Seven plant certified reference materials (NIST SRM1515 Apple Leaves, NIST SRM1547 Peach Leaves, BCR-129 Hay Powder, BCR-670 Aquatic Plant, GBW07603 Bush Twigs and Leaves, GBW10015 Spinach Leaves and NCS ZC73036a Green Tea) were analysed for their mass fractions of 48 elements by inductively coupled plasma tandem-mass spectrometry (ICP-MS/MS): Li, Be, Na, Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Nb, Mo, Ag, Cd, Sb, Te, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ta, Tl, Pb, Bi, Th, U. Special focus was put on the determination of technology-critical elements (TCEs), to which, e.g. Li, Be, Ga, Ge, Nb, Sb, Ta, Tl, Bi, and the rare-earth elements (REEs, lanthanides and Y) are counted. Closed-vessel microwave digestion was performed using HNO₃, H₂O₂ and HBF₄. The average bias for certified values is − 1% ± 13% (SD). Limits of detection (x_L) in the measured solutions lie between 13 fg g⁻¹ (Tb) and 52 ng g⁻¹ (Ca). This article seeks to provide an optimised measurement procedure for the determination of element mass fractions of emerging importance in environmental samples, which are challenging to analyse with more traditional techniques such as single-quad ICP-MS. In addition, it aims to improve the characterisation of commonly used plant reference materials by providing mass fraction data for rarely studied elements. Graphical abstract

As the drive towards recycling electronic waste increases, demand for rapid and reliable analytical methodology to analyse the metal content of the waste is increasing, e.g. to assess the value of the waste and to decide the correct recycling routes. Here, we comprehensively assess the suitability of different x-ray fluorescence spectroscopy (XRF)-based techniques as rapid analytical tools for the determination of critical raw materials, such as Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nb, Pd and Au, in three electronic waste matrices: printed circuit boards (PCB), light emitting diodes (LED), and lithium (Li)-ion batteries. As validated reference methods and materials to establish metrological traceability are lacking, several laboratories measured test samples of each matrix using XRF as well as other independent complementary techniques (instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS) and ICP optical emission spectrometry (OES)) as an inter-laboratory comparison (ILC). Results highlighted key aspects of sample preparation, limits of detection, and spectral interferences that affect the reliability of XRF, while additionally highlighting that XRF can provide more reliable data for certain elements compared to digestion-based approaches followed by ICP-MS analysis (e.g. group 4 and 5 metals). A clear distinction was observed in data processing methodologies for wavelength dispersive XRF, highlighting that considering the metals present as elements (rather than oxides) induces overestimations of the mass fractions when compared to other techniques. Eventually, the effect of sample particle size was studied and indicated that smaller particle size (<200 µm) is essential for reliable determinations.

Particulate matter (PM) exposure in urban areas is a continuous threat to human health and requires sustainable solutions for effective reduction. The aim of this study is to provide a comprehensive overview of façade greening and its effects on PM and to identify knowledge gaps. We systematically screened, analyzed, and re-evaluated previous reviews according to the criteria established for an umbrella review. As a result, this study covers and discusses common measurement methods, influencing factors, the effectiveness of façade greening, leaf characteristics, and plant species from different subtopics. The main findings are that inconsistent measurement methods limit the comparability of the analyzed reviews, and different climatic conditions affecting the use of plant species lead to different international effects. Despite the existing studies reporting a positive effect on the reduction of PM, comparability is difficult due to methodological differences and external influences. Given the complexity, interdisciplinary collaboration with experts is essential to increase the effectiveness of façade greening for PM accumulation for healthy urban air. We suggest that this umbrella review provides a foundation for future research and practical implementations, such as a suitable plant selection or façade design, by integrating the results.

Over the recent decades, technological advancements have led to a rise in the use of so-called technology-critical elements (TCEs). Environmental monitoring of TCEs forms the base to assess whether this leads to increased anthropogenic release and to public health implications. This study employs an exploratory approach to investigate the distribution of the TCEs Li, Be, V, Ga, Ge, Nb, Sb, Te, Ta, Tl, Bi and the REYs (rare-earth elements including yttrium) in urban aerosol in the city of Vienna, Austria. Leaf samples (n = 292) from 8 plant species and two green facades and water samples (n = 18) from the Wienfluss river were examined using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Surface dust contributions were assessed by washing one replicate of each leaf sample and analysing the washing water (n = 146). The impacts of sampling month, plant species and storey level on elemental distribution were assessed by statistical tools and generative deep neural network modelling. Higher TCE levels, including Li, V, Ga, Ge, Tl, Bi, and the REYs, were found in the winter months, likely due to the use of de-icing materials and fossil fuel combustion. A. millefolium and S. heufleriana displayed the highest levels of Li and Ge, respectively. In addition, increased elemental accumulation at lower storeys was observed, including Be, Sb, Bi and the REYs, indicating greater atmospheric dust deposition and recirculation closer to ground level. The results suggest a broad association of TCE levels with urban dust. This study enhances the current understanding of TCE distribution in urban settings and underscores the importance of their inclusion in pollution monitoring. It highlights the complex interplay of human activities, urban infrastructure, and environmental factors, offering valuable insights for managing urban environmental health risks and underlining the need for comprehensive urban ecosystem studies.

Honeybees ( Apis mellifera ) and their products are valuable biomonitors of environmental pollution. This study reports the contents of 48 elements in samples of propolis, bees, pollen, honey, honeycomb, and wax from bee hives in Leoben, Austria. The samples were taken in three campaigns over a period of twelve months. After microwave-assisted acid digestion, the samples were measured with inductively coupled plasma tandem-mass spectrometry (ICP-MS/MS) using nitrous oxide (N ₂ O) as reaction gas for analytes affected by spectral interferences. Matrix-specific patterns in multielement variations were explored with univariate and multivariate statistical analysis. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed four matrix clusters (propolis; bee; pollen; honey/honeycomb/wax), with element mass fractions generally decreasing in the order propolis > bee > pollen > wax ≈ honeycomb ≈ honey. Two analyte groups could be separated by their PCA loadings, one interpreted as predominantly particle-associated (Li, Al, V, Cr, Fe, Nb, Y, La, Ce, Sm, Eu, Gd, Tb, Dy, Ho, Ta, Sb, Bi, Pb) and the other as more soluble/bioavailable (Na, Mg, Ca, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Cd, Ba, Tl). Chondrite-normalized patterns of rare-earth elements including yttrium (REY) showed smooth profiles across all matrices, suggesting geogenic sources and negligible fractionation from biotransformation. Only minor differences were observed between different matrices from the same location. The observed contrasts in REY patterns in honey samples from Austria, Belgium, and Russia support their suitability for tracking regional environmental conditions. Graphical abstract

The rollout of electric vehicles and photovoltaic panels is essential to mitigate climate change. However, they depend on technology‐critical elements (TCEs), which can be harmful to human health and whose use is rapidly expanding, while recycling is lacking. While mining has received substantial attention, in‐use dissipation in urban areas has so far not been assessed, for example, corrosion and abrasion of vehicle components and weather‐related effects affecting thin‐film photovoltaic panels. Therefore, the question arises to which extent TCEs dissipate during use and which potential non‐occupational human health impacts could occur. We assessed the available information on urban in‐use dissipation and human health concerns and conducted exploratory modeling of in‐use technology stocks, in‐ and outflows, and in‐use dissipation of neodymium, dysprosium, lanthanum, praseodymium, cerium, gallium, germanium, and tellurium contained in 21 vehicle and renewable energy technologies, for Vienna, Austria. In prospective scenarios, TCE dynamics in a trend‐continuation vis à vis official city policy plans and a more ambitious transition scenario were then assessed. We find that electrifying the vehicle fleet without demand‐reduction is the main driver of TCE consumption, effectively doubling cumulative end‐of‐life outflows to 3,073 [2,452–3,966] t and cumulative in‐use dissipation to 9.3 [5.2–15.7] t by the year 2060. Sufficiency‐based measures could reduce demand and in‐use dissipation well below levels with continued trends, thus highlighting the need to combine decarbonization with demand‐reducing measures. These results help assess potential future in‐use dissipation dynamics and inform discussions about potential public health hazards associated with exposure to TCEs accumulating in the urban environment.