarcity.
*Chemistry student at Mackenzie Presbyterian University, São Paulo
Sources:
Comments