The loss of cadmium and zinc from sea water during accumulation experiments: its implication on toxicity threshold concentrations

The loss of cadmium and zinc from solutions contained in glass and polystyrene vessels has been determined at different metal concentrations (0.2–3 μg ml^?1). A substantial amount (37%) of cadmium was lost after 15 days, while 4% zinc was lost after 50 h. In view of this metal loss, it is stressed that interpretation of graphs, calculations and deductions cannot be made on the basis of spiking amounts alone. It is also suggested that in accumulation experiments use should be made of precontaminated apparatus and the fate of metals for each experiment must be monitored separately. These precautions were omitted in 62% of all papers dealing with metal pollution published by one serious biological journal in 1979. This greatly reduces the value of the reported results and conclusions. Similarly, many earlier papers and reviews reporting acute toxicity concentrations should be viewed with extreme caution.