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Aspergillus fumigatus


Aspergillus fumigatus is a fungus that contains a range of mycotoxins some of which are similar to some of the ergot alkaloids found in Claviceps purpurea. It seems probable that it caused the mass poisoning in Pont-Saint-Esprit in August 1951.

Blog Entries

Read more about Aspergillus fumigatus in these blog entries (most recent first);
Pretty solid proof that CIA was not involved in Point St Esprit poisoning
Mandatory minimums in the USA and the Pont St Esprit poisoning


Aspergillus fumigatus is a common fungus that is often present in decaying plant material, typically compost heaps. Its spores are present in the atmosphere but, in healthy people, the amount inhaled does not result in symptoms. It is generally thought to only cause problems to those whose immune system is impaired in some way. The conditions caused primarily affect the respiratory system and are known as aspergillosis.

If you reached this page while searching for information on aspergillosis, you should find The Aspergillus Website at useful.

With an increase in the number of people with impaired immune systems, due to cancer treatment, use of steroids or HIV/AIDS, the incidence of aspergillosis is thought to be increasing and more information about it is now available with further research being done.

An important feature of Aspergillus fumigatus is that it is tolerant of temperatures up to 55oC and grows vigorously at body temperature (37oC). Though more is now known about the effects of inhaling spores the same is not true for ingestion of Aspergillus fumigatus on mouldy foods. Or, rather, what is known has not become widely known, perhaps, because the most detailed summary appeared in a French journal.

Properties and Effects of Aspergillus fumigatus Ingestion

In 1982, ‘Bulletin Trimestriel de la Société Mycologique de France’ contained a paper by Claude Moreau entitled ‘Les Mycotoxines Neurotropes de L’Aspergillus fumigatus’ (Neurotropic Mycotoxins of Aspergillus fumigatus).

Moreau points out that the pulmonary effects of the fungus are well-documented but its effects on the nervous system and muscles are not often considered. This in spite of three papers, during the first twenty years of the twentieth century, which note that the fungus has been found to cause death in animals after "after spasms, convulsions and tetanic seizures”.

A fourth paper, in 1906, from a German source, noted that there were wide variations between the effects caused depending on the season and the particular strain of the fungus.

In 1939, experiments involving the injection of extracts from Aspergillus fumigatus into animals produced a variety of severe symptoms but the precise toxins could not be isolated.

It was only after 1960 that advances in food toxicology led to a better understanding of the chemistry. A number of different toxins were isolated, including a mild antibiotic containing helvolic acid. Derivatives of ergoline and fumitremorgin were found to be the cause of nervous system effects. Ergoline is a mycotoxin first identified in Claviceps purpurea, ergot of rye, and is similar in structure to lysergic acid. Ingestion of ergoline is known to produce symptoms similar to LSD.

Fumitremorgin mycotoxins have been shown to produce “strong tremors, impaired tetanus, agitations, hyperirritability, spasms and seizures that are epileptic in appearance”. Very small amounts of toxin are required to produce symptoms and Aspergillus fumigatus has been shown to produce substantial amounts in certain circumstances.

Moreau goes on to give examples of animal poisonings from his own experience where various symptoms and different severities were observed after cattle, pigs, turkeys, sheep, and ducks had consumed mouldy food contaminated with Aspergillus fumigatus. He also had a case where dogs that died from similar symptoms were found to have eaten dead pigs that had, in turn, consumed mouldy feed.

He concludes that the variety of effects and severity could result from differences in the relative amounts of the constituent toxins.

Having examined the effects it can cause, Moreau goes on to look at what conditions most suit its growth and reports on studies which show that Aspergillus fumigatus grows very fast in damp, warm and dark conditions and does not need a large amount of oxygen. A bag of grain or flour, if warm and damp, provides ideal growing conditions.

Though the mould itself is destroyed at typical baking temperatures, the mycotoxins themselves have been found to survive at temperatures above 200oC so could well be present in bread baked from mouldy flour.

Pont-Saint-Esprit Mass Poisoning, August 1951

The true cause of the outbreak of poisoning in the French village of Pont-Saint-Esprit in 1951 has never been fully explained but ergot-like alkaloids remain the most likely culprit. Several hundred people were affected, with typical symptoms being insomnia, lasting several weeks, obsessive behaviour, with one victim counting his window panes for days on end and another writing for days on end, and a desire to fly. Seven people died.

After a lengthy investigation of the possibility that the poisoning was due to alkaloids from the ergot fungus, the official enquiry concluded that the poisoning was due to a mercury based seed fungicide. This in spite of a lack of many of the symptoms associated with mercury poisoning and the absence of a credible explanation for how the flour believed to have caused the poisoning could have become contaminated with the mercury compound. The principle basis for this conclusion seems to have been the detection of an acid in some samples which was thought to demonstrate the presence of a fungicide.

A court case seeking compensation for the victims lasted several years and resulted in some compensation being paid to one of the sufferers whose case had been chosen as a test. The court, however, ruled that others who thought they might be due compensation as a result of the judgement would have to pay for their own medical examinations which would have to show that they had been harmed. After so many years and with the perceived bias of the authorities against the villagers none of the other victims submitted themselves for testing.

In 'LSD — My Problem Child', Albert Hofmann says that the 1951 incident at Pont-Saint-Esprit was not the result of ergot poisoning but was a result of a mercury based compound used to disinfect seed. This is often given as proof that mercury was the cause but it is worth noting Hofmann deals with the outbreak in a single sentence in parentheses.

His conclusion is in contrast with the reported outcome of a meeting between Hofmann and Dr. Stoll, a colleague of Hofmann's, with the doctors involved in treating the villagers which concluded that mercury poisoning was 'not evident in any manner'.

In August 2010, BBC Radio 4 broadcast a programme in its 'Document' series about claims made by an American author that the CIA had adulterated the bread with LSD in order to research its potential as a weapon. In the face of evidence that pure LSD would not survive the temperatures at which bread is baked, the suggestion was made that it might have been added to each loaf after baking. Presumably because it destroys the claim, no mention was made of Aspergillus fumigatus.

So, was it a mercury based fungicide, ergot or LSD? Or, could it have been something else altogether?

An Hypothesis

Based on the conditions offering fastest growth for Aspergillus fumigatus, its various effects and the ability of its toxins to survive baking, Moreau suggests that it could have been the guilty party in the mass poisoning which occurred in Pont-Saint-Esprit in 1951.

Though he fully accepts that what he is putting forward is an unprovable hypothesis, he does point out a number of factors which previous investigations had not considered.

• One difficulty in determining the cause of the poisoning was the wide variety of symptoms observed and the differences in severity. The complex structure of Aspergillus fumigatus lends itself to such diversity.

• The effects of Aspergillus fumigatus mycotoxins share many of the characteristics of ergot alkaloids, still thought by many people to have been the cause of the poisoning.

• Some of the tests conducted at the time reported finding traces of fungicide. This was a key factor in the official conclusion that a mercurial fungicide had been the cause of the outbreak. As Moreau points out, these tests were not particularly rigorous or sensitive and may simply have detected the helvolic acid from the antibiotic component of the mycotoxins.

• The poisoning at Point-Saint-Esprit occurred in mid-August 1951 at the height of the summer. It should be possible to find weather records for the area to get an indication of the temperatures.

• Crucially, Moreau received a personal communication explaining that the mill of the miller of Saint-Martin-la-Riviere, who had supplied the flour in question, had been flooded earlier in 1951. It may be possible to obtain further information on the flooding. Its timing and the extent of the inundation of the mill would support or destroy the proposition that this flooding resulted in only a limited amount of grain becoming wet and liable to mould explaining the limited nature of the poisoning and, also, the timing would indicate if such mouldy grain could have been baked in Pont-Saint-Esprit in August.

Taken together, Moreau presents a good case for Aspergillus fumigatus being the cause of the Pont-Saint-Esprit poisoning.

The Alternative Theory

Whilst the available evidence seems to support the case for Aspergillus fumigatus being the cause, the case for deliberate adulteration by the CIA seems, to me, to have a number of flaws.

There is no doubt that the USA has some very dark doings in its past and new episodes are coming to light but that, alone, is not sufficient to give credibility to the argument for CIA involvement in this case.

The first puzzle, if one is seeking to demonstrate that this was a CIA event, is the choice of location. Most of the CIA's dubious activities have happened in its own backyard; Central or South America or the Caribbean. Why choose a small village in France? You would have thought that, if the CIA were interested in learning, at first hand, about the effects of LSD it would not choose subjects whose language was not spoken widely within the organisation.

Given that, one assumes, the intention would be to interview people during intoxication, it must be assumed that the testimony could be quite incoherent. Such testimony would be expected to be reviewed by a number of people in order to achieve a consensus on what the subject was experiencing. Such a review would, almost certainly, require expertise from beyond the CIA's pool of French speakers so translation would be required with all the possibility of introducing errors.

This is not to say that the CIA might not have been capable of mounting a large scale operation using French speaking agents. It is rather to ask why bother when similar experiments could have been conducted on English or Spanish speaking subjects in countries where the CIA had a much more established infrastructure.

Then there is the very important matter of administration of the LSD. Since LSD is destroyed at baking temperatures for bread, adding pure LSD to flour would be a very imprecise method of administration relying on an unknown amount of the LSD surviving.

The difficulties of contaminating loaves with LSD, especially enough loaves to poison 300 people, are immense; especially so 'in the field'. Much simpler, surely, to adulterate a mass- produced food product which could be achieved away from the area of the experiment and with more time to ensure consistent dosing. As is well-known bread produced in village bakeries in France is on the shelves for a matter of a very few hours. It seems highly improbable that contamination could have been achieved, with any sort of consistency of dose, a key requirement for the experiment to produce useful results, in the time available, even with the co-operation of the baker.

'The co-operation of the baker'. There is no evidence to suggest that there was any local co-operation. This creates a 'catch 22' for the 'CIA experiment' theory. Could the CIA have mounted an operation on this scale without any involvement, of any sort, of local people or the French authorities? And, if there was local involvement, of any sort, is it credible that nothing has emerged from local sources in the intervening fifty-nine years? It is hard not to believe that the operation would not have been possible without local involvement and would not have stayed secret with it.  

There is No Conclusion

There is no way, at this distance in time, to ever be certain of what caused the Pont-Saint-Esprit poisoning but the chances that it resulted from Aspergillus fumigatus seem to me to be far higher than that it was deliberate poisoning by the CIA.