Contamination par le nickel et d'autres métaux lors de la manipulation des pièces de monnaie – comparaison entre francs français et euros

Abstract

Reçu le 1 er mars 2002 ; accepté le 26 juin 2002Note présentée par Pierre-Gilles de Gennes. RésuméL'introduction de l'euro a renouvelé l'intérêt porté aux allergies dues au nickel. Nous montrons que la manipulation d'une pièce de monnaie ancienne en nickel libère en moyenne 0,45 µg de nickel, 0,26 µg de cuivre et 0,08 µg de zinc, alors q'un euro récent en alliage de nickel libère 0,25 µg de nickel, 1,3 µg de cuivre et 0,17 µg de zinc. Ces contaminations, favorisées par le frottement, différent de celles obtenues à l'aide du test EN 1811 de solubilisation dans la sueur artificielle. L'évaluation du risque allergique suite à l'introduction de l'euro devrait probablement tenir compte d'une synergie éventuelle entre ces métaux.

Euro coins and the potential risk of nickel allergy

“…Details ofthe procedure can be found in references [7] and [12]. Table 1 summarizes the results of such tests carried out by 3 people counting three sets of25 used coins each: bi-metallic euros (12 pieces of 1€ and 13 of2€), Cu75Ni25 copper-nickel coins (2SFr), and pure-nickel2FF pieces.…”

“…All data are expressed in I-Ig. Uncertainties are 90% confidence limits.The first column recalls the average contamination levels found on three fingers as a result of daily activities [7].…”

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Manipulation testsTo take friction into account,we have evaluated metal contamination from coins by means of a simple test that simulates daily handling [7]; participating volunteers count a set of coins by transferring them from one polyethylene container to another, and metal contamination sampled by wiping the fingers with cellulose cloths is analysed by inductively-coupled plasma emission spectroscopy (ICP-OES). Details ofthe procedure can be found in references [7] and [12].

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“…Handling of a used coin is seen to quite effectively limit of the "nickel directive". But the directive does not apply to coins, and rightly so: interpolating the release rates obtained, taking into account that the manipulation of a coin typically takes less than three seconds rather than a week, one finds numbers that are several orders of magnitude lower than what is actually observed in tests that simulate the daily manipulation of coins [11,7]. The ENI811 test is relevantto long-term solvation upon contact with the skin, but because it does not account for the friction that characterises the manipulation of coins, it is not representative of the amount of nickel transferred to the fingers by the handling of coinage.…”

“…At time of writing, an internet query with the keywords "euro + nickel + allergy" brought up close to 900 web pages using a popular search engine. VIrtually all of these claim that the euro coins represent a danger in regard to nickel allergy, ignoring the fact that the only two nickel-containing euro denominations release less nickel upon manipulation than pure-nickel or nickel-alloy coins of comparable size [7].The 1994 EU"nickel directive" [8] concerns objects designed to come into direct and prolonged contact with the skin. The corresponding normalised test procedure, ENI811 [9], measures the amount of nickel dissolved when the object concerned is immersed in synthetic sweat during one week.…”