茶园土壤酸化对氟的影响及茶叶氟安全限量的探讨

在分析国内外茶园土壤酸化现状的基础上,概述了关于土壤水溶性氟与土壤pH值关系的研究进展,并通过实地调研和培养实验研究了茶园土壤酸化对土壤水溶性氟的影响.实地调研中土壤水溶性氟含量与土壤pH值无显著相关性.培养实验中,当pH＞4.00时,模拟土壤水溶性氟含量随土壤pH值的下降变化不显著;而当pH＜4.00时,土壤水溶性氟含量随着pH值的下降迅速增加,且达到极显著水平.同时描述了世界各国制订的每人每天最大摄氟量标准,对我国现行茶叶标准与国外一些国家的同类标准之间的差异做了评析.茶叶溶出实验的结果表明,我国茶叶氟安全限量需要进一步完善.

Effects of soil acidification by tea plantation on fluoride and discussion of safety level of tea fluoride

Based on the analysis of the tea plantation soil acidification in China and other countries, this paper has summarized the latest research progress of the relation between the soil water-soluble fluorine and soil pH. Moreover, our field investigations and simulated experiments have given explanations on how soil acidification affect the soil water-soluble fluorine. Needless to say, as one of the essential microelements for human body, fluorine influences man's health. So far, quite a few studies indicate that tea drinking may lead to fluorosis and other diseases. Over intake of high fluoride from tea drinking may lead to dental fluorosis and even skeleton deformities. Among the above said detriments, soil fluoride can be a primary cause, which is actually the chief factor affecting absorbable fluoride (water-soluble fluorine) for tea plants. Our investigations prove that the content of soil water-soluble fluorine does not rely on soil pH. On the contrary, it proves that soil water-soluble fluorine would change in the soil indiscriminately when the soil pH decreased above 4.00. However, when soil pH is below 4.00, the content of soil water-soluble fluorine would increase significantly with the decrease of soil pH. Thus, our study reveals that it depends on the soil pH significantly. Hence we suggest that it is essential to control the soil acidification in tea plantation. At the same time, it is necessary to study the standards of fluorine daily maximal allowance for average person made in different countries. The results of tea dissolving experiments indicate that the standard of the tea fluorine content in our country is not strict enough in comparison with those in other countries. In hoping to produce tea with less fluoride, and advance the applicability of our national tea production standards and international trade regulations, the present article provides valuable scientific evidence for the experts concerned to refer to.