Environmental Effects of French Nuclear Testing
The following report has been distributed by the International Physicians for the Prevention of Nuclear War and the Institute for Energy and Environmental Research, as a result of renwewed interest in French nuclear testing in the South Pacific. It is an updated version of Chapter 9 from the book "Radioactive Heaven and Earth: the health and environmental effects of nuclear weapons testing, in, on, and above the earth."(New York, Apex Press, 1991) It is one of the few published sources for information on this subject, and reveals that although only limited environmental impact reports have been conducted in French Polynesia,and despite restrictions imposed by the French, they still highlight the threat to the environment in the Pacific posed by the French nuclear testing programme.
The report contains information under the following headings:
For further information concerning the effects of nuclear testing on the health of French Polynesians, click here
- Locations, Numbers and Types of Tests
- Historical Context of Testings
- Downwind Communities
- Army Personnel
- Hot Spots
- Environmental Effects of Atmospheric Testing
- Environmental Effects of Underground Testing
- References
For an update on the latest news concerning nuclear testing and disarmament issues, click here
Locations, Numbers and Types of Tests
The first French nuclear tests were conducted in Algeria between 1960 and 1965. The first test took place on February 13, 1960 at Reggan when Algeria was still a colony in the throes of a war for independence. In all, fourteen nuclear weapons tests were conducted at the two Algerian locations, four atmospheric and 10 underground. The French government made preparations to move the testing to its colony Polynesia after Algeria won its independence.
The French test sites in the Pacific are Moruroa and Fangataufa, two atolls in the southeastern area of the Tuamotu Archipelago, French Polynesia. The Moruroa Atoll (21.83o Southern latitude and 138.88o Western longitude) is one of the largest coral atolls in that area. The atoll, in the form of an incomplete ring encircling a lagoon, measures 26 km. east to west and 10 km north to south. The 65km.-long reefcrown, with a mean height of 2 meters and rarely exceeding 400 meters in width, is open, leaving a 5-km-wide passage into the lagoon on the northwestern side. The lagoon has an average depth of 40 meters and is the crater of an extinct underwater volcano, around which outer coral has grown above sea level to form the visible rim. The distance to the nearest inhabited island (Tureia) is 100 kilometers, the distance to Tahiti is 1,200 kilometers, and New Zealand is 4,200 kilometers away. The atoll was uninhabited before the installation of the test center.(1)
Fangataufa, a much smaller atoll, is located 41 kilometers south- southeast of Moruroa (22.25o Southern latitude and 138.63o Western longitude). It measures 5 by 8 kilometers and was also uninhabited before the tests. In contrast to Moruroa, Fangataufa was a closed atoll. The French military therefore opened a 400 meter gap in the coral ring to enable ships to enter the lagoon.(2)
From 1966 to 1990, 167 nuclear test explosions have been performed on these two atolls. These tests were used for the development of at least eight types of nuclear warheads. Of the 167 tests, 44 were atmospheric, 39 over Moruroa, 5 over Fangataufa. The overall yield of these atmospheric explosions was 12,000 kilotons of TNT. The first atmospheric test was performed on Moruroa on July 2, 1966, the last on September 15, 1974. Most of the early tests were performed on the surface or on a barge anchored in the lagoon. Because of the large amount of radioactive fallout resulting from the low burst altitude, most further tests were performed with warheads hanging under balloons. Very few tests were conducted as air-drops from planes. One test, designed to check the security apparatus of the warhead, resulted in no nuclear detonation, but the fragmented bomb spread huge amounts of plutonium over the coral rim. The first explosion of a two stage fissionfusion device on August 24, 1988 at Fangataufa was also the largest explosion, with a yield of 2.6 megatons.
After June 5, 1975 the tests were conducted underground. Since then between 4 and 11 underground explosions have been conducted each year. Of the total, 3 were in Fangataufa in 1975 and 1988, the other 120 at Moruroa. The yields of these explosions have never been officially released but the total yield is estimated at about 2,500 kilotons TNT. This estimate is based largely upon observations by the New Zealand Department of Scientific & Industrial Research (DSIR) and the Swedish National Defense Research Institute (FOA), which recorded and analyzed the seismic data from these tests.(3)
The underground tests have been conducted at the bottom of shafts bored 500-1200 meters into the basalt core of the atoll. Initially these shafts were drilled in the outer rim of the atoll. In 1981, most likely due to the weakening of that rim, the tests with higher yields were shifted to shafts drilled under the lagoon itself. In 1986 all tests were shifted to this so called 'zone-central'.(4)
The independence of Algeria in 1962 threatened further testing at the Algerian sites. The French Defense Department therefore started to look for other suitable test sites. Possible locations included Clipperton Island in the Pacific as well as the Kerguelen Islands in the Southern Indian Ocean, which were eventually ruled out because of their hostile climate and remote location. The final decision was in favor of the uninhabited islands of Moruroa and Fangataufa, and in 1962 the 'Center d'Experimentation du Pacifique' (CEP) was established.(5)
The main argument favoring the selection was that only 5,000 inhabitants lived within a 1,000 kilometer radius of the planned ground zero in Moruroa and that it would therefore be suitable for atmospheric testing. Although the 1963 Limited Test Ban Treaty banned the testing of nuclear weapons in the atmosphere, underwater and in space, France was not a signatory to it, and the French government under President de Gaulle announced that it would continue its atmospheric nuclear tests using the Moruroa Atoll. (According to US government sources, President Kennedy offered help in the development of a French nuclear program if France would stop atmospheric testing. This offer was refused by the French government.)(6)
In 1972 the French government bowed to public pressure from Pacific and Latin American countries. The government tried to find a suitable location for underground testing. The island initially considered, Eiao, in the Marquesas Group, was found to be unsuitable because of fragile basalt layers. In 1973 Fangataufa was chosen, and in 1974 President Giscard d'Estaing announced that as of that year only underground tests would be performed. After initial tests in Fangataufa, the testing was moved back to Moruroa, presumably to avoid the costs of running two test-sites.(7) However, after many tests, Moruroa was deemed to fragile for larger underground testing, and in 1988 a high-ranking French officer commented that the larger tests would be relocated to Fangataufa to avoid serious damage to the rock of Moruroa. Although the remark was later denied, on November 13, 1988 a test was performed at Fangataufa.(8)
Sources of reliable information on the tests and their outcome are extremely limited due to the extreme secrecy of the French military. Limited investigations by four groups have been permitted by the French authorities in recent years: a French scientific mission in 1982;(9) a New Zealand, Australian, and Papua New Guinea scientific mission in 1983;(10) the Cousteau scientific mission in 1987;(11) and the mission of the associated French Physicians for the Prevention of Nuclear War (AMFPGN), the IPPNW affiliate, in 1990.(12)
The reports of these committees are the most important available source of information on the consequences of the testing. All these missions were extremely restricted in duration, 3-5 days, and in preparation time. They were, therefore, only exploratory. All four missions were restricted in their access to relevant data, sites or samples, such as coral and sediment from within the lagoon and specific areas of the atoll. Epidemiological data presented by French authorities were insufficient or unreliable. Despite these deficiencies, these studies as well as New Zealand and Swedish seismic data are, to date, the best sources of information on the effects of French testing.
The French government has not made public any documents about nuclear tests in Algeria. In the absence of official documentation about armed forces participation, participation of Algerians and dose and contamination levels, there has been considerable speculation and rumor about all of these subjects. The one figure that we have seen on radiation doses was reported by Greenpeace:
"The first underground test, on 1 May 1962, code-named Beryl, was to test the prototype for the AN 11 bomb for the Mirage IVA aircraft. Despite adverse winds, and against the advice of the Commission of Nuclear Safety the explosion went ahead because two VIPs, one from the Ministere des Armees, were present. Twelve soldiers were contaminated when radioactive vapor escaped through a fissure in the rock; nine of them received more than 100 rem of radiation."(13)
Moruroa was selected for atmospheric testing because only 5,000 inhabitants lived within a 1,000 kilometer radius of the testing site. Yet, the initial dangerzone around the test site, which was to be kept free of planes and ships during a test, contained seven inhabited atolls. When this was pointed out to the French authorities, they reduced the radius of the zone designated as dangerous, but the atoll of Tureia, with around 60 inhabitants, 100 kilometers away from Moruroa, remained in the danger area. This island seems to have received severe radioactive fallout several times. One occasion was the test series of JuneJuly 1967, when two French meteorologists on Tureia were evacuated two days after a test and transferred to the hospital at Hao. A complete evacuation of Tureia took place in 1968.(14) Despite these evacuations, the French authorities described the radiation doses on Tureia and Gambier from these tests as never exceeding 75 millirems per year.(15)
The French Atomic Energy Commission acknowledged many years later that the 1966 Aldebarran tests covered the islands of Mureia, Tamoure, and Gambier with radioactive fallout resulting in radiation doses of 200 to 400 millirems.(16) Because the immediate downwind communities are very small and under the control of the French government and independent radiation data are not available, the impact of the atmospheric tests on nearby communities cannot be judged. French military control over the health system of Polynesia is an obstacle to data collection. Health statistics from the period of atmospheric testing were either not collected, poorly collected, or not published. Missions of longer duration, a lifting of the "military secret" classification on health and environmental aspects of testing, and careful epidemiological surveys would be needed to assess the radiological impact of testing on the health of the population across the region.
The most intense monitoring program of the Pacific region was performed by the National Radiation Laboratory of the New Zealand Department of Health, in co operation with the Meteorological Service, the Australian Radiation Laboratory, and the governments of various Pacific islands. These measurements show that, although fission products from the tests were expected to circle the globe in an eastward direction, reaching the southern Pacific again after three weeks, rapid changes in radioactivity concentration in the days immediately after a test were occasionally observed in various Southern Pacific monitoring stations, indicating that radioactive material had been caught up and swept west to the central South Pacific.
The whole South Pacific should be considered a downwind community. Total beta activity in the air was elevated for all monitoring stations in New Zealand as well as on Pacific islands including Fiji, Samoa, Tonga and Tahiti for the whole period from 1966 to 1975. The same is true for total beta activity in rain. Measurements of gamma emitters in air at Tahiti returned to pre test levels in 1975, after being elevated for the five previous years. Approximate mean effective dose equivalent commitments from nuclear test fallout in New Zealand, Fiji and Tahiti normalized finally between 1975 and 1980.(17) All these data suggest a strong linkage between the concentration of fission products and French atmospheric tests from 1966 until 1974.
In a broader sense, downwind communities also include the South American countries. Most tests were performed with winds blowing to the east to avoid direct contamination of the Pacific islands west of Moruroa. Radiation levels up to 12 millirems were attributed to the French test as far away as Peru and Baja California.(18)
The tests at Moruroa are shrouded in extreme secrecy. All exposure information is controlled by the French military and nuclear establishment. Measurements of radiation exposure of armed forces personnel have never been made available the scientists or the public. No known followup of exposed personnel of the sort that was done on British, Australian and New Zealand personnel involved in British tests has taken place. Nevertheless, it is reasonable to assume that comparable exposures have occurred. Measurements were performed by airplanes and helicopters flying into the radioactive clouds. There are also reports of equipment, planes, ships and shelters needing to be decontaminated after certain tests.(19)
To estimate the number of potentially exposed personnel it is relevant to consider the organizational structure of the CEP. The Center is run by the government authority 'Directions des Centres d'Experimentations Nucleaires' (DIRCEN), under the control of the French Ministry of Defense. This authority has personnel on the atolls of Moruroa and small peripheral stations on the atolls of Tureia, Tematangi and Reao. Between 3,000 and 3,600 people, military and civilian, are based at these locations. In the early 1960's the atoll of Hao was used as a rear base for assembling the nuclear weapons to be tested, which came from France by plane. This airbase, 400 kilometers northwest of Moruroa, houses around 400 people, of whom 270 are French military personnel. An additional 1,100 people are based in Tahiti, providing the administrative and back-up services for the testing center.(20)
The first and only report about the problems encountered by personnel at the CEP came from the civilian technicians and engineers employed to conduct the tests on the atoll. A report by their trade union released in 1981 gave detailed information on the careless way in which waste has been managed on the Moruroa Atoll. The report does not contain radiation measurements.(21)
In summary, it seems highly likely that French and Polynesian civilian and military personnel at the CEP were exposed to radiation from the tests. However, the health implications of this exposure cannot be stated with any precision, due to lack of published radiation exposure data, epidemiological studies, or reasonable followup.
At least two hot spots in the South Pacific have been identified by radiation measurements. Both are linked to rainouts. One occurred in Samoa, 3,610 kilometers from Moruroa, on September 12, 1966. This was a consequence of the test Betelgeuse on the previous day, in which a 120 kiloton bomb hanging under a balloon was exploded at a height of 600 meters, despite worsening wind conditions. (President de Gaulle attended this test, and it has been suggested that this was why the bomb was detonated in spite of unfavorable winds.)(22) As a result of that rain-out, the total beta activity in rain in Apia/Samoa in the year 1966 increased from a normal level of around 200 megabecquerels per square kilometer to 370,000 megabecquerels per square kilometer.
Another incident of similar magnitude occurred at Tahiti on July 19, 1974, following a test on July 17 or 18 of unknown yield and burst height. As a consequence, the average annual concentration of total beta activity in the air, which is normally below 0.3 millibecquerels per cubic meter, increased to 1,460 millibecquerels per cubic meter in Papeete Tahiti. The effective dose equivalent from nuclear test fallout due to external shortlived gamma exposure increased from below 1 millisieverts to 154 millisieverts.(23) It is not known whether there have been additional incidents because detailed information for other locations in French Polynesia is not available.
The total amount of plutonium-239 dispersed as a result of the 45 announced French atmospheric tests, including the four in Algeria, would be about 6750 curies, assuming 150 curies per test. Table 2, in Chapter 3, gives an estimate for the fission yield of the announced French atmospheric tests of about 10.9 megatons. On this basis, the amount of cesium-127 and strontium90 dispersed would have been 1.7 million curies and 1.1 million curies respectively. About onehalf of the cesium and strontium still remains in the atmosphere, on the ground, and in water bodies. French testing in the Pacific was the source of almost all the atmospheric fission product contamination, due to the much larger number of tests and the far greater yields of the French tests there than in Algeria.
The possible environmental effects of underground testing include short-term and longterm effects. At the time of the explosion, fracturing of the atoll surface triggers landslides, tsunamis (tidal waves), and earthquakes. There is also evidence that radionuclides have vented to the environment. Possible long-term effects include leakage of fission products to the biosphere and transfer of dissolved plutonium from the lagoon to the ocean and the food chain.
- Physical Damage to the Reef
The upper layer of the atoll is made up of reef carbonates, mainly limestone. This limestone cover is approximately 300 meters in the south of the atoll, increasing to 430 - 550 meters in the north. The upper part of this limestone layer is undolomitized and comprises porous coral debris, approximately 125 meters thick. The lower part is dolomitized and therefore quite compact.
This limestone layer is separated from the underlying volcanic material by a transitional zone of variable thickness, composed mainly of weathered clays. It can vary in thickness from 40 to 45 meters below the atoll to a mere 50 centimeters or even nothing beneath most of the lagoon.
The clay zone is impervious. The underlying volcanics are initially aerial volcanics, which then change to more homogeneous submarine volcanics at greater depths.
Each scientific mission to Moruroa has described severe impairment of the integrity of at least the carbonate part of the atoll. The damage includes fissures in the limestone and surface subsidences of large areas of the atoll. Fissures are propagated by the testing, a result of the cumulative compacting of the limestone. Fissuring serves to increase lateral and vertical water transport in the carbonate body of the atoll,(24) possibly resulting in more rapid leakage of the fission products. The French authorities claim that no new damage is occurring because the tests are no longer conducted under the reef crown but under the lagoon.(25) This claim is contradicted by underwater observations of the Cousteau mission, which discovered recently fallen noncolonized limestone blocks, suggesting that tests were carried out in the months immediately preceding their arrival and that on-going tests are still damaging the reef. (26)
- Triggering of Landslides, Tsunamis and Earthquakes
At least one major test-related landslide and consequent Tsunami in Moruroa, on July 25, 1979. Apparently, the 120kiloton weapon, which was supposed to be lowered into a shaft of 800 meters, got stuck at a depth of 400 meters and could not be dislodged. The French authorities decided to explode the device anyway. This explosion resulted in a major underwater landslide of at least one million cubic meters of coral and rock and created a cavity, probably 140 meters in diameter. The underwater landslide produced a major tidal wave comparable to a tsunami, which spread through the Tuamotu Archipelago and injured people on the southern part of Moruroa Atoll. (27)
French authorities initially denied that any mishap had occurred and declared that the tidal wave was of natural origin, but in a publication in 1985 they did acknowledge "the accident of 25 July 1979".(28)
- Venting of Gaseous and Volatile Fission Products
Unusual concentrations of short-lived iodine131 in marine organisms and krypton 85 and tritium in air or water indicate that venting has occurred.
The scientists of the Australia, New Zealand and Papua New Guinea Mission in 1983 were authorized to carry out a single experiment in situ at Moruroa. Their measurements demonstrated a high level of tritium in the interstitial air of the surface terrain. The measured tritium levels were 500 Becquerels per liter while the expected concentration due to atmospheric fallout should have been in the range of 0.2 Becquerels per liter. The report of this mission offers two explanations for these extremely high unexpected tritium levels: either venting of gaseous tritium directly from underground cavities or a faster ground water flow rate than admitted. (29)
The venting explanation appears to be more likely, based on findings of Cousteau mission in 1987. Just days after a test, iodine 131 (half life of 8.05 days) was found in all sediment samples. The same mission measured radioactivity of plankton, which is an even better indicator of venting. In plankton, they found an iodine131 concentration of 22,000 picocuries per kilogram, by far the strongest radioactivity found during their mission. The Cousteau report stated that iodine-131 most likely reached the surface via the test bore. The report overlooked the fact that the spot with the maximum iodine131 concentration in sediment was the farthest away from the test site. Nevertheless, because of the short halflife of this radioisotope, its presence could only be attributed to a recent emission. Although authorities at the testing center claimed that this was due to an accidental leak of exceptional character during post-test drilling for purposes of monitoring, the Cousteau Mission was not able to verify that directly.(30) In any case, even such a posttest valve decoupling accident constitutes a venting phenomenon. The fact that the French did not report this venting accident until forced to do so by having to explain the presence of iodine131 indicates that venting may have been more common than the French nuclear authorities have so far acknowledged.
In summary, two scientific missions, on which major restrictions were imposed, were still able, independently of each other, to find typical indicators of short-term venting.
- Medium and Long-term Leakage of Fission Products to the Biosphere According to a model formulated by Hochstein and O'Sullivan (1985), an underground nuclear explosion in rock saturated with seawater can set up an artificial geothermal system. The heat stored in the explosion chamber is on the order of 10E12 calories per kiloton of yield. In addition, heat generation due to radioactive decay goes on after the explosion of fission bombs, at a rate of about 595 calories per second per kiloton of yield. After the explosion, seawater enters the chamber and is heated by about 25o - 50o C by both stored and newly generated heat. The heated seawater dissolves the glassy materials, liberating the nuclear waste.
At the same time, the heated seawater sets up an artificial geothermal system, which transfers the dissolved nuclear waste slowly upwards through the extended chimney. While the concentration of the radionuclides decreases by diffusion and absorption, the heated cell transferring the radionuclides moves upwards with a speed of about 10 meters per year, according to the computer simulation of Hochstein and O'Sullivan. Under the assumptions of this model, radionuclides from a depth of around 500 meters would reach the cracks of the lagoon in less than 50 years instead of the 500 to 1,000 years assumed by the French authorities.(31)
A first hint that the model of Hochstein and O'Sullivan might be correct was the discovery of cesium-134 by the Cousteau Mission in 1987.(32) In December 1990, too, Greenpeace found cesium-134 in plankton collected outside the 12-mile exclusion zone around Moruroa.(33) While the measured concentrations of cesium-137 are consistent with the consequences of local and global atmospheric tests, the concentrations of cesium134 are less explicable. Global atmospheric fallout does not contain cesium134, which is produced by the addition of one neutron to the nucleus of stable cesium-133.
A recent study reviewing the Cousteau Mission's water samples comes to the conclusion that the measured concentrations of cesium-134 are attributable to the underground tests and that only leakage can explain the presence of this radionuclide in Moruroan waters. This study also attempted to identify the source of the leakage by matching the coordinates of French underground tests with the coordinates of the places where samples were taken. Leakage is occurring even faster than initially predicted by the model of Hochstein and O'Sullivan (which assumed equal permeability in all directions), probably only six years after a test.(34) Venting, which happens occasionally, may open pathways for more rapid leakage than predicted by the model.
The 120 underground tests conducted at Moruroa have in effect turned it into a longterm waste dump. The total amount of plutonium-239 from these tests and the three at Fangataufa is about 18,450 curies, assuming 150 curies per test. Based on a rough estimate of 2.5 megatons total yield of underground tests, the amount of cesium127 and strontium90 dispersed would have been 400,000 curies and 250,000 curies respectively. About three-fourths of the cesium and strontium still remain underground and some may have found its way into the lagoons and ocean. As a repository for nuclear wastes from underground testing, Moruroa is less than ideal. Natural barriers play the most important role in the confinement of nuclear waste.(35) Consequently, a planned storage site should meet very strict criteria including exclusion of water, lack of natural fractures or fissures, and a high absorption of radionuclides. According to these criteria, Moruroa is a very poor choice: the geological structure of Moruroa is water-saturated; there are natural fractures as well as a veritable network of fissures due to the explosions. These fissures affect the volcanic layer. Moreover, the absorption coefficient for the basalt of Moruroa as estimated by the French authorities is very low.
In conclusion, Moruroa Atoll is a very poor site for storing nuclear waste of any type. If certain confinement criteria are considered necessary for the storage of waste from nuclear power stations, the same would be necessary for the storage of waste as a consequence of nuclear explosions. The discovery of cesium-134 indicates only the beginning of longterm leakage from the underground "storage" sites.
Transfer of dissolved plutonium from the lagoon to the ocean as a consequence of poor waste management.
Radioactive materials deposited on Moruroa have found their way into the lagoon. The land area of Moruroa has been used to store radioactive waste (including metal scrap, wood, plastic bags and clothing) in a huge heap on the north coast of the atoll, which covers 30,000 square meters. In addition, on July 21, 1966 a bomb broke apart on the surface of Moruroa, dispersing plutonium239. This plutonium 239 was confined to the area by fixing it in place with a layer of bitumen. Moruroa was also used as a safety trial area.(36) (A safety trial area is a test to check whether an atomic bomb will explode on impact with a hard surface -as in the event of a plane crash. In the case of a "safe" bomb, or a "successful" safety trial, the impact does not cause a nuclear detonation but breaks apart the bomb, scattering plutonium-239 about the site.) Cyclones hit Moruroa mainly in 1981, washing radioactive waste from the coral rim into the lagoon, including the plutonium-impregnated bitumen.
Due to these waste management practices, the sediment of the lagoon contains an estimated 20 kilograms of plutonium. At the time the Australian, New Zealand and Papua New Guinea Mission visited Moruroa, plutonium239 concentrations in the air were about 4 times greater than in continental France. The Mission estimated that about 20 gigabecquerels of plutonium from the sediment of the lagoon are transported annually to ocean waters.(37)
This is consistent with findings of the Cousteau Mission that concentrations of plutonium in the lagoon entrance are about 10 times greater than in the lagoon itself. They also stated that the observed concentrations in the sediment and in the water are much too high to be attributed to global atmospheric fallout and are therefore of local origin and due to remobilization from sedimentary deposits.
There is evidence that plutonium-239 is accumulating in the food chain. While the concentration of plutonium-239 and plutonium 240 are around .01 picocuries/liter in the water of the lagoon, the respective concentrations for dry sediment are 1,1OO picocuries/kilogram and for dry plankton 9,700 picocuries/kilogram. (Enrichment can be found for cesium 137, also, where the respective concentrations are 0.14 picocuries/liter, 3.5 picocuries/kilogram and 70 picocuries/kilogram.)(38)
- Ciguatera Fish Poisoning Due To Changes in Reef Ecology
Ciguatera fish poisoning, discussed in Chapter 5, is a major public health problem in the South pacific, with nutritional, social, and economic implications. The annual average incidence for the South Pacific area is around 200 cases per 100,000 population per year, but incidences as high as 20,700 per 100,000 population per year are reported for the Gambier Islands.
A review of the epidemiology of ciguatera in French Polynesia from 1960 to 1984 clearly demonstrates a general flare-up in ciguatera, with more than 24,000 cases among a population that grew from 84,500 in 1962 to 174,000 by mid1985. The incidence rose dramatically through the 1960s, peaking from 1972 to 1975 at 1,200 per 100,000, a tenfold increase over the 1960 figure.(39) Some of this increase may be due to improved case reporting, but this has never been presented as a major reason for the increase. In the areas most affected, the eastern Tuamotu, Gambier, and Marquesas Archipelagos, the incidence in the 1980s remains at high levels.
The most important cause of ciguatera outbreaks is the disturbance of the sensitive ecology of the coral reef. Natural events, such as storms, earthquakes and tidal waves, can disturb reef ecology, as can human activities. Nuclear test explosions and the construction of supporting infrastructures have been linked with ciguatera outbreaks.(40) For example, the Tuamotu Archipelago was more or less free of ciguatera before the early 1960's. Epidemiological studies show that in parallel with the installation and running of the test facilities, repeated outbreaks occurred. This is the case for the Hao Atoll (staging base for the testing since 1965, first ciguatera outbreak in 1966), the Gambier Islands (construction of military facilities in 1967, first outbreak in 1968) and Moruroa Atoll (highest density of Gambierdiscus toxicus after the Gambier Islands in 1981 ).(41)
A study by the US Atomic Energy Commission showed no correlation between radioactivity and ciguatoxicity in fish.(42) It is most likely that ancillary military activities linked to the nuclear testing facilities, like runway construction, waste dumping, ship decontamination, are causing ciguatoxicity by disturbance of reef ecology.
1) Atkinson, H.R., et al., "Report of a New Zealand, Australian, and Papua New Guinea Scientific Mission to Moruroa Atoll, October-November 1983," Wellington: New Zealand Ministry of Foreign Affairs (1984); Cousteau Foundation Scientific Mission of the Calypso at the Moruroa Nuclear Test Site, (official translation by External Assessments Bureau, Ministry of External Relations and Trade, Wellington), Paris (November 1988); Burrows, A.S., Norris, R.S., Arkin, W.M., Cochran, T.B., "French Nuclear Testing 1960 1988," Natural Resources Defense Council, Washington (1989).
2) Atkinson, et al. 1984, Cousteau Foundation 1988, Burrows et al. 1989. 3) Swedish National Defense Research Institute. 1987. Computer printout of nuclear explosions. Hagsfors Observatory; Smith, W., "Underground Nuclear Explosions in the Tuamotu Archipelago," Geophysics Dept., DSIR, Wellington, 1989.
4) Burrows et al, 1989 and May, John. 1989. "The Greenpeace Book of the Nuclear Age." Pantheon Books.
5) Direction Des Centres d'Experimentations Nucleaires. 1985. Dossier No. 1: Organization et Fonctionnement des Centers d'Experimentations, Nucleaires, Paris.
6) Greenpeace New Zealand. 1985. "French Polynesia: The Nuclear Tests - a Chronology," Auckland, New Zealand; Hughes, S., European Parliament Session, Document A2 0283/88, (1 December 1988); Burrows et al. 1989.
7) Danielsson, B. 1984. "Under the Cloud of Secrecy: The French Nuclear Tests in the South-Eastern Pacific," Ambio, 13 (5-6).
8) Burrows et al. 1989.
9) Tazieff, H. 1982. Rapport d'Haroun Tazieff sur l'ensemble de la Mission Scientifique en Polynesie Francaise, Paris.
10) Atkinson et al. 1984.
11) Cousteau Foundation 1988.
12) Association Des Medicins Francais pour la Prevention de la Guerre Nucleaire. 1990. Les essais nucleaires francais en Polynesie: mission d'etudes et de recontres, 9 16 avril 1990. Medicine at Guerre Nucleaire, vol. 5, no. 3.
13) May 1989, p. 132.
14) Hughes 1988.
15) French Atomic Energy Commission. 1988. Memorandum of the Directorate for Nuclear Test Centers, August 25, 1988. Villecoublay, France.
16) French Atomic Energy Commission.1988.
17) Atkinson et al. 1984.
18) French Atomic Energy Commission 1988.
19) Danielsson 1984.
20) Burrows et al. 1989 and Direction Des Centres d'Experimentations Nucleaires. 1985.
21) Confederation Francaise Democratique du Travail. 1981. Contamination de Moruroa. Statement by CFDT, Section BIII, Paris.
22) Burrows et al. 1989.
23) Atkinson et al. 1984.
24) Atkinson et al. 1984.
25) Direction Des Centres d'Experimentations Nucleaires. 1985.
26) Cousteau Foundation 1988.
27) Tazieff 1982, Atkinson et al. 1984, and Cousteau Foundation 1988.
28) Direction Des Centres d'Experimentations Nucleaires. 1985.
29) Atkinson et al. 1984.
30) Cousteau Foundation 1988.
31) Hochstein, M.P. and M.J. O'Sullivan. 1985. Geothermal Systems created by Underground Nuclear Testing, Proceedings 7th New Zealand Geothermal Workshop. 32) Cousteau Foundation 1988, and Cousteau, J. 1990. Assessment of artificial radionuclides issued from French nuclear bomb testing at Moruroa (French Polynesia), Environmental Technology, vol. 11.
33) Leland, B. 1990. "Greenpeace finds trace radioactivity near Moruroa." PeaceNet, Dec. 10.
34) Buske, N. 1990. Cesium 134 at Moruroa - Review of the Calypso Water Samples, SEARCH Technical Services, Davenport.
35) Marsily, G., E. Lepoux, A. Barbreau, J. Margat. 1977. "Nuclear Waste Disposal: Can the Geologist Guarantee Isolation?" Science.
36) Confederation Francaise Democratique du Travail. 1981.
37) Atkinson et al. 1984.
38) Cousteau Foundation 1989
39) Bagnis, R., et al. 1985. Epidemiology of Ciguatera in French Polynesia from 1960 to 1984, in Gabrie, C. and Salvat, B., eds., Proceedings of the Fifth International Coral Reef Congress, Tahiti, Vol. 4, Moorea: Antenne Museumephe.
40) Ruff, T.A. 1989. Ciguatera in the Pacific: a link with military activities. "Lancet," vol. 1, no. 8631, pp. 201-205.
41) Inoue, A. 1983. Distribution of a Toxic Dinoflagellate, Gambierdiscus toxicus, in French Polynesia, Memoirs of the Kagoshima University Research Centre for the South Pacific, vol.4, no. 1, pp. 918.
42) Helfrich, P. 1960. A Study of the Possible Relationship Between Radioactivity and Toxicity in Fishes from the Central Pacific. U.S. Atomic Energy Commission, Technical Information Service Publication No. TID-5748, Oak Ridge, Tenn.
