ANNALES DE TOXICOLOGIE ANALYTIQUE
VOL. XIV, NO2, 2002
Pascal KINTZ, IML de Strasbourg
(Received June 3, 2002; accepted, June 7 2002)
In the popular imagination, arsenic and poisoning are practically synonymous.
In the light of the conclusions of the Marie Besnard affair, the authors of the article presenting the results of a new series of analyses on the Emperor’s hair (1) prefer to use the term chronic intoxication rather than poisoning.
In their letter to the editor, Hindmarsh and Corso again contest the conclusions of scientific investigations.
From a clinical perspective, can we justify a conclusion of chronic exposure to arsenic? Certain signs reported by Dr Antommarchi (2) and recently completed by Dr Paul Fornes (3) are very suggestive, while other, more classic explanations (cutaneous accidents, Mées bands) leave much to be desired. This is what led Professor Chantal Bismuth to conclude recently (4) that “the clinician recognizes that he is incapable of reaching a conclusion, only analytical studies can resolve the enigma.” It is therefore false that Napoleon had no signs of chronic arsenic intoxication. The truth is that the signs are insufficient.
Several crucial points of our investigation seem to provide a satisfactory response to Hindmarsh and Corso, who can offer nothing better than the hypothesis of external contamination to explain the positive levels in the hair. This already represents a substantial progress over their previous critique (5).
In the contamination experiments selected by Hindmarsh and Corso, three points need to be emphasized: these references are particularly old, and date from a time when legal medicine did not yet routinely integrate hair into an investigative matrix, nor accordingly, the dynamics of decontamination (6); the studies were performed mostly on rodents, who are not equipped with an exudation system and thus do not incorporate xenobiotics in the same manner as humans (7); finally, and most importantly, all the studies were conducted after soaking already cut hairs in an aqueous environment; which obviously constitutes a central route for arsenic to be introduced by capillary action into the medulla (8), which is totally incompatible with the facts.
There is no possibility of arsenic contamination after the samples were collected, as this would have been deposited along the cuticle, resulting in the decontamination liquids being highly positive in arsenic, which was not the case.
We do not contest that soaking hairs for several days in an arsenic bath can lead to positive results, even after severe decontamination. This is the technique, moreover, that we use to artificially prepare hair enriched in xenobiotics in order to validate our methods (9). I nevertheless have serious doubts about using such a method to preserve the Emperor’s hair, all the more so since this should have been done under the same conditions on all the available samples (analyzed since 1960 in several laboratories) and at every period. One should not forget that the lock of hair collected in 1816 (1), i.e. five years before Napoleon’s death, was positive. Finally, this highly “popular” explanation of why all the hair samples were positive was never reported by anyone whatever in the entourage on St Helena.
It is true that there is a high degree of variability among the hair samples, which can easily be explained by different growth phases, since the arsenic was only absorbed during the anagenic phase (rather than the catagenic and teleogenic phases), which in any case, accounts for 85% of the hair present on the scalp. The fact of having so many different samples, in our case, locks of hair, allows us to easily avoid this physiological aspect (10), if by misfortune, the only hair analyzed was in the teleogenic phase (and thus would not have absorbed any arsenic).
In total, what explanations remain to account for the presence of arsenic in the Emperor’s hair? Chronic exposure to arsenic by mouth, or an unrealistic, pointless, external exposure of all the hair, every time it was cut, over a period of years, and in the greatest secrecy, in a long arsenic bath?
A mixture of doubts, certitudes and common sense … so much the better! As for me, I’ve already made my choice.