Department of Anthropology, Northwestern University, Evanston, Illinois 60208.
Program in International Nutrition, Cornell University, Ithaca, New York 14850.
Am J Hum Biol. 2018 Jul;30(4):e23130. doi: 10.1002/ajhb.23130. Epub 2018 May 3.
Geophagy is commonly reported by pregnant women and children, yet its causes and consequences remain poorly understood. Therefore, we sought to determine if geophagy could contribute micronutrients and/or be a source of heavy metal exposure by examining the elemental composition of earths consumed in Kakamega, Kenya.
Ten samples of earths commonly consumed during pregnancy were collected by study enumerators and analyzed using inductively coupled plasma-atomic emission spectroscopy. Samples were either collected at markets or from walls of participants' homes, based on where participants reported most commonly sourcing their consumed earths.
Based on estimated intakes (40 g/day), all samples had lead levels that exceeded the provisional maximum tolerable daily intake, and one sample exceeded the threshold for arsenic. Further, estimated intakes of iron for all samples were at least 8.9 times higher than the established threshold. Elemental concentrations were also compared by the site of sample collection (market vs. household wall); market samples had significantly higher iron concentrations and lower calcium concentrations than wall samples.
Geophagic earths in Kakamega may be harmful because of dangerously high levels of lead, arsenic, and iron. The prevalence of geophagy among vulnerable populations underscores the importance of understanding its causes and consequences for accurate public health messaging.
食土癖在孕妇和儿童中较为常见,但人们对其原因和后果仍知之甚少。因此,我们试图通过检测肯尼亚卡卡梅加地区食用的土壤中的元素组成,来确定食土癖是否可以提供微量元素,或是否是重金属暴露的来源。
由研究人员收集 10 份孕妇常食用的土壤样本,并使用电感耦合等离子体原子发射光谱法进行分析。根据参与者报告的最常食用的土壤来源,样本可以在市场上收集或从参与者家中墙壁上收集。
根据估计的摄入量(40 克/天),所有样本的铅含量都超过了暂定最大耐受日摄入量,并且有一个样本的砷含量超过了阈值。此外,所有样本的铁摄入量至少是既定阈值的 8.9 倍。还通过样本采集地点(市场与家庭墙壁)比较了元素浓度;与墙壁样本相比,市场样本的铁浓度更高,钙浓度更低。
卡卡梅加的食土可能是有害的,因为其中的铅、砷和铁含量过高。脆弱人群中普遍存在食土癖,这突显了准确的公共卫生信息传播的重要性,需要了解其原因和后果。