Department of Biology, University of the Azores, 9501-801 Ponta Delgada, Azores, Portugal; CVARG, Center for Volcanology and Geological Risks Assessment, University of the Azores, 9501-801 Ponta Delgada, Azores, Portugal.
Department of Biology, University of the Azores, 9501-801 Ponta Delgada, Azores, Portugal; CE3C, Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, University of the Azores, 9501-801 Ponta Delgada, Azores, Portugal.
Sci Total Environ. 2015 Dec 15;538:531-8. doi: 10.1016/j.scitotenv.2015.08.109. Epub 2015 Aug 28.
Iodine deficiency is the most common cause of preventable mental impairment. Although several studies have established an association between ocean proximity and iodine environmental availability, recent studies revealed an inadequate iodine intake in the Azorean islands. In this study, we aim to understand the underlying causes of iodine environmental availability in oceanic islands and its association with iodine intake in schoolchildren, using the Azores as case-study. Iodine concentration in soil and grass pasture was measured by INAA and in drinking water by spectrophotometry. Urinary iodine concentration (UIC) in schoolchildren was assessed by ICP-MS in a randomized cross-sectional survey with 315 participants from S. Miguel (study group) and Sta. Maria islands (reference group). A validated diet questionnaire assessing sources of iodine was recorded. The iodine concentration in soils of the reference group was significantly higher than in the study group (58.1ppm vs. 14.5ppm, respectively; p=0.001). The prevalence of schoolchildren with inadequate UIC was significantly higher in the study group than in the reference one (63.0% vs. 37.8%, respectively; p<0.001). Chronic exposure to low iodine environmental availability was significantly associated with the exacerbation in iodine deficiency, with a risk 4.94 times higher in the study group. The differences observed in the studied islands are related with each island geomorphology (soil properties and orography) and climate, which can promote or inhibit iodine environmental availability, contributing distinctively to iodine bioavailability and human intake. These findings draw attention to an urgent need for a full investigation of Azores iodine status to apply evidence-based recommendations for iodine supplementation.
碘缺乏是可预防的智力障碍的最常见原因。尽管有几项研究已经确定了接近海洋与碘环境可获得性之间的关联，但最近的研究表明，亚速尔群岛的碘摄入量不足。在这项研究中，我们旨在了解海洋岛屿中碘环境可获得性的潜在原因及其与学龄儿童碘摄入量的关系，以亚速尔群岛为案例研究。通过 INAA 测量土壤和草牧场中的碘浓度，通过分光光度法测量饮用水中的碘浓度。在一项随机的横断面调查中，使用 ICP-MS 评估了来自圣米格尔岛（研究组）和圣玛丽亚岛（对照组）的 315 名参与者的尿碘浓度（UIC）。记录了一份经过验证的饮食问卷，评估了碘的来源。对照组土壤中的碘浓度明显高于研究组（分别为 58.1ppm 和 14.5ppm；p=0.001）。研究组学龄儿童 UIC 不足的患病率明显高于对照组（分别为 63.0%和 37.8%；p<0.001）。慢性暴露于低碘环境可获得性与碘缺乏症的恶化显著相关，研究组的风险是对照组的 4.94 倍。在所研究的岛屿上观察到的差异与每个岛屿的地貌（土壤特性和地形）和气候有关，这些因素可以促进或抑制碘环境的可获得性，从而对碘的生物利用度和人体摄入量产生不同的影响。这些发现提请人们注意，迫切需要对亚速尔群岛的碘状况进行全面调查，以便根据证据提出补充碘的建议。
