Cold Vapor Atomic Absorption Spectrophotometry Research Articles

The levels of mercury (Hg) and arsenic (As) in wild boar’s liver (Sus scrofa) in eleven hunting areas from the Republic of North Macedonia

The monitors have recently been defined as the organisms in which changes in known characteristics can be measured to assess the extent of the environmental contamination. Among the numerous game species, the wild boar as omnivore is characterized as an exceptionally good biomonitor. The concentrations of one heavy metal (Hg) and one metalloid (As) were measured using cold vapor atomic absorption spectrometer and atomic absorption spectrophotometry in the liver tissue of free-living wild boars. From 11 hunting areas locations that cover the whole territory of North Macedonia in a period of 7 years (2016-2022) a total of 608 wild boar liver samples were harvested during the regular hunting season. The mean concentration of Hg from 11 hunting grounds ranged from 12.7 μg/kg to 68.8 μg/kg, and mean concentration for all was 45.67 μg/kg. The average concentration of As ranged from 22 μg/kg to 55.3 μg/kg, and mean concentration for all was 33.1 μg/kg. For mercury, 6.56% or 40 of the total number of samples (608) exceeded the maximum allowed limits, and for arsenic none of the examined samples exceeded the allowed limit. For both elements a statistically significant difference was determined in relation to the years, with irregular oscillations from year to year. The mean values for mercury and arsenic are encouraging and generally indicate the relatively low contamination in the territory of the Republic of North Macedonia. However, the statistical differences due to the year as a factor suggest there is the need for the further research.

Analysis and Risk Assessment of Essential and Toxic Elements in Algerian Canned Tuna Fish.

In Algeria, the data and research on the essential and toxic chemical elements in food are limited and insufficient; therefore, the present study focused on evaluating the essential and toxic elements content in different 11 brands with two types (tomato and oil) of canned tuna fish, consumed in Algeria in 2022, by inductively coupled plasma-optical emission spectrometer (ICP-OES), while mercury (Hg) levels were determined by cold vapor atomic absorption spectrophotometry, as well as estimate the probabilistic risk assessment. The elements in canned tuna fish commercialized for human consumption in Algeria were determined by ICP-OES methods, The results showed that the heavy metal concentration in the samples under study ranged from 49.11 to 289.80mg.kg-1 (Ca), 0.0045 to 0.2598mg.kg-1 (Cd), 0.128 to 1.21mg.kg-1 (Cr), 8.55 to 35.94mg.kg-1 (Fe), 121.27 to 379.17mg.kg-1 (Mg), 0.0767 to 1.2928mg.kg-1 (Mn), 2.10 to 3.95mg.kg-1 (Mo), and 2.86 to 35.90mg.kg-1 (Zn), whereas Cu, Pb, Cu, Ni, and As were under limit of detection (LOD), while the toxic elements of mercury (Hg) levels were determined by cold vapor atomic absorption spectrophotometry which showed a content ranged from 0.0186 to 0.0996mg.kg-1. The levels of mineral elements concentration were close to the minimum recommended by Food and Agriculture Organization (FAO). Obtained data for this investigation can be suitable for Algerian food purposes.

Mercury in fish tissues from the Galapagos marine reserve: Toxic risk and health implications

Fishing is one of the most important economic and cultural activities in Galapagos and Hg presence in aquatic ecosystems is a serious problem for human health, so its concentrations should be studied. We sampled five demersal species (Caulolatilus princeps, Caulolatilus affinis, Mycteroperca olfax, Hyporthodus mystacinus and Pontinus clemensi) and four pelagic species (Coryphaena hippurus, Acanthocybium solandri, Thunnus albacares and Seriolella violacea) to evaluate Hg concentration in muscle, liver and gonads. Hg was analyzed by Cold Vapor Atomic Absorption Spectrophotometry with Flow Injection System (CV-AAS-FIAS). Demersal species had higher Estimated Weekly Intakes (EWI) of Hg than pelagic species. According to the Codex Alimentarius (1995), EFSA (2018), FDA (2021) regulations, and according to the regulations in Europe, A. solandri, P. clemensi, and H. mystacinus were found above the maximum allowed concentration (MAC) (0.65, 0.65 and 1.26 mg/kg wet weight, respectively) so they could not be ingested nor commercialized. The Margin of Safety (MoS) of these species was above 1, so they could pose a risk to human health. We hypothesize that the Hg concentrations found in the studied species could come from the volcanism of the archipelago, since no major sources of anthropogenic Hg contamination can be found in the islands.

The presence of hydroquinone, and mercury in skin toning creams, as well as lead in turmeric powder, pose potential health risks to Bangladeshi women

Skin toning creams and turmeric powders are widely used among Bangladeshi fashion and beauty concerned women and young girls in general. However, it has been reported that excessive use of skin toning cream and turmeric powder can cause various dermatological problems, including skin cancer. These creams and turmeric powder contain a wide variety of active ingredients, including Hydroquinone (HQ), Mercury (Hg), and Lead (Pb), that are toxic, and hazardous to health, especially after prolonged application. As a result, in the current study, we tried to assess HQ and Hg level in commonly used skin toning creams and Pb in turmeric powder in the context of Bangladeshi women collected from the local markets in Dhaka city. HQ, Hg, and Pb levels were analyzed for 40 different Bangladeshi skin toning cream products and 40 different turmeric powder samples. The HQ level was determined by the high-performance liquid chromatography (HPLC) method, the Hg level was determined by Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) using an automatic mercury analyzer, and Pb was measured by the flame atomic absorption spectrometry method. Among the 40 samples, 23 samples (57.5%) did not contain HQ, whereas 17 samples (42.5%) contained a high level of HQ compared to the standard limit. In the case of Hg analysis, we found that 28 (70%) out of 40 samples complied with the standard level of Hg, whereas 12 samples (30%) contained a higher level of Hg compared to the standard limit. Among the 40 samples of turmeric powder, 20 samples (50%) complied with the standard level of Pb, whereas 20 samples (50%) contained a high level of Pb compared to the standard limit. After three and six months of storage, we had similar results in all the samples for the three cases. After combining HQ and Hg data sets, we found that 14 (35%) out of the 40 samples had HQ and Hg levels within the standard limit, and 3 samples (7.5%) had higher quantities of both HQ and Hg levels and did not comply with the standard limit. 14 samples (35%) in the data set had higher HQ levels but complied only with the standard Hg level, whereas 9 samples (22.5%) had higher Hg levels and thus complied only with the standard HQ level. So, in 65% of the samples, we found the presence of excess level of either both HQ and Hg at the same time or any one of the measured chemical parameters. The use of these creams and turmeric powders, which did not comply with the standard limit, may pose a serious health risk to consumers. So, consumers should be aware of the risks associated with using these creams and turmeric powders, and policymakers should take appropriate measures to prevent the manufacturing and marketing of skin toning creams containing high levels of HQ and Hg and turmeric powder with high levels of Pb. Bioresearch Commu. 8(2): 1132-1142, 2022 (July)

Bioaccumulation of cd and hg in Muscle of Juvenile Pacific Sharpnose Shark Rhizoprionodon longurio from the SE Gulf of California.

In this study, the concentrations of Cd and Hg were measured in muscle of juvenile individuals at an importan fishing ground in southeastern Gulf of California to assess the health risk to human consumers considering elemental levels and rate of shark consumption in NW Mexico. Twenty-eight individuals were sampled in September 2019. Quantification of Hg was made by cold vapor-atomic absorption spectrophotometry, analyses of Cd were made by graphite furnace atomic absorption spectrophotometry. In general, average Hg (1.27µg g-1 dry weight) concentrations were higher than Cd (0.059). In comparison to results of Cd and Hg in muscle of several species of genus Rhizoprionodon sp., our reported concentrations were comparable. Maximum permissible limits (Cd 0.5 and Hg 0.5µg g-1 wet weight) in fish products for human consumption were not exceeded. Health risk assessment to shark consumers indicated that Hg is of more concern than Cd but no hazards exist.

Metallic Study of the Invasive Species Cronius ruber—Assessment of Toxic Risk

Three toxic heavy metals (Cd, Pb, and Hg) were analyzed in the newly found invasive species in the Canary Islands, Cronius ruber. Its high growth rate and its widely varied diet are affecting the Canary marine ecosystem. The study was conducted using electrothermal vaporization atomic absorption spectrometry (GF-AAS) and cold-vapor atomic absorption spectrophotometry (CV-AAS). Significant differences were found in terms of the location and sex of the specimens, with the highest concentrations being found in areas with higher tourism activity and in the female specimens. On the other hand, the conclusion of the study is that human consumption of this species does not pose any toxic risk to public health, as the levels obtained in muscle tissue do not exceed the established limits for these metals. Therefore, its consumption and the fishing of this species can stop the proliferation of the same in the Canary coasts and thus not be harmful for the ecosystem.

Heavy metal impression in surface sediments and factors governing the fate of macrobenthic communties in tropical estuarine ecosystem, India.

The present study aims to investigate the contamination of heavy metals in the sediments of a tropical ecosystem, India, and to evaluate the factors responsible for the dominance of specific macrobenthic communities, particularly in estuarine sediments. For the analysis of Cu, Cr, Ni, Zn, Pb and Cd in sediments, acid digestion and subsequent quantification by microwave plasma atomic emission spectroscopy was performed, whereas for Hg determination, cold vapour atomic absorption spectrophotometry was used. The general trend of the heavy metal concentration was observed as Cr > Cu > Zn > Ni > Pb > Cd > Hg, regardless of any seasonal alteration. The estuarine region was considerably contaminated by Cu and Cr (C.F. > 2) irrespective of any seasonal difference, and by Cd in 2017 non-monsoon (CF > 3). Heavy metal contamination was most pronounced during the monsoon (2018). Estuarine and marine zone together considered as deteriorated zone especially during monsoon seasons (PLI > 1, 2018 monsoon) while riverine zone remained poorly contaminated (PLI < 1). Clay Loam/Clay/Heavy Clay textures preferred polychaetes and bivalves in the estuarine and marine zone as compared to other macrobenthic communities (OMC). Among the hydrochemical parameters, total dissolved solids in general and euryhaline and slightly alkaline pH preferred domination of bivalves followed by polychaetes in non-monsoon seasons. The trace metal contamination in estuarine sediments increases the concern of bioaccumulation tendency of dominant bivalves of the estuarine and coastal sediments.

Mercury in muscle and liver of Plagioscion squamosissimus (Acanthuriformes: Sciaenidae) from the Machado River, Brazilian Amazon

ABSTRACT The Machado River is the main tributary of the Madeira River in the state of Rondônia, a region that has been impacted by deforestation, livestock, urban development, alluvial gold mining and urban and industrial effluents that likely contribute to the introduction of mercury (Hg) in the aquatic system. We aimed to determine the concentrations of total Hg (THg) in muscle and liver of Plagioscion squamosissimus, a main fishing resource in the region. Fish were sampled for two years at five sites, along a 90-km stretch of the middle Machado River. THg concentrations were analyzed in 64 muscle and 54 liver samples by cold vapor atomic absorption spectrophotometry (FIMS-400). THg levels were related with fish size and sex and with periods of the hydrological cycle. THg concentrations in both organs were positively and significantly related with fish body size. There was no significant variation in THg among periods of the hydrological cycle. Mean THg concentrations in muscle (1.09 ± 0.72 mg kg-1) and liver (1.28 ± 1.23 mg kg-1) were higher than the limit established by the WHO. Our results suggest that residual mercury from former alluvial gold extraction and lixiviation of mercury naturally occurring in the soil due to large-scale deforestaion is accumulating in the aquatic food chain in the Machado River. We conclude that it is necessary to monitor the levels of mercury in commercially important fish species in the region.

Silver nanoparticles embedded cation-exchange membrane for remediation of Hg species and application as the dip catalyst in organic transformation

Silver nanoparticles (Ag NPs) embedded in poly(perfluorosulfonic) acid cation-exchange membrane (Nafion-211) were synthesized by in situ reductions of Ag+ ions by sodium borohydride at room temperature and formamide at 65 °C. The formamide-reduction formed Ag NPs uniformly distributed in the membrane matrix. Therefore, the formamide-reduced Ag NPs embedded membranes were used for the sorption-preconcentration of Mercury (Hg)2+ ions by the galvanic reaction with Ag NPs in the membrane matrix. The replacement of Ag0 in NPs with Hg2+ ions resulted in the formation of Hg0 accumulated as nanodroplets in the membrane matrix as indicated by the field emission scanning electron microscopy studies. The sorption of Hg2+ ions via galvanic reaction in the Nafion membrane was found to be maximum (>93%) from pH = 2.5 to pH = 6.5. The Ag NPs embedded membrane was studied for Hg2+ ions sorption from the aqueous samples by radiotracer (203Hg), spectrophotometry, energy dispersive X-ray fluorescence and cold vapor atomic absorption spectrophotometry. This membrane was successfully applied for the determination and quantification of Hg2+ ions in the real water samples and safe storage of Hg for the remediation objective. The Hg0 embedded membrane was also found to be promising as the dip catalyst in the representative organic transformation of phenylacetylene to acetophenone. The Hg0 embedded membrane dip catalyst was reused in four consecutive cycles under similar conditions and found to be successful by giving an almost similar yield (%) of the product. This demonstrated a possibility of safe application of Hg0 stored in the matrix of poly(perfluorosulfonate) membrane for catalysis.

Blood total mercury levels of Brazilian preschool children and associated risk factors: preliminary results

BACKGROUND AND AIM: Environmental exposure to mercury in preschool children can impact their health by increasing its blood levels, which can cause negative health outcomes. This study aimed to set the reference value for blood mercury in preschool children from a megacity in Brazil, and investigating associated risk factors. METHODS: Blood samples were collected of 2,463 children and the present study reports preliminary results from 1,020 1-4-year-old children attending 29 daycare centers (DCC) located in São Paulo, Brazil, 2013. Guardians answered sociodemographic and potential risk factors questionnaires. DCC and metal contaminated-sites (MCS) were georeferenced (QGIS™). Blood total mercury levels (BTM) were determined by Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS). BTM was dichotomized (low/high levels) in a cut-off point of 1.06 μg.L⁻¹, which represents the 95th percentile reference value for total mercury established by the U.S. Centers for Disease Control and Prevention (CDC). Summary data and multiple logistic regression were performed (p0.05). RESULTS:The geometric mean for BTM was 1.71 μg.L⁻¹ (95%CI: 1.64-1.78 μg.L⁻¹) and the 95th percentile was 5.43 μg.L⁻¹ (95%CI: 4.89-6.26 μg.L⁻¹). DCCs located in the Northwest geographic zone were associated with high BTM when the model was adjusted for fish intake, age, sex, geographic zone, mother schooling, and amalgam (p=0.018). No associations were found between high BTM and fish consumption, amalgam teeth fillings, and georeferenced vicinity of the DCC to MCS. CONCLUSIONS:BTM in Brazilian preschoolers (95th percentile) was more than five times higher than U.S. children’s levels. Even the Brazilian geometric mean was higher than the U.S. BTM 95th percentile. More studies are necessary to identify potential mercury exposure sources for preschool children. Nevertheless, these results showed the need to formulate public health policies, intending to better understand and eliminate mercury sources. Funded by Fapesp (2011/13076-0, 2011/23272-0, 2012/21840-4) and Capes. KEYWORDS: Mercury, Preschool children, Environmental exposure, Public Health, Blood, Potentially Toxic Elements

Evaluation of heavy metal pollution in coastal sediments of Bandar Abbas, the Persian Gulf, Iran: Mercury pollution and environmental geochemical indices

Mercury has been measured by using Cold Vapor-Atomic Absorption Spectrophotometry in coastal sediments of the Persian Gulf (Bandar Abbas region). The mean concentration of the six stations followed a decreasing order of S6 (3.95) > S1 (3.75) > S4 (3.55) > S5 (3.33) > S2 (2.72) > S3 (2.17), and the mean concentration ± standard error was calculated to be 3.24 ± 0.28 (μgg−1 dry weight) for the heavy element Mercury in the sediments. The statistical investigation indicated that the concentration means of the Mercury existing in transects sediments are meaningfully different from each other (p < 0.05). To properly assess the availability and mobility of elements, Enrichment Factor (EF), Geoaccumulation index (Igeo), Contamination factor (Cf) and Toxicity Risk Index (TRI) were provided. The results show that the pollution caused by Mercury in sediments is highly polluted and the source of the presence of Mercury in the region is human-made.

Enhanced digestion of complex cosmetic matrices for analysis of As, Hg, Cd, Cr, Ni, and Pb using triton X-100

A suitable optimized digestion method for lipsticks and powders for the analysis of As, Hg, Cd, Cr, Ni and Pb by Hydride Generation Atomic Absorption Spectrophotometry (HG-AAS), Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) and Flame Atomic Absorption Spectrophotometry (FAAS) was developed using common acid digestion methods enhanced by the use of Triton X-100. The three acid digestion methods used in this study were Method A (nitric acid and hydrogen peroxide), Method B (nitric acid and hydrochloric acid) and Method C (nitric acid, hydrochloric acid and hydrogen peroxide). Triton X-100 was added to each of these and the effects were studied. The acid digestion method that was determined to be the most suitable and efficient for lipsticks and powders was Method A-1 (nitric acid and hydrogen peroxide with 5% Triton X-100 at 95 °C for 3 h). The range of percentage recoveries obtained were; powders (98.50% to 92. 61%) and lipsticks (100.96% to 99.41%) for As, Cd, Cr, Pb, Hg and Ni. The addition of Triton X-100 significantly improved the efficiency of the method.•Triton X-100 improves the efficiency of acid digestion of fatty hydrophobic samples by dispersing the sample throughout the acid digestant.

Determination of spatial mercury concentration by laser ablation-inductively coupled plasma mass spectrometry.

Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) is capable of metal imaging by acquiring local spatial information. However, the preparation of an appropriate standard for quantitative analysis is difficult because the matrices between the standard and the sample should match, and homogeneity of metal concentration in the standard is required. Hence, the aim of this study was to establish a highly quantitative mercury imaging method that utilizes LA-ICP-MS and an appropriate mercury standard consisting of rat tissue. Our standard showed homogeneous mercury concentration and good linearity between concentration and signal intensity, and met the qualifications for quantitative imaging by LA-ICP-MS. Mercury concentration in MeHg-exposed rat kidneys obtained by LA-ICP-MS measurement of the standard (7.84 ± 0.57 µg/g) was comparable to that obtained by cold vapor atomic absorption spectrophotometry (AAS, 7.27 ± 0.46 µg/g). The results indicate that LA-ICP-MS enabled quantitative imaging with the appropriate standard.

Measuring mercury in urine among students &amp; professors at the faculty of dentistry exposed to mercury vapor by cold vapor atomic absorption technique

Introduction: Dentists are exposed to mercury vapor due to the occupational exposure to amalgam, which can endanger their health. The aim of this study was to determine the effect of mercury vapor on urinary mercury concentration of dental students and the restorative specialists in one of the dental schools of Iran.&#x0D; Methods: The study population consisted40 dental students and 10 restoration specialists. Sample urine at the end of work time was collected, and the concentration of mercury in urine was measured by cold vapor atomic absorption spectrophotometry. A questionnaire was completed to determine the effects of some personal and environmental factors on the amount of urinary mercury. Data were analyzed using SPSS-22 software.&#x0D; Results: The mean concentration of urinary mercury in dental students was 15.18±4.34μg/L and the restoration specialists were 4.11±1.05μg/l. In addition, there was a significant difference between the concentrations of urinary mercury in the two groups (P &lt;0.001). At specialist professors there was a negative correlation between urinary mercury and working hours per day (r=-0.78, p=0.007). Also, in this study, there was a significant relationship between urine mercury and sex, age, type of amalgam consumed, consumption of smoking and the number of amalgam restorations.&#x0D; Conclusion: The level of urine mercury in all samples was lower the recommended amount of ACGIH. The study is recommended mercury level monitoring for regularly evaluation of the workplace.

Seasonal variation of mercury in commercial fishes of the Amazon Triple Frontier, Western Amazon Basin

Abstract Artisanal and Small-scale Gold Mining (ASGM) has been spreading in the Western Amazon. ASGM is one of the main sources of pollution by anthropogenic mercury on the environment in the Amazon. Ecotoxicological approaches are important to monitoring aquatic ecosystems. They evaluate interactions among contaminants and living organisms and detect possible risks to animal and human health. The hydrological cycles of Amazonian rivers influence the fishery production. Depending on the period, the availability of mercury may also variate in these aquatic systems. This study aimed to monitoring mercury in commercial fishes from the Amazon Triple Frontier. Total mercury (THg) concentrations in muscle (MTHg), liver (LTHg), and gills (GTHg) of Hoplerythrinus unitaeniatus, Hoplias malabaricus, and Pterygoplichthys pardalis caught in the Western Amazon Basin were assessed during the ebb and flood periods. The determination of total mercury concentration in fish samples was done by Cold Vapor Atomic Absorption Spectrophotometry (CVAAS). In both periods, H. unitaeniatus and H. malabaricus presented the highest levels of THg in tissues. In the ebb period, H. unitaeniatus and H. malabaricus had higher levels of MTHg > LTHg > GTHg. All species of the flood period had higher levels of LTHg > MTHg > GTHg. Mercury concentrations of all tissues of H. malabaricus showed significant relationship with length and weight. In P. pardalis, negative length-GTHg and weight-GTHg relationship were observed as well as a negative weight-LTHg correlation. Liver presented the highest levels of THg found in this study. Some individuals of H. malabaricus presented MTHg above safe limits for consumption. These results suggest that fish and human exposure to Hg in the Western Amazon Basin is not constant throughout the year. The flood period seems to be critical for high Hg exposure. This information can be used to development of more specific public policies to reduce the risks of mercurialism in humans from Amazon Triple Frontier as well as impacts on fish diversity and fishery production of Solimoes-Amazonas Basin.

Risk assessment of mercury in sharks (Rhizoprionodon longurio) caught in the coastal zone of Northwest Mexico

Adult sharpnose sharks (Rhizoprionodon longurio) with a mean total length of 110.93 ± 5.30 cm were obtained from a local fishery in Mazatlan (Southeast Gulf of California, Mexico). The total mercury content in muscle was analyzed by cold vapor atomic absorption spectrophotometry. The minimum and maximum total mercury content were 0.77 ± 0.23 and 2.33 ± 0.57 µg/g (dry weight), respectively. Only 6.6 % of the organisms did show mercury content higher than the permissible limit. No significant relationship was observed between weight and total mercury content in edible muscle of the sharks (r = 0.364, p > 0.05). The Hazard Quotient values for total mercury (0.005–0.015) and methyl mercury (0.022–0.065) indicated no risk by edible muscle consumption of the shark Rhizoprionodon longurio.

Exposure profile of mercury, lead, cadmium, arsenic, antimony, copper, selenium and zinc in maternal blood, cord blood and placenta: the Tohoku Study of Child Development in Japan

BackgroundThe effects of prenatal exposure to toxic elements on birth outcomes and child development have been an area of concern. This study aimed to assess the profile of prenatal exposure to toxic elements, arsenic (As), bismuth (Bi), cadmium (Cd), mercury (total mercury (THg), methylmercury (MHg), inorganic mercury (IHg)), lead (Pb), antimony (Sb) and tin (Sn), and essential trace elements, copper (Cu), selenium (Se) and zinc (Zn), using the maternal blood, cord blood and placenta in the Tohoku Study of Child Development of Japan (N = 594–650).MethodsInductively coupled plasma mass spectrometry was used to determine the concentrations of these elements (except mercury). Levels of THg and MeHg were measured using cold vapour atomic absorption spectrophotometry and a gas chromatograph-electron capture detector, respectively.ResultsMedian concentrations (25th–75th) of As, Cd, Pb, Sb, Sn and THg in the maternal blood were 4.06 (2.68–6.81), 1.18 (0.74–1.79), 10.8 (8.65–13.5), 0.2 (0.06–0.40) and 0.2 (0.1–0.38) ng mL−1 and 5.42 (3.89–7.59) ng g−1, respectively. Median concentrations (25th–75th) of As, Cd, Pb, Sb, Sn and THg in the cord blood were 3.68 (2.58–5.25), 0.53 (0.10–1.25), 9.89 (8.02–12.5), 0.39 (0.06–0.92) and 0.2 (0.2–0.38) ng mL−1 and 9.96 (7.05–13.8) ng g−1, respectively.ConclusionsTHg and Sb levels in the cord blood were twofold higher than those in the maternal blood. Cord blood to maternal blood ratios for As, Cd and Sb widely varied between individuals. To understand the effects of prenatal exposure, further research regarding the variations of placental transfer of elements is necessary.

Leachate seepage from landfill: a source of groundwater mercury contamination in South Africa

Mercury has been used for many centuries in the production of consumer products such as thermometers, electrical switches, fluorescent light bulbs, batteries, biocides and pesticides, cosmetics and dental amalgam filling, among others. After use, these mercury-containing consumer products form part of the municipal solid waste (MSW). As a result of an unseparated solid waste collection system, mercury-containing wastes tend to end up in landfills where mercury and other pollutants can leach out of products into landfill leachates. The present study, therefore, was conducted with the aim of determining the total mercury (THg) concentrations in leachate and sediment samples collected from 4 selected landfill sites (3 sites in Gauteng Province – Soshanguve, Hatherly, Onderstepoort and 1 site in Limpopo Province – Thohoyandou). Groundwater samples were collected from the monitoring boreholes at the four selected landfill sites in the summer and winter periods. An acid digestion method was employed for sample preparation and this was followed by analysis using cold vapour atomic absorption spectrophotometry (CVAAS). The concentration range of total mercury in the Thohoyandou leachate, sediment and groundwater samples was 0.12–2.07 μg/L, 0.03–0.48 μg/g and 0.09–2.12 μg/L, respectively. In Soshanguve, the concentration range of total mercury in leachate, sediment and groundwater samples was 0.10–1.20 μg/L, 0.04–0.62 μg/g and nd –1.66 μg/L respectively, Hatherly concentration range was 0.42–1.31 μg/L and 0.06–0.78 μg/g in leachate and sediment, respectively and in Onderstepoort the concentration range was 0.12–2.41 μg/L, 0.03–0.50 μg/g and 0.05–2.44 μg/L, in leachate, sediment and groundwater, respectively. The findings from this study suggest that there is a likelihood of groundwater pollution by mercury from landfill leachate seepage, particularly for landfills that are not lined with a geomembrane.

Assessment of Total Mercury in Hair, Urine and Fingernails of Small-Scale Gold Miners in the Amansie West District, Ghana.

Background.Mercury (Hg) is a heavy metal that can cause several adverse health effects based on its form (organic, inorganic or elemental), duration and pathway of exposure. Measurement of mercury present in human biological media is often used to assess human exposure to mercury at mining sites.Objectives.The aim of the present study was to measure the concentrations of total mercury in urine, hair, and fingernails of miners and inhabitants of Amansie West District, Ghana.Methods.Concentrations of total mercury were measured in sixty–eight miners and twelve non–miners in the study area using cold vapor atomic absorption spectrophotometry with an automatic mercury analyzer (HG 5000).Results.Total mercury in nails and hair of smelter miners was 3.32 ± 0.36 and 6.59 ± 0.01 μg/g, respectively. Total mercury concentrations in hair samples obtained from smelter miners were above the 1 μg/g guideline set by the United States Environmental Protection Agency (USEPA). Moreover, the total mercury concentration in urine samples was 6.97 ± 0.06 μg/L, far below the >25 μg/L level considered to be a high level of mercury contamination. The total mercury accrued by the individuals was not dependent on age, but was positively associated with duration of stay.Conclusions.Based on the total mercury (THg) levels analyzed in the biological media, artisanal gold mining activities in Amansie West District are on the increase with a potential risk of developing chronic effects. However, the majority of the population, particularly those engaged in artisanal small–scale gold mining, are unmindful of the hazards posed by the use of mercury in mining operations. The results showed that THg in urine, hair, and fingernails more efficiently distinguished mercury exposure in people close to mining and Hg pollution sources than in people living far from the mining sites. Further education on cleaner artisanal gold mining processes could help to minimize the impact of mercury use and exposure on human health and the environment.Participant Consent.ObtainedEthics Approval.This study was approved by the Ghana Environmental Protection Agency and the Ministry of Local Government and Rural Development in Manso Nkwanta.Competing Interests.The authors declare no competing financial interests.

Toxic metals (Al, Cd, Pb and Hg) in the most consumed edible seaweeds in Europe

Algae are becoming increasingly common because of their importance in vegan and vegetarian diets. Although they are a source of essential minerals, vitamins and antioxidants, these marine organisms have a high absorption capacity that can lead to the accumulation of toxic metals which are dangerous in humans. The objective of this study is to determine the content of toxic metals (Al, Cd, Pb and Hg) in edible seaweed samples marketed in Spain (Europe) to assess the toxicological risk from the intake of these metals. A total of 73 European and Asian algae samples marketed in Tenerife (Canary Islands, Spain) were analyzed by ICP - OES (Inductively Coupled Plasma – Optical Emission Spectrometry) and by CV-AAS (Cold Vapor – Atomic Absorption Spectrophotometry). The major toxic metal was Al, whose highest level was recorded in seaweed salad (57.5 mg Al/kg dry weight). Regarding the origin, the highest concentrations of Al (38.9 mg/kg dw), Cd (0.59 mg/kg dw) and Pb (0.40 mg/kg dw) were found in Asian algae, which may be due to the high levels of industry in the Asian countries. However, the highest concentration of Hg (0.017 mg/kg dw) was found in European algae. The consumption of 5 g of dehydrated seaweed per day represents a percentage of contribution to the tolerable weekly intake of Cd of 22.7%, this percentage may entail a risk when considering total Cd intake. However, the consumption of 5 g a day of dehydrated seaweed would not, pose a risk to the health of adults.