Multidimensional Drivers of Mercury Distribution in Global Surface Soils: Insights from a Global Standardized Field Survey.

Soil stores a large amount of mercury (Hg) that has adverse effects on human health and ecosystem safety. Significant uncertainties still exist in revealing environmental drivers of soil Hg accumulation and predicting global Hg distribution owing to the lack of field data from global standardized analyses. Here, we conducted a global standardized field survey and explored a holistic understanding of the multidimensional environmental drivers of Hg accumulation in global surface soils. Hg content in surface soils from our survey ranges from 3.8 to 618.2 µg kg-1 with an average of 74.0 µg kg-1 across the globe. Atmospheric Hg deposition, particularly vegetation-induced elemental Hg0 deposition, is the major source of surface soil Hg. Soil organic carbon serves as the major substrate for sequestering Hg in surface soils and is significantly influenced by agricultural management, litterfall, and elevation. For human activities, changing land-use could be a more important contributor than direct anthropogenic emissions. Our prediction of a new global Hg distribution highlights the hot spots (high Hg content) in East Asia, the Northern Hemispheric temperate/boreal regions, and tropical areas, while the cold spots (low Hg content) are in arid regions. The holistic understanding of multidimensional environmental drivers helps to predict the Hg distribution in global surface soils under a changing global environment.

Mercury Reduction, Uptake, and Species Transformation by Freshwater Alga Chlorella vulgaris under Sunlit and Dark Conditions.

As a major entry point of mercury (Hg) to aquatic food webs, algae play an important role in taking up and transforming Hg species in aquatic ecosystems. However, little is known how and to what extent Hg reduction, uptake, and species transformations are mediated by algal cells and their exudates, algal organic matter (AOM), under either sunlit or dark conditions. Here, using Chlorella vulgaris (CV) as one of the most prevalent freshwater model algal species, we show that solar irradiation could enhance the reduction of mercuric Hg(II) to elemental Hg(0) by both CV cells and AOM. AOM reduced more Hg(II) than algal cells themselves due to cell surface adsorption and uptake of Hg(II) inside the cells under solar irradiation. Synchrotron radiation X-ray absorption near-edge spectroscopy (SR-XANES) analyses indicate that sunlight facilitated the transformation of Hg to less bioavailable species, such as ß-HgS and Hg-phytochelatins, compared to Hg(Cysteine)2-like species formed in algal cells in the dark. These findings highlight important functional roles and potential mechanisms of algae in Hg reduction and immobilization under varying lighting conditions and how these processes may modulate Hg cycling and bioavailability in the aquatic environment.

Assessment of the Bioavailability of Mercury Sulfides in Paddy Soils Using Sodium Thiosulfate Extraction - Results from Microcosm Experiments.

Mercury sulfides (HgS), one of the largest Hg sinks in the lithosphere, has long been considered to be highly inert. Recently, several HgS speciation (e.g., nano- or micro-sized HgS particles) in paddy soils have been found to be reactive and bioavailable, increasing the possibility of methylation and bioaccumulation and posing a potential risk to humans. However, a simple and uniform method for investigating HgS bioavailability is still lacking. To address this issue, we extracted dissolved Hg from HgS particles by sodium thiosulfate (Na2S2O3) in paddy soils and analyzed the correlation between extracted Hg and soil methylmercury (MeHg). Results showed that the amounts of Hg extracted by Na2S2O3 had a strong positive correlation with the levels of soil MeHg (R 2 adj = 0.893, p < 0.05). It is suggested that Na2S2O3 extraction may be a good method of predicting Hg bioavailability in paddy soils. Our results would help to give clues in better predicting Hg risk in natural environments.

MALDI-TOF-MS and XAS analysis of complexes formed by metallothionein with mercury and/or selenium.

Mercury (Hg) is highly toxic while selenium (Se) has been found to antagonize Hg. Both Hg and Se have been found to induce metallothioneins (MTs). In this study, the complexes formed by metallothionein-1 (MT-1) with HgCl2 and/or Na2SeO3 was studied using matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and X-ray absorption spectrometry (XAS). MALDI-TOF-MS and XAS indicated the formation of Hg-S bond or Se-S bond when MT-1 reacted with HgCl2 or Na2SeO3, respectively. The bond lengths of Hg-S and coordination number in MT-Hg are 2.41 ± 0.02 Å and 3.10 and in MT-Se are 2.50 ± 0.03 Å and 2.69. A MT-Se-Hg complex was formed when MT-1 reacted with both HgCl2 and Na2SeO3, in which the neighboring atom of Hg is Se, while the neighboring atoms of Se are S and Hg. Our study is an important step towards a better understanding of the interaction of HgCl2 and/or Na2SeO3 with proteins like MT-1.

Understanding the hepatoxicity of inorganic mercury through guts: Perturbance to gut microbiota, alteration of gut-liver axis related metabolites and damage to gut integrity.

Mercury (Hg) brings adverse effects to the environment and human beings and inorganic mercury (IHg) is a typical hepatic toxin. This work studied the impacts of IHg on gut microbes and metabolome together with its damage to liver and gut in rats through gut microbiome, metabolomics and metallomics. Sprague Dawley (SD) rats were orally exposed to 0.4 µg/mL IHg and sacrificed after 24 h. It was found that IHg perturbed greatly on the gut microbiota, such as increased pathogenic bacteria like G. bacillus. In addition, IHg also changed gut-liver axis related metabolites, which was confirmed by the secretion of a large number of inflammatory factors in both the gut and the liver. The changed gut-liver axis related metabolites correlated well to the changes of gut microbiome. In all, besides the direct deposition in liver of Hg, the perturbance to gut microbiome and alteration of gut-liver axis related metabolites by IHg also contributed to its hepatoxicity, which provides new insights about the hepatoxicity of chemicals. The strategy applied in this work may also be used to understand the hepatoxicity of other chemicals.

Temporal trends of urinary mercury in Chinese people from 1970s to 2010s: A review.

Mercury (Hg) is one of the most toxic heavy metals. It can migrate around the globe and magnify through the food chain, ultimately harming human health. Urinary Hg reflects recent exposure of Hg, which reflects the status of environmental contamination by Hg. This review summarized the levels and presented temporal trends of urinary Hg in Chinese people (both the general public and the occupationally exposed people) reported from 1970s to 2010s. It was found that urinary Hg levels in 92.3% of the reported population were less than the reference value (10.0 µg/L) recommended by Chinese health authority, while 76.9% were less than the reference value (4.0 µg/L) recommended by World Health Organization (WHO) in the general public in China. For the temporal trend from 1970s to 2010s, the urinary Hg levels in the general public in China were found to decrease gradually. In the occupationally exposed people, the urinary Hg levels generally exceeded the reference value (10.0 µg/L) for the general public, and about half of them were higher than the occupational exposure limit (35.0 µg/g creatinine) set by Chinese Occupational Health Standard (WS/T 265 - 2006). From 1970s to 2010s, the urinary Hg levels in occupationally exposed population increased first and then decreased slowly. Hg miners in Guizhou were found to have the highest urinary Hg levels, while workers in Anhui, Chongqing, Qinghai and Shanxi also had high levels of urinary Hg. In all, the urinary Hg levels in both the general public and the occupationally exposed people decreased from 1970s to 2010s, especially in recent decades. Attention should be paid to occupationally exposed people since high levels of urinary Hg were found in them. The message provided in this review can help better understand the situation of Hg burden in Chinese people and lay a basis for the coming effectiveness evaluation on the implementation of Minamata Convention on Mercury. Capsule abstract: The urinary Hg levels in both the general public and the occupationally exposed people in China are decreasing.

Comparative study of the effects of different chelating ligands on the absorption and transport of mercury in maize (Zea mays L.).

Mercury (Hg) pollution seriously threatens food safety and has attracted global attention. Phytoextraction, due to its low cost, applicability, and environmental friendliness, is considered a new technology for clean-up of heavy metal contamination in the environment. However, the low bioavailability of Hg in polluted areas greatly limits the applicability of phytoextraction. Here, we compared the effects of six common chelating ligands on the absorption and transport of Hg in maize (Zea mays L.), which has a high biomass and short growth cycle. The results showed that the root length and biomass of maize seedlings of the groups treated with the six chelating ligands (EDTA, iodide, ammonium, thiosulfate, thiocyanate, and thiocarbamide) did not change compared with those of the non-treated groups. Co-exposure to Hg and each chelating ligand markedly alleviated the inhibitory effect induced by Hg. Iodide treatment resulted in the lowest root Hg content and highest translocation factor (TF) value, while ammonium treatment gave rise to the highest shoot Hg concentration and lowest TF. Compared with other chelating ligands, thiosulfate exhibited the maximum alleviation of Hg toxicity and achieved the highest concentration of Hg in the roots and aerial parts. Moreover, the TF and Hg accumulation in the thiosulfate and Hg co-exposed group were much higher than those in the group exposed to Hg alone. This finding suggests that, among these common chelating ligands, thiosulfate compounds have great potential for Hg phytoextraction, while the others can immobilize Hg in polluted areas.

A comparative study on the accumulation, translocation and transformation of selenite, selenate, and SeNPs in a hydroponic-plant system.

Plants can play important roles in overcoming selenium (Se) deficiency and Se toxicity in various regions of the world. Selenite (SeIV), selenate (SeVI), as well as Se nanoparticles (SeNPs) naturally formed through reduction of SeIV, are the three main Se species in the environment. The bioaccumulation and transformation of these Se species in plants still need more understanding. The aims of this study are to investigate the phytotoxicity, accumulation, and transformation of SeIV, SeVI and SeNPs in garlic, a relatively Se accumulative plant. The spatial distribution of Se in the roots were imaged using synchrotron radiation micro-focused X-ray fluorescence (SR-µXRF). The chemical forms of Se in different plant tissues were analyzed using synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The results demonstrate that 1) SeNPs which has the lowest phytotoxicity is stable in water, but prone to be converted to organic Se species, such as C-Se-C (MeSeCys) upon uptake by root. 2) SeIV is prone to concentrate in the root and incorporated into C-Se-C (MeSeCys) and C-Se-R (SeCys) bonding forms; 3) SeVI with the lowest transformation probability to organic Se species has the highest phytotoxicity to plant, and is much easier to translocate from root to leaf than SeNPs and SeIV. The present work provides insights into potential impact of SeNPs, selenite and selenate on aquatic-plant ecosystems, and is beneficial for systematically understanding the Se accumulation and transformation in food chain.

Acute oral methylmercury exposure perturbs the gut microbiome and alters gut-brain axis related metabolites in rats.

Environmental pollutants like methylmercury (MeHg) can bring devastating neurotoxicity to animals and human beings. Gut microbiota has been found to demethylate MeHg and promote the excretion of Hg through feces. However, the impacts of MeHg on gut microbiota and metabolites related to gut-brain interactions were less studied in mammals. The object of this study was to investigate the impacts of acute MeHg exposure on gut microbiome and metabolites together with its impact on gut integrity and related biological responses in rats. Rats were exposed to MeHg through oral administration and were sacrificed after 24 h 16 S rRNA gene sequencing was used to study the perturbance to gut microbiome and liquid chromatography mass spectrometry (LC-MS) was used for metabolomics profiling. It was found that gut was one of the target tissues of MeHg. MeHg induce the changes of intestinal microbial community structure and induce the regulating neuron activity change of intestinal neurotransmitters and metabolites on intestinal neurotransmitters and metabolites regulating the neuron activity. This was supported by the increased BDNF level. These findings may suggest a potential new mechanism regarding the neurotoxicity of MeHg. The protocols used in this study may also be applied to understand the neurotoxicity of other environmental neurotoxins like Pb, Mn, polychlorinated biphenyls, and pesticides, etc and to screen the neurotoxicity of emerging environmental contaminants.

Stepwise Reduction Approach Reveals Mercury Competitive Binding and Exchange Reactions within Natural Organic Matter and Mixed Organic Ligands.

The kinetics of mercuric ion (Hg2+) binding with heterogeneous naturally dissolved organic matter (DOM) has been hypothesized to result from competitive interactions among different organic ligands and functional groups of DOM for Hg2+. However, an experimental protocol is lacking to determine Hg2+ binding with various competitive ligands and DOM, their binding strengths, and their dynamic exchange reactions. In this study, a stepwise reduction approach using ascorbic acid (AA) and stannous tin [Sn(II)] was devised to differentiate Hg(II) species in the presence of two major functional groups in DOM: the carboxylate-bound Hg(II) is reducible by both AA and Sn(II), whereas the thiolate-bound Hg(II) is reducible only by Sn(II). Using this operational approach, the relative binding strength of Hg2+ with selected organic ligands was found in the order dimercaptopropanesulfonate (DMPS) > glutathione (GSH) > penicillamine (PEN) > cysteine (CYS) > ethylenediaminetetraacetate > citrate, acetate, and glycine at the ligand-to-Hg molar ratio < 2. Dynamic, competitive ligand exchanges for Hg2+ from weak carboxylate to strong thiolate functional groups were observed among these ligands and within DOM, and the reaction depended on the relative binding strength and abundance of thiols and carboxylates, as well as reaction time. These results provide additional insights into dynamic exchange reactions of Hg2+ within multicompositional DOM in controlling the transformation and bioavailability of Hg(II) in natural aquatic environments.

Rapid Hydrolysis of Penicillin Antibiotics Mediated by Adsorbed Zinc on Goethite Surfaces.

The soil environment is an important sink for penicillin antibiotics released from animal manure and wastewater, but the mineral-catalyzed transformation of penicillins in soil has not been well studied. To simulate this environmental process, we systematically investigated the behavior of penicillin G and amoxicillin, the two most widely-used penicillin antibiotics, in the presence of goethite and metal ions. The results demonstrated that Zn ions significantly promoted the hydrolysis of penicillins in goethite suspensions, as evidenced by the degradation rate nearly 3 orders of magnitude higher than that of the non-Zn-containing control. The spectroscopic analysis indicated that the specific complexation between penicillins, adsorbed Zn, and goethite was responsible for the enhanced degradation. Metastable interactions, involving hydrogen bonds between carbonyl groups in the ß-lactam ring and the double/triple hydroxyl groups on goethite surface, and coordination bonding between carboxyl groups and surface irons were proposed to stabilize the ternary reaction intermediates. Moreover, the surface zinc-hydroxide might act as powerful nucleophile to rapidly rupture the ß-lactam ring in penicillins. This study is among the first to identify the synergic roles of Zn ion and goethite in facilitating penicillin degradation and provides insights into ß-lactam antibiotics to assess their environmental risk in soil.

Increased Methylmercury Accumulation in Rice after Straw Amendment.

Consumption of rice has been shown to be an important route of dietary exposure to methylmercury (MeHg, a neurotoxin) for Asians having a low fish but high rice diet. Therefore, factors that increase MeHg production and bioaccumulation in soil-rice systems, could enhance the risk of MeHg exposure. On the basis of a national-scale survey in China (64 sites in 12 provinces) and rice cultivation experiments, we report that straw amendment, a globally prevalent farming practice, could increase MeHg concentrations in paddy soils (11-1043%) and rice grains (95%). By carrying out a series of batch incubation, seedling uptake and sand culture experiments, we demonstrate that these increases could be attributed to (1) enhanced abundances/activities of microbial methylators and the transformation of refractory HgS to organic matter-complexed Hg, facilitating microbial Hg methylation in soils; (2) enhanced MeHg mobility, and increased root lengths (35-41%) and tip numbers (60-105%), increasing MeHg uptake by rice roots; and (3) enhanced MeHg translocation to rice grains from other tissues. Results of this study emphasize fresh organic matter-enhanced MeHg production and bioaccumulation, and highlight the increased risk of MeHg after straw amendment and thus the need for new policies concerning straw management.

Understanding Enhanced Microbial MeHg Production in Mining-Contaminated Paddy Soils under Sulfate Amendment: Changes in Hg Mobility or Microbial Methylators?

Elevated methylmercury (MeHg) production in mining-contaminated paddy soils, despite the high fraction of refractory HgS(s), has been frequently reported, while the underlying mechanisms are not fully understood. Here, we hypothesized that sulfate input, via fertilization, rainfall, and irrigation, is critical in mobilizing refractory HgS(s) and thus enhancing Hg methylation in mining-contaminated paddy soils. To test this hypothesis, the effects of sulfate amendment on Hg methylation and MeHg bioaccumulation in mining-contaminated soil-rice systems were examined. The results indicated 28-61% higher net MeHg production in soils under sulfate amendment (50-1000 mg kg-1), which in turn increased grain MeHg levels by 22-55%. The enhancement of Hg methylation by Hg mobilization in sulfate-amended soils was supported by two observations: (1) the increased Hg(aq) release from HgS(s), the dominant Hg species in the paddy soils, in the presence of sulfide produced following sulfate reduction and (2) the decreases of refractory HgS(s) in soils under sulfate amendment. By contrast, changes in the abundances/activities of potential microbial Hg methylators in different Hg-contaminated soils were not significant following sulfate amendment. Our results highlight the importance to consider enhanced Hg mobility and thus methylation in soils under sulfate amendment.

Selenium decreases methylmercury and increases nutritional elements in rice growing in mercury-contaminated farmland.

Methylmercury (MeHg) in rice grains grown in Hg-contaminated areas has raised environmental health concerns. Pot experiments found that selenium (Se) could reduce MeHg levels in rice grains. However, relatively high levels of Se (up to 6 mg/kg) were applied in these pot experiments, which may have adverse effects on the soil ecology due to the toxicity of Se. The aims of this work were thus to study 1) the effect of low levels of Se on the accumulation and distribution of Hg, especially MeHg, in rice plants grown in a real Hg-contaminated paddy field and 2) the effect of Se treatment on Se and other nutritional elements (e.g., Cu, Fe, Zn) in grains. A field study amended with different levels of Se was carried out in Hg-contaminated paddy soil in Qingzhen, Guizhou, China. The levels of MeHg and total Hg were studied using cold vapor atomic fluorescence spectrometry (CVAFS) and inductively coupled plasma mass spectrometry (ICP-MS). The distribution and relative quantification of elements in grains were examined by synchrotron radiation X-ray fluorescence analysis (SR-XRF). This field study showed that low levels of Se (0.5 µg/mL, corresponding to 0.15 mg Se/kg soils) could significantly reduce total Hg and MeHg in rice tissues. Se treatment also reduced Hg distribution in the embryo and endosperm and increased the levels of Fe, Cu, Zn and Se in grains and especially embryos. This field study implied that treatment with an appropriate level of Se is an effective approach to not only decrease the level of MeHg but to also increase the levels of nutritional elements such as Fe, Cu, Zn and Se in rice grains, which could bring beneficial effects for rice-dependent residents living in Hg-contaminated areas.

Selenium modulated gut flora and promoted decomposition of methylmercury in methylmercury-poisoned rats.

INTRODUCTION: Selenium plays important roles in antagonizing the toxicity of methylmercury. The underlying mechanism for the antagonism between Se and MeHg is still not fully understood. OBJECTIVE: The role of gut flora against the toxicity of environmental contaminants is receiving more and more attention. The objective of this study was to investigate the role of Se against MeHg-poisoning in the modulation of gut flora and the decomposition of MeHg. METHODS: MeHg-poisoned rats were treated with sodium selenite every other day for 90 days. Fecal samples were collected on Day 8, 30, 60 and 90. Gut flora in feces was determined using 16S rRNA gene profiling, and the concentrations of Se and total mercury (THg) were measured by ICP-MS, and the concentration of MeHg was measured by CVAFS. RESULTS: Gut flora at both the ranks of phylum and genus in the MeHg-poisoned rats after Se treatment was modulated towards that in the control group, suggesting the restoration of the profile of gut flora. Increased THg was found in fecal samples after Se treatment on day 30. The percentage of MeHg (of total mercury) in the MeHg-poisoned group was in the range of 81-105% while it was 65-84% in the Se treatment group on different days, suggesting the increased decomposition of MeHg in MeHg-poisoned rats after Se treatment. CONCLUSIONS: This study suggests that MeHg poisoning damaged the abundance of gut flora and decreased their capacity for the decomposition of MeHg. After Se treatment, the abundance of gut flora was partially restored and the decomposition and excretion of MeHg was enhanced. These findings suggest that the modulation of gut flora may be one way to promote the health status in MeHg-poisoned rats and possibly in human beings.

Nanoelemental selenium alleviated the mercury load and promoted the formation of high-molecular-weight mercury- and selenium-containing proteins in serum samples from methylmercury-poisoned rats.

Selenite (Se4+) has been found to counteract the neurotoxicity of methylmercury (MeHg) in MeHg-poisoned rats. However, Se4+ has narrow range between its toxic and beneficial effects. Nanoelemental selenium (SeNPs) was found to be less toxic than other forms of Se such as Se4+. In this study, the effects of SeNPs on the load of mercury (Hg) in rats were investigated. Hyphenated technique based on size-exclusion chromatography coupled with UV and inductively coupled plasma mass spectrometry (SEC-ICP-MS) detection and synchrotron radiation X-ray fluorescence spectroscopy (SR-XRF) were used to analyze the Hg-Se-containing proteins in the serum from MeHg-poisoned rats. The Hg-Se-containing fractions monitored by UV and ICP-MS were further characterized by MALDI-TOF-MS. Elevated serum Hg and Se levels were found in MeHg-poisoned rats after SeNPs treatment. Three main Hg-containing bands with molecular weights (MWs) of 25, 62 and 140 kDa were detected in the control samples. Treatment with SeNPs increased the Hg content in proteins at 62 and 170 kDa and decreased the Hg content at 25 kDa. The fraction with 25 kDa was assigned to metallothioneins (MTs), and fractions with 40 and 75 kDa were assigned to albumin. This study showed that the low-toxicity SeNPs could reduce the Hg load in the tissues and promote the formation of high molecular weight Hg- and Se-containing proteins in MeHg-poisoned rats.

Human Biological Monitoring of Mercury Through Hair Samples in China.

Mercury (Hg) is a global pollutant that affects environmental and human health. Considering the high toxicity of Hg, it is required to assess the exposure of Hg in human body for appropriate risk management. In this review paper, we summarized data obtained through regional and small-scaled human biomonitoring (HBM) program for Hg in hair samples in China, which can deliver scientific data to make decisions on environmental health policy. Besides, the major conclusions got from this study and perspectives for future works through these HBM program in China were presented. To better understand the current situation of hair Hg levels in China, a well-coordinated and designed national HBM program is urgently needed considering the requirements of the Minamata Convention on Mercury for effectiveness evaluation.

Botanic Metallomics of Mercury and Selenium: Current Understanding of Mercury-Selenium Antagonism in Plant with the Traditional and Advanced Technology.

The antagonistic effect between mercury (Hg) and selenium (Se) is conclusively established in animals and human beings in the past decades. However, the underlying mechanisms of the interactions between Hg and Se in plants, as well as the metabolism of Hg-Se compounds in crops are still far from being understood. The botanic metallomics of Hg and Se mainly focuses on the translocation, transformation, and metabolism of Hg and Se in the environmental and botanic systems employing metallomics methods. An adequate understanding of the biological behavior of Hg and Se in plant is beneficial for sequestration of Hg and Se in soil-plant systems with high Hg and Se contamination. It can also provide a molecular mechanistic basis for Se supplementation in Se-deficient areas. Here, the key developments in current understanding of Hg and Se interactions in plants are reviewed. The metabolism and antagonism of Hg and Se in various plants, as well as the advanced analytical methods commonly used in this field, are summarized and discussed. As suggested, plant Hg and Se uptake, metabolism, and antagonism can be taken into account for detoxification and remediation strategies for the reduction of Hg and Se in the food chain.

Intestinal Methylation and Demethylation of Mercury.

Mercury (Hg) is a global pollutant, which is linked with different diseases. The methylation of Hg and demethylation of methylmercury (MeHg) in the environment were extensively studied and summarized; however, the transformation of Hg in the intestine is less presented. In this review, the research progress and the perspectives on the intestinal transformation of Hg were discussed. Studies found that MeHg could be formed when exposed to inorganic Hg by the gut microbiota in aquatic organisms, terrestrial invertebrates, and mammals, etc. hgcAB genes could be used as indicators for predicting Hg methylation potential. In vitro studies using fecal specimen, intestinal contents, and the isolated intestinal microbes confirmed the intestinal demethylation of MeHg. The investigation on the effects of Hg exposure to the abundance and diversity of intestinal microbes and their metabolites could shed light on the mechanism of the toxicity of Hg, especially the neurotoxicity of MeHg, which deserves further study.

Advanced Nuclear and Related Techniques for Metallomics and Nanometallomics.

Metallomics, focusing on the global and systematic understanding of the metal uptake, trafficking, role, and excretion in biological systems, has attracted more and more attention. Metal-related nanomaterials, including metallic and metal-containing nanomaterials, have unique properties compared to their macroscale counterparts and therefore require special attention. The absorption, distribution, metabolism, excretion (ADME) behavior of metal-related nanomaterials in the biological systems is influenced by their physicochemical properties, the exposure route, and the microenvironment of the deposition site. Nanomaterials not only may interact directly or indirectly with genes, proteins, and other molecules to bring genotoxicity, immunotoxicity, DNA damage, and cytotoxicity but may also stimulate the immune responses, circumvent tumor resistance, and inhibit tumor metastasis. Because of their advantages of absolute quantification, high sensitivity, excellent accuracy and precision, low matrix effects, and nondestructiveness, nuclear and related analytical techniques have been playing important roles in the study of metallomics and nanometallomics. In this chapter, we present a comprehensive overview of nuclear and related analytical techniques applied to the quantification of metallome and nanometallome, the biodistribution, bioaccumulation, and transformation of metallome and nanometallome in vivo, and the structural analysis. Besides, metallomics and nanometallomics need to cooperate with other -omics, like genomics, proteomics, and metabolomics, to obtain the knowledge of underlying mechanisms and therefore to improve the application performance and to reduce the potential risk of metallome and nanometallome.