Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovak Republic.
DEKONTA Slovensko, Ltd., Odeská 49, 821 06 Bratislava, Slovak Republic.
Chemosphere. 2024 Aug;362:142677. doi: 10.1016/j.chemosphere.2024.142677. Epub 2024 Jun 21.
Landfills, especially those poorly managed, can negatively affect the environment and human beings through chemical contamination of soils and waters. This study investigates the soils of a historical municipal solid waste (MSW) landfill situated in the heart of a residential zone in the capital of Slovakia, Bratislava, with an emphasis on metal (loid) contamination and its consequences. Regardless of the depth, many of the soils exhibited high metal (loid) concentrations, mainly Cd, Cu, Pb, Sb, Sn and Zn (up to 24, 2620, 2420, 134, 811 and 6220 mg/kg, respectively), classifying them as extremely contaminated based on the geo-accumulation index (I >5). The stable lead isotopic ratios of the landfill topsoil varied widely (1.1679-1.2074 for Pb/Pb and 2.0573-2.1111 for Pb/Pb) and indicated that Pb contained a natural component and an anthropogenic component, likely municipal solid waste incineration (MSWI) ash and construction waste. Oral bioaccessibility of metal (loid)s in the topsoil was variable with Cd (73.2-106%) and Fe (0.98-2.10%) being the most and least bioaccessible, respectively. The variation of metal (loid) bioaccessibility among the soils could be explained by differences in their geochemical fractionation as shown by positive correlations of bioaccessibility values with the first two fractions of BCR (Community Bureau of Reference) sequential extraction for As, Cd, Mn, Ni, Pb, Sn and Zn. The results of geochemical fractionation coupled with the mineralogical characterisation of topsoil showed that the reservoir of bioaccessible metal (loid)s was calcite and Fe (hydr)oxides. Based on aqua regia metal (loid) concentrations, a non-carcinogenic risk was demonstrated for children (HI = 1.59) but no risk taking into account their bioaccessible concentrations (HI = 0.65). This study emphasises the need for detailed research of the geochemistry of wastes deposited in urban soils to assess the potentially hazardous sources and determine the actual bioaccessibility and human health risks of the accumulated metal (loid)s.
垃圾填埋场，特别是管理不善的垃圾填埋场，可能通过土壤和水体的化学污染对环境和人类造成负面影响。本研究调查了位于斯洛伐克首都布拉迪斯拉发一个居民区中心的历史城市固体废物（MSW）垃圾填埋场的土壤，重点研究了金属（类）污染及其后果。无论深度如何，许多土壤都表现出高浓度的金属（类），主要是 Cd、Cu、Pb、Sb、Sn 和 Zn（分别高达 24、2620、2420、134、811 和 6220mg/kg），根据地质累积指数（I>5）将其归类为极度污染。垃圾填埋场表土的稳定铅同位素比值变化范围很广（Pb/Pb 为 1.1679-1.2074，Pb/Pb 为 2.0573-2.1111），表明 Pb 含有天然成分和人为成分，可能是城市固体废物焚烧（MSWI）灰和建筑废物。表土中金属（类）的口服生物可利用性变化不定，Cd（73.2-106%）和 Fe（0.98-2.10%）分别是最易和最难生物利用的。土壤中金属（类）生物可利用性的变化可以用 BCR（社区参考局）连续提取法的前两个分馏物与 As、Cd、Mn、Ni、Pb、Sn 和 Zn 的正相关关系来解释。地球化学分馏的结果加上表土的矿物特征表明，生物可利用金属（类）的储库是方解石和 Fe（氢）氧化物。根据王水金属（类）浓度，儿童表现出非致癌风险（HI=1.59），但考虑到他们的生物可利用浓度（HI=0.65）则没有风险。本研究强调需要对城市土壤中沉积废物的地球化学进行详细研究，以评估潜在的危险来源，并确定积累金属（类）的实际生物可利用性和人类健康风险。
