Metal concentrations in coastal zones are a critical study subject since anthropogenic activities surrounding these zones are increasing and affecting environmental concentrations of metals. Macroalgae have been used as biomonitors since they can act as indicators of metal concentrations in the water column. Tissue samples of three abundant macroalgae species (Spyridia filamentosa, Padina mexicana and Ulva ohnoi) were collected from three sites with different anthropogenic impacts at La Paz Bay and Guaymas Bay, Mexico, during three contrasting seasons (dry, rainy and cold) in the year 2016. Tissue concentrations of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), nickel (Ni), cadmium (Cd) and lead (Pb) were determined by atomic absorption spectrophotometry. The highest concentrations were found in S. filamentosa inhabiting both bays. The highest Cd and Mn concentrations were recorded in algae from La Paz Bay, while the highest concentrations of Cu, Zn, Pb and Fe were recorded in algae from Guaymas Bay. Metal concentrations varied seasonally; the highest Fe, Cu, Zn, Ni and Pb levels were recorded in the cold season in algae from both bays. S. filamentosa concentrated more Fe, Ni, Cu, Zn and Pb, while P. mexicana and U. ohnoi showed higher Mn and Cd. Therefore, S. filamentosa proved to be the most suitable indicator of metal concentrations, followed by P. mexicana and U. ohnoi. The high metal concentrations recorded in algae from San Juan de la Costa, La Paz Bay, are related to mining activities, whereas those in algae from Guaymas Bay are related to canneries, maritime traffic and others.

Atom probe tomography (APT) is a single-ion sensitive time-of-flight mass spectrometry method with near-atomic spatial resolution. In principle, it can be used to detect any chemical element, but so far hydrogen in the form of protium (1H) had to be largely excluded. This is owing to the residual H emitted from the stainless-steel chambers and in-vacuum parts commonly used in atom probe instrumentation. This residual H is then picked up in the APT experiment. In this paper, we show that by replacing the stainless-steel chamber and in-vacuum parts with titanium parts, this residual H can largely be removed, thus enabling the direct imaging of H using APT. We show that besides the drastic reduction of H, also other contaminants such as O, OH, and H2O are reduced by employing this instrument. In the current set-up, the instrument is equipped with high-voltage pulsing limiting the application to conductive materials.

Among the parasitic taxa studied for their metal accumulation properties, especially Acanthocephala and Cestoda proved to be promising sentinels for metal pollution. However, studies on metal accumulation are still sparse for other parasite groups, mainly due to their small body size. In the present study, we collected the relatively large-sized monogenean Mazocraes alosae Hermann, 1782 from the gills of Pontic Shad (Alosa immaculata Bennet 1835) from its spawning region – the Danube River. The host tissues gills, muscle, intestine and liver, the monogeneans as well as the nematode Hysterothylacium aduncum (Rudolphi, 1802), in the cases of coinfected fish, were analysed for the elements As, Cd, Co, Cu, Fe, Mn, Pb, Se and Zn. All elements (except of As) were found in higher concentrations in monogeneans and nematodes compared to host muscle tissue. High bioconcentration factors were obtained for toxic elements such as Cd and Pb with concentrations being approximately 12 and 251 times higher in monogeneans and 773 and 33 in nematodes, respectively, as compared to host muscle tissue. In comparison to other host organs, however, some elements were found in similar or even lower concentrations in the parasites. Thus, monogeneans do not exhibit the high accumulation potential reported for other parasitic taxa. Physiological adaptations of the migratory host fish between freshwater and marine habitats with differences in uptake pathways and biological availability of elements can be discussed as a possible explanation for this divergent accumulation pattern.

Finely laminated (cm–μm scale) metalliferous precipitates are widespread in the surficial environment, especially around mineral deposits and reflect biogeochemical processes that can pervade near-surface environments on a larger scale. Examples in this paper involve precipitates of the transition metals Fe, Cu and Mn with minor Co, Ni, V and Zn; the metalloids As and Sb; and authigenic Au. Mobility and re-precipitation are driven primarily by geochemical disequilibrium, especially with respect to pH and redox states, that arises from complex interactions between biological processes, geological processes, and variations in the surrounding environment. Different degrees of chemical disequilibrium arise on small spatial scales on time scales of days to millennia. Interactions between biota, waters and rocks in these small near-surface settings affect the biogeochemical environments. Sulfur- and iron-oxidising bacteria are common biogeochemical agents associated with sulfide-bearing lithologies, but localised reductive environments can also develop, leading to gradients in pH and redox state and differential metal mobility. In general, there is commonly a spatial separation of Fe-rich precipitates from those with Cu and Mn, and other transition metals also follow Cu and Mn rather than Fe. Metalloids As and Sb have a strong affinity for Fe under oxidising conditions, but not under more reducing conditions. However, complex biogeochemical parageneses of laminated metalliferous deposits preclude prediction of finer formation details. The textures, mineral species, and metal associations within these deposits are likely to be encountered in all facets of mineral deposit development: initial exploration activity of near-surface locations, mining of shallow portions of orebodies, especially supergene zones, and downstream environmental management with respect to discharging metalliferous waters.

This article tracks the formation of the rich and socially complex Nordic Bronze Age (NBA), c. 2000–1500 bc, by applying a scalar methodology and using the entrepôt and early metalworking site of Pile in Scania as its point of departure. By regarding the Bronze Age as an ancient example of globalisation, Island Melanesia at the outskirts of contemporary globalisation is first examined to provide an analogue to the Nordic entrepreneurial and maritime culture into which metallurgy was first adopted. How did this northern margin become ‘Bronze Age’, and what impact did its inclusion have? Various scales, from local to Bronze-Age-global were found to intersect in the Pile hoard, and in similar sites near and far. By c. 2000 bc, metals and other commodities travelled along well-established local, regional, and super-regional networks, which even incorporated the British Isles and Únětician hubs at the Middle Elbe–Saale. Back in Scandinavia, metal and metal-related culture provided a comparative advantage when navigating local competition for influence and leadership. The transculturally global was strategically appropriated locally, using the reinvention of tradition as a principal strategy. The first metal boom caused friction and slow social change, rather than a social revolution. The real tipping point came in 1600–1500 bc, when the nearly full-blown NBA emerged, through engagement with a considerably expanded world. By this time, large amounts of metal were in circulation. Seen from the non-urban north, this unprecedented expansion of their world brought new opportunities but likely also deep social tensions. Thus, the effects of adopting metallurgy permeated society and connectivity at every level, even at the outskirts of the Bronze Age world.

Exposures to endocrine disrupting chemicals and metals are near ubiquitous worldwide, and their potential impact on children is a major public health concern. This pilot study was designed to characterize exposures to phthalates, phenols and metals among pregnant women in the first trimester, and to examine associations with fetal biometrics and birth weight. A total of 41 chemicals and elements were analyzed in urine from 56 mothers with full-term newborns from the Michigan Mother–Infant Pairs study. Bivariate analyses identified predictors of exposure biomarkers. Associations between birth weight, Fenton z-scores and second trimester fetal biometrics with toxicants were examined via multivariable linear regression. An average of 30 toxicants were detected in maternal urine. Fast food consumption was associated with several phthalate metabolites, phenols and metals, and canned food consumption with bisphenol F (P <0.05). Mono (3-carboxypropyl) phthalate was significantly associated with higher birth weight and Fenton z-score while the opposite was observed for bisphenol S. Estimated femur length from ultrasonography was significantly inversely associated with arsenic, barium and lead. While limited by sample size, this study is one of the first to evaluate birth outcomes with respect to emerging endocrine disrupting chemicals and to examine associations between toxicants and fetal biometrics. Exposure assessment was provided by the National Institute of Environmental Health Sciences’ Children’s Health Exposure Analysis Resource (NIEHS CHEAR), a resource available to children’s studies with the goal of combining data across cohorts in an effort to characterize the impact of toxicants on child health from birth and beyond.

Gilding threads collected from Spanish and Portuguese palaces and from the embroideries and adornments of sculptures of the Virgin and Christ that form part of Sevillian Holy Week were analyzed and compared (20 artifacts were evaluated). The study covered a broad time period with examples from the 13th to 14th centuries, 18th to 20th centuries, and also including modern embroideries. A combination of scanning electron microscopy and energy-dispersive X-ray spectroscopy was used. The knowledge of the layered structures of the threads has provided very valuable information regarding the manufacturing techniques. The different metal threads found in the embroidery studied consisted of gold, silver, copper, and alloys of these metals and aluminium. The fabrication procedures often differed in the different workshops and changed with time. In the modern embroideries, a decrease of precious metal concentration was detected. The threads were wound around a core of silk threads.

Aspects of the (bio)geochemical cycling of metals (including Fe, Cu, Pb, Zn, Hg, As, Sb, U, Tc, Np) at or near the Earth's surface are discussed with reference to the recent work of the authors. Key stages of the breakdown of metalliferous minerals, transport of metals as solution complexes or colloidal precipitates, and interaction of metals in solution with the surfaces of minerals are considered. Emphasis is on molecular-scale observations using techniques such as scanning probe microscopy, photoelectron and (synchrotron) X-ray spectroscopies. The importance of the biological/mineralogical interface is also emphasized with reference to the bacterial colonization of mineral surfaces and formation of biofilms, and their influence on mineral surface reactivity and flow of fluids through rocks and sediments. Also noted is the importance of relating molecular and micro-scale observations to macroscopic phenomena. Molecular-scale understanding is central to attempts to model many processes of relevance in mineral exploration and exploitation, and in the containment of hazardous wastes and remediation of polluted areas. Mineralogists have a central role to play in the relevant environmental sciences and technologies.

In the Earth’s lithosphere, fungi are of fundamental importance as decomposer organisms, animal and plant pathogens and symbionts (e.g. lichens and mycorrhizas), being ubiquitous in sub-aerial and subsoil environments. The ability of fungi to interact with minerals, metals, metalloids and organic compounds through biomechanical and biochemical processes, makes them ideally suited as biological weathering agents of rock and building stone. They also play a fundamental role in biogeochemical cycling of nutrients, (e.g. C, N, P and S) and metals (e.g. Na, Mg, Ca, Mn, Fe, Cu, Zn, Co and Ni) essential for the growth of living organisms in the biosphere. In addition they play an integral role in the mobilization and immobilization of non-essential metals (e.g. Cs, Al, Cd, Hg and Pb). Most studies on mineral-microbe interactions and microbial involvement in geological processes have concentrated on bacteria and archaea (Prokaryota): fungi (Eukaryota) have, to a certain extent, been neglected. This article addresses the role of fungi in geomicrobiological processes, emphasizing their deteriorative potential on rock, building stone and mineral surfaces and involvement in the formation of secondary mycogenic minerals. Such roles of fungi are also of importance for the global carbon reservoir and have potential biotechnological applications, e.g. in the bioremediation of xenobiotic-, metal- and/or radionuclide-contaminated soils and wastes, and metal/radionuclide recovery.

Soil profiles developed in different climates and physical settings are highly variable in structure, in mineralogy, in the local biosphere and in the compositions of the soil gas and water phases. Discussion of metals in ‘the weathering environment’ needs to acknowledge and address this diversity.

The thermochemical methods developed by Pourbaix (1949) and Garrels and Christ (1965) remain useful predictors of metal speciation and solubility but the approach is valid only for processes involving carbonates, sulphides, hydroxides and similar minerals in soils and sediments. Almost no primary silicates are thermodynamically stable: they spontaneously decompose to non-equilibrium solid products with metal release determined by kinetics.

Hydrolysis constants for aquo-complexes are useful indicators of metal speciation, mobility and availability. Recent work on soluble soil organic matter confirms that the active ligands are overwhelmingly oxygen based: phenols, carboxylic acids, alcohols. Many of these molecules compete very effectively with aquo-complexes to form strong metal chelates and appear to be responsible for substantial Al and Fe mobilization within and translocation down soil profiles.

It is important to note also that strong clay mineral/organic matter associations (clay-organic complex) will fix metals as a consequence of the same chelation reactions (in this case removing them from solution - retardation).

Lichen element content is a reliable indicator for relative air pollution load in research and monitoring programmes requiring both efficiency and representation of many sites. We tested the value of costly rigorous field and handling protocols for sample element analysis using five lichen species. No relaxation of rigour was supported; four relaxed protocols generated data significantly different from rigorous protocols for many of the 20 validated elements. Minimally restrictive site selection criteria gave quality data from 86% of 81 permanent plots in northern Midwest USA; more restrictive criteria would likely reduce indicator reliability. Use of trained non-specialist field collectors was supported when target species choice considers the lichen community context. Evernia mesomorpha, Flavoparmelia caperata and Physcia aipolia/stellaris were successful target species. Non-specialists were less successful at distinguishing Parmelia sulcata and Punctelia rudecta from lookalikes, leading to few samples and some poor quality data.

Geochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contamination from different sources to be suggested. Dating was also attempted using microfossils, radiocarbon and 210Pb, but with limited success. Some of the spatial distribution of contaminants in the surface sediments can be related to grain-size variations. Contaminants are highest, both in absolute terms and in enrichment relative to the natural background, in the urban and inner estuary and in the Holy Loch, reflecting the concentration of industrial activity.

The chemical composition of soil from the Glasgow (UK) urban area was used to identify the controls on the availability of potentially harmful elements (PHEs) in soil to humans. Total and bioaccessible concentrations of arsenic (As), chromium (Cr) and lead (Pb) in 27 soil samples, collected from different land uses, were coupled to information on their solid-phase partitioning derived from sequential extraction data. The total element concentrations in the soils were in the range <0.1–135mgkg–1 for As; 65–3680mgkg–1 for Cr and 126–2160mgkg–1 for Pb, with bioaccessible concentrations averaging 27, 5 and 27% of the total values, respectively. Land use does not appear to be a predictor of contamination; however, the history of the contamination is critically important. The Chemometric Identification of Substrates and Element Distribution (CISED) sequential chemical extraction and associated self-modelling mixture resolution analysis identified three sample groupings and 16 geochemically distinct phases (substrates). These were related to iron (n=3), aluminium–silicon (Al–Si; n=2), calcium (n=3), phosphorus (n=1), magnesium (Mg; n=3), manganese (n=1) and easily extractable (n=3), which was predominantly made up of sodium and sulphur. As, Cr and Pb were respectively found in 9, 10 and 12 of the identified phases, with bioaccessible As predominantly associated with easily extractable phases, bioaccessible Cr with the Mg-dominated phases and bioaccessible Pb with both the Mg-dominated and Al–Si phases. Using a combination of the Unified Barge Method to measure the bioaccessibility of PHEs and CISED to identify the geochemical sources has allowed a much better understanding of the complexity of PHE mobility in the Glasgow urban environment. This approach can be applied to other urban environments and cases of soil contamination, and made part of land-use planning.

Three-dimensional (3D) printing of metallic materials involves the layerwise consolidation of feedstock materials in the form of powder, wire, or sheet using various energy sources to form complex shapes. The past two decades have witnessed significant advances in the field, in terms of both technologies and materials for metal 3D printing. This has led to widespread exploration and adoption of the technologies across industry, academia, and R&D organizations. This article presents an overview of the field of metal 3D printing. A brief history of metal 3D printing is followed by an overview of metal 3D printing methods and metallic material systems used in these methods. Microstructure and properties, and their relationship to process parameters are discussed next, followed by current challenges and qualification issues. The article concludes with future trends and a brief description of the invited articles included in this special issue.

Several particles of copper accompanied by a few particles of nickel, lead, and a compound composed of selenium containing minor Ni, Si, Cu, and Co were found in human gall, kidney, and bladder stones. The investigated particles occur as tiny grains, <10 µm in size, that are irregularly dispersed in the stones. Therefore, they were studied by scanning electron microscopy and qualitatively analyzed by energy dispersive system. One grain of copper contained a small amount of Ni and Zn, and some grains of nickel proved to contain Cr as trace element. Most of the discovered metals formed a single-phase grain. However, a few grains found in two gallstones were associated with inclusions of calcium and apatite. Based on the results presented in this contribution, we argue that most of the studied metals can be classified as endogenous particles, i.e., directly precipitated from the same fluids that formed their host human stones. This observation suggests that the precipitation and accumulation of metals in some human stones can be considered an efficient way to eliminate them from the human body.