As for professional exposure, usually chronic accumulation of small dose of radiation, there is few data by large case number and strict study model; therefore, no agreement at this point is got and it sill waits for further reserch.

• 至于一般之职业性曝露系以低剂量之慢性累积剂量为主，由于缺乏较大规模之样本数和较严谨之研究模式，因此至目前仍无较一致的结论，尚待进一步的研究。