Nickel coins from 1925

Nickel Release from Euro and Polish Coins: a Health Risk?

The role of contact with nickel-containing coins has been controversial. The aim of our study was to compare the release of nickel from Euro (1 and 2) coins and from Polish coins (2 PLN and 5 PLN) at 4oC and 32oC in an immersion test using artificial sweat according to the EU reference method. Nickel extract was analyzed at 8 time points starting from 1 h up to 168 h. After 7 days of test durat...

Nickel-plated steel coins: the risk to the nickel-allergic public needs wider consideration.

New coins from old, smoothly

Given a (known) function f : [0, 1] → (0, 1), we consider the problem of simulating a coin with probability of heads f(p) by tossing a coin with unknown heads probability p, as well as a fair coin, N times each, where N may be random. The work of Keane and O’Brien (1994) implies that such a simulation scheme with IPp(N < ∞) = 1 exists iff f is continuous. Nacu and Peres (2005) proved that f is ...

Fast Simulation Of New Coins From Old

Let S ⊂ (0, 1). Given a known function f : S → (0, 1), we consider the problem of using independent tosses of a coin with probability of heads p (where p ∈ S is unknown) to simulate a coin with probability of heads f(p). We prove that if S is a closed interval and f is real analytic on S, then f has a fast simulation on S (the number of p-coin tosses needed has exponential tails). Conversely, i...

Contamination by nickel, copper and zinc during the handling of euro coins.

The introduction of the euro has revived interest in the risk of nickel allergy due to the handling of coins. In the present work, the transfer of metallic contamination during the manipulation of coins is examined by means of leaching experiments and manipulation tests. It is shown that pre-existing metallic species present on the surface of the coins are the major source of contamination duri...