Mercury Mine Research Articles

Isotope-Based Characterization of Soil Elemental Mercury Emissions from Historical Mercury Mining Areas: Driving Pathways and Relative Contributions.

Photo-, microbial, and abiotic dark reduction of soil mercury (Hg) may all lead to elemental mercury (Hg(0)) emissions. Utilizing lab incubations, isotope signatures of Hg(0) emitted from mining soils were characterized to quantify the interplay and contributions of various Hg reduction pathways, which have been scarcely studied. At 15 °C, microbial reduced Hg(0) showed a negative mass-dependent fractionation (MDF) (δ202Hg = -0.30 ± 0.08‰, 1SD) and near-zero mass-independent fractionation (MIF) (Δ199Hg = 0.01 ± 0.04‰, 1SD), closely resembling dark reduced Hg(0) (δ202Hg = -0.18 ± 0.05‰, Δ199Hg = -0.01 ± 0.03‰, 1SD). In comparison, photoreduced Hg(0) exhibited significant MDF and MIF (δ202Hg = -0.55 ± 0.05‰, Δ199Hg = -0.20 ± 0.07‰, 1SD). In the dark, Hg isotopic signatures remained constant over the temperature range of 15-35 °C. Nonetheless, light exposure and temperature changes together altered Hg(0) MIF signatures significantly. Isotope mixing models along with Hg(0) emission flux data highlighted photo- and microbial reduction contributing 79-88 and 12-21%, respectively, of the total Hg(0) emissions from mining soils, with negligible abiotic dark reduction. Microorganisms are the key driver of soil Hg(0) emissions by first dissolving HgS and then promoting ionic Hg formation, followed by facilitating the photo- and microbial reduction of organically bound Hg. These insights deepen our understanding of the biogeochemical processes that influence Hg(0) releases from surface soils.

Horizontal gene transfer of the Mer operon is associated with large effects on the transcriptome and increased tolerance to mercury in nitrogen-fixing bacteria

BackgroundMercury (Hg) is highly toxic and has the potential to cause severe health problems for humans and foraging animals when transported into edible plant parts. Soil rhizobia that form symbiosis with legumes may possess mechanisms to prevent heavy metal translocation from roots to shoots in plants by exporting metals from nodules or compartmentalizing metal ions inside nodules. Horizontal gene transfer has potential to confer immediate de novo adaptations to stress. We used comparative genomics of high quality de novo assemblies to identify structural differences in the genomes of nitrogen-fixing rhizobia that were isolated from a mercury (Hg) mine site that show high variation in their tolerance to Hg.ResultsOur analyses identified multiple structurally conserved merA homologs in the genomes of Sinorhizobium medicae and Rhizobium leguminosarum but only the strains that possessed a Mer operon exhibited 10-fold increased tolerance to Hg. RNAseq analysis revealed nearly all genes in the Mer operon were significantly up-regulated in response to Hg stress in free-living conditions and in nodules. In both free-living and nodule environments, we found the Hg-tolerant strains with a Mer operon exhibited the fewest number of differentially expressed genes (DEGs) in the genome, indicating a rapid and efficient detoxification of Hg from the cells that reduced general stress responses to the Hg-treatment. Expression changes in S. medicae while in bacteroids showed that both rhizobia strain and host-plant tolerance affected the number of DEGs. Aside from Mer operon genes, nif genes which are involved in nitrogenase activity in S. medicae showed significant up-regulation in the most Hg-tolerant strain while inside the most Hg-accumulating host-plant. Transfer of a plasmid containing the Mer operon from the most tolerant strain to low-tolerant strains resulted in an immediate increase in Hg tolerance, indicating that the Mer operon is able to confer hyper tolerance to Hg.ConclusionsMer operons have not been previously reported in nitrogen-fixing rhizobia. This study demonstrates a pivotal role of the Mer operon in effective mercury detoxification and hypertolerance in nitrogen-fixing rhizobia. This finding has major implications not only for soil bioremediation, but also host plants growing in mercury contaminated soils.

Recent environmental and morphosedimentary evolution of the mining-impacted Nalón Estuary (Asturias, N Spain): Disentangling natural and anthropogenic processes

Distinguishing between natural and anthropogenic processes in sedimentary records from estuaries with legacy pollutants is an essential task, as it provides baselines to predict future environmental trajectories of coastal areas. Here, we have addressed the recent transformation history of the mining-impacted Nalón Estuary (Asturias, N Spain). Surface and core sediment records from marshes and tidal flats were examined through a broad multidisciplinary approach, involving micropaleontological (benthic foraminifera), sedimentological (grain-size), geochemical (trace metals, major element Al and total organic carbon), physical (magnetic susceptibility, frequency-dependent magnetic susceptibility and large microplastics) and radioisotopic (210Pb, 137Cs and 239+240Pu) proxies. Results suggest that the interplay between natural (high fluvial influence and extreme hydrological events) and anthropogenic (coal and mercury mining disposals) factors induced strong sedimentation-erosion processes, further shaping the recent evolution of the estuary. Short-time scale and intense sedimentation processes were revealed by overall high sediment accumulation rates, the dilution of some geological signatures and the rapid formation of a marsh in the lower estuary bay. The increasing mining fingerprints during the 20th century were shortly interrupted by the catastrophic riverine flooding of 1938. Conversely, current erosional processes by fluvial influence led to the remobilization of contaminated sedimentary materials and exposure of mining-legacy Hg levels in tidal flats from the middle sector. Fluvial activity, floodings and taphonomic biases exerted a major control on benthic foraminifera since the 19th century, although Hg ecotoxicological effects on modern assemblages at certain areas within the estuary cannot be discarded. These findings, along with the documented enhanced erosion of marshes with ‘trapped’ pollutants (Hg, coal microparticles and microplastics), highlight the importance of monitoring the environmental and geomorphic processes taking place in historically-contaminated estuaries.

Arsenic and mercury exposure in different insect trophic guilds from mercury mining areas in Mexico.

The exposure to arsenic and mercury in various insect trophic guilds from two mercury mining sites in Mexico was assessed. The two study sites were La Laja (LL) and La Soledad (LS) mines. Additionally, a reference site (LSR) was evaluated for LS. The terrestrial ecosystem was studied at LL, whereas both the terrestrial ecosystem and a stream called El Cedral (EC) were assessed at LS. The study sites are situated in the Biosphere Reserve Sierra Gorda (BRSG). Mercury vapor concentrations were measured with a portable analyzer, and concentrations of arsenic and mercury in environmental and biological samples were determined through atomic absorption spectrophotometry. Both pollutants were detected in all terrestrial ecosystem components (soil, air, leaves, flowers, and insects) from the two mines. The insect trophic guilds exposed included pollinivores, rhizophages, predators, coprophages, and necrophages. In LS, insects accumulated arsenic at levels 29 to 80 times higher than those found in specimens from LSR, and 10 to 46 times higher than those from LL. Similarly, mercury exposure in LS was 13 to 62 times higher than LSR, and 15 to 54 times higher than in LL. The analysis of insect exposure routes indicated potential exposure through air, soil, leaves, flowers, animal prey, carrion, and excrement. Water and sediment from EC exhibited high levels of arsenic and mercury compared to reference values, and predatory aquatic insects were exposed to both pollutants. In conclusion, insects from mercury mining sites in the BRSG are at risk.

Heavy metal contamination in duck eggs from a mercury mining area, southwestern China.

Mercury (Hg) contamination in the environment around mercury mines is often accompanied by heavy metal contamination. Here, we determined concentrations of chromium (Cr), zinc (Zn), strontium (Sr), barium (Ba), and lead (Pb) in duck eggs from a Hg mining area in Southwest China to assess the contamination and health risk. Duck eggs obtained from the mining area exhibit higher concentrations of Cr, Zn, Sr, Ba, and Pb compared to those from the background area, with egg yolks containing higher metal levels than egg whites. Specifically, the mean Cr, Zn, Sr, Ba, and Pb concentrations of duck eggs from the Hg mining area are 0.38, 63.06, 4.86, 10.08, and 0.05 μg/g, respectively, while those from the background area are only 0.21, 24.65, 1.43, 1.05, and 0.01 μg/g. Based on the single-factor contamination index and health risk assessment, heavy metal contamination in duck eggs poses an ecological risk and health risk. This study provides important insight into heavy metal contamination in duck eggs from Hg mining areas.

Mercury pollution risks of agricultural soils and crops in mercury mining areas in Guizhou Province, China: effects of large mercury slag piles.

The historical large mercury slag piles still contain high concentrations of mercury and their impact on the surrounding environment has rarely been reported. In this study, three different agricultural areas [the area with untreated piles (PUT), the area with treated piles (PT), and the background area with no piles (NP)] were selected to investigate mercury slag piles pollution in the Tongren mercury mining area. The mercury concentrations of agricultural soils ranged from 0.42 to 155.00mg/kg, determined by atomic fluorescence spectrometry of 146 soil samples; and mercury concentrations in local crops (rice, maize, pepper, eggplant, tomato and bean) all exceeded the Chinese food safety limits. Soil and crop pollution trends in the three areas were consistent as PUT > PT > NP, indicating that mercury slag piles have exacerbated pollution. Mercury in the slag piles was adsorbed by multiple pathways of transport into soils with high organic matter, which made the ecological risk of agricultural soils appear extremely high. The total hazard quotients for residents from ingesting mercury in these crops were unacceptable in all areas, and children were more likely to be harmed than adults. Compared to the PT area, treatment of slag piles in the PUT area may decrease mercury concentrations in paddy fields and dry fields by 46.02% and 70.36%; further decreasing health risks for adults and children by 47.06% and 79.90%. This study provided a scientific basis for the necessity of treating large slag piles in mercury mining areas.

Ecological restoration reduces mercury in corn kernel and the distinction of mercury in corn plants in rural China – A case in Wuchuan mercury mining area

Corn is a crucial crop in China and is widely cultivated in the mercury (Hg) mining region of Guizhou. This study analyzed the Hg content in soil and corn plant samples from the Wuchuan Hg mining area (WCMA) and the surrounding non-Hg mining regions (SNMR). The findings suggest that ongoing ecological rehabilitation and environmental conservation measures in the WCMA have significantly decreased the Hg content in corn kernels. The Hg concentration in different parts of the corn plant varied, being higher in the roots, tassels, and leaves and lower in kernels and stalks. Hg stored in corn plant growing in the WCMA primarily originates from the soil (55.4%), while in the SNMR, it mainly comes from the atmosphere (74.9%). Despite counted only about 7% of the total plant mass, corn roots play a crucial role in soil Hg pollution remediation when corn is used for remediation. Household corn residues burning release about 58.5% and 66.9% of the stored Hg in corn plants growing in the WCMA and the SNMR, respectively, into the atmosphere. Our findings indicate that corn cultivation acts as a reservoir for both soil and atmospheric Hg in the SNMR, while in the WCMA, it serves as a source of atmospheric Hg.

Intoxication in a Colombian mercury mine: Aranzazu, 1948-1975.

This study analyzes the activities, poisoning, and medical treatment of the "La Esperanza" mercury mine workers in Aranzazu (Caldas, Colombia) between 1948 and 1975. The mining work there was difficult due to the geological instability of the area and the use of inappropriate mining technology, which generated a high occurrence of poisoning manifested in tremors of limbs, bleeding gums, loss of teeth, and bad mouth odor. The mine was the first Colombian company to treat its poisoned workers with dimercaprol and penicillamine. Occupational toxicology in Colombia was thus born during one of the most significant occupational health disasters in the country.

The study on the effect of mercury pollution on soil microorganisms around mercury mining area

In order to further explore the effects of soil mercury pollution on soil microbial diversity and community structure, soil samples were randomly collected from 2 m, 20 m, 30 m, 500 m and 650 m periphery of Wanshan mining area, as 5 different treatments. Each treatment had 4 replicates. Soil microbial DNA was extracted from 20 soil samples, and then high-throughput sequencing technology was used to analyse the structure and distribution of bacterial and fungal communities. The results showed that the number of bacterial and fungal communities in T0–T30 treatments was significantly larger than that in T500–T650 treatments at order, family and genus level. Whatever, the number of uniquely distributed bacterial and fungal communities among 4 replicates soil samples was quite different at order, family and genus level. The results of the effect on the microbial community structure showed that there were both the same dominant bacterial and fungal communities, and the different dominant bacterial and fungal communities at any classification level, moreover, the number of same dominant bacterial and fungal communities was larger than that of different dominant bacterial and fungal communities. The results of relationship between soil environment factors and bacterial and fungal community structure showed that distance (Hg2+), EC and pH had a high correlation with community structure, especially the distance factor, that is, the content of mercury in soil had the highest effects on community structure. The internal heterogeneity of soil caused significant differences in bacterial and fungal community structure, and the emergence of dominant bacterial and fungal communities was a manifestation of better adaptability to long-term mercury stress and other stresses in soil, which will provide a scientific reference for further exploring the mechanism of mercury enrichment between microorganisms and plants.

Legacy Contamination from Mercury Mining in the Fergana Valley Region of Central Asia

Legacy Contamination from Mercury Mining in the Fergana Valley Region of Central Asia

Home-produced eggs: An important pathway of methylmercury exposure for residents in mercury mining areas, southwest China

In light of the documented elevated concentrations of total mercury (Hg) and methylmercury (MeHg) in poultry originating from Hg-contaminated sites, a knowledge gap persists regarding the levels of Hg found in home-produced eggs (HPEs) and the associated dietary exposure risks in regions affected by Hg mining. To address this knowledge gap, a comprehensive investigation was undertaken with the primary objectives of ascertaining the concentrations of THg and MeHg in HPEs and evaluating the potential hazards associated with the consumption of eggs from the Wanshan Hg mining area in Southwest China. The results showed that THg concentrations in HPEs varied within a range of 10.5–809 ng/g (with a geometric mean (GM) of 64.1 ± 2.7 ng/g), whereas MeHg levels spanned from 1.3 to 291 ng/g (GM, 23.1 ± 3.4 ng/g). Remarkably, in half of all eggs, as well as those collected from regions significantly impacted by mining activities, THg concentrations exceeded the permissible maximum allowable value for fresh eggs (50 ng/g). Consumption of these eggs resulted in increased exposure risks associated with THg and MeHg, with GM values ranging from 0.024 to 0.17 µg/kg BW/day and 0.0089–0.066 µg/kg BW/day, respectively. Notably, the most substantial daily dosage was observed among children aged 2–3 years. The study found that consuming HPEs could result in a significant IQ reduction of 34.0 points for the whole mining area in a year. These findings highlight the potential exposure risk, particularly concerning MeHg, stemming from the consumption of local HPEs by residents in mining areas, thereby warranting serious consideration within the framework of Hg exposure risk assessment in mining locales.

Micronuclei, Pesticides, and Element Mixtures in Mining Contexts: The Hormetic Effect of Selenium.

The contexts where there are mining and agriculture activities are potential sources of risk to human health due to contamination by chemical mixtures. These contexts are frequent in several Colombian regions. This study explored the potential association between the frequency of micronuclei and pesticides and elements in regions with ferronickel (Montelibano, Córdoba) and gold (Nechí, Antioquia) mining, and a closed native mercury mine (Aranzazu, Caldas), with an emphasis in the potential effect of selenium as a potential chelator. A cross-sectional study was carried out with 247 individuals. Sociodemographic, occupational, and toxicological variables were ascertained. Blood and urine samples were taken for pesticide analysis (5 organophosphates, 4 organochlorines, and 3 carbamates), 68 elements were quantified in hair, and micronuclei were quantified in lymphocytes. The mixtures of elements were grouped through principal component analysis. Prevalence ratios were estimated with robust variance Poisson regressions to explore associations. Interactions of selenium with toxic elements were explored. The highest concentrations of elements were in the active mines. The potentially most toxic chemical mixture was observed in the ferronickel mine. Pesticides were detected in a low proportion of participants (<2.5%), except paraoxon-methyl in blood (27.55%) in Montelibano and paraoxon-ethyl in blood (18.81%) in Aranzazu. The frequency of micronuclei was similar in the three mining contexts, with means between 4 to 7 (p = 0.1298). There was great heterogeneity in the exposure to pesticides and elements. The "hormetic effect" of selenium was described, in which, at low doses, it acts as a chelator in Montelibano and Aranzazu, and at high doses, it can enhance the toxic effects of other elements, maybe as in Nechí. Selenium can serve as a protective agent, but it requires adaptation to the available concentrations in each region to avoid its toxic effects.

Use of Genus Cistus in Phytotechnologies: Application in a Closed Mercury Mine

The Almadén mining district is known to be one of the richest mercury areas in the world. Despite the high concentrations of this metal, this territory has well-established vegetation that provides a wide range of mercury-tolerant plants that can be used as ecosystem services. This is the case of some species of Cistus that grow wild and spontaneously as part of the natural flora of Almadén. The objective of this study was to evaluate if there were differences between the absorption and distribution of Hg of five species of the genus Cistus in spontaneous growth and to evaluate their potential application in phytotechnologies. The work has been carried out with plant samples collected under field conditions in the “Fuente del Jardinillo” located in the old mining area of Almadén (Ciudad Real). The experimental plot was divided into three previously characterised subplots to ensure that all the sampled plants had grown in similar soil conditions (pH, organic matter content, EC, CEC, total Hg and available Hg). Additionally, the experiment was carried out in triplicate. The results showed that despite the homogeneity of the soil, the absorption of Hg in the aerial part of the plants showed significant differences related to Cistus species. The values in the bioaccumulation of mercury in the aerial part were also different. Based on the uptake of mercury by the plants sampled in this study, its potential use in phytotechnologies was established, classifying them as phytoextractors (Cistus albidus, C. ladanifer and C. monspeliensis) and phytostabilisers (C. crispus and C. salviifolius).

Application of a Novel Amendment for the Remediation of Mercury Mine Sites with Hydrologic Controls

MercLokTM P-640 (MercLok) is a proprietary product developed by Albemarle as a mercury (Hg) treatment technology. MercLok captures mercury and sequesters it for a long period under ambient environmental conditions. For this project, MercLok was applied to Hg-contaminated calcines at two abandoned Hg mine sites in northern California to evaluate its efficacy in rendering such contaminated materials less hazardous and thereby reducing remediation project costs. The first application (Site 1) consisted of two calcines amended with MercLok in isolated reactor buckets under two hydrologic remediation approaches (“repository cap” and “reactive barrier”) while exposed to ambient environmental conditions. Non-amended and amended calcines and their leachates were analyzed for Hg content and related conditions during a five-month study period, demonstrating &gt;95% reduction in leachable Hg. The second application (Site 2) involved full-scale site remediation with the application of both approaches and additional hydrologic controls to minimize run-on, erosion, and runoff. Confirmation sampling and subsequent observations indicate that the amendments and hydrologic controls effectively stabilized the site and minimized Hg releases. These application projects demonstrate the efficacy of MercLok as a component of hydrologic controls for treating Hg-contaminated material to achieve long-term mine site remediation objectives.

Archaeological Investigation and Industrial Heritage Study of the Wanshan Mercury Mining Site in Guizhou Province, China

ABSTRACT Mercury is the only natural liquid non-ferrous metal that occurs under normal temperature. Cinnabar, also known as Chensha 辰砂 and Dansha 丹砂 in ancient China, is a natural ore of mercury sulphide that exists in mercury mines and is the most common source ore for refining elementary mercury. The largest cinnabar deposit in China is at the Wanshan mercury mine in Wanshan Town, Guizhou Province, which was an important centre for the mercury production industry since the Tang Dynasty (AD 618–907). An archaeological field survey of the area identified 36 locations related to cinnabar mining and mercury production spanning the period from the Tang and Song Dynasties (AD 960–1279) to the late 20th century. This survey was the first comprehensive archaeological investigation and exploratory research of these materials, and provides a fresh insight into the evolution of the Wanshan mercury mine and its secondary development as a unique industrial heritage site.

Source Analysis of Soil Heavy Metals in Agricultural Land Around the Mining Area Based on APCS-MLR Receptor Model and Geostatistical Method

In order to identify the source of heavy metals in the soil around a mining area and provide effective suggestions for the prevention and control of regional soil pollution, 118 topsoil samples (0-20 cm) were collected in the northern part of Wuli Township, Qianjiang District, Chongqing. The heavy metal (Cd, Hg, Pb, As, Cr, Cu, Zn, and Ni) contents in the soil and soil pH were analyzed, and the spatial distribution and sources of heavy metals in the soil were studied using the geostatistical method and APCS-MLR receptor model. The results showed that the content of heavy metals in the soil was significantly higher than the background value in Chongqing; there was obvious surface accumulation; and Hg, Pb, Cd, As, and Zn showed strong variation. The proportions of soil Cd, Hg, Pb, As, and Zn exceeding the risk screening values were 47.11%, 6.61%, 4.96%, 5.79%, and 7.44%, respectively, and the proportions of soil Cd, Hg, Pb, and As exceeding the risk control values were 0.83%, 4.13%, 0.83%, and 0.83%; thus, the problem of excessive heavy metals in the soil was significant. Soil Cd, As, Cr, Cu, and Ni were mainly affected by soil parent materials, and their contribution rates to the total soil elements were 77.65%, 68.55%, 71.98%, 90.83%, and 82.19%, respectively. Soil Hg, Pb, and Zn were mainly affected by the mining of mercury mines and lead-zinc mines, with the contribution rates of 86.59%, 88.06%, and 91.34%, respectively. In addition, agricultural activities also affected soil Cd and As contents. It is recommended to strengthen the safety monitoring of agricultural products and agricultural inputs, plant varieties with a low accumulation of heavy metals, reduce the use of livestock manure, and grow non-edible agricultural products in areas that exceed the control value of heavy metal pollution risk.

Mercury Biogeochemical Cycle in Yanwuping Hg Mine and Source Apportionment by Hg Isotopes.

Although mercury (Hg) mining activities in the Wanshan area have ceased, mine wastes remain the primary source of Hg pollution in the local environment. To prevent and control Hg pollution, it is crucial to estimate the contribution of Hg contamination from mine wastes. This study aimed to investigate Hg pollution in the mine wastes, river water, air, and paddy fields around the Yanwuping Mine and to quantify the pollution sources using the Hg isotopes approach. The Hg contamination at the study site was still severe, and the total Hg concentrations in the mine wastes ranged from 1.60 to 358 mg/kg. The binary mixing model showed that, concerning the relative contributions of the mine wastes to the river water, dissolved Hg and particulate Hg were 48.6% and 90.5%, respectively. The mine wastes directly contributed 89.3% to the river water Hg contamination, which was the main Hg pollution source in the surface water. The ternary mixing model showed that the contribution was highest from the river water to paddy soil and that the mean contribution was 46.3%. In addition to mine wastes, paddy soil is also impacted by domestic sources, with a boundary of 5.5 km to the river source. This study demonstrated that Hg isotopes can be used as an effective tool for tracing environmental Hg contamination in typical Hg-polluted areas.

Ecological and health risks from heavy metal sources surrounding an abandoned mercury mine in the island paradise of Palawan, Philippines

A recent survey that determined heavy metal concentrations in an abandoned Hg mine in Palawan, Philippines, found the occurrence of Hg with As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Tl, V, and Zn. While the Hg originated from the mine waste calcines, the critical knowledge about the origin of the other heavy metals remains unknown. This study assessed the ecological and health risks from heavy metal pollution surrounding the abandoned Hg mine. Principal component analysis (PCA) showed that the abandoned mine and natural sources (i.e., local geology) are the two main contributors of heavy metal pollution. Historically, the mine waste calcines (retorted ore) were used as construction material for the wharf and as land filler for the adjacent communities. There is highly strong ecological risk associated with the heavy metals: Ni, Hg, Cr, and Mn contribute 44.3%, 29.5%, 10.7%, and 8.9% to the potential ecological risk index (RI), respectively. Hazard index (HI) exceeded 1 for both adults and children in all the sampling locations, implying non-carcinogenic adverse effects. The total cancer risk over a lifetime (LCR) also exceeded the threshold limit of 10−4 for both adults and children, contributed mainly by Cr (91.8%) and As (8.1%). By combining the results of the PCA and risk assessments, a clear link between heavy metal source apportionment to ecological and health risks was established. It was estimated that the abandoned mine contributed to most of the ecological and health risks for people living near the wharf that was built using the calcine, as well as the nearby Honda Bay. The findings of this study are expected to help policy makers develop regulations that will safeguard the ecosystem and the general public from the damaging impacts of heavy metals from the abandoned mine.

From a mining town to a town of industrial multinationals: Explaining transformation through human agency and mining assets

The article examines the transformation of a mining town to an industrial powerhouse by focusing on relations between specific agents and assets in the community. The objectives of this research are 1) to outline how human agency in a mining town mediated key transformation events, 2) to identify skills or specific capabilities of these agents which enacted changes, and 3) to recognize which (mining-related) assets were used or altered in the process. We take a closer look at Idrija, a former mercury mining town in Slovenia that has been transformed into a successful industrial town, also home to two multinational firms. The study is based on desk-based research, 12 semi-structured interviews with key agents and thematic interview analysis. We discover that the transformation of Idrija has been a gradual process, spanning four decades and consisting of several critical junctures where different types of human agency were required to make changes to existing mining assets. Interpersonal and institutional trust, loyalty, paternalism of incumbent firms, strategic thinking of agents, external market orientation and smallness are some of the soft assets that have proven time and again to be crucial for human agency at critical junctures. These soft assets, especially in institutionally thick post-mining areas, could become a tool for designing visions for the future, matching the expectations and capabilities of mining communities.

Database on the Standardized mortality ratio (SMR all causes and SMR all cancer) for various professions (706 cohorts/groups): the maximum "health worker effect" for cosmonauts and doctors

Researchers have formed a database for work on the evaluation of the indices of the "standardized mortality ratio" (SMR±95% confidence intervals — CI) in comparison with the general population for total mortality and mortality from all malignant neoplasms ("all cancers") for various professions and types of employment (mainly men). The database includes 689 publications (706 cohorts/groups, 67 professions and types of employment).&#x0D; Experts have conducted an assessment the presence of the "healthy worker effect" (HWE) in the studies included in the database based on the criterion of the upper 95% CI value of less than one.&#x0D; Among all professions and types of employment, scientists have identified HWE in total mortality only in 52%, and in mortality from all types of cancer — only in 28% of cohorts/groups.&#x0D; HWE for both indicators simultaneously and only for total mortality occurred in 26% of cases. For 2% of the studies, there is an inverse relationship (absence of HWE for total mortality in the presence of an effect on mortality from all types of cancer), which is most likely accidental.&#x0D; There were no strict dependencies between HWE and the carcinogenic potential of activity, although there was a definite trend. &#x0D; The frequency of work with HWE for specific professions identified as the most "unprofitable" work with such heavy metals as Hg, Cd, Pb, Cu (the frequency of HWE is 0% for total mortality and 5% (mercury miners) for mortality from malignant neoplasms; one publication), followed by activities related to dust exposure (talc, quartz, various minerals, etc.; 5% and 6%) and asbestos (10% and 2%). Pilots (89% and 65%), oil and petrochemical industry workers (97% and 56%), as well as doctors (94% and 96%) and cosmonauts/astronauts (100% and 67%; the sample is small) occupied leading positions in the highest frequency of HWE.&#x0D; A complete sample of SMR studies of foreign doctors (1886–2017) demonstrated a strict linear decrease in the SMR value in total mortality compared with the population since the 1940s (r=–0.927; p&lt;0.001), with SMR=0.38 (95% CI: 0.01; 0.76) achieved by the 2010s.&#x0D; At the same time, mortality from all cancers among doctors was reduced in comparison with the population almost equally for all time periods since 1926 (average SMR=0.6; 95% CI: 0.53; 0.66).&#x0D; Possible reasons for the reduced mortality among foreign doctors compared to the population are not only in prevention and professional skills, but probably in better access to medicine and specialists. In connection with professional solidarity, medical care and informing doctors is apparently distinguished by great attention.&#x0D; Earlier treatment of non-cancerous pathologies is also important, preventing their transformation into chronic ones, which can subsequently lead to carcinogenic consequences.