Contaminants, pollution and man-made perturbations

Jérôme VIERS
05 61 33 26 24

05 34 32 37 79

pollutant cycling • biogeochemistry • toxicology • climate change • remote sensing • vegetation stress • species • trace elements • mercury

Learning objectives

The course will provide a spatial and temporal perspective on the impact of humans on their environment through innovative tools (e.g. isotopes, remote sensing)

and will allow students to broaden their initial expertise to interdisciplinary issues such as microplastic pollution, mercury or agricultural issues.



Brief description of the course

In 1995, Paul Crutzen (Nobel Prize in Chemistry) and his biologist colleague Eugene Stoermer proposed the term Anthropocene, to designate the period we are living through, which began at the end of the 18th century.

The introduction will cover this period, both from a historical and environmental point of view. After this introduction, the course will be divided into 3 lectures devoted to major environmental problems or innovative techniques.

The first class will be about microplastics and nanoplastics which are the invisble side of global plastic pollution. Human use of plastics is massive and poor waste treatment and use of single-use plastics leads to a global dispersion of microplastics and nanoplastics in the environment.

This course will first present what a microplastic is, how to determine it, its origins and dispersion modes as well as its potential impacts on human health and ecosystems. It will be accompanied by a practical course with the analysis of real samples, the quantification of microplastic flows in environments such as the Atlantic coast, the Toulouse metropolitan area or the Pyrenean mountains.

The second class will focus on mercury. Mercury is a natural element, and an unusual heavy metal because it is present as a liquid and a gas at room temperature. Gaseous mercury is naturally emitted by volcanoes, but also by human activities such as mining and coal combustion.

Atmospheric mercury deposits to aquatic ecosystems, including oceans, where it is methylated by microbes into the toxic methylmercury form. Methylmercury accumulates in aquatic food webs, reaching toxic levels in top predators including birds, fish, marine mammals and humans. This course will present an overview of the global biogeochemical mercury cycle, human perturbations to the mercury cycle, fundamentals of mercury toxicity; use of mercury isotopes to understand mercury cycling and notions on how climate change will affect mercury cycling. Practical work will include the analysis of mercury in commercial fish products and human hair in order to assess risk of exposure.

The last class will concern Detection and Quantification of contamination and chemical stress by optical remote sensing for vegetated surface. The first section of this course will deal with the contamination impact on biophysical and biochemical parameters at sub-individual plant scale but also on vegetation cover (species and assemblage, density). In the second section, the course will focus on optical measurement devices: from in-field to satellite and the link between biophysical and biochemical variables and spectral measurements will be detailed. Finally, the last section will focus on vegetation characterization methodology (modelisation, classification, regression…) using optical remote sensing data in order to detect and quantify stress, species modification…