The ornamental rock exploration and coating industry has led to significant environmental impacts due to the inadequate manner in which these residues are released into the environment. This impact may be reduced by using these residues for soil enrichment, as they contain high levels of inorganic nutrients. However, some elements may be potential contaminants, thus requiring a thorough previous research before employing these substances in agriculture. In this context, this study aims to determine potentially toxic elements present in rock dust residues, As, Cd, Cr, Cu, Pb, and V, through Inductively Coupled Plasma Optical Emission Spectroscopy (ICP OES) after wet decomposition. Cd concentrations in residual rock dust waste surpassed the maximum limit established by the Brazilian Ministry of Agriculture, Livestock and Supply stipulated in normative instruction No. 5/2016 for remineralizers and substrates for plants intended for agriculture. In addition, the official digestion method adopted by the Brazilian Agricultural Research Corporation Embrapa (used for soil analysis) was used for a rock dust waste analysis and compared to two different block digester-based procedures. Accuracy was confirmed by using the Certified Reference Material (CRM) NIST SRM 1646^a (Estuarine Sediments) and addition/recovery tests. The limits of detection for the aforementioned elements, after aqua-regia-induced digestion, were of 0.07 mg kg⁻¹ for As, 0.06 mg kg⁻¹ for Cd, 0.01 mg kg⁻¹ for Cr, 0.2 mg kg⁻¹ for Cu, 0.03 mg kg⁻¹ for Pb, and 0.09 mg kg⁻¹ for V.

中文翻译：

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来自巴西里约热内卢西北部的岩粉废物的无机含量：将其用作天然肥料会带来环境风险吗？

由于这些残留物释放到环境中的方式不充分，装饰性岩石勘探和涂层行业已导致严重的环境影响。通过将这些残留物用于土壤富集，可以减少这种影响，因为它们含有大量的无机养分。但是，某些元素可能是潜在的污染物，因此在将这些物质用于农业之前需要进行全面的研究。在此背景下，本研究旨在通过湿分解后的电感耦合等离子体发射光谱法（ICP OES）来确定岩石粉尘残留物中As，Cd，Cr，Cu，Pb和V中存在的潜在有毒元素。残留的岩石粉尘废物中的Cd浓度超过了巴西农业部设定的最高限值，第5/2016号规范性指令中规定的牲畜和补给品，用于再矿化剂和用于农业的植物基质。此外，巴西农业研究公司Embrapa采用的官方消化方法（用于土壤分析）被用于岩屑废物分析，并与两种不同的基于块消化的程序进行了比较。通过使用认证参考材料（CRM）NIST SRM 1646来确认准确性^a（河口沉积物）和添加/恢复测试。检测的用于上述元件的限制，水中王水诱导的消化后，分别为0.07毫克千克^-1对As，0.06毫克千克^-1镉，0.01毫克千克^-1对Cr，0.2毫克千克^-1对Cu ，对于Pb为0.03 mg kg ^-1，对于V为0.09 mg kg ^-1。