High Levels Of Mercury Research Articles

Ventral feathers contained the highest mercury level in brown booby (Sula leucogaster), a pantropical seabird species

Seabirds are extensively used as environmental biomonitors and feathers are among the most analyzed matrices because they are one of the main excretory pathways to detoxify the bird's body of environmental contaminants. Still, there is a variation in contamination level between the different feathers of seabird species, driven by diet and physiology, such as molt strategy and feather formation sequence. We measured total mercury (THg) concentration in different types of feathers (wing, tail, ventral and dorsal) of the same individual in adults and juveniles of brown boobies (Sula leucogaster) from the northern coast of Rio de Janeiro state, Brazil. Brown booby had higher mean THg concentration (μg.g−1 d. w.) in ventral (adults: 6.46 ± 1.19, 4.79 to 8.34; juveniles: 4.23 ± 0.60, 3.07 to 5.07) and wing (adults: 5.85 ± 1.10, 4.66 to 8.32; juveniles: 3.86 ± 0.54, 3.23 to 4.63), compared to dorsal (adults: 4.52 ± 1.33, 3.01 to 6.44; juveniles: 3.51 ± 0.19, 3.29 to 3.8) and tail feathers (adults: 2.94 ± 0.45, 2.32 to 3.46; juveniles: 2.8 ± 0.23, 2.45 to 3.08). This difference may be explained because feathers grow in a specific sequence during molts leading to different THg concentrations in each type of feather. Additionally, juveniles had significantly lower concentrations of THg than adults in all feather types, which may be explained by the shorter life span, leading to less time to bioaccumulate Hg in their body. It is essential to choose carefully which feather type is more suitable to be used as a biomonitor of THg contamination in a particular species. For brown boobies, we suggest the use of ventral feathers, which represent the highest Hg concentration, are easy to sample and do not impair the seabird's flight ability, although more studies are needed to replicate these results in other tropical seabirds species.

Chronic Mercury Poisoning: A Cause for Reversible Cardiomyopathy

We report a case of dilated cardiomyopathy because of chronic mercury poisoning. A 12-year-old girl was repeatedly admitted with severe congestive heart failure. She received indigenous medication for vitiligo for several months. A transthoracic echocardiogram showed severe ventricular dysfunction (left ventricle fractional shortening: 14%). She had a stormy course in the hospital, complicated by ventricular arrhythmias and multiorgan dysfunction. Careful interrogation and analysis of local medication and patient serum showed high levels of mercury. She was treated with British anti-Lewisite. She improved over the period of time, and her left ventricle fractional shortening improved to 22%.

DISTRIBUTION OF MERCURY IN THE HAIR OF RESIDENTS OF AKTASH (REPUBLIC OF ALTAI)

The aim of the study: to reveal the peculiarities of mercury distribution in the hair of residents of the Aktash settlement, which is located within the natural mercury anomaly (Kurai mercury zone, Russia) and influence area of a mercury deposit with stored mercury-containing waste.
 Location and time of the study. Sampling was carried out in 2019 in Aktash village (Ulagan district, Altai Republic), which is part of the Kurai mercury zone.
 Methodology. Mercury in the samples was determined by the atomic absorption method using a RA-915M mercury analyzer. 
 Results. High concentrations of Hg in the atmospheric and soil air were revealed. The average mercury content in the hair of Aktash residents was 0.23 μg/g, which was significantly lower than the reference value. An increased content of mercury in the hair of the indigenous population of the Aktash settlement was revealed, the differences being sex-related. The highest mercury levels were found in former mining workers. It was found that mercury enters the body of the inhabitants of the settlement to a greater extent by breathing and as a result of adsorption from the atmosphere on the hair surface, and to a lesser extent through the consumption of food containing mercury (fish, mushrooms) or as a result of smoking.

Mercury Contamination in Selected Edible Plants and Soil from Artisanal and Small-scale Gold Mining in Sukabumi Regency, Indonesia

Artisanal and small-scale gold mining (ASGM) activities often pollute soil, water, and air, thereby achieving widespread proliferation, and contaminating the surrounding biota including plants. Mercury contamination on agricultural land around ASGM areas has been widely reported. This study aims to determine the total mercury contamination in plants and soil around active ASGM sites in Sukabumi Regency, Indonesia, namely, Waluran, Lengkong, and Ciemas Districts. Total mercury (Hg) content was measured from 27 plant samples (including cassava [Manihot utilisima], rice [Oryza sativa], and papaya [Carica papaya]), 7 rhizosphere soil samples, and 7 non-rhizosphere soil samples. Data were analyzed using Kruskal–Wallis test. Results showed no significant difference in total mercury concentrations among locations or plant parts, between rhizosphere and non-rhizosphere soils (p > 0.05), and among cassava plant parts, papaya, and rice. The highest mercury level was found in cassava (0.33–43.27 ppm). Mercury contamination in rice and papaya was relatively low at 0.03–1.22 and 0.06–5.11 ppm, respectively. According to the Regulation of the Head of BPOM of the Republic of Indonesia Number 23 of 2017 concerning the Maximum Limit of Heavy Metal Contamination in Processed Food, 0.03 ppm is the maximum limit of mercury contamination in fruits, vegetables, and cereals. Therefore, all plant samples around the ASGM sites have exceeded the maximum mercury contamination and thus are not suitable for consumption.

Analisis Kadar Merkuri Dalam Rambut Penambang Emas Desa Alue Baro Kecamatan Meukek Secara Spektrofotometri Serapan Atom

The activity of using mercury in gold mining in Alue Baro Village, Meukek District is carried out freely so that it has a negative impact on the environment and the health of the miners. This study aims to determine the level of mercury in the hair of artisanal gold miners in Alue Baro village by referring to the reference that has been set by WHO. The data sample collection was carried out by taking 6 hair samples from the Alue Baro village gold miners who were selected with various types of work, namely gold processing, waste processing and waste waste until the time of the interview with a minimum working period of 1 year with sample codes R1, R2, R3, R4, R5 and R6 as control samples. The six samples were analyzed using Atomic Absorption Spectrophotometry equipped with a Mercury Analyzer which showed results, respectively, 1.01; 2.38; 1.65; 1.35; 1.66; and 0.64 ppm. The results of this study indicate that all hair samples have mercury levels above the mercury threshold that has been set by WHO, namely 1 ppm. High levels of mercury in hair samples were analyzed on exposure to mercury. Further research was conducted to analyze other metals contained in the hair of gold miners in Alue Baro village

High levels of lead and mercury in Ayurvedic products in Canada

High levels of lead and mercury in Ayurvedic products in Canada

Mercury Exposure in Artisanal Mining: Assessing the Effect of Occupational Activities on Blood Mercury Levels Among Artisanal and Small-Scale Goldminers in Ghana.

A cross-sectional survey of 425 male artisanal and small-scale goldminers (ASGM) was conducted to examine the relationship between the occupational activities of the miners and their blood mercury levels while controlling for relevant biosocial and socio-cultural factors. The data was subjected to descriptive and inferential statistics. Initial findings showed that 43.29% of the ASGM miners had blood mercury levels above the occupational exposure threshold. Among the occupational factors, ASGM miners who amalgamate gold, burn amalgam, and ASGM miners who smelt gold were 2.260, 1.881, and 2.094 times respectively more likely to have high blood mercury levels as compared to ASGM miners who did not carry out these activities. Also, ASGM miners who suck excess mercury with their mouth (OR = 0.197, p < 0.001) were less likely to have high blood mercury levels. For the biosocial and socio-cultural attributes, high blood mercury levels was less likely among older ASGM miners (OR = 0.507, p < 0.05). Inversely, high blood mercury levels was more likely among ASGM miners who are married (OR = 1.627, p < 0.05), ASGM miners with junior (OR = 2.240, p < 0.001) and senior (OR = 1.575, p < 0.05) high school education, and ASGM miners who have 6-10years (OR = 3.802, p < 0.001) and above 10years (OR = 2.591, p < 0.001) work experience. ASGM miners who amalgamate gold, burn amalgam, and smelt gold are exposed to mercury and are at risk of mercury poisoning. This could, however, be minimized with the right capturing devices and personal protective equipment. This notwithstanding, unsafe, and unsustainable occupational practices such as working in mercury contaminated water and sucking excess mercury with the mouth should be discouraged.

The legacy of artisanal gold mining and its impact on fish health from Tapajós Amazonian region: A multi-biomarker approach

Tapajós Region, is an area with intense historical artisanal and small-scale gold mining. Therefore, the core objective of this study was to evaluate the environmental status of different rivers located in this region, using biomarker endpoints in Serrasalmus rhombeus as a tool. Fish and sediment were collected from two rivers, Tropas and Crepori, affluent of Tapajós River, located inside a Federal Protection Area and in a Reference site. Mercury concentration in sediment and fish were traced, and biomarkers in gills and liver were analyzed. Results showed a clear difference between these two rivers compared to the Reference site. Fish tissues presented biomarker responses according to the site of collection. Catalase (CAT) activity was statistically higher in fish gills from Crepori, confirming the capacity of mercury interference with redox equilibrium. High levels of lipid peroxidation were also noted to contribute greatly in incidence of morphological changes in the liver and gills, suggesting that mercury bioaccumulation during continuous exposure promote biological responses in a cumulative manner, from molecules to tissues. This study also indicates adaptation in fish defense mechanisms given the conditions in the Tropas River, as well as a variation in biomarker responses to that of the Crepori river. In summary, Tapajós affluents presented high mercury levels in fish tissues leading to biomarker responses, demonstrating a hazardous signal of a long history of mercury pollution.

Bluefin tuna reveal global patterns of mercury pollution and bioavailability in the world's oceans

Bluefin tuna (BFT), highly prized among consumers, accumulate high levels of mercury (Hg) as neurotoxic methylmercury (MeHg). However, how Hg bioaccumulation varies among globally distributed BFT populations is not understood. Here, we show mercury accumulation rates (MARs) in BFT are highest in the Mediterranean Sea and decrease as North Pacific Ocean > Indian Ocean > North Atlantic Ocean. Moreover, MARs increase in proportion to the concentrations of MeHg in regional seawater and zooplankton, linking MeHg accumulation in BFT to MeHg bioavailability at the base of each subbasin's food web. Observed global patterns correspond to levels of Hg in each ocean subbasin; the Mediterranean, North Pacific, and Indian Oceans are subject to geogenic enrichment and anthropogenic contamination, while the North Atlantic Ocean is less so. MAR in BFT as a global pollution index reflects natural and human sources and global thermohaline circulation.

Mercury in Sediment Core Samples From Deep Siberian Ice-Rich Permafrost

We determine Hg concentrations of various deposits in Siberia’s deep permafrost and link sediment properties and Hg enrichment to establish a first Hg inventory of late Pleistocene permafrost down to a depth of 36 m below surface. As Arctic warming is transforming the ice-rich permafrost of Siberia, sediment is released and increases the flux of particulates to the Arctic shelf seas through thawing coasts, lakeshores, and river floodplains. Heavy metals within soils and sediments are also released and may increasingly enter Arctic waters and the biological food chain. High levels of mercury (Hg) have been reported from shallow soils across the Arctic. Rapid thawing is now mobilizing sediment from deeper strata, but so far little is known about Hg concentrations in deep permafrost. Here, forty-one samples from sediment successions at seven sites and of different states of permafrost degradation on Bykovsky Peninsula (northern Yakutian coast) and in the Yukechi Alas region (Central Yakutia) were analyzed for Hg, total carbon, total nitrogen, and total organic carbon as well as grain-size distribution, bulk density, and mass specific magnetic susceptibility. We show average Hg concentrations of 9.72 ± 9.28 μg kg−1 in the deep sediments, an amount comparable to the few previous Arctic studies existing, and a significant correlation of Hg content with total organic carbon, total nitrogen, grain-size distribution, and mass specific magnetic susceptibility. Hg concentrations are higher in the generally sandier sediments of the Bykovsky Peninsula than in the siltier sediments of the Yukechi Alas. The ratio of Hg to total organic carbon in this study is 2.57 g kg−1, including samples with very low carbon content. We conclude that many deep permafrost sediments, some of which have been frozen for millennia, contain elevated concentrations of Hg and the stock of Hg ready to be released by erosion is of significance for the Arctic ecosystem. The Hg mobilized may accumulate on the way to or in the shallow sea, and where it enters into active biogeochemical cycles of aquatic systems it may concentrate in food webs. Our study highlights the need for better understanding Hg stocks and Hg release from permafrost.

Normal concentration range of blood mercury and bone mineral density: a cross-sectional study of National Health and Nutrition Examination Survey (NHANES) 2005–2010

High blood mercury levels could lead to mercury poisoning, undoubtedly causing great harm to human health. However, the impact of the normal concentration of blood mercury on bone mineral density (BMD) is unclear. Therefore, this study explored the relationship between blood mercury levels and BMD and determined whether the relationship between blood mercury and BMD differs by populations. Two researchers extracted data from the 2005-2010 National Health and Nutrition Examination Survey database. Multivariate linear regression models were performed to evaluate the relationship between mercury level and BMD of the femoral regions and spine. Subgroup analysis was used to estimate differences according to population subgroups. Moreover, the nonlinear relationship of blood mercury levels and BMD was assessed using smooth curve fitting and generalized additive models. The results showed increased BMD with increasing mercury levels by multivariable-adjusted linear regression models, especially in the femoral regions. Subgroup analysis showed that the relationship was more likely to be present in non-Hispanic Whites, while a negative correlation between blood mercury levels and spinal BMD was observed in non-Hispanic Blacks. Furthermore, males (aged 20 to 29 years) and females (aged 30 to 39 years) with low blood mercury levels (< 3 ug/L) had increased risks of osteopenia or osteoporosis. This study showed that blood mercury level within the normal reference value of 10 μg/dL may be associated with BMD, especially with a lower blood mercury level, which may suggest an elevated risk of osteopenia or osteoporosis. However, causation could not be established due to the study design.

Evaluation of Some Toxic Heavy Metals in Rice and Beans Samples Cultivated in Yobe State, Nigeria

Grains have become an integral part of the human diet due to their nutritional values, thus any form of contamination especially by heavy metals is of great concern. This research evaluated the level of Cadmium, Chromium, Lead and Mercury in the commonly consumed foods (Rice and Beans) across Yobe State, North-eastern Nigeria. A composite sample from each of the three Senatorial Zones was collected from farm harvests and designed as ZAR, ZAB, ZBR, ZBB, ZCR and ZCB for Zone A Rice, Zone A Beans, Zone B Rice, Zone B Beans, Zone C Rice and Zone C Beans respectively. The metal Concentration was determined using atomic absorption spectroscopy (AAS). Results in mg/Kg across the local governments indicates respective ranges for Hg, Pb, Cd, and Cr of 0.30 - 4.04, 0.16 - 0.92, 0.03 - 0.05 and 0.02- 0.52 in Rice, 0.14-3.73, 0.05-0.33, 0.05-0.07 and 0.00-0.14 in beans. Comparison of the results showed that with the exception of mercury, all metals are within the tolerable ranges set by International Standard Tolerable Limits and European Regulatory Standard. Potential hazards may be speculated because the detected levels are on the higher side of the tolerable ranges. A higher level of mercury in samples collected from Zone C might be associated with the reported cases of chronic kidney diseases from those areas.

Impacts of the Goldmining and Chronic Methylmercury Exposure on the Good-Living and Mental Health of Munduruku Native Communities in the Amazon Basin.

This paper is an exploratory study that examines the illegal goldmining impacts on Munduruku communities’ “Good-Living” (Xipan Jewewekukap) and explores the possible relationship between chronic methylmercury (MeHg) exposure and the worsening mental health conditions in three villages in the Middle-Tapajós River, Brazilian Amazon. The region has been experiencing a long-lasting threat of goldminers’ invasions. A total of 109 people were interviewed and evaluated. Total mercury (THg) exposure levels were evaluated through hair samples analysis, from which MeHg exposure levels were calculated. The Geriatric Depression Scale—Short Form (GDS-SF) was used as a screening tool in order to assess mental health indicators. Brief non-structured interviews were carried out to investigate how goldmining is impacting the communities Good-Living. A Poisson regression model was used to estimate the possible association between mental health indicators (assessed through the GDS-SF) and the following independent variables: (i) mercury exposure level (<10.0 μg/g vs. ≥10.0 μg/g), (ii) self-reported nervousness, (iii) self-reported irritability, (iv) age group, and (v) monthly income. The analysis revealed high levels of mercury in hair samples (median: 7.4 µg/g, range 2.0–22.8; 70% and 28% of the participants had THg levels ≥6.0 and ≥10.0 µg/g, respectively) and pointed to a tendency in which higher levels of methylmercury exposure (Hg ≥ 10.0 µg/g) could be linked to worse mental health indicators. Although the GDS-SF has presented limitations due to the Munduruku sociocultural context, our findings suggest a tendency of worse mental health indicators in participants presenting high levels of MeHg exposure. Despite this limitation, the qualitative approach indicates an evident association between the impacts of goldmining and the Munduruku people’s decreasing autonomy to maintain a Good-Living on their own terms, pointing to the importance of carrying out new investigations, especially considering longitudinal studies with qualitative methodologies and ethnographic approaches.

Case Report: Gold Miner’s Lung: A Case of Chronic Hypersensitivity Pneumonia in Amazonian Forest

The hostile conditions at informal and illegal mining sites in the Amazonian forest erode the miner’s health, exposing workers to a broad range of diseases because most of the gold is extracted using mercury (Hg). The Hg vapor used daily at gold panning sites presents an environmental threat to the ecosystems and human health. We report the case of a 58-year-old man who has worked in gold panning for over 30 years, presented with diffuse interstitial pneumonia characterized by bilateral images of ground glass and mosaic opacities on the chest CT scan. Based on the negative differential diagnosis (cardiovascular, infectious, autoimmune or cancer), the context of chronic exposure to Hg in a patient who has been working for decades on illegal gold panning sites, we concluded to a chronic form of heavy metal hypersensitivity pneumonia. This hypothesis was supported by high levels of mercury in blood and urine. Mercury hypersensitivity pneumonia might be more frequent than presently thought with thousands of workers chronically exposed to high mercury concentrations among others pollutants. Medical practitioners should systematically seek for chronic respiratory illnesses associated with pollutants exposure in these vulnerable workers with poor health.

Lead, cadmium, mercury, and chromium in urine and blood of children and adolescents in Germany - Human biomonitoring results of the German Environmental Survey 2014-2017 (GerES V).

Metals reach humans through food and drinking water intake and inhalation of airborne particles and can have detrimental health effects in particular for children. The metals presented here (lead, cadmium, chromium, and mercury) could lead to toxic effects such as neurotoxicity, mutagenicity, and have been classified as (possible) carcinogens. Using population representative data from the German Environmental Survey 2014-2017 (GerES V) from 3- to 17-year-old children on lead and cadmium in blood (n=720) and on cadmium, chromium, and mercury in urine (n=2250) we describe current internal exposure levels, and socio-demographic and substance-specific exposure determinants. Average internal exposure (geometric means) in blood was 9.47μg/L for lead and below 0.06μg/L (limit of quantification) for cadmium, and in urine 0.072μg/L for cadmium, 0.067μg/L for mercury, and 0.393μg/L for chromium, respectively. Younger children have higher concentrations of lead and chromium compared to 14-17-year-old adolescents, and boys have slightly higher mercury concentrations than girls. With respect to substance specific determinants, higher lead concentrations emerged in participants with domestic fuel and in non-smoking children with smokers in the household, higher levels of cadmium were associated with smoking and vegetarian diet and higher levels of mercury with the consumption of seafood and amalgam teeth fillings. No specific exposure determinants emerged for chromium. The health based guidance value HBM-I was not exceeded for mercury and for cadmium in urine it was exceeded by 0.6% of the study population. None of the exceedances was related to substantial tobacco smoke exposure. Comparisons to previous GerES cycles (GerES II, 1990-1992; GerES IV, 2003-2006) indicate continuously lower levels.

Particle-Bound Mercury Characterization in the Central Italian Herbarium of the Natural History Museum of the University of Florence (Italy).

Museums air quality can be negatively affected by treatments with heavy metals compounds employed to prevent pest infestations. Among these, the past use of mercury dichloride (HgCl2) on herbaria artifacts currently produces high levels of indoor atmospheric gaseous mercury (Hg0) and possibly of particulate bound Hg (PBM), i.e., the particulate matter containing Hg. This study evaluates the PBM pollution in the Central Italian Herbarium (Natural History Museum of the University of Florence, Italy), characterizing the size range and chemical speciation with SEM-EDS microanalysis. The analysis of the total Hg concentration in the samples allowed to calculate the workers exposure risk to this pollutant. PBM is almost totally classifiable as fine particulate with a significant dimensional increase in a period of scarce attendance of the Herbarium rooms. The microanalysis indicates that Hg is essentially bound to S, highlighting the change of Hg speciation from the original association with Cl. The average Hg concentration reveals a potential health risk for workers as result of multiple Hg exposure pathways, mainly by ingestion. The study provides information for characterizing PBM pollution that could affect a workplace atmosphere and a useful basis to evaluate and correctly design solution strategies to reduce the contamination levels and protect workers’ health.

Mercury mobility, colloid formation and methylation in a polluted Fluvisol as affected by manure application and flooding–draining cycle

Abstract. Floodplain soils polluted with high levels of mercury (Hg) are potential point sources to downstream ecosystems. Repeated flooding (e.g., redox cycling) and agricultural activities (e.g., organic matter addition) may influence the fate and speciation of Hg in these soil systems. The formation and aggregation of colloids and particles influence both Hg mobility and its bioavailability to microbes that form methylmercury (MeHg). In this study, we conducted a microcosm flooding–draining experiment on Hg-polluted floodplain soils originating from an agriculturally used area situated in the Rhone Valley (Valais, Switzerland). The experiment comprised two 14 d flooding periods separated by one 14 d draining period. The effect of freshly added natural organic matter on Hg dynamics was assessed by adding liquid cow manure (+MNR) to two soils characterized by different Hg (47.3±0.5 or 2.38±0.01 mg kg−1) and organic carbon (OC: 1.92 wt % or 3.45 wt %) contents. During the experiment, the release, colloid formation of Hg in soil solution and net MeHg production in the soil were monitored. Upon manure addition in the highly polluted soil (lower OC), an accelerated release of Hg to the soil solution could be linked to a fast reductive dissolution of Mn oxides. The manure treatments showed a fast sequestration of Hg and a higher percentage of Hg bound by particulate (0.02–10 µm). Also, analyses of soil solutions by asymmetrical flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (AF4–ICP–MS) revealed a relative increase in colloidal Hg bound to dissolved organic matter (Hg–DOM) and inorganic colloidal Hg (70 %–100 %) upon manure addition. Our experiment shows a net MeHg production the first flooding and draining period and a subsequent decrease in absolute MeHg concentrations after the second flooding period. Manure addition did not change net MeHg production significantly in the incubated soils. The results of this study suggest that manure addition may promote Hg sequestration by Hg complexation on large organic matter components and the formation and aggregation of inorganic HgS(s) colloids in Hg-polluted Fluvisols with low levels of natural organic matter.

Large subglacial source of mercury from the southwestern margin of the Greenland Ice Sheet

The Greenland Ice Sheet is currently not accounted for in Arctic mercury budgets, despite large and increasing annual runoff to the ocean and the socio-economic concerns of high mercury levels in Arctic organisms. Here we present concentrations of mercury in meltwaters from three glacial catchments on the southwestern margin of the Greenland Ice Sheet and evaluate the export of mercury to downstream fjords based on samples collected during summer ablation seasons. We show that concentrations of dissolved mercury are among the highest recorded in natural waters and mercury yields from these glacial catchments (521–3,300 mmol km−2 year−1) are two orders of magnitude higher than from Arctic rivers (4–20 mmol km−2 year−1). Fluxes of dissolved mercury from the southwestern region of Greenland are estimated to be globally significant (15.4–212 kmol year−1), accounting for about 10% of the estimated global riverine flux, and include export of bioaccumulating methylmercury (0.31–1.97 kmol year−1). High dissolved mercury concentrations (~20 pM inorganic mercury and ~2 pM methylmercury) were found to persist across salinity gradients of fjords. Mean particulate mercury concentrations were among the highest recorded in the literature (~51,000 pM), and dissolved mercury concentrations in runoff exceed reported surface snow and ice values. These results suggest a geological source of mercury at the ice sheet bed. The high concentrations of mercury and its large export to the downstream fjords have important implications for Arctic ecosystems, highlighting an urgent need to better understand mercury dynamics in ice sheet runoff under global warming.

Dental Amalgam- Anthropogenic Aspects

Mercury is released in the environment by various natural and anthropogenic activities. As mercury is toxic, presence of high levels of mercury in the environment is a major concern. One source of mercury in humans is dental amalgam fillings. Dental amalgam has been used for ages in dental clinics and dental hospitals for restoring defective and decayed teeth. This raises concern regarding the use of dental amalgam and its disposal. The purpose of this article is to sensitize people about the hazards of mercury, make them cognizant with guidelines regarding the use of mercury in dental clinics and enforce the use of alternatives to mercury when possible.

Anodic Stripping Voltammetry with the Hanging Mercury Drop Electrode for Trace Metal Detection in Soil Samples

The widely spread use of the hanging mercury drop electrode (HMDE) for multi-ion analysis is primarily ascribed to the following reasons: (i) excellent reproducibility owing to the easy renewal of the electrode surface avoiding any hysteresis effect (i.e., a new identical drop is generated for each measurement to be accomplished); (ii) a wide cathodic potential window originating from the passive hydrogen evolution and solvent electrolysis; (iii) the ability to form amalgams with many redox-active metal ions; and (iv) the achievement of (sub)nanomolar limits of detection. On the other hand, the main controversy of the HMDE usage is the high toxicity level of mercury, which has motivated the scientific community to question whether the HMDE deserves to continue being used despite its unique capability for multi-metal detection. In this work, the simultaneous determination of Zn2+, Cd2+, Pb2+, and Cu2+ using the HMDE is investigated as a model system to evaluate the main features of the technique. The analytical benefits of the HMDE in terms of linear range of response, reproducibility, limit of detection, proximity to ideal redox behavior of metal ions and analysis time are herein demonstrated and compared to other electrodes proposed in the literature as less-toxic alternatives to the HMDE. The results have revealed that the HMDE is largely superior to other reported methods in several aspects and, moreover, it displays excellent accuracy when simultaneously analyzing Zn2+, Cd2+, Pb2+, and Cu2+ in such a complex matrix as digested soils. Yet, more efforts are required towards the definitive replacement of the HMDE in the electroanalysis field, despite the elegant approaches already reported in the literature.