弗化水素に対するアサクサノリの感受性

抄録

Leakage of hydrogen fluoride HF from aluminum metallurgical plants has been noticed consequent to its tendency to kill land vegetation_8-11) The construction of such plants on seaside areas, therefore, may induce killing Porphyra tenera when smog occurs. The present study was thus designed to decide the critical concen-tration of atmospheric HF to Porphyra tenera for discussing the possibility of the industrial hazards of this toxic gas on areas of Porphyra tenera culture.
In order to proceed with the tests efficiently, an HF dispensing apparatus was devised as illustrated in Fig. 1. This apparatus can concurrently supply air with seven different concentrations of HF gas into fumigation bottles at a nearly constant flow as shown in Table 1. In the tests, very young Porphyra tenera were fumigated for four hours, corresponding to the maximum time period for this alga on the sea, with diluted HF gas ranging from 0.2 ppm to 30 ppm. From these tests it was concluded that Porphyra tenera gets killed when atmospheric concentrations of HF are higher than 1.8 ppm, but not destructively influenced when the concentrations are lower than 0.6 ppm. The critical concentration was estimated to be 0.9 ppm after a deliberate culture of algae subjected to the fumigation test. The suscepti-bility of Porphyra tener to HF gas was evaluated to be more resistant than tomato which belongs to the most resistant vegetation to this toxic gas^{5, 8, 9)}. This probably suggests that the hazard of leaked HF gas on the culture areas of Porphyra tenerais not severe, even if it may occur.