scope:

Introduction

The maximum ambient levels (maximum immission levels MI) presented in the following for nickel are intended to protect livestock. Maximum immission levels are derived from long-term experiments with exposure to nickel to determine the dose-response relationships in livestock. They can be established only for those animals for which experiments were conducted. For horses, goats and confined deer no such data are available. However, because all investigated species reacted uniformly to the exposure to nickel in fodder, horses, sheep, goats and confined deer can be expected to show reactions to the exposure against nickel that are similar to those of cattle, pigs and hens [2; 3; 7; 10; 13; 16; 25].

Under the usual conditions livestock is kept and fed, ruminants are affected more often than pigs or poultry. The MI-values are valid for the mentioned species under the usual conditions of care and feeding. A deficiency in the supply of zinc, magnesium, manganese or other essential fodder ingredients may enhance the nickel sensitivity of these animals.

Combined effects of nickel with other heavy metals or with other air pollutants occur in the form of interactions of nickel with zinc, magnesium and manganese and may lead to secondary symptoms of deficiency of these elements in domestic fowl, pigs and beef cattle. The redistribution of zinc induces tissue-specific deficiencies in the form of reproductive disorders and damages to the epithelium [5; 8 through 10; 13; 27; 28].