In Australia, the regulatory framework for assessing the risk of soil contamination assumes there is minimal risk from the natural enrichment of potentially toxic elements in soil. When this assumption is applied to land cleared for anthropogenic purposes, non-adapted biota including humans, domestic animals and garden plants can be exposed to these soils. While the impacts of natural arsenic (As) and fluorine (F) in waterways are widely reported, little is known about the biological impacts of natural As and F in non-aquatic soils. We investigated four field sites with naturally elevated soil As and F around Melbourne, Australia. All sites were assessed for As and F in soil, tree and herb (grasses and forbs) foliage. Soil concentrations of As and F ranged from near to above mean ambient background concentrations for Victoria. Soil As and F under trees were consistently higher than under herbs, suggesting deeper tree roots resulted in translocation and accumulation of As and F from deeper soil layers. While surface soil enrichment by plants is known for nutrients, there is less information about enrichment of potentially toxic elements. No clear relationships between soil and foliar As/F concentrations were found. However, there was a range of As and F accumulations in foliage across the four sites: from low to concentrations representative of contaminated sites and above regulatory guidelines. We demonstrated that soils naturally enriched in As and F can be bioavailable and accumulated in plant foliage. Thus, we suggest reassessment of the assumption in Australian guidance that naturally elevated concentrations of potentially toxic elements are not bioavailable and pose minimal risk.

在澳大利亚，评估土壤污染风险的监管框架假设土壤中潜在有毒元素的自然富集风险最小。当这一假设适用于为人为目的而开垦的土地时，包括人类、家畜和园林植物在内的非适应生物群可能会暴露于这些土壤中。虽然天然砷 (As) 和氟 (F) 在水道中的影响已被广泛报道，但对非水生土壤中天然砷和氟的生物影响知之甚少。我们调查了澳大利亚墨尔本周围具有自然升高的土壤 As 和 F 的四个现场。对所有地点的土壤、树木和草本植物（草和杂草）叶子中的 As 和 F 进行了评估。维多利亚州土壤中 As 和 F 的浓度范围从接近到高于平均环境背景浓度。树木下的土壤 As 和 F 始终高于草本下的土壤，这表明较深的树根导致 As 和 F 从较深的土壤层转移和积累。虽然植物对表层土壤的富集以营养物质而闻名，但关于潜在有毒元素富集的信息却很少。没有发现土壤和叶面 As/F 浓度之间的明确关系。然而，四个地点的树叶中存在一系列 As 和 F 积累：从低到代表受污染地点和高于监管准则的浓度。我们证明了天然富含 As 和 F 的土壤可以生物利用并在植物叶子中积累。因此，