温泉型氟中毒地区环境本底高氟对农作物及人体健康的影响

Influence of High Fluorine Background on the Crops and Humans in Hotspring-induced Fluorosis Areas

饮水型地方性氟中毒是我国危害最广、患者最多的地方性流行病。改水降氟政策的施行虽然有效地遏制了该地方病的肆虐,但是改水并不能杜绝氟中毒的流行,病区高氟的环境背景仍然会通过食物链危害人体的健康,有必要对其进行系统研究。本文选择自然背景和社会背景相近的非病区为对照,系统采集水、稻田土、大米、整株蔬菜及其根周土,以研究温泉型氟中毒病区高氟环境背景对农作物和人体健康的影响。结果表明粮食、蔬菜能够富集土壤的水溶性氟和灌溉水中的氟,不同品种的作物氟富集能力不同。将病区和非病区蔬菜不同部位的含氟量进行归类统计,结果表明氟在病区蔬菜根、茎、叶和花中的含量分别为3.56、1.17、3.07和3.23 mg/kg;在非病区蔬菜这些部位中的含量分别为2.17、0.70、1.91和2.52 mg/kg。农作物不同部分的氟富集能力不同,新陈代谢旺盛的部分氟含量较高,根、叶、花的含氟量明显高于茎,籽粒对氟的富集能力很弱。为降低人体氟暴露风险,要将温泉水对农作物富集氟的影响尽可能降到最低,因此要尽量避免用温泉水灌溉农作物、在受温泉影响较大的地方种植氟富集能力较低的作物品种、选择种植以籽粒和茎干为主要食用部位的农作物品种。

Drinking-water type endemic fluorosis is the most destructive endemic and has the largest number of sufferers in China. The implementation of the policy of altering water sources to lower fluoride level has effectively controlled the prevalence of this endemic, but it is not eradicated yet. The high-fluoride environmental background in these endemic areas could also do harm to human health through food chain, so more researches should be done. To investigate the effect of high fluorine environmental background on the crops and human health in hotspring-induced fluorosis areas, local water, paddy soils, rice, total vegetables and soils around their roots were systemically collected and analyzed, compared with the non-fluorosis areas where were similar to the fluorosis areas in both natural background and social background. The results indicated that rice and vegetables could accumulate both the water-soluble fluorine in soil and the fluorine in irrigative water and there exists a significative difference of the fluorine fixation potential among various crops. The fluorine contents of different parts of vegetables in the fluorosis and non- fluorosis areas were categorized. The results showed that the fluorine contents of the roots, tubers, leaves and flowers of the vegetables in the fluorosis areas were 3.56, 1.17, 3.07 and 3.23 mg/kg, respectively. By comparison, however, in the non-fluorosis areas, they were 2.17, 0.70, 1.91 and 2.52 mg/kg, respectively. Apparently, the fluorine fixation potential in different parts of a crop were also quite different, it is showed that fluorine contents existed in the hearty metabolism parts were higher, for example, fluorine contents in roots, leaves and flowers were much higher than these in stems obviously. The fluorine fixation potential of seeds was very weak. To reduce the risk of human fluoride exposure and to make the impacts of hotspring water on the fluorine fixation of crops as lowly as possible, it is of great importance to avoid irrigating crops with hot spring water and planting crops with relatively lower fluorine fixation ability or species with seeds and tubers as the main edible part in the areas severely affected by hot spring.