The invisible pollution of dishwashers that can harm the human body
(Rinnovabili.it) – It is widely believed that the use of dishwasheris, under certain conditions, a more environmentally friendly practice than washing dishes by hand, but a new Swiss study could partially dispel this myth.
A group of scientists from the Swiss Institute for Allergy and Asthma Research (SIAF), associated with the University of Zurich (UZH), has discovered that rinse aid residues left on freshly washed dishes have a harmful effect on the natural protective layer of the ‘intestine. The resulting consequences have different gradual intensity but can determine the onset of chronic pathologies. “The effect we found could mark the beginning of the destruction of the epithelial layer of the intestine and trigger the onset of many chronic diseases – explained Cezmi Akdis, professor of experimental allergy and immunology at UZH and director of SIAF – It is important to educate the public about this risk, as ethoxylated alcohols appear to be commonly used in commercial dishwashers.”
A common commercial dishwasher works with washing cycles which see the circulation of hot water and detergents for about one minute at very high pressure; this cycle is usually followed by a second wash and rinse cycle. Then comes drying, during which the rinse aid is applied. “What is particularly alarming is that in many appliances there is no additional wash cycle to remove the remaining rinse aid – illustrated Akdis. – “This means that the potentially toxic substances remain on the dishes, where they then dry out”.
Chemical residues thus dry up and, in contact with food, can end up in the gastrointestinal tract.
At this point the research of the Akdis team comes into play, which investigated the effects of these residues on the human body, in particular on the epithelial barrier of the intestine, the tract of intestinal cells that controls what enters the body and which, if damaged, it can lead to health consequences such as allergies, gastritis, diabetes, obesity, liver cirrhosis, rheumatoid arthritis, multiple sclerosis, autism spectrum disorders, chronic depression and Alzheimer’s disease.
Several studies have already shown that the chemicals we commonly use can damage these cells, which are also present on the skin and in the lungs. Through a new technology that develops human organoids on microchips, the researchers analyzed a tissue that mimicked the intestinal tract in question to visualize the biomolecular effects of residues of dishwasher detergents and found that high doses of rinse aid kill epithelial cells, while doses more diluted they make them more permeable. Furthermore, with contact with these substances, a series of genes and proteins are activated which generally trigger inflammatory responses.
References to the study are available on the University of Zurich website