Release of nickel from coins and deposition onto skin from coin handling -: comparing euro coins and SEK

Background: Nickel exposure is the most common cause of contact allergy. The role of contact with nickel-containing coins has been controversial. Objectives: To compare the release of nickel from 1 and 2 EUR coins (both composed of two alloys: Cu 75%, Zn 20%, Ni 5% and Cu 75%, Ni 25%) and Swedish 1 SEK coin (alloy: Cu 75%, Ni 25%) and to assess the deposition of nickel onto skin by coin handling. Methods: Nickel release was determined by immersion in artificial sweat (2 min, 1 hr, 24 hr, and 1 week). Deposition of nickel onto the skin was assessed in three subjects after 1-hr handling of 2 EUR and 1 SEK coins. Samples (n = 48) were taken from fingers and palms by acid wipe sampling and analysed by inductively coupled plasma mass spectrometry. Results: Amounts of nickel released by 1 week from 1 SEK, 1 EUR, and 2 EUR coins were 121, 86, and 99 mu g/cm(2), respectively. Corresponding 2 min values were 0.11, 0.25, and 0.22 mu g/cm(2). Nickel was deposited onto the skin by 1 hr coin handling (range 0.09-4.1 mu g/cm(2)), the largest amounts were on fingers; similar amounts of nickel were deposited from 1 SEK and 2 EUR coins. Conclusions: Nickel is released from 1 and 2 EUR and 1 SEK coins at similar amounts. Nickel is deposited onto skin at substantial and similar amounts by coin handling. Acid wipe sampling is suitable for studies of skin exposure to nickel and in risk assessment.