<b>Assessment of agricultural soil metal pollution in Crocodile River (West) Catchment, South Africa</b>

The contamination of ecosystems by toxic metals remains a public health and ecological concern. Anthropogenic pollution threatens many agricultural systems and the Crocodile River (West) Catchment is South Africa is under such threat. Dams such as Roodeplaat and Hartbeespoort found in this catchment are known to be highly contaminated by human activities taking place in and around them and water abstracted from these dams is used for agricultural purposes. The study aimed to determine the levels of toxic metals in agricultural soils collected from cropping fields from Roodeplaat and Hartbeespoort dam sites, asses the suitability of using such soils for agricultural purposes and also establish the possible contamination sources. Soil samples were collected from 4 cropping sites (2 located at Hartbeespoort and 2 at Roodeplaat Dam site) in June 2019, September 2019; February 2020 and March 2021 and water pH and anionic surfactants levels monitored in farm dams adjacent to the sampling stations. Soil samples were acid digested using the aqua-regia method and analysed for major, minor &amp; trace elements combined using ICP-AES and ICP-MS.有毒金属对生态系统的污染仍是公共卫生与生态领域的重点关切问题。人为活动造成的污染威胁着诸多农业系统，南非西鳄鱼河流域（Crocodile River (West) Catchment）正面临此类污染威胁。该流域内的罗得普拉特坝（Roodeplaat Dam）与哈特比斯普特坝（Hartbeespoort Dam）等水库，因流域内外的人类活动已遭受严重污染，从这些水库抽取的水体被用于农业生产。本研究旨在测定采自罗得普拉特坝与哈特比斯普特坝周边农田的农业土壤中有毒金属的含量水平，评估此类土壤用于农业生产的适宜性，并明确可能的污染来源。研究分别于2019年6月、2019年9月、2020年2月及2021年3月，从4个农田采样点（2个位于哈特比斯普特坝周边，2个位于罗得普拉特坝周边）采集土壤样本，并对采样站点周边农用水库的水体pH值与阴离子表面活性剂（anionic surfactants）含量进行监测。土壤样本采用王水（aqua-regia）法进行酸消解，随后通过电感耦合等离子体原子发射光谱法（ICP-AES）与电感耦合等离子体质谱法（ICP-MS）联合分析其中的常量、微量与痕量元素。