A standardized protocol will allow the evaluation of chemical contamination in the water of natural spaces in Spain

    The methodological procedure for the monitoring of polluting chemical substances on a large scale, tested in the aquatic ecosystems of Important Areas for the Conservation of Birds and Biodiversity (IBA) in Spain, will allow the evaluation of the potential impact of this environmental threat on the conservation of fauna in the most pristine aquatic ecosystems.


    Some of the most severe, damaging and worrisome pollution problems are imperceptible to the senses, and perhaps for this reason we have spent too much time without paying due attention to their causes and consequences. We refer to the majority of cases of chemical pollution, which is due to the introduction of potentially toxic substances in the environment.

    This form of pollution is fundamentally associated with human activities, and is one of the most harmful for different reasons: usually involves various chemical substances with high toxic potential and persistence, knows no boundaries and is practically invisible. In this way, its effects on the health of living beings are manifested in silence, without attracting attention. This contamination often becomes chronic and affects individuals and their populations, putting the survival of many species at risk.

    Chemical pollution and its effects are especially worrying when it reaches aquatic ecosystems., since they suppose the degradation of the habitat and the loss of biodiversity in the most fragile places. And it is that not even the theoretically most pristine natural spaces, such as the Important Areas for the Conservation of Birds and Biodiversity (IBA), are free of this environmental problem.

     

    Important Areas for the Conservation of Birds and Biodiversity (IBA) are places of high ecological value and importance for the conservation of biodiversity, especially for bird populations, identified by BirdLife International based on scientific criteria.

    Assess contamination in biodiversity hotspots such as IBAs It is not usually considered in the framework of environmental monitoring programs due to its difficulty, since it requires an intense sampling effort, logistics and coordination from the collection of the samples to their analysis in the laboratory. Furthermore, for these samples, it is crucial to use multi-residue analysis methods capable of simultaneously detecting various types of contaminants whose concentrations are theoretically expected to be low.

    In order to address the possible problems of chemical contamination that may be generated in natural areas of high ecological value, a team of scientists from the Institute for Environmental Diagnosis and Water Studies (IDAEA - CSIC), the Spanish Ornithological Society (SEO/BirdLife ) and the Research Group in Wildlife Toxicology of the Instituto de Investigación en Recursos Cinegéticos (IREC – CSIC, UCLM, JCCM), has developed and implemented a methodological procedure to determine a large amount of organic micropollutants from different chemical families and simultaneously, in water samples collected in 21 IBA representative of the different types of habitats existing in Spain.

     

    The results of this methodology show the frequency of detection of each polluting substance in the samples analyzed (left) and the number and type of chemical substances detected in the different representative habitats of the IBAs monitored, together with the total concentration (ng/L). (right).

    The analytical part of the methodological procedure is based on the use of liquid chromatography techniques coupled with tandem mass spectrometry (LC-MS/MS). Thanks to this technique, it has been possible to simultaneously analyze 21 drugs, 17 phytosanitary products, 3 organophosphorus esters, 17 perfluorinated compounds and benzophenone.

    The results show that 83% of the chemical substances analyzed (a total of 59) have been detected in the Spanish IBAs, which shows that Even the natural spaces with the greatest ecological value, which in theory would be the most pristine, suffer the impact of chemical contamination.

    Among the micropollutants studied, drugs (such as caffeine, ibuprofen or paracetamol) and organophosphate esters turn out to be the most ubiquitous. The caffeine, which was detected in 79% of the samples analyzed, is an indicator of anthropogenic contamination, so its presence is a symptom of human intrusion into natural spaces.

    The presence of drugs in the IBA water, detected in 98% of the samples analyzed, is of great ecological relevance because these chemical substances are bioactive, so they can interfere with the regulation and expression of genes and the immune response, affect development and the neuroendocrine and cardiovascular systems of vertebrate fauna.

    According to the European Medicines Agency (EMA), drugs present in water at concentrations greater than 10 ng/L should be subjected to an ecotoxicological risk assessment. Unfortunately, the drugs analyzed exceed this limit in 12% of the samples collected in the Spanish ABIs.

     

    Considering the different types of IBA, watercourses in the area of ​​influence of agricultural habitats, coastal aquatic habitats and water masses in riparian forests are the environments most affected by chemical contamination, the proximity of nuclei being a key factor. urban.

    Meanwhile, the organophosphate esters have been detected in 76% of the samples. These chemical compounds are used as flame retardants and as additives in plastics, paints and other furniture materials and electronic components.

    Other chemical contaminants, such as pesticides (closely associated with agricultural activities), the perfluorinated compounds (components of GoreTex®, Teflon, used as surfactants, in the agrochemical industry and as an additive in fire-fighting foams, for example) and the benzophenone (used in cosmetics and as an additive in the plastics industry) were detected in 60, 29 and 17% of the samples analyzed, respectively.

    As a whole, this methodology, developed and implemented within the framework of the LIBERA project promoted by SEO/BirdLife in alliance with Ecoembes, shows the need to dedicate research and management efforts to assess chemical contamination, the "garbage" that is not seen, even in the natural spaces of Spain that, in theory, are considered freer from anthropic pressures. This involves the identification of the sources of contamination and polluting substances, as well as the evaluation of their impact on fauna with the aim of implementing mitigation measures.

    The scientific publication of this research is available at: