Studies on Distribution of Fluoride-injured vegetation and Indicator Plants of Fluoride

• Main Authors: ShuTzu Wang, 王淑姿
• Other Authors: EnJang Sun
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/24492538370083324472

碩士 === 國立臺灣大學 === 植物病理學研究所 === 87 === English Summary Fluoride is the most phytotoxic of the common air pollutants. The losses to agriculture and forestry from fluoride have been greatly noticed since the second world war with the vast expansions of industries that are major users of materials high in fluoride. The Fluorides-mitting industrial sources are mostly brick factory, ceramic factory and phosphate fertilizer factory in Taiwan. However brick factory is the most important Fluorides-emitting sources in Taiwan, because a large amount of bricks and tiles are utilized in the construction of houses. In Taiwan the brick factories are mostly located Hsinchu, Miaoli, Changhua and Kaohsiung. The materials included cryolite and clays are heated to high temperatures during processing of bricks and tiles, fluoride such as HF and SiF4 , are emitted and cause damage to crops. The fluoride concentration that accumulated in the same plant in a long term was closely related with the distances from the pollution source and a seasonal wind. The purposes in this study were 1) investigated degree of fluoride concentration in plants that were variant distances from pollution source. 2) drew the damaged rang of fluoride that used bananas and acacias in an area. 3) examined the symptoms and dose-response of different plants that were caused by HF produced by production and fumigation system with CSTRs. From the fluoride content in banana and Taiwan acacia collected in large area in Ying Ko, Taipei, the isofluor maps were drawn by surfer software. The fluoride distribution in affected areas and in vegetation was analyzed to illustrate the relationship between pollution source and affected areas. The affected areas in Ying Ko area in 1997 according to the isofluor map of banana leaves was over 32×64Km2. The most severely affected area was at a distances of 4~4.5Km south western from ht suspect ceramic factory. The 1999 isofluor map in Ying Ko area, However, showed that the most severely affected area was very close to the pollution source. The difference between 1997 and 1999 was supposed to be caused by different meteorological factors. In 1998, the isofluor map was analyzed at Huatan area of Changhwa country. The results showed that the most severly affected area was located at a distance of about 5.9Km southeastern away from the source area. The fluoride different a pottions of showed that the highest concentration existed usually at the diseased leaf portion, followed in decreasing order by healthy base; branches flowers, and fruits. For the very large leaf of banana, the fluoride contents in diseased portion at basal section were high than those at the tip portion ,indicating the effect of leaching. Bananas and acacia trees were exposed to 38ppb HF for 7hrs×4days, that proved to be the threshold dose of these two plants. The 4 gladiolus varieties, however, showed much higher sensitivty to fluoride. The limited abundance of gladiolus limited the usefulness of gladiolus as a field indication plant in Taiwan, whereas, the banana and Taiwan acacia are usually widely grown, and are suitably for use as field indicator as in this report, although they are the second highest sensitive species toward the fluoride.