In a previous study, a high concentration of Pb, Zn, Cr, and Mn in soil profiles located in the semiarid region of Brazil were found in areas used for decades by small family farmers for the production of the crops and raising small animals. This question motivated the current study to evaluate the soil variability spatial dependence on trace elements to quantify and map its occurrence in this area, comparing their concentration with reference values set by the Brazilian environmental agencies. Soil samples were collected at 0-0.20 and 0.20-0.40 m depths and 25, 50, 100, 200, and 400 m from the center and to both sides of five transects spaced from 1,000 m, forming a grid. The concentration of the trace elements As, Cd, Pb, Cu, Cr, Fe, Mn, Ni, Ti, and Zn was obtained in SW-846 3050B USEPA soil extract by ICP-OES. Spatial dependence for all evaluated elements allowed the elaboration of dispersion maps in the area, except for Cd. Trace elements concentrations were below the investigation values (limit value of a trace element in the soil with risk potential to humans and the environment) of the Brazilian environmental legislation (Conama). Pb and As concentrations were above the prevention values (limit value of a trace element in the soil that can sustain its primary functions), but, still, they presented low dispersion in the area. Zn concentration was above the prevention value, and dispersion was higher, regardless sampling point, which requires a major concern. Cr, Cu, Ni, Fe, Mn, and Ti concentrations were below the Conama reference values, and the dispersion was also low. Fortunately, except for Fe, it was observed that trace elements were concentrated around the central point of the "gossan", instead of distributed throughout in the agricultural area around it.

在先前的研究中，在巴西半干旱地区的土壤剖面中发现了高浓度的Pb，Zn，Cr和Mn，这些地区被小型家庭农民用来生产农作物和饲养小型动物的地区使用了数十年。这个问题促使当前的研究评估土壤变异性对痕量元素的空间依赖性，以量化和绘制其在该地区的分布，并将其浓度与巴西环境机构设定的参考值进行比较。收集土壤样品的深度为0-0.20和0.20-0.40 m，从中心到距1,000 m的五个样带的两侧分别为25、50、100、200和400 m，形成一个网格。ICP-OES在SW-846 3050B USEPA土壤提取物中获得了痕量元素As，Cd，Pb，Cu，Cr，Fe，Mn，Ni，Ti和Zn的浓度。除Cd外，所有评估元素的空间相关性都允许在该区域中绘制散布图。痕量元素的浓度低于巴西环境立法（Conama）的调查值（土壤中痕量元素的极限值，对人类和环境具有潜在危险）。铅和砷的浓度高于预防值（土壤中可维持其主要功能的微量元素的极限值），但它们在该地区的分散性仍然很低。无论采样点如何，锌浓度均高于预防值，且分散度较高，这是一个主要问题。Cr，Cu，Ni，Fe，Mn和Ti的浓度低于Conama参考值，并且分散度也较低。幸运的是，除了铁