Plant Uptake of Airborne Cadmium

Atmospheric inputs of cadmium directly to a selection of agricultural crops, via surface contamination, were determined in Eastern Denmark by isotopic labelling of the experimental soils. Bulk precipitation of cadmium in the growth period was measured in the range 12–26 μg m−2 (30 day)−1. The cadmium concentrations in the experimental plants were in the range 0·08–0·79 μg g−1.

These figures confirm that the experimental site was situated in an unpolluted agricultural area not influenced by local emissions of the metal. Atmospheric cadmium surface contamination of crops contributed 0·02–0·4 μg g−1 to the dry matter, or 20–60% of the total plant cadmium. The atmospheric cadmium appears to be absorbed into, and transported throughout the volume of the plant.

Airborne cadmium thus seems to be a significant contribution to the cadmium content in crops and thereby to the human food intake of this toxic metal.