Article by: Álvaro Vázquez González, Research Assistant, Groundwater Ecology Group, IMDEA Water
Bisphenol A, a chemical used for the manufacture of plastics and other everyday objects is a substance that is included in the list of candidates for products of concern, because it presents toxic properties that affects human health, acting as an endocrine disruptor and interfering with some types of cancer. However, it has not been until 16th of June of 2017 that this substance has been unanimously included in the list of substances of very high concern by the European Chemicals Agency (ECHA), in support of the proposal of the French Agency for health and environmental safety (ANSES), that warned of its potential negative effects since 2011 (Maisons-Alfort, 2011).
The chemical industry produces bisphenol A in large quantities (European Commission joint Research Center, 2008, U.S. National Toxiciligy Program, 2008), which ultimately increases its discharges to the environment. A large number of studies have detected concentrations of this compound in urban ecosystems in Asia, Europe and North America. In Spain, bisphenol A has been detected too, one of the most polluted rivers is the Llobregat River, in Cataluña, with an average concentration of 3 micrograms per liter, other contaminated spots are in central Spain, in the rivers Manzanares and Jarama, where the values can be up to 126 nanograms per liter of water (Esteban et al., 2014), wich shows low concentrations, but it remind us that the substance is there, persisting and doing damage.
The growing concern of bisphenol A will make it possible to establish an effective regulation to prevent its effects on humans, supported by recent scientific studies. But bisphenol A not only causes effects on human health, it also damages the environment and organisms living in, especially the aquatic ones, that are poisoned by it when it is dissolved in water. The negative effects it produces on aquatic vertebrates, amphibians, reptiles and birds are several, affecting their development, reproduction, production of hormones, egg production and even the immune system and metabolism. In aquatic invertebrates, several studies show a high chronic toxicity, however there is little detailed documentation about the specific impacts it can produce (Canesi & Fabbri, 2015). Populations of ground and surface water invertebrates can be affected by its endocrine disrupting effects and ultimately affect the entire ecosystem.
Our preliminary results were obtained from two different populations of ostracods (Heterocypris incongruens), collected from different sites in water of Madrid area in Alcalá de Henares (Madrid, Spain) and the ostracods kit from the MicroBioTests laboratories. The results shows that this type of crustaceans are sensitive to bisphenol A, whose lethal dose for them varies between 10-20 mg/L. Using environmentally relevant concentrations (between 1.5 and 85 micrograms) negative effects are also observed, they slow down their life cycles, affecting their development and reproduction. These concentrations of bisphenol A specifically reduce the hatching success of their dormant eggs (eggs designed to not hatch immediately and allow the species to spread and adapt to temporary habitats) and increase the proportion of offspring that hatch from imminent eggs (Namiotko et al., 2017). It has also been observed that the effects are different in the laboratory population and the one obtained from natural environment.
This study attempts to contribute to the little knowledge that exist about the effects of this substance on these benthic aquatic animals, trying to provide help to create efficient protocols and regulations for the protection of groundwater ecosystems and their organisms.
ANSES. French agency for food, environmental and occupational health & safety, 2016. Accesible en: <https://www.anses.fr/en/content/bisphenol
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ECHA. Agencia Europea de Sustancias Químicas, 2017. Accesible en: <https://echa.europa.eu/-/msc-unanimously-agrees-that-bisphenol-a-is-an-endocrine-disruptor>
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