Plastics, pesticides, endocrine disruptors*… human activity is to thank for these substances’ presence in our environment. Consumers, associations, industrial players, elected officials and others are all concerned about the impact of these chemical pollutants on earth’s air, water and soil, not to mention the organisms that call these spaces home. This is the subject of ecotoxicology, which plays a role in the work of INRAE teams every day.
Ecotoxicology is a very recent discipline, born at the end of the 1960s out of an awareness of the extent and seriousness of the contamination of ecosystems by toxic substances. At the same time, more and more research went into the problems of the pollution of natural environments.
Ecotoxicology studies what becomes of chemical contaminants in the environment, and the effects they have on living organisms. It is a discipline whose contours have evolved as a result of recent thinking, and in which INRAE plays a leading role. We take a closer look.
How INRAE research in ecotoxicology takes shape
An interdisciplinary field faced with major challenges
Ecotoxicology initially sought to characterise the effect of contaminants on organisms, whether or not they were targets, living in natural environments. With the widespread presence in the environment of mixtures of various substances that act at very low doses (pharmaceutical substances, endocrine disruptors, etc.), it now seeks to characterise all the exposures to which organisms are subjected, following the example of the study of the exposome* in humans. Ecotoxicology aims to gain a better understanding of the effects that occur under conditions of sublethal concentrations (i.e. not leading to death) for substances dispersed, in a diffuse or punctual manner, in the environment.
Food safety, climate change, the environment, health... Current issues raise new research questions in ecotoxicology. At the intersection of these issues, the Green Deal for Europe encourages the evolution of food systems towards practices that preserve environmental and human health as well as the sustainability of systems. In a context of agro-ecological transition, ecotoxicology has its rightful place. It contributes to providing information that enables the preservation and sustainable management of soils, water resources, biodiversity and ecosystems.
Between pollution and innovation, plastic seeks its place in the world
For example, INRAE scientists are looking for solutions to combat plastic pollution, in particular by developing innovative biodegradable packaging, and by anticipating all of their impacts from the design stage. Interview with Nathalie Gontard, a researcher specialising in plastic-free and zero-waste packaging. Interview with Nathalie Gontard.
Exploring the impacts of plastic debris on soil health and agricultural productivity: the MINAGRIS project
Although the amount of plastic entering soils is equal to or greater than that which ends up in rivers, seas and oceans, the impact of plastic debris on soil health is largely unknown. The MINAGRIS project (EU, 2021-2026), in which INRAE is a partner, is studying how plastic debris affects soil biodiversity, soil functions, associated ecosystem services and agricultural productivity.
Biodiversity and nature's services: what is known about the impact of pesticides?
To what extent are birds, insects and other living organisms affected by pesticides? What is the effect of these substances on services as essential as pollination or biological pest control? An INRAE-Ifremer collective scientific report provides updated information on the impact of plant protection products on biodiversity and on the services that ecosystems provide to society. It also identifies ways to cut back on the use of these harmful products.
Exposure to dioxins and PCBs and the risks to human health
Some INRAE research focuses on the chemical safety of food and the characterisation of the human chemical exposome in order to study the exposure-health link. Among the work of the Institute's teams, three studies point to the health effects of certain chemical pollutants, in particular persistent endocrine disruptors such as dioxins and certain polychlorinated biphenyls (PCBs).
Three questions for a start-up: Biomae
Measuring contamination, assessing the toxicity of micropollutants... Monitoring the quality of water and aquatic environments in France is now based on bio-testing developed by the start-up Biomae in INRAE laboratories. This success owes much to a small freshwater crustacean, Gammarus. Interview with Guillaume Jubeaux, co-director of Biomae.
Development of passive integrative tools and biomonitoring to better measure water quality
The Impact-CE project (AFB & Ministry of Agriculture, 2016-2019), coordinated by INRAE, focused on the development and application of measurement tools and indicators of the in situ impact of plant protection products on watercourses in order to better characterise their average concentrations and assess their impacts on the aquatic environment.
What comes next?
The challenge for ecotoxicology is to be able to anticipate the consequences of contamination before it is too late. To do so, tools and methods must be developed to predict, highlight or qualify the exposure of organisms (eco-exposome) and to anticipate impacts, especially on biodiversity (diversity of species and their functions). This involves identifying and monitoring markers of exposure, effects and even adaptation, among other things.
It will also be crucial to decompartmentalise research. That is, to get people and teams from different scientific disciplines working together to tackle the problem from different angles. This should lead to combining academic dimensions with innovation and support for public policies, associating multiple scales (temporal, spatial and also organisational), modelling, carrying out simulations, integrating the complexity of systems and uncertainties, and forging partnerships, all the while expanding the range of concerned stakeholders.
RESEARCH QUESTION: TAKING BETTER ACCOUNT OF THE SOIL-WATER CONTINUUM
The various physical compartments that structure ecosystems are linked to each other and form an environmental continuum. When two ecosystems, characterised by their own environment and their own communities, come into contact, a new community emerges. This new community is the result of the mixing of the original communities and develops in a new environment. Still little taken into account in ecotoxicology, these so-called coalescence processes help to better understand the response of communities exposed to toxic substances.
Pioneering work on an experimental research site in the Rhône basin, in the heart of the Beaujolais wine-growing area, has focused on terrestrial and aquatic microbial communities: microbial transfers from the vine-covered drainage basin* to the Morcille catchment have a major influence on the capacity of the microbial communities present in the river to adapt to contamination by plant protection products from the vineyards. They stimulate their capacity to (bio)degrade diuron, once one of the most widely used herbicides and frequently detected in the Morcille.
In the same way as plant protection products, pharmaceutical compounds, including antibiotics used in animal farming and human medicine, represent an important source of environmental contamination, exerting a selection pressure on the environment susceptible to giving rise to resistant bacteria. Very recently, the importance of biological transfers at the basis of community coalescence processes has been confirmed by the identification of the transfer of biodegradation capacities of antibiotic substances, but also of antibiotic resistance, in agroecosystems (ANR Antibiotox, 2017- 2021).
At the spatial scale of the landscape, the soil-water continuum is of great importance. A recent study (PSDR Dynamique 2016-2019) has shown the influence of the landscape (urban, peri-urban or agricultural area) on the state of contamination of aquatic ecosystems such as ponds by organic pollutants (plant protection products, polycyclic aromatic hydrocarbons, pharmaceutical products) or inorganic pollutants (nitrate, phosphates, trace elements) and on the associated risks for organisms living in or dependent on these environments.
These perspectives were the subject of lively discussions at a recent seminar organised by the Ecotox network. They are part of INRAE's strategic orientations and come into play on a daily basis in the Institute’s research.
Tools and infrastructures
Against a backdrop of partnerships of excellence, national infrastructures supported by INRAE or in which the Institute is a partner, bring together systems and tools dedicated to understanding biological processes within continental ecosystems.
- AnaEE – France, managed by INRAE and the CNRS, is a research infrastructure dedicated to analysis and experimentation on ecosystems in which experimental platforms and analytical platforms perform complementary functions.
- The “workshop zones” focus on one functional unit (a river and its drainage basin, landscapes and biodiversity, etc.). They serve as a setting for a specific long-term scientific approach based on observations and experiments. On a national scale, these workshop areas constitute a network of workshop areas in which INRAE is a partner.
- The Carnot Water & Environment Institute offers integrated R&D schemes to boost innovation in the fields of water quality and aquatic environment preservation, access to water resources adapted to uses, and protection of populations against risks related to water cycles.
- Scientific networks bring together thematic or disciplinary groups for events, discussions and exchanges. At the national level, the INRAE ecotoxicology network focuses on continental aquatic and terrestrial ecosystems. The Recotox inter-infrastructure initiative aims to coordinate, through a network of already-equipped sites, research to understand, anticipate and limit the ecotoxicological impacts of pesticides on socio-agrosystems. On an international scale, the EcotoxicoMic microbial ecotoxicology network, initiated by INRAE, currently brings together more than 200 scientists from some forty countries.
Lamy I., Faburé J., Mougin C. et al. 2022. Aquatic and terrestrial ecotoxicology considering the soil: water continuum in the Anthropocene context. Environ Sci Pollut Res. 29: 29221–29225.