Reducing harm done by man-made chemicals to terrestrial wildlife

The chemicals industry is important for the European economy. It creates jobs and generates wealth. Chemicals are used in many sectors and contribute to our health, nutrition, and well-being. Yet, man-made chemicals can also pose a threat to the environment and human health.

Risks of chemicals

Many chemicals can disrupt animal immune systems and reproduction or cause cancers. Some toxic substances can persist for a long time in the environment and can accumulate along food chains. This can result in high concentrations in top predators, such as birds of prey and carnivorous mammals. Pesticides and biocides, such as rodenticides, also severely deplete plant and invertebrate diversity, which affects bird and mammal populations higher up the food chain.

Paola Movalli, researcher and ecotoxicologist at Naturalis Biodiversity Center, studies the impacts of chemicals on European terrestrial wildlife. “Compared with the marine and freshwater environments, the exposure of terrestrial wildlife to chemicals, and the related effects and impacts, have been little studied”, she says. “We need to understand this better in order to prevent and minimise negative impacts on wildlife and on the important benefits provided by ecosystems to our societies and economies.”

Regulatory challenges

The EU has put in place regulations to address the risks posed by the various man-made chemicals and has adopted a strategy for a ‘toxic-free environment’ to minimise the risks to human and wildlife health. However, given the quantity of new chemicals entering the market, regulators are struggling to manage the risks.

The TerraChem project, led by the Environmental Institute in Slovakia, offers a new approach to help regulators deal with the risk posed by chemicals to terrestrial wildlife. “We are working with institutions across Europe to shed light on which substances are turning up in terrestrial wildlife food chains and at what concentrations, on resulting effects and damages to genes, species, and ecosystems, and on regulatory solutions to reduce any harm”, says Movalli.

“My research over recent years on bird species in the Netherlands, including the black-tailed godwit (the Dutch national bird), the peregrine falcon, and the common buzzard, shows that these animals are indeed exposed to a ‘cocktail’ of pesticides, industrial chemicals, pharmaceuticals, and other substances”, says Movalli. “TerraChem goes a big step further by looking at this in the context of the whole food chain and the effects of chemical mixtures on birds and mammals. We can use this information to better predict damage to biodiversity. Our findings can be used to improve regulatory risk assessment and management.”

TerraChem case studies

At Naturalis, Movalli has led a unique Europe-wide set of case studies to monitor the exposure of top predators and their food chains to all possible man-made chemicals, and to assess effects of chemical mixtures. “We have sampled apex mammal species and their food chains in six European countries – the stone marten in The Netherlands, grey wolf in Germany, badger in Spain, Egyptian mongoose in Portugal, northern white-breasted hedgehog in Greece, and red fox in Romania”, says Movalli. “And we have sampled the barn owl and its food chain in all six countries to provide a Europe-wide picture of contamination. In total, we have gathered around 1500 samples from the top predators, their immediate prey (mostly rodents), invertebrates, plants, and soil. Importantly, our approach avoids killing any birds or mammals.”

The case studies are a big logistical effort, involving scientists in each country. Hundreds of valuable frozen samples were shipped to Naturalis for processing, and onward to the Institute of Environmental Sciences at Leiden University and the Laboratory of Analytical Chemistry at the National and Kapodistrian University of Athens for analysis. “We can identify the presence or absence of over 100,000 different man-made chemicals in a single wildlife sample of a few grams. Together with isotope analyses organised by the University of Leiden, these analyses will tell us which chemicals, and in which concentrations, are turning up at each level of the food chain and how chemicals move through and accumulate along food chains. And we are also testing for toxic effects on birds and mammals of the ‘cocktail’ of contaminants found in our samples, and metabarcoding soil and invertebrate samples to identify species present”, Movalli explains.

Prioritisation scheme and early warning system

TerraChem’s modelling partners at Leiden University and the Danish Technical University will use the data from the case studies to train models for impacts on species richness, on functional diversity, and on ecosystem services. Meanwhile, researchers of the Swiss Federal Institute of Aquatic Science and Technology (EAWAG) are modelling impacts of chemicals on genetic diversity.

The results will guide regulators in prioritising chemicals for regulatory risk assessment with a prioritisation scheme being developed by the German Environment Agency. They will also feed into a new European early warning system for chemicals in terrestrial wildlife. “This system, which is being developed by the Environmental Institute in the Slovak Republic, helps regulators identify problematic contaminants and move quickly to reduce any risks. Full results are expected by this time next year”, Movalli elaborates.

Blueprint for a new EU approach

The ultimate goal of TerraChem is to provide a blueprint for monitoring and regulation of chemical contamination within the European Union. “We hope to convince the EU to put in place the periodic monitoring of chemicals in terrestrial top predators and their food chains, and to adopt TerraChem’s integrated ‘Monitor, Model, Prevent & Manage Risk’ approach. This can deliver a more efficient reduction of chemical risks, and so help the EU meet its ‘zero pollution ambition’ with huge benefits for both wildlife and humans”, Movalli concludes.

More information

• Common buzzard in The Guardian.
• Black-tailed godwit on Nature Today (in Dutch).

Text: Naturalis Biodiversity Center  
Images: Adi Dedu (lead image: red fox Vulpes vulpes); Paola Movalli; Mariana Tomaz