Soaps, detergents, shampoos and many other personal hygiene products contain mixtures of ‘odorous’ molecules that have passed safety tests for human health with little or nothing known about their impact on the environment. Researchers at the Ca’ Foscari University of Venice and the Institute for the dynamics of environmental processes of the National Research Council (CNR – IDPA) have been investigating the canals to look for traces of these molecules which are referred to as ‘perfumes ‘ in the ingredients of products that we use daily.
The results were published in the scientific journal “Science of the total environment”. The lagoon is thus the first case study on the levels of certain fragrances, chemically produced by humans and widely used in everyday life, in the environment.
Between April and December 2015, scientists repeatedly collected water samples from 22 places between the inner canals in the historic center of Venice, the island of Burano and at two points in the far-north lagoon. They were looking for the presence of 17 fragrances among the most used and chemically stable between the thousands available to the cosmetics industry.
Traces of ‘scented’ molecules have been identified in all sampling sites, including those more distant from inhabited areas, though illustrating concentrations up to 500 times higher in the inner city canals. Samples collected during conditions of low tide in Venice and Burano showed concentrations comparable to those of untreated waste water.
In Venice, the city without sewers, wastewater treatment through biological tanks which then flow directly into the canals thus seems an insufficient method of lowering the concentration of these molecules. For example, one of the most frequently found compounds in the waters of the lagoon was benzyl salicylate, a known allergenic which has to be indicated on the labels of cosmetic products which contain it.
— source unive.it