Alain Manceau, born September 19, 1955, is a French environmental

mineralogist Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

and biogeochemist. He is known for his research on the structure and reactivity of nanoparticulate

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

and

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

oxides and

clay mineral Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay minera ...

s, on the

crystal chemistry Crystal chemistry is the study of the principles of chemistry behind crystals and their use in describing structure-property relations in solids, as well as the chemical properties of periodic structures. The principles that govern the assembly of ...

of strategic metals and

rare-earth elements The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), are a set of ...

, and on the structural

biogeochemistry Biogeochemistry is the Branches of science, scientific discipline that involves the study of the chemistry, chemical, physics, physical, geology, geological, and biology, biological processes and reactions that govern the composition of the natu ...

of mercury in natural systems,

animal Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, ...

s, and

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

Biography

Manceau is a former pupil of the École Saint-Martin-de-France in

Pontoise Pontoise () is a commune north of Paris, France. It is located from the centre of Paris, in the "new town" of Cergy-Pontoise. Administration Pontoise is the official (capital) of the Val-d'Oise '' département'', although in reality the ' ...

, then of the

Lycée Henri IV In France, secondary education is in two stages: * ''Collèges'' () cater for the first four years of secondary education from the ages of 11 to 14. * ''Lycées'' () provide a three-year course of further secondary education for students between ...

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

where he completed his preparatory classes before entering the

École Normale Supérieure de Saint-Cloud École or Ecole may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * Éco ...

(now

École Normale Supérieure de Lyon École or Ecole may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * Éco ...

) in 1977. He obtained the

agrégation In France, the () is the most competitive and prestigious examination for civil service in the French public education A state school, public school, or government school is a primary school, primary or secondary school that educates all stu ...

natural science Natural science or empirical science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer ...

s in 1981, then his

doctorate A doctorate (from Latin ''doctor'', meaning "teacher") or doctoral degree is a postgraduate academic degree awarded by universities and some other educational institutions, derived from the ancient formalism '' licentia docendi'' ("licence to teach ...

in 1984 at the University Paris VII (now Université Paris Cité) under the direction of George Calas. He spent his entire academic career at the

French National Centre for Scientific Research The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 engi ...

(CNRS), first as a research fellow from 1984, then as a research director from 1993 to 2022. From 1984 to 1992, he worked at the Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC) in Paris, and from 1993 to 2022 at the Institut des Sciences de la Terre (ISTerre) of the

Grenoble Alpes University The (, ''Grenoble Alps University'', abbr. UGA) is a ''grand établissement'' in Grenoble, France. Founded in 1339, it is the third largest university in France with about 60,000 students and over 3,000 researchers. Established as the Univer ...

. He was appointed emeritus CNRS Researcher at the ENS-Lyon in 2022, and research scientist at the

European Synchrotron Radiation Facility The European Synchrotron (ESRF) is a joint research facility situated in Grenoble, France, supported by 19 countries (13 member countries: Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Norway, Russia, Spain, Sweden, Switz ...

(ESRF) in 2023. In 1997, he was a visiting professor at the

University of Illinois Urbana-Champaign The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public university, public land-grant university, land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United ...

, then

Adjunct professor An adjunct professor is a type of academic appointment in higher education who does not work at the establishment full-time. The terms of this appointment and the job security of the tenure vary in different parts of the world, but the term is gen ...

until 2001. He was a visiting professor at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

from 2001 to 2002.

Scientific works

''Environmental

mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

and

geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ...

Mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

s play a key role in the biogeochemical cycling of the elements at the Earth's surface, sequestering and releasing them as they undergo

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

crystal growth Crystal growth is a major stage of a crystallization, crystallization process, and consists of the addition of new atoms, ions, or polymer strings into the characteristic arrangement of the crystalline lattice. The growth typically follows an ini ...

, and dissolution in response to chemical and biological processes. Manceau's research in this field focuses on the structure of disordered minerals (

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

s, iron ( Fe) and manganese ( Mn) oxides, including

ferrihydrite Ferrihydrite (Fh) is a widespread hydrous ferric oxyhydroxide mineral at the Earth's surface, and a likely constituent in extraterrestrial materials. It forms in several types of environments, from freshwater to marine systems, aquifers to hydro ...

and

birnessite Birnessite (nominally MnO2·''n''H2O), also known as δ-, is a hydrous manganese dioxide mineral with a chemical formula of Na0.7Ca0.3Mn7O14·2.8H2O. It is the main manganese mineral species at the Earth's surface, and commonly occurs as fine-gra ...

), on chemical reactions at their surface in contact with aqueous solutions, and on the

of trace metals in these phases. In 1993, he established in collaboration with Victor Drits a structural model for

based on the modeling of the

X-ray diffraction X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering, when there is no change in the energy of the waves. ...

pattern. This model was confirmed in 2002 by

Rietveld refinement Rietveld refinement is a technique described by Hugo Rietveld for use in the characterisation of crystalline materials. The neutron diffraction, neutron and x-ray crystallography, X-ray Powder diffraction, diffraction of powder samples results in ...

of the

neutron The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...

diffraction pattern, and in 2014 by simulation of the

pair distribution function The pair distribution function describes the distribution of distances between pairs of particles contained within a given volume. Mathematically, if ''a'' and ''b'' are two particles, the pair distribution function of ''b'' with respect to ''a'', ...

measured by high-energy X-ray scattering. D-MnO2 HRTEM image

In 1997, he and Victor Drits led the synthesis and resolution of the structure of

hexagonal In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A regular hexagon is d ...

and

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

, and they showed in 2002 that the

form possesses a

triclinic class=skin-invert-image, 180px, Triclinic (a ≠ b ≠ c ≠ a and α, β, γ, 90° pairwise different) In crystallography, the triclinic (or anorthic) crystal system is one of the seven crystal systems. A crystal system is described by three b ...

distortion. The

form prevails at the Earth's surface and owes its strong chemical reactivity to the existence of heterovalent Mn⁴⁺-Mn³⁺-Mn²⁺ substitutions and Mn⁴⁺ vacancies in the MnO₂ layer. The Mn⁴⁺-Mn³⁺ and Mn³⁺-Mn²⁺ redox couples confer to this material oxidation-reduction properties used in

catalysis Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

electrochemistry Electrochemistry is the branch of physical chemistry concerned with the relationship between Electric potential, electrical potential difference and identifiable chemical change. These reactions involve Electron, electrons moving via an electronic ...

, and in the

electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

transfer during the photo-dissociation of

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

photosystem II Photosystem II (or water-plastoquinone oxidoreductase) is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. It is located in the thylakoid membrane of plants, algae, and cyanobacteria. Within the photosystem ...

, while the vacancies are privileged sites for the adsorption of cations. He has characterized and modeled a number of chemical reactions occurring at the

interface, including those of complexation of transition metals ( Ni, Cu, Zn, Pb, Cd...), and oxidation of As³⁺ to As⁵⁺, Co²⁺ to Co³⁺, and Tl⁺ to Tl³⁺. The oxidative uptake of

cobalt Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. ...

leads to its billion-fold enrichment in marine ferromanganese deposits compared to

seawater Seawater, or sea water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximat ...

. From 2002 to 2012, he applied the knowledge base acquired on the

of trace metals and biogeochemical processes at mineral surfaces and the root-soil interface (

rhizosphere The rhizosphere is the narrow region of soil or Substrate (biology), substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Pore space in soil, Soil pores in the rhizosphere can ...

) to the

phytoremediation Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as "the use of green plants and the associated microorganisms, along with proper soil amendments and agronom ...

of contaminated

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s and

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

s, and abandoned mine sites. He contributed to improving the Jardins Filtrants® (Filtering Gardens) process for treating

wastewater Wastewater (or waste water) is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of do ...

and solid matrices by phytolixiviation, phytoextraction, and rhizofiltration developed by th
Phyto''r''estore
company. In 2022, he extended his research on the

of trace metals to processes responsible for the 10⁶ to 10⁹ times enrichment of strategic

(REE) and

redox Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is t ...

-sensitive elements (

cerium Cerium is a chemical element; it has Chemical symbol, symbol Ce and atomic number 58. It is a hardness, soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it ...

thallium Thallium is a chemical element; it has Symbol (chemistry), symbol Tl and atomic number 81. It is a silvery-white post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Che ...

platinum Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...

) in marine deposits relative to

. REE are associated with

fluorapatite Fluorapatite, often with the alternate spelling of fluoroapatite, is a phosphate mineral with the formula Ca5(PO4)3F (calcium fluorophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various color (green, brown, blu ...

marine sediments Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles either have their origins in soil and rocks and have been transported from the land to the sea ...

, whereas redox metals are oxidatively scavenged by

manganese nodules Polymetallic nodules, also called manganese nodules, are mineral concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. As nodules can be found in vast quantities, and contain valuable metals, ...

and crusts. ''Structural

of mercury'' Mercury (Hg) is a global pollutant that is generated both by natural sources, such as volcanic eruptions and

wildfire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

s, and human activities, such as coal combustion,

gold mining Gold mining is the extraction of gold by mining. Historically, mining gold from Alluvium, alluvial deposits used manual separation processes, such as gold panning. The expansion of gold mining to ores that are not on the surface has led to mor ...

, and the incineration of industrial waste. In aquatic and terrestrial

food chain A food chain is a linear network of links in a food web, often starting with an autotroph (such as grass or algae), also called a producer, and typically ending at an apex predator (such as grizzly bears or killer whales), detritivore (such as ...

s, mercury accumulates as

methylmercury Methylmercury is an organometallic cation with the formula . It is the simplest organomercury compound. Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environment ...

(MeHg), a potent toxin that affects the function of animal's and human's brain and reproductive system. Understanding the internal detoxification processes of MeHg in living organisms is essential for protecting

wildlife Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introdu ...

and

s, and designing treatments against

mercury poisoning Mercury poisoning is a type of metal poisoning due to exposure to mercury. Symptoms depend upon the type, dose, method, and duration of exposure. They may include muscle weakness, poor coordination, numbness in the hands and feet, skin rashe ...

. In 2015, Manceau led foundational studies on the structural

of mercury in

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

plants Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars f ...

animals Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a ...

, and

s using X-ray emission

spectroscopy Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectro ...

at the

ESRF The European Synchrotron (ESRF) is a joint research facility situated in Grenoble, France, supported by 19 countries (13 member countries: Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Norway, Russia, Spain, Sweden, Switz ...

. In 2021, he found that the

Clark's grebe Clark's grebe (''Aechmophorus clarkii'') is a North American waterbird species in the grebe family. Until the 1980s, it was thought to be a pale morph of the western grebe, which it resembles in size, range, and behavior. Intermediates between ...

(''Aechmophorus clarkii'') and the

Forster's tern Forster's tern (''Sterna forsteri'') is a tern in the family Laridae. The genus name ''Sterna'' is derived from Old English "stearn", "tern", and ''forsteri'' commemorates the naturalist Johann Reinhold Forster. It breeds inland in North America ...

(''Sterna forsteri'') from California, the

southern giant petrel The southern giant petrel (''Macronectes giganteus''), also known as the Antarctic giant petrel, giant fulmar, stinker, and stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar northern giant pe ...

(''Macronectes giganteus'') and the

south polar skua The south polar skua (''Stercorarius maccormicki'') is a large seabird in the skua family, Stercorariidae. An older name for the bird is MacCormick's skua, after explorer and naval surgeon Robert McCormick, who first collected the type specime ...

(''Stercorarius maccormicki'') from the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

, and the

Indo-Pacific blue marlin The Indo-Pacific blue marlin (''Makaira mazara'') is a species of marlin belonging to the family Istiophoridae. Taxonomy ''Makaira mazara'' is closely related to, and usually considered conspecific with, the Atlantic blue marlin, then simply c ...

(''Makaira mazera'') from

French Polynesia French Polynesia ( ; ; ) is an overseas collectivity of France and its sole #Governance, overseas country. It comprises 121 geographically dispersed islands and atolls stretching over more than in the Pacific Ocean, South Pacific Ocean. The t ...

, detoxify the organic

cysteine Cysteine (; symbol Cys or C) is a semiessential proteinogenic amino acid with the chemical formula, formula . The thiol side chain in cysteine enables the formation of Disulfide, disulfide bonds, and often participates in enzymatic reactions as ...

complex (MeHgCys) in inorganic mercury-

selenocysteine Selenocysteine (symbol Sec or U, in older publications also as Se-Cys) is the 21st proteinogenic amino acid. Selenoproteins contain selenocysteine residues. Selenocysteine is an analogue of the more common cysteine with selenium in place of the ...

complex (Hg(Sec)₄). A few months later, he extended this result to

long-finned pilot whale The long-finned pilot whale, or pothead whale (''Globicephala melas'') is a large species of oceanic dolphin. It shares the genus ''Pilot whale, Globicephala'' with the short-finned pilot whale (''Globicephala macrorhynchus''). Long-finned pilo ...

from the analysis of 89 tissues (liver, kidney, muscle, heart, brain) from 28 individuals stranded on the coasts of

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

and the

Faroe Islands The Faroe Islands ( ) (alt. the Faroes) are an archipelago in the North Atlantic Ocean and an autonomous territory of the Danish Realm, Kingdom of Denmark. Located between Iceland, Norway, and the United Kingdom, the islands have a populat ...

. This body of work shed light on how

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

cetacea Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...

, and

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

es manage to get rid of

toxicity. Demethylation of the MeHgCys complex to Hg(Sec)₄ and very poorly

soluble In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubi ...

inorganic HgSe is

catalyzed Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

selenoprotein P In molecular biology, the protein domain selenoprotein P (SelP) is the only known eukaryotic selenoprotein that contains multiple selenocysteine (Sec) residues. It is a secreted glycoprotein, often found in the plasma. Its precise function rema ...

(SelP) within which nucleate clusters of Hg_x(Sec,Se)_y that grow, likely by

self-assembly Self-assembly is a process in which a disordered system of pre-existing components forms an organized structure or pattern as a consequence of specific, local interactions among the components themselves, without external direction. When the ...

of mercurial

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s as is common in

biomineralization Biomineralization, also written biomineralisation, is the process by which living organisms produce minerals, often resulting in hardened or stiffened '' mineralized tissues''. It is an extremely widespread phenomenon: all six taxonomic kingd ...

processes, to form ''in fine'' inert, non-toxic mercury selenide (HgSe) crystals. The new Hg(Sec)₄ species identified by Manceau and his collaborators was the main “missing intermediate” in the chemical reaction that helps

s to survive high levels of mercury. However, because Hg(Sec)₄ has a molar ratio of

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

to mercury of 4:1, four

atoms are required to detoxify just one mercury atom. Thus, Hg(Sec)₄ severely depletes the amount of bioavailable

Selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

deficiency can affect the function of

s’

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

and reproductive system, as

selenoprotein In molecular biology a selenoprotein is any protein that includes a selenocysteine (Sec, U, Se-Cys) amino acid residue. Among functionally characterized selenoproteins are five glutathione peroxidases (GPX) and three thioredoxin reductases, (TrxR/TX ...

s serve critical

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

functions in the

and

testes A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of androgens, primarily testosterone. The ...

. His works on the Hg-Se antagonism won him the ES&T 2021 Best Pape
Award
The stepwise MeHgCys → Hg(Sec)₄ + HgSe demethylation reaction is accompanied by the fractionation of the ²⁰²Hg and ¹⁹⁸Hg

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

s, denoted δ²⁰²Hg. The δ²⁰²Hg fractionation measured on whole

tissues (δ²⁰²Hg''_t'') is the sum of the fractionations of the MeHgCys, Hg(Sec)₄, and HgSe species, weighted by their relative abundance: δ²⁰²Hg''_t'' =

\sum

''f''(Sp''_i'')''_t'' × δ²⁰²Sp''_i'' where δ²⁰²Sp''_i'' is the fractionation of each chemical species, and ''f''(Sp''_i'') their relative abundance, or mole fraction. Manceau and his co-authors found that δ²⁰²Sp''_i'' can be obtained by mathematical

inversion Inversion or inversions may refer to: Arts * ''Inversion'' (artwork), a 2005 temporary sculpture in Houston, Texas * Inversion (music), a term with various meanings in music theory and musical set theory * ''Inversions'' (novel) by Iain M. Bank ...

of macroscopic isotopic and microscopic spectroscopic data. The combination of isotopic and spectroscopic data on

s and

revealed that dietary

and the Hg(Sec)₄-SelP complex are distributed to all tissues (

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...

, sketetal muscle,

) via the

circulatory system In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart ...

with, however, a hierarchy in the tissular percentage of each species. Most of the

detoxification Detoxification or detoxication (detox for short) is the physiological or medicinal removal of toxic substances from a living organism, including the human body, which is mainly carried out by the liver. Additionally, it can refer to the period o ...

process is carried out in the

, whereas the

, which is particularly sensitive to the neurotoxic effects of mercury, is distinguished from other tissues by a low mercury concentration and a high proportion of inert HgSe. These results appear to be transposable to

Publications

Manceau has published more than 200 scientific papers in

Science Citation Index The Science Citation Index Expanded (SCIE) is a citation index owned by Clarivate and previously by Thomson Reuters. It was created by the Eugene Garfield at the Institute for Scientific Information, launched in 1964 as Science Citation Index ( ...

journals totalizing more than 24,000 citations and garnering an h-index over 90. In 2020, he was ranked 111th out of a total of 70,197 researchers in Geochemistry/Geophysics in a bibliometric study by scientists of the Stanford University based on the Elsevier Scopus database.

Awards and honors

* 1989, Bronze Medal, French National Centre for Scientific Research (CNRS) * 2002, Fellow of the

Mineralogical Society of America The Mineralogical Society of America (MSA) is a scientific membership organization. MSA was founded in 1919 for the advancement of mineralogy, crystallography, geochemistry, and petrology, and promotion of their uses in other sciences, industry, ...

(MSA). * 2003, Brindley Lecture,

The Clay Minerals Society The Clay Minerals Society is an international non-profit organization devoted to the study of clays and clay minerals. History The Clay Minerals Society began as the Clay Minerals Committee of the National Academy of Sciences— National Resea ...

(CMS). * 2006, George Brown Lecture,

Mineralogical Society of Great Britain and Ireland The Mineralogical Society of Great Britain and Ireland (now known as the Mineralogical Society of the United Kingdom and Ireland) was founded in 1876. Its main purpose is to disseminate scientific knowledge of the Mineral Sciences (mineralogy) as ...

(MinSoc). * 2010, Silver Medal,

(CNRS). * 2011, EcoX Équipex Grant. * 2022, Elected member of the

Academia Europaea The Academia Europaea is a pan-European Academy of humanities, letters, law, and sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europe ...

. * 2022,

European Research Council The European Research Council (ERC) is a public body for funding of scientific and technological research conducted within the European Union (EU). Established by the European Commission in 2007, the ERC is composed of an independent Scientific ...

Advanced Grant. * 2022, ES&T 2021 Best Paper Award. * 2023, Léon Lutaud Price and Georges Millot Medal,

Académie des sciences (France) An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the go ...

Online conference and research highlight

Phytotechnology in the Present and Future: Remedies for Contaminated Soil and Water

From Antarctica to California : how birds detoxify mercury

References

{{Reflist French mineralogists French geochemists 1955 births Living people Research directors of the French National Centre for Scientific Research Members of Academia Europaea