Abstract
The most common sources of nickel in drinking water are metallic products situated at the end of plumbing systems, especially taps. For this reason, and because of various water stagnation times, the concentration of nickel at one sampling point can vary within the range of several orders of magnitude, and following overnight stagnation may reach peak values of up to 500 ug/l, i.e. 20 times higher than the current limit value (20 ug/l).
Such a single oral nickel dose can provoke systemic contact dermatitis in nickel-sensitive individuals, who represent about 5% of the population.