Murphy Tom, Irvine Kim, Phan Kongkea, Lean David, Wilson Ken
International University, Phnom Penh, Cambodia.
Nanyang Technological University, Singapore.
J Health Pollut. 2019 May 20;9(22):190603. doi: 10.5696/2156-9614-9.22.190603. eCollection 2019 Jun.
In parts of Cambodia, irrigation of rice with groundwater results in arsenic accumulation in soils and rice, leading to health concerns associated with rice consumption. In Bangladesh and China, low zinc levels in rice have been found in regions where arsenic levels in rice are high. Furthermore, there have been claims that zinc deficiency is responsible for stunting of children in Cambodia. There are limited data on zinc in Cambodian rice, but in rural Asia, rice is the major source of zinc.
To provide a preliminary evaluation of the zinc content in rice grain in Preak Russey, an area with elevated levels of arsenic. The importance of zinc in rice for infants was also assessed.
Rice cultivation was evaluated in sixty farms along the Mekong River in Cambodia. Analyses for metals, total arsenic, and arsenic species in the water and rice were conducted at the University of Ottawa, Canada by inductively coupled plasma - mass spectrometry. Analysis of total zinc and arsenic in soils were analyzed in Phnom Penh using X-ray fluorescence spectrometry (XRF). Total zinc in rice was also measured by XRF analysis.
Rice in the Preak Russey area contained zinc with ½ to ¼ of the 1987 Codex standard for rice in Infant Formula. Moreover, our average zinc concentration in rice samples was less than a third that recommended for zinc fortification in rice by the United Nations World Food Programme. There was a significant (α=0.05) negative correlation between the arsenic and zinc content of rice with the lowest zinc levels occurring near the irrigation wells, the source of arsenic. There was a significantly higher content of zinc in rice from farms that fertilized with cow manure.
Handheld XRF spectrometers are useful tools for detection of zinc levels in rice. The potential for zinc deficiency in farmers in areas of Cambodia with arsenic toxicity is high.
The authors declare no competing financial interests.
在柬埔寨部分地区，用地下水灌溉水稻会导致土壤和水稻中砷的积累，引发与食用水稻相关的健康问题。在孟加拉国和中国，水稻砷含量高的地区已发现水稻锌含量低。此外，有人声称柬埔寨儿童发育迟缓是锌缺乏所致。柬埔寨水稻中锌含量的数据有限，但在亚洲农村地区，水稻是锌的主要来源。
对砷含量较高的Preak Russey地区水稻籽粒中的锌含量进行初步评估。还评估了水稻中的锌对婴儿的重要性。
对柬埔寨湄公河沿岸60个农场的水稻种植情况进行了评估。加拿大渥太华大学采用电感耦合等离子体质谱法对水和水稻中的金属、总砷及砷形态进行了分析。金边采用X射线荧光光谱法（XRF）分析土壤中的总锌和砷。水稻中的总锌也通过XRF分析进行测定。
Preak Russey地区的水稻含锌量仅为1987年婴儿配方奶粉中大米法典标准的二分之一至四分之一。此外，我们水稻样品中的平均锌浓度不到联合国世界粮食计划署建议的水稻锌强化量的三分之一。水稻中的砷和锌含量之间存在显著（α=0.05）负相关，锌含量最低的地方靠近砷的来源——灌溉井。使用牛粪施肥的农场种植的水稻锌含量明显更高。
手持式XRF光谱仪是检测水稻锌含量的有用工具。柬埔寨砷中毒地区农民锌缺乏的可能性很高。
作者声明不存在相互竞争的财务利益。
