The suitability of gallium as a substitute for aluminum in tracing experiments

Aluminum is a toxic metal whose complex aquatic chemistry, mechanisms of toxicity and trophic transfer are not fully understood. The only isotope of Al suitable for tracing experiments in organisms-26Al-is a rare, costly radioisotope with a low emission energy, making its use difficult. Gallium shares a similar chemistry with Al and was therefore investigated as a potential substitute for Al for use in aquatic organisms. The freshwater snail, Lymnaea stagnalis was exposed to either Al or Ga (0.0135 mM) under identical conditions for up to 40 days. Behavioural toxicity, metal accumulation in the tissues, and sub-cellular partitioning of the metals were determined. Al was more toxic than Ga and accumulated to significantly higher levels in the soft tissues (P