Little is known about the toxicity of aluminium; the issue is becoming ever more timely, particularly in areas affected by acid rain. Here are published some contributions from participants in a conference devoted to this topic, at the Research Institute of the State Department of Hygiene.
The behaviour of exchangeable aluminium and hydrogen in the broad range of pH was studied at model conditions on clays taken from acidic soils of different origin. Sodium and aluminium forms of clays were used and ion exchange experiments were performed. On the basis of the results obtained and data previously reported, it was calculated that exchangeable aluminium below pH 4 is trivalent and in the pH range between 4 to 6 its average charge decreases. Measurable, exchangeable hydrogen quantities occur only at very low pH values.
Physiological and genetic basis of plant reaction to aluminium ions were presented. The mechanisms of aluminium toxicity and aluminium tolerance were discussed with the special reference to findings of aluminium tolerance markers and their chromosomal location.