First field study
In September-October 2018 we implemented our first field campaign in Chile, which was run along the Aconcagua river. The river contains one of Chile’s largest agricultural areas, with major vineyards and vegetable farming, hence an area with extensive pesticide use. Additionally, the area is one of Chile’s biggest copper-mining regions and a major petrochemical installation can be found at the river mouth. In summary, the river hosts a broad range of industrial activities that are all well known to emit toxic chemicals into the surrounding environment.
Result: Insecticides impact the biodiversity in the river
The chemical load at the sampling sites was analyzed using high-resolution mass spectrometry, coupled to an LC and GC system. 679 chemicals were included in the LC-based analysis, of which we actually found 138 chemicals at one or more of the Chilean sites (4 biocides, 31 industrial chemicals, 45 pharmaceuticals and personal care products, 57 pesticides).
The GC based analysis is still ongoing, we expect another 100+ legacy chemicals (PCBs, chlorinated pesticides, dioxins, etc.) to be found with this method. These data are currently combined with information on the ecotoxicity of the detected chemicals, in order to gain a first overview of whether the ecosystem is at risk.
DNA samples were collected at all sites, which were analyzed (sequencing, metabarcoding) in close collaboration with our Chinese partners, in order to get an understanding of the biodiversity impacts of chemical pollution. For the same purpose, we also collected invertebrate samples.
We can clearly show that especially the use of insecticides has a clear impact on the biodiversity in the exposed parts of the river, while other chemicals (e.g. pharmaceuticals and personal care products) seem to be of minor concern for the communities analysed.
Second field study
Based on the results, we are currently setting up the next sampling campaign (to be implemented in autumn 2020), which will in particular extend the scope of the considered chemical pollutants by including metal pollution from mining activities.