scope:

Introduction

The maximum Immission doses (MID) for molybdenum presented in the following are intended to protect livestock raised on pastures or in animal houses.

The limits are based on the results of feeding experiments with farni animals raised for use. In these experiments the animals received fodder to which sodium or ammonium molybdate was added or whose content of sodium or ammonium molybdate was naturally high or was increased by ambient air pollution. The dose-time-effect relationships were determined after oral intake. Limits could be derived for beef cattle, dairy cattle, sheep, goats, horses, pigs and chickens.

Grazing cattle are affected most by higher molybdenum concentrations in the Vegetation. The molybdenum concentrations in the Vegetation growing on pastures are influenced by the location, too much molybdenum fertilisation or industrial emissions. The use of fodder contaminated by molybdenum may affect animals outside polluted areas [2].

According to present knowledge the molybdenum concentrations presented in the following do not lead to any impairment of the health and Performance of fann animals raised for use not even after long-term exposure so that no detrimental effects on human health are to be feared after consumption of food Coming from such animals [1; 3; 7].

The hannful effect of molybdenum is greatly reduced by copper and sulfur contained in the fodder. The extent of the reduction depends on the concentrations involved. The presented maximum Immission doses MID for the mentioned animals are based on the usual conditions under which the animals are fed and kept. Such animals normally do not suffer from a mo¬ lybdenum deficiency. A copper deficiency may enhance the effects of higher molybdenum concentra¬ tions to which the animals are exposed. No other combined effects which would enhance the toxicity of molybdenum have become known [4; 9; 13].