Cover Page

Microbiology of Aerosols

 

Edited by

Anne-Marie Delort
Pierre Amato

 

Université Clermont Auvergne, CNRS, Institut de Chimie de Clermont-Ferrand
(ICCF), France

 

 

 

 

 

Wiley Logo

List of Contributors

P. Amato
Université Clermont Auvergne
CNRS
Institut de Chimie de Clermont-Ferrand
Clermont-Ferrand
France

 

P. Blais Lecours
Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec
PQ
Canada

 

E. Brisebois
Département de Biochimiede Microbiologie et de Bioinformatique—Université Laval
Institut Universitaire de Cardiologie et Pneumologie de Québec
PQ
Canada

 

Y. Brunet
UMR 1391 ISPA
Centre INRA Bordeaux-Aquitaine
Villenave d'Ornon
France

 

I. Canet
Université Clermont Auvergne
CNRS
Institut de Chimie de Clermont-Ferrand
Clermont-Ferrand
France

 

N. Chaumerliac
Université Clermont Auvergne
CNRS
Laboratoire de Métérologie Physique/OPGC
Clermont-Ferrand
France

 

F. Conen
Department of Environmental Sciences
University of Basel
Bernoullistrasse
Basel
Switzerland

 

L. Deguillaume
Université Clermont Auvergne
CNRS
Laboratoire de Météorologie Physique/OPGC
Clermont-Ferrand
France

 

A.-M. Delort
Université Clermont Auvergne
CNRS
Institut de Chimie de Clermont-Ferrand
Clermont-Ferrand
France

 

P.J. De
Mott

Department of Atmospheric Science (Atmospheric Chemistry)
Colorado State University
Fort Collins
Colorado
USA

 

M. Draghi
Centre Scientifique et Technique du Bâtiment (CSTB)
Division Agents Biologiques et Aérocontaminants
Champs-sur-Marne
Marne-la-Vallée
France

 

C. Duchaine
Département de Biochimiede Microbiologie et de Bioinformatique—Université Laval
Institut Universitaire de Cardiologie et Pneumologie de Québec
Canada

 

J. Fröhlich-Nowoisky
Max Planck Institute for Chemistry
Multiphase Chemistry Department
Mainz
Germany

 

A. Galès
LBE
INRA
Narbonne
France

 

C. Gonzalez-Martin
Instituto Universitario de Enfermedades Tropicales y Salud Publica de Canarias
Universidad de La Laguna
San Cristobal de La Laguna
Tenerife
Islas Canarias
Spain

 

D.W. Griffin
U.S. Geological Survey
St. Petersburg
Florida
USA

 

T.C.J. Hill
Department of Atmospheric Science (Atmospheric Chemistry)
Colorado State University
Fort Collins
Colorado
USA

 

C. Hoose
Karlsruhe Institute of Technology
Institute of Meteorology and Climate Research
Gebaude
Karlsruhe
Germany

 

J.A. Huffman
Department of Chemistry and Biochemistry
University of Denver
Denver
Colorado
USA

 

G. Mainelis
Department of Environmental Sciences
School of Environmental and Biological Sciences
Rutgers
The State University of New Jersey
New Brunswick
New Jersey
USA

 

D. Marsolais
Département de Médecine—Université Laval
Québec
PQ
Canada

 

O. Möhler
Karlsruhe Institute of Technology (KIT)Institute of Meteorology and Climate Research
Karlsruhe
Germany

 

C.E. Morris
Plant Pathology Research Unit
INRA
Montfavet
Franceand Department of Plant Sciences and Plant Pathology
Montana State University
Bozeman
Montana
USA

 

M.-L. Nadal
artist
Cité Internationale des Arts
Paris
France

 

P. Renard
Université Clermont Auvergne
CNRS
Institut de Chimie de Clermont-Ferrand
Clermont-Ferrand
France

 

E. Robine
Centre Scientifique et Technique du Bâtiment (CSTB)
Division Agents Biologiques et Aérocontaminants
Champs-sur-Marne
Marne-la-Vallée
France

 

D.C. Sands
Department of Plant Sciences and Plant Pathology
Montana State University
Bozeman
Montana
USA

 

J. Santarpia
WMD Counterterrorism and Response
Sandia National Laboratories
Albuquerque
New Mexico
USA

 

S.C. Saragoni
poet
Paris
France

 

D.J. Smith
NASA Ames Research Center
Space Biosciences Research Branch
Moffett Field
California
USA

 

M. Thibaudon
Réseau National de Surveillance Aérobiologique (RNSA)
Brussieu
France

 

M. Vaïtilingom
Université Clermont Auvergne
CNRS
Institut de Chimie de Clermont-Ferrand
Clermont-Ferrand
France

 

V. Vinatier
Université Clermont Auvergne
CNRS
Institut de Chimie de Clermont-Ferrand
Clermont-Ferrand
France

 

N. Wéry
LBE
INRA
Narbonne
France

Preface

Despite its proximity, the air we breathe is an environment where the biology and its spatial and temporal variability remains poorly known and understood. Many airborne biological particles, bioaerosols, are transported in the atmosphere: animal and plant fragments, pollens, fungal spores, bacteria, viruses, proteins, etc. They are present among all particle size ranges in the atmosphere, from submicron to hundreds of micrometers, at concentrations of up to billions per cubic meter of air. Among the large variety of bioaerosols, microorganisms in particular are raising interest from the scientific community. Indoor and at short spatial scale, these are mostly regarded as potential allergens and pathogens to humans. Outdoors, they can be transported over long distances up to high altitudes, and their presence is also related to epidemiology and biogeography. In addition, airborne biological particles and microorganisms probably contribute to atmospheric physical and chemical processes, such as cloud formation, precipitation, and the processing of chemical compounds. The microbial cells surviving their travel in the atmosphere are also new incomers to natural and agricultural surface ecosystems, which they will eventually colonize or where they will compete with established communities.

In this volume, current scientific knowledge about the different aspects of the research on microbial aerosols is synthesized; this consists of four parts:

We warmly acknowledge all the authors, an interdisciplinary and international panel of experts on the multiple facets of this fascinating topic, for their precious contribution and their effort in constructing this book collectively. The result is a high-level and up-to-date piece of work, which, we hope, will serve as a reference book for researchers and Master's degree to PhD students entering the emerging field of aerobiology. Finally, we are happy to thank two French artists for their humanistic bird's-eye-view contributions introducing this book.

Anne-Marie Delort and
Pierre Amato, editors

Hunting fog

At an early age, I started watching the rockets taking off from my grandfather's launch site. He didn't work for NASA though. At the age of 60, he had decided to trade his illegal hunting rifle for rockets.

The Pyrenean chamois that he had been chasing is not an easy animal to catch. One has to follow its track along craggy mountain paths. It is frail and light-footed, but also fearful and elusive. It always travels in groups. You can't ever let it see you—or smell you. You should know the territory better than your prey: the prevailing winds, and also the breezes, as well as their trajectories through the rocks.

I used to believe that the one they called the dahu1 was this trophy, this chamois that one absent-minded day ended up getting shot by my grandfather, before being skinned and stretched out on a wooden board to be exposed in the living room.

When he could no longer attend to the fate of dahus, when he could no longer set off on exploration and measure himself against faster animals, my grandfather decided to stay with us.

On his territory.

He tended to our stomachs in a wiser, slower manner, taking care of the harvest that needed so much attention. Fortunately, he had acquired during the war a slower, tenacious type of endurance, carved out over months and maybe years, and he was now able to answer vigilantly to all of the soil's demands.

The love he felt for his land was quickly overpowered by the distrust and hatred toward everything that could harm it: caterpillars, lice, mildew, mushrooms … .

But fighting all these diseases and vermin from the land was nothing compared with the swift and cataclysmic power of the weather. One summer in 1959, after a destructive rain of hail, my grandfather fell seriously ill.

He then joined another war, an insidious one, harder to comprehend. A war against anything that could come from the sky.

I don't mean a war of religion. I mean a war with no prey or ally. A war against the wind, the rain, and the importunate storms. A war for himself, which he justified by claiming it for mankind.

He would shoot rockets toward the sky as others throw bottles into the sea, because he wanted to be heard.

He attacked visible yet unpredictable targets, all potentially guilty by intent.

Alone, one knee to the ground, he would aim precisely for the heart of these masses, clouds, huge pachyderms and would set their evanescent and ephemeral souls free.

It took me a while to understand the enormous explosion that I could hear a few minutes after the launch. Even though I knew that it was all a game, I kept looking up, hoping to finally see the fireworks. But the missile would disappear in a loud and powerful discharge.

One day when I was watching him fire a rocket, the base moved during the launch, propelling it horizontally.

It spun, hit against the front of the building, bounced against a tree, and dug into the leaves before exploding over the lake a few yards away.

It was an astonishing vision when, running toward the lake, I saw the surface covered with silvery particles. The water seemed rough, thicker; as so many bubbles on a boiling pot of soup, fishes were coming up, one by one, revealing their bellies about to burst.

The lake was shiny, frozen, and lifeless. Immaculate.

My grandfather never recovered.

After that afternoon, we built him a chimney, small but firmly fixed, so he could keep on shooting at clouds.

Sitting on his chair near the pipe, fingers on the trigger, he is on the lookout: for the sky, the wind, and the humidity.

Only he knows when to shoot to avoid the hail or dry the storms.

Now he has gone, and the Météo-France2 has taken over; they call to tell us when to light up the fireplace or kill the fire. But Météo-France is far less precise than my grandfather.

Marie-Luce Nadal,
Artist and PhD Candidate,
SACRe, PSL Research University
(Paris Sciences et Lettres)

It all happens up there …

It all happens up there, inside the large floating bellies of the clouds. Looking at them, what we believe we see is their ample motion. We follow their peaceful progression. Or are they disturbing? They scud along. We imagine them to be full of a remarkable accumulation of an uncertain substance. Sometimes we think they must be heavy, even though they may be inflated only with light water vapor, whose fine and dispersed moisture weighs little, and sometimes we sense that they are much weightier, laden with water that has already formed into droplets ready to fall back down on our heads, maturing into precipitations in the form of rain, snow, hailstones, maturing into our fogs and our monsoons.

We watch the passing clouds. Ascending and sliding sideways, they seem to come to life at the point where those two intersecting motions meet. We might notice also some changes in shape as they roll, twist, contract, or stretch out. Even when combined with these other changes, the sideways slipping motion still continues, and it is this vast translatory movement in the sky that we witness most frequently: with our nose in the air, we see them traveling along up there, dressed in their suit of light, bathed in more or less pronounced shades of grey, or sparkling tons of white. That is the sight that we see, and the motion that we follow, because the other movement, that is, the ascending motion, which is how they gradually come into being, is invisible to our eyes. At the start of the journey, there was a light moisture, a vapor, a breath, which managed to rise up, to detach itself from the ground, or to take flight from the foam of a wave. It ascends, the molecules bond together, and the huge floating mass comes into being. It is the source of our dreams, and the focus of our enchanted contemplation. It questions us too: who are they? But really, who are they?

At the end of the journey, up above, the moment finally arrives when the shape that we had been following with our eyes begins to dissipate. Whether by thinning out, by dislocation, or by dissolving, its gargantuan architecture is steadily dismantled, and its bulk, once so heavy, simply melts away. Like invisible balloons falling back down to Earth, the clouds then come to rest on the page where our children are drawing pictures, and are reborn beneath their chubby fingers, which press hard on paper as they delineate these puffy giants' cheeks.

We are able to capture virtually nothing of the clouds. They are but transition and transformation. We can never grasp the definition of their being. Terms belatedly applied to their shapes enable us to improve our way of looking at them. Yet we must also accept that, each time, these names refer to a kind of transient that enjoys only a brief existence—that of the ephemeral lifespan of a form also characterized by its color, however fleeting, and an altitude at which it lingers, however briefly … .

We have always found it difficult to follow clouds, and to conceptualize them. The airplane introduced us to their vertical dimension, whose existence we had not suspected from below, and to the gigantic stature developed by their upward billowing. In this way, we gained a more accurate picture of their vast bulk. We also came to appreciate that they evolve between two or three different states of being, quivering internally with droplets of water that hesitate here and there, either to continue life in liquid form or, on the contrary, to pack tightly together into small prism or needle-shaped crystals, unless the two states briefly coexist.

And so today, we understand that an invisible other is in action in the clouds—that we must now enter into their own being, deep into the grasping of a flux that we can see even less well from below, the flux which drives their inner life, this great traffic of within, these sweeping motions in which minute particles of matter bathe, combine, and recombine, where fragments of our deserts, our meadows, and our oceans can be found, and, who knows, where one day we may be able to identify a few specks of dust from our own skins, some atoms of our own breath, anything that the wind is strong enough to carry aloft, anything which, however tiny it may be down here, then coalesces in the sky into formations of gigantic proportions.

Perched atop conveniently located hills, we probe these bellies, and take samples of this medium in which ceaseless mutations are unfolding. Is it movement, is it both direction and speed of travel that control the current state of being of the clouds, for individuals have left one aggregate behind to go and establish themselves inside another?

Is it the change of components that builds up a new kingdom, as compounds break down? Is it the predominance of specific elements that prevails and reshapes the properties of a given chunk of a cloud? We would like to grasp them more clearly, we need something to match the wanderings of our minds, a chronology of these transformations perhaps, or, for one phase of the process, an indication of the forces that prevail, even temporarily, because chemical constituents obey their own laws, but, now, molecules will be affected if exposed to stronger light, and will also react if subjected to a fading away of radiation. And then the wind gets involved, smashes up the existing masses, divides clusters of dust particles, and binds others together. It would be useful to have some large machinery, some sort of giant MRI scans, that could provide us with sections of their inner state of being. For the moment, the large machinery we have at our disposal is that of measurements. With those curves, diagrams, average values, and sharpened analysis, we are gradually building up our interpretations … .

In view of the specific nature of this constantly changing object, the study of clouds, perhaps more than any other branch of research, requires us to engage in a peculiar mental exercise, and to undergo the experience of an elusiveness perpetually renewed. Yet this feeling of the transient, which troubles our minds, once we accept it, then becomes the spring for our lively questioning; it too is continuously restored. In the quest that drives us, we are conducting an exhilarating experiment.

Today, to be sure, Caspar David Friedrich, with one foot firmly planted on a rock, stands observing the flying clouds, admiring the infinite combinations of these celestial constructions, then, his lungs replete with ethereal air, he strides back down to his laboratory.

Sara Chantal Saragoni,
poet,
Paris, France

Cela se passe là-haut …

Cela se passe là-haut, dans les grands ventres flottants des nuages. Nous croyons voir d'eux d'amples déplacements, nous suivons leurs circulations tranquilles. Ou bien inquiétantes. Ils passent. Nous nous les figurons tout pleins d'une accumulation phénoménale d'une substance à la vérité incertaine. Tantôt nous les devinons lourds certes, pourtant seulement gonflés de vapeur encore légère, par le peu de poids d'une humidité dispersée, tantôt nous les pressentons bien plus pesants, chargés d'une eau déjà formée en gouttelettes prêtes à redescendre vers nous en devenant nos précipitations de pluie, de neige ou de grêlons, nos brouillards et nos moussons.

Nous observons leurs passages. Ascension, et translation, ils semblent prendre vie au croisement de ces deux mouvements. À quoi peut bien s'ajouter quelque figure d'enroulement, de torsion, de contracture ou d'étirement. Même combiné à ces autres figures, le glissement latéral se poursuit toujours, et c'est à ce mouvement majeur de translation dans le ciel que nous assistons le plus souvent : le nez en l'air, nous les voyons là-haut voyager en habit de lumière, dans ces gris plus ou moins prononcés, et ces blancheurs étincelantes. C'est cela que nous voyons, ce déplacement que nous suivons, car l'autre mouvement, le premier, celui de l'ascension par lequel ils se sont progressivement constitués, nous ne le voyons pas. Au tout début du voyage, il y eut une humidité légère, c'était une vapeur, une haleine, elle a pu monter, s'extraire de la terre ou bien prendre son envol depuis l'écume d'une vague. Elle s'élève, les molécules se rallient, et le grand être flottant se constitue, source de nos rêves, lieu de nos contemplations enchantées. De nos interrogations aussi : qui sont-ils, mais qui sont-ils donc ?

Au bout du voyage, là-haut, arrive pourtant le moment où la forme que l'on suivait des yeux s'efface. Par amenuisement, par dislocation, par dissolution, la formidable architecture se défait, son poids, un temps si lourd, s'évanouit. Invisibles ballons revenant au sol, les nuages viennent alors se poser sur la page où dessinent nos enfants, ils renaissent sous les doigts potelés qui appuient très fort sur la feuille pour cercler d'un trait les joues des géants.

Tout d'eux ou presque nous échappe. Ils ne sont que transition, transformation. Nous ne parvenons jamais à fixer la définition de leur être. Les dénominations si tardives de leurs formes nous aident un peu à progresser dans le regard que nous leur portons. Mais ils faut accepter que ces noms désignent à chaque fois une sorte de « transitoire » qui ne se maintient qu'un temps, celui de la durée éphémère d'une forme que caractérisent également une couleur, mais passagère, une altitude de séjour, mais provisoire … Nous avions des difficultés à les suivre, à les « penser ». L'avion nous avait découvert une dimension verticale que nous ne soupçonnions pas d'en bas, un gigantisme développé dans la hauteur. Par là nous avions accédé à une connaissance un peu plus juste de leurs grands corps. Nous avions compris aussi qu'ils naviguent entre deux ou trois états de vie, tout tremblant intérieurement de gouttelettes d'eau qui hésitent ici et là sur le point de poursuivre leur vie sous forme liquide, ou au contraire de se resserrer en petits cristaux de prismes ou d'aiguilles, à moins que les deux états brièvement ne coexistent.

Et voilà qu'aujourd'hui nous comprenons qu'un autre invisible est en action dans les nuages, qu'il nous faut désormais entrer dans leur être propre, dans un mouvement que d'en bas nous voyons moins encore, et qui est celui qui anime leur vie intérieure, ce grand trafic du dedans, ces amples remuements où baignent et se combinent et se recombinent les infimes matières, où se rencontrent des parcelles de nos déserts de nos prairies ou de nos océans, et qui sait, où nous identifierons peut-être un jour quelques poussières de nos propres peaux, quelques atomes de nos souffles, tout ce que le vent a la force de hisser, tout ce qui, minuscule ici, s'accumule là-haut en formations alors gigantesques.

Perchés sur les dômes de reliefs bien situés, nous auscultons les ventres, nous prélevons des échantillons de ce milieu où se jouent d'inlassables mutations. Est-ce le mouvement, sont-ce les orientations et la vitesse des déplacements qui commandent l'état présent, des individus ayant quitté tel agrégat pour aller s'établir en un autre ?

Est-ce la modification des constituants qui, par dégradation des composés, édifie un nouveau règne ? Est-ce la présence en nombre d'éléments spécifiques qui l'emporte pour remanier les propriétés de telle portion de nuage ?

On voudrait y voir mieux, il nous faudrait on ne sait quoi qui réponde au balancement de nos esprits, une chronologie de ces transformations peut-être, ou encore, pour une phase, l'indication des forces qui prévalent, même temporairement, car les constituants chimiques vivent selon leur loi, mais voilà les molécules aux prises avec une lumière accrue qui agit, ou au contraire soumises à la diminution, tout aussi efficiente, de ce rayonnement, et puis le vent s'en mêle, bousculant les agglomérations existantes, dégrafant tels amas de poussières, en recombinant d'autres, On voudrait de grandes machines, des IRM géants nous donnant les coupes de leur état de vie.

Pour le moment, la grande machine dont nous disposons est celle des chiffres, avec leurs courbes, leurs moyennes, l'analyse qui s'affine, la construction progressive des interprétations…

Par la spécificité de son objet mouvant, l'étude des nuages, plus que d'autres recherches peut-être, commande que nous nous tenions dans un exercice singulier, que nous supportions l'expérience d'un éphémère perpétuellement reconduit. Mais ce sentiment du passager qui bouscule nos esprits, une fois admis, devient le formidable ressort d'une vitalité de questionnement elle aussi continuellement restaurée. Dans la quête qui nous anime, nous faisons cette expérience exaltante.

Aujourd'hui à n'en pas douter, Caspar David Friedrich, un pied sur le roc, regarde un temps les nuages, admire la combinatoire infinie des constructions du ciel, puis, les poumons gonflés d'air, il redescend à grandes enjambées vers son laboratoire.

Sara Chantal Saragoni,
poète,
Paris, France

Part I
Bioaerosols, Sampling, and Characterization