|1. The Great Hall of the Bulls.|
The damage and degradation of the fantastic cave art of Lascaux is a long, complicated, and depressing tale. Caves systems are remarkably fragile environments that are easily disturbed, often irreparably. Ignorance, greed, good intentions, poor oversight, denial of problems, organizational rivalries, cover ups, actions taken with no scientific evaluation, public fascination and desire to see this great human legacy -- all contributed to what happened in the cave.
How to tell this story in a reasonably short post is a challenge. I decided that a long narrative piece would actually reduce the impact of what transpired. I have opted for a more telegraphic, chronological approach because that is simpler and makes it easier to see and understand the cascade of events. It also emphasizes the compexity of the problems Lascaux faces and the difficulty in preserving the cave and its artwork. It seems that in spite of all the efforts, heroic and otherwise, the future of the Lascaux artwork remains, unfortunately, somewhat uncertain.
What is clear is that the environment of Lascaux that preserved the artwork is irretrievably gone. The enlarging of the cave opening, the high public visitation, and other factors ensured that. Efforts to try and recreate that original environment are futile. The goal now is to stabilize the cave environment and to avoid the massive shifts that have occurred since 2001. That will end the repeated microbial outbreaks that threaten the artwork and allow a program to be developed and implemented that will ensure the long-term preservation of Lascaux.
Finally, the cave paintings and etchings do not exist in isolation. They must be preserved in their context, in this case the cave and its environment. The walls and ceilings are the canvas for the art. Is those are damaged or destroyed some part of the artwork is lost, as well as some of the potential to understand this priceless heritage. The problem is not to just to prevent damage to the art, it is to preserve the cave in its entirety.
On 12 September, the dog Robot, accompanied by four French teenagers, discovers the cave of Lascaux and its paintings. For 18,000 years these paintings had been sitting in a stabilized cave environment, in an equilibrium that preserved them. That had now come to an end.
In December of that year the French government designates the cave a Historic Monument.
|2. Some of the first visitors in 1940 shortly after discovery.|
|3. Building the entrance, 1947.|
The cave is developed for public access. The entrance is widened, a concrete entrance ramp built, a bronze door installed, electricity is run into the cave for lighting, and the floor of the cave lowered for steps leading directly down to the Hall of the Bulls. To do this work, some 600 cubic meters (22,000 cubic feet) of rock and sediment was dug out and removed.
That work removed the cone of soil and rock that buffered the cave. The cave and its environment had now been completely disturbed. Cave development was spurred on by both the intense public interest in seeing the cave paintings and the desire for economic development in a rural part of post-war France.
Lascaux opens to the public on July 14 and receives as many as 1700 visitors a day. This is an impressive visitation number given the remoteness of the cave and general transportation at the time.
First signs of mold seen.
Two airlocks are installed at cave entrance.
Visitation reaches 30,000 people per year.
The first signs of deterioration appear in the cave due to excess carbon dioxide, elevated temperatures, and intermittent condensation of water on the walls. This is the result of the large number of visitors.
The first air-conditioning system is installed. Some 440 cubic meters of earth and rock are removed for the project.
Visitation reaches over 100,000 per year.
The changes in humidity and carbon dioxide cause the growth of algae (Bracteacoccus minor) on the walls of the cave. This is given the name “The Green Sickness”.
At the same time, the mineral calcite begins to form over the paintings due to condensation on the surfaces. This is given the name “The White Sickness”.
|4. The White Disease, calcite encrusting the walls.|
The growth of the green algae is such that it is now observed growing next to, and threatening, some of the paintings.
Because of the negative effects of high visitation on the cave and the artwork , the owner of the cave, Count de la Rochefoucald-Montbel, closes the cave in January. The government forbids the April reopening planned by the owner.
In addition the air-conditioning system is turned off. It is hoped that these actions will stop the cave degradation.
In March a Committee for the Study and Preservation of the Lascaux Cave (CSPLC) is established. It includes prehistorians, hydrologists, physicists, microbiologists, and curators and works to develop an intervention strategy for the cave’s problems. It meets regularly until 1976.
A program of spraying antibiotics (streptomycin and penicillin) directly on the walls to kill bacteria begins. This is intended to kill the microbes, but after the second application the treatment proves ineffective.
Following the recommendation of The Pasteur Institute, formalin is applied to affected areas in the cave. This successfully eliminates The Green Sickness but does nothing to stop The White Sickness. Formalin is a 40 per cent solution of formaldehyde (a known carcinogen in humans) mixed in water, which is used as a disinfectant, preservative for biological specimens, etc.
1965 – 1967
A new cooling system is installed based on the recommendation and study of the CSPLC. This system is designed to reduce condensation and have less impact on the cave environment because it works by convection with cave’s natural air currents.
Declaring Lascaux stabilized, the CSPLC disbands. The cave remains closed to the public.
A White Paper by the cave’s curator notes the failures of the cooling system installed in 1967. It underscores the need to limit cave visitation and installation of a new climate control system.
Research scientists notice lichens growing inside the cave.
A decision is made to replace the air conditioning system installed in 1965-1967. Although that older system used the natural air currents of the cave to stabilize the cave’s climate, the new system will use a totally different method, that of forced air.
The installation of the new air conditioning system begins. Teams of workers installing the system work unsupervised in the cave on a daily basis.
|5. The air unit installed in 1999-2000.|
Weeks after the installation begins mold (fungi) appears on the walls of the engine room inside the cave. Because of the appearance of fungi, the thermal insulation is removed from the system, which alters its effectiveness. It is thought that the cave was contaminated with the mold by the unsupervised workers who did not sterilize their boots when entering the cave.
It is now generally agreed that the new air system, because it worked via forced air, was the catastrophic act that destabilized the cave’s environment and disrupted the natural air currents within the cave. This led to the explosive microbial infestations and other disasters over the following decade.
The new air condition system is completely installed.
In a second major microbial crisis, the fungus Fusarium solani and its associated bacterium Pseudomonas flourescens has colonized and spread across the cave, forming a white coating over the floor and ledges. This fungus is common in agricultural areas, such as those surrounding Lascaux Cave, further suggesting it was brought in on the unsterilized boots of the workers.
Massive amounts of antibiotics and fungicides (streptomycin, polymyxin, benzalkonium chloride) are sprayed on the affected areas, but this proves ineffective. The application leaves large spots, up to six inches across, on the walls. Within weeks after the spraying the fungus reappears and quickly develops a resistance to the antibiotics being applied.
Cloth compresses soaked in fungicides and antibiotics are applied directly to the cave’s walls.
|6. Biocide soaked sheets on unpainted cave walls.|
When it is realized that the biocide and fungicide applications are not working, an emergency effort is implemented. Quicklime is spread all over the cave floor. The intent is to sterilize the ground and stop mold growth.
|7. Quicklime on the floor near the entrance to the Hall of the Bulls.|
Quicklime is a caustic calcium oxide and releases significant heat when reacting with water. As a result, the application of the large amounts of quicklime causes the cave’s interior temperature to rise. Because of its strong reaction with water, quicklime can cause severe irritation when inhaled if it is in contact with moist skin or eyes.
Recognizing that the just installed forced air system is not appropriate to the cave environment, authorities shut most of it down.
Dark spots now begin to appear on the ceilings of the decorated chambers. The decision is made to start invasive mechanical removal of the fungus, scraping and pulling fungal “roots” (hypae) out of the rock by hand. This work requires bright lights, which affects the cave’s temperature.
The massive spraying of antibiotics is terminated.
The French Ministry of Culture appoints a new scientific commission which is to examine the impacts of previous emergency measures on the paintings and develop a strategy to stabilize the cave environment.
Mechanical removal of fungal hyphae continues, resulting in teams of workers continually inside the cave.
The problems at Lascaux captures the attention of the press, with exposés appearing in La Recherche, Le Point and The Wall Street Journal.
The new scientific committee releases its plan with short, medium, and long term components.
A 3D survey of the cave begins. This is intended to document baseline conditions so that changes and effectiveness of actions can be evaluated.
|8. Scaffolding erected as part of the cave survey.|
Although the growth of fungi is slowed by the program of mechanical removal, the fungi are not eliminated. Teams continue to work inside the cave.
The 3D survey of the cave is completed.
An exhaustive and detailed survey begins to document artwork and etchings throughout the cave. Work is carried out by art restorers with assistance from geologists.
A digital simulation of the cave is developed to model how the addition of equipment, changes in air flow, etc. will affect the cave environment. This will help decide what kind of air regulation system should be installed in Lascaux.
Hydrologists begin a study of condensation and groundwater movements to understand what role they may have played in growth of white mold and black stains.
The International Committee for the Preservation of Lascaux is established. Its goal is to preserve the prehistoric paintings in the cave of Lascaux. It also works to raise public awareness about the deterioration of the cave and the art and stimulate public action to safeguard Lascaux’s artwork and interest scientists from diverse disciplines in Lascaux’s preservation. This organization is not part of the French government and is suspect of much of what the French government is doing at Lascaux. This relationship becomes increasingly confrontational over time, with the ICPL charging the French government of a cover-up of the threats and damage to the paintings and etchings.
In what is the third major microbial crisis, large numbers of new clusters of black spots appear near the cave entrance? Although reported, they are not analyzed. By the end of the year they have spread throughout the cave. They begin to cover paintings. Biologists cannot identify what species of mold makes the black spots, do not know what made them appear and grow explosively, and cannot recommend a treatment strategy.
|9. Microbiological sampling of a black, discolored area.|
Removal of fungus by mechanical means continues. This work is being done by unsupervised teams of three to four people working all day three times a week. Teams consist of art restorers, scientists are not part of the teams. The art restorer work requires additional lighting that raises the temperature. The number of people and the amount of time they are in the cave are well above the levels known to have impacts on cave environment.
Small meteorological stations are set up in the cave to monitor microenvironment to investigate changes in microorganisms and changes in environment.
There is little scientific follow up. Scientific specialists, such as microbiologists, come only twice a year to the cave.
The workers lean ladders against unpainted parts of the wall. Ladders of the workers lean against the walls (un-painted) breaking off some ledges. Prehistoric paint drippings on ledges in the Hall of the Bulls are lost when the ledges are accidentally broken off.
The decision is made to remove the quicklime put in the cave in 2001 to control fungal growth. This requires digging up the quicklime. In some areas the cave floor itself is excavated.
Calcite mineral deposits are appearing on the paintings themselves, as well as the walls.
Color tones on some paintings are beginning to fade.
The ill-fitted air machine is operating on a partial basis but is not able to stabilize the cave environment.
The May 16 edition of TIME runs the Lascaux crisis as its cover story: http://www.savelascaux.org/TIMEMagazine.pdf
The black spots, some as large as human hands, continue to grow everywhere in the cave. The number of spots triples in late summer 2007. They are still unidentified. Even so, a debate erupts over what to do about them. Some want to start to again spray antibiotics on the cave walls. Others oppose that because of problems caused by the previous spraying. The decision is made to spray the cave and then close it to all human access.
|10. Spraying biocides on part of the cave roof with no artwork on it.|
Lab work reveals that the black spots contain melanin which is triggered by light. There is a strong suspicion that the invasion and explosive growth of the black spots is the result of extensive use of lights by the survey and restoration teams that have been working in the cave for the last four years.
The head of the famous Black Cow painting is now threatened and surrounded by the black spots.
Six additional genera of fungi are reported in the cave (Chrysosporium, Gliocladium, Gliomastix, Paecilomyces, Trichoderma, Verticilium).
The air conditioning system is finally completely shut down.
A new study is launched to analyze historic data and draw up specifications for a new climate regulation system.
A temporary roof set up in 2000 to aid in the installation of the air system is exposing the cave to sudden variations in exterior climate and precipitation.
The cave has become very wet. Water is observed running down many of the paintings.
The white calcite which forms the bright canvas for the Lascaux paintings is turning gray.
Because of the worsening conditions, Lascaux Cave in placed on the World Heritage in Danger list by the United Nations Educational, Scientific and Cultural Organization (UNESCO).
Fifty percent of the cave walls are infested with the black dots, including areas such as The Nave and the Passage which contain much artwork as well as the area with 1600 prehistoric engravings (the highest concentration in the world).
The melanin produced by the bacteria stains the walls and remains even after the bacteria are killed. The melanin might be a permanent alteration to the cave and the artwork.
An experimental approach to remove the melanin is undertaken. This involves physically scraping the walls affected. This scrapping removes the melanin but also the outer surface of the wall, painted or not. New biocide treatments are also started.
After mechanical treatment is completed, a Gregomatic is used to remove residual organic deposits from undecorated areas. A Gregomatic injects pure cold water onto a stone surface and immediately vacuums up the water and the loosened material, and cleans the pores of the rock surface. The Gregomatic is designed to remove dust, dirt, grease, bacteria and poisonous substance from the surfaces.
French National Television claims that the Lascaux crisis is solved. The International Commission for the Preservation of Lascaux (ICPL) disagrees and condemns the process of scraping the melanin.
Although French officials claim that the cave is reaching a microbiological equilibrium, scientists dispute that. Antibiotic sprays kill some of the bacteria, but the spray contains chemicals that are nutrients for other microorganisms. This further disrupts the microbial community which must reach another state of equilibrium. The problem is that no one can predict if this new equilibrium will be favorable or unfavorable to the cave art.
The magazine Archaeology runs a story Who’s Killing Lascaux? http://www.savelascaux.org/Archaeology%20May%202008.pdf
In January 2009, concerned scientists and citizens establish Lascaux International Scientific Thinktank. This organizations purpose is based on the belief that :
“a multidisciplinary approach involving "hard sciences" like microbiology (bacteriology, mycology, biofilms), physics, chemistry, climatology and physical-chemistry, conducted independently from the administration which remains responsible for making the decisions and implementing them, is the only way to identify the real causes of microorganism proliferation in the cave and to propose the most adapted curative measures to treat it.”
Based on analysis of data, human presence in the cave is restricted to 800 hours per year. This includes maintenance activity as well as scientific research. New restrictions require all visitors to the cave to wear sterile white coveralls, a plastic hair caps, latex gloves, and two pairs of slip on shoe covers. The shoe covers replace the previous practice of having visitors step into an antibacterial liquid bath. That bath was later determined to have further disturbed the cave’s microbial community.
Entering the cave is now made through two airlocks. These are designed to keep out the external humidity but still allow for the natural air currents that enter the cave through natural crack systems.
In February the French Ministry of Culture convenes an international symposium “Lascaux and Preservation Issues in Subterranean Environments”. Attended by three hundred participants from seventeen countries, the symposium brought experience elsewhere in the world in the area of cave preservation to bear on the problems of Lascaux. Participants included specialists from diverse disciplines (biology, biochemistry, botany, hydrology, climatology, geology, fluid mechanics, archaeology, anthropology, restoration and conservation). However, by November the International Committee for the Preservation of Lascaux is publicly claiming that the French government is willfully ignoring critical conclusions of the symposium, to the detriment of Lascaux.
Ten genera of bacteria are reported present in Lascaux (Ralstonia, Psudomonas, Exherichia, Achromobacter, Afipia, Ochrobactrum, Legionella, Alcaligenes, Stenotrophomonas, Symbiobacterium). No studies had been done on the bacteria of Lascaux before the benzalkonium chloride treatments, so there is no way to know what the original bacterial community was and how it has been changed by the treatments. However, there two of the bacteria in the cave (Ralstonia and Pseudomonas) are biocide resistant strains and might have evolved that resistance as a result of the treatments. Legionella is pathenogenic to humans and is the infectious agent causing Legionnaire’s disease.
Ten species of fungi are reported from Lascaux (Penicillium namyslowskii, Isaria farinose, Aspergillis versicolor, Tolypocladium cylindrosporum, richoloma saponaceum, Geomyces pannorum, Geosmithia putterillii, Engyodontium album, Kraurogymnocarpa trochleospora, Calvicipitacea sp.). Only two of these are soil bacteria. The rest are bacteria that attack and feed on insects. The other fungi may have been brought into the cave as various small arthropods invaded it.
The rarity of Fusarium in 2010 suggests that the prolonged biocide treatments had drastically reduced the populations of this fungus.
Analysis based on samples collected between 2007 and 2009 found the fugus Scolecobasidium tshawytschae frequently isolated from the black stains. This species is known to synthesize melanin. It is usually rare in its normal environment of soil and decaying leaves. Researchers think the degradation of benzalkonium chloride by cave bacteria provided a source of nitrogen and carbon source that allowed Scolecobasidium populations to explode.
In February 2010 the French government establishes a new Scientific Council to oversee the conservation of Lascaux. However, the Lascaux International Scientific Thinktank is critical of the committee because they feel the committee composition is not appropriate for a multidisciplinary approach to the problem and is not independent of the government agencies administering the cave. This working relationship becomes more strained over time.
The fungus-eating springtail soil arthropod Folsomia candida is discovered in and around the black stains. This animal is found in caves where the cave is disturbed and normal cave dwelling arthropods are absent. They probably entered Lascaux from leaf litter outside, attracted by the abundant food sources of the various microbial outbreaks in the cave. Folsomia candida feeds on both Scolecobasidium and Fusarium, the fungi responsible for two of the microbial outbreaks. The fecal pellets of Folsomia contain abundant fungal spores. Thus the springtails feed on the fungus and wander around the cave walls defecating fungal spores. This dispersal may account for the very rapid spread of the fungi in the cave.
In January The Ministry of Culture issues a report on the conservation status of Lascaux Cave. It briefly describes what happened at Lascaux, the major efforts underway, and makes the claim that the cave environment is stabilized and many areas show reduction or disappearance of fungal infestations. Work hours spent in the cave is kept low and the access criteria have been strengthened. Monitoring of microbial problems continue.
The proceedings of 2009 symposium are published in 2011 in a volume which is composed of the studies presented during the sessions and full transcriptions of the debates. Given the importance of Lascaux, the intense international interest in the cave, and the severe threats to one of the world’s great cultural resources it seems unfortunate that the report was not made freely available on line, rather than as a book to be sold.
1. Lascaux Cave - Grotte de Lascaux http://www.donsmaps.com/lascaux.html
2. All others: http://www.lascaux.culture.fr
1. International Committee for the Preservation of Lascaux
2. Lascaux, Wikipedia http://en.wikipedia.org/wiki/Lascaux
3. Lascaux Cave - Grotte de Lascaux http://www.donsmaps.com/lascaux.html
4. Lascaux International Scientific Thinktank http://louxorsarl.free.fr/LIST/indexLISTenglish.html
5. Time Magazine http://www.savelascaux.org/TIMEMagazine.pdf
6. Bastian, F., Jurado, V., Novakova, A., and Alabouvette, C. 2010, The microbiology of Lascaux Cave. Microbiology 156: 644-652. Freely available on line at http://mic.sgmjournals.org/content/156/3/644.short?cited-by=yes&legid=mic;156/3/644
For the more technically curious reader, this review paper is a good summary of recent work on the cave’s microbiology and an excellent lead into the primary scientific literature, most of which is quite recent.
8. Report on the conservation status of Lascaux Cave 31st January, 2011 www.culture.gouv.fr/culture/dp/archeo/pdf/lascaux_unesco2011.pdf Media Release by the Ministry of Culture and Communication
Translated and abridged by Don Hitchcock http://www.donsmaps.com/lascaux.html
9. Archaeology http://www.savelascaux.org/Archaeology%20May%202008.pdf
10. Preservation Interventions. Lascaux. http://www.lascaux.culture.fr/