High Mercury Concentrations Research Articles

Mercury content and consumption risk of the invasive Arapaima gigas (paiche) in Bolivia

Mercury is a global pollutant present in the environment. The most frequent non-occupational human exposure pathway is fish consumption. Generally, fish species of large size and with carnivorous or omnivorous feeding habits have higher mercury concentrations. The invasive fish Arapaima (popularly known as paiche), an omnivorous large-sized species introduced in northern Bolivian Amazon about 50 years ago after escape from aquaculture in Peru, has successfully colonized this region and is now the main commercial fish species. Consumption of this species in Bolivia is increasing, and an evaluation of the risk of mercury exposure for human health is warranted. Muscle samples from 86 fish were taken from four different sub-basins (Orthon, Madre de Dios, Beni and Yata). 8.1% of the samples showed mercury content above the safe consumption recommendation of the World Health Organization (0.5 mg kg-1). Samples from the Madidi and Yata rivers scored the highest mean concentrations (0.367 and 0.306 mg kg-1, respectively), whereas individuals from the lower Beni subbasin showed the lowest (0.105 mg kg-1). According to our results, the maximum recommended paiche meat consumption is 316 g per week, divided into two meals, which is in agreement with international recommendations for fish consumption (227 g to 340 g per week), although this can vary according the place of origin of the meat. Following these recommendations, mercury exposure through paiche consumption should not represent a risk for human health.

Induction of phytoextraction, phytoprotection and growth promotion activities in Lupinus albus under mercury abiotic stress conditions by Peribacillus frigoritolerans subsp., mercuritolerans subsp. nov.

Strain SAICEUPBMT was isolated from soils of Almadén (Ciudad Real, Spain), subjected to a high mercury concentration. SAICEUPBMT significantly increased aerial plant weight, aerial plant length and the development of secondary roots under mercury stress; increased twice the absorption of mercury by the plant, while favoring its development in terms of biomass. Similarly, plants inoculated with SAICEUPBMT and grown in soils contaminated with mercury, express a lower activity of antioxidant enzymes; catalase enzymes (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR) for defense against ROS (reactive oxygen species). Whole genome analysis showed that ANI (95. 96 %), dDDH (72.9 %), AAI (93.3 %) and TETRA (0.99) values were on the thresholds established for differentiation a subspecies. The fatty acids analysis related the strain with the Peribacillus frigoritolerans species. And the synapomorphic analysis reveals a common ancestor with analysis related the strain with the Peribacillus frigoritolerans species. Results from genomic analysis together with differences in phenotypic features and chemotaxonomic analysis support the proposal of strain SAICEUPBMT as the type strain of a novel subspecies for which the name Peribacillus frigoritolerans subps. mercuritolerans sp. nov is proposed. The absence of virulence genes and transmissible resistance mechanisms reveals its safety for agronomic uses, under mercury stress conditions. The ability of Peribacillus frigoritolerans subsp. mercuritolerans subsp. nov to improve plant development was tested in a Lupinus albus model, demonstrating a great potential for plant phytoprotection against mercury stress.

Joint effects of tobacco smoke exposure and heavy metals on serum sex hormones in adult males.

This study aimed to explore the associations of tobacco smoke exposure (TSE) and heavy metal exposure on sex hormones and the joint effects between them in adult males. The study used data of 2244 adult males from the National Health and Nutrition Examination Survey (NHANES, 2013-2016). Weighted linear regression models were used to calculate their beta (β) coefficients and corresponding confidence interval (95% CI), which assessed the joint effects of TSE and heavy metals on sex hormones. Sex hormone-binding globulin (SHBG) showed a positive association with increased per standard deviation (SD) for cotinine (β=0.024 [0.004, 0.043]; P<0.001), lead (β=0.021 [0.002, 0.039]; P=0.028), and cadmium (β=0.034 [0.015, 0.053]; P<0.001). Manganese was positively associated with estradiol (E2) (β=0.025 [0.009, 0.042]; P=0.002). The subjects with higher cadmium levels were more likely to have higher total testosterone (TT) (β=0.042 [0.023, 0.062]; P<0.001). TSE and lead exerted synergistic effects on TT (p for interaction = 0.015) and E2 (p for interaction = 0.009), as also did TSE and cadmium on SHBG (p for interaction = 0.037). Compared with the reference group, TSE participants who were exposed to high concentrations of lead, cadmium, mercury, and manganese had significantly elevated TT levels, but these high levels presented no significant association with E2 levels. A significantly higher level of SHBG among TSE participants was detected in high concentrations for lead, cadmium, and mercury. TSE exacerbated sex hormone imbalances when combined with high levels of metal exposure. Smoking cessation is crucial, especially in the case of high levels of occupational exposure to heavy metals.

A Study on Total Mercury Content in Surface Water and Backwater Fishes of Periyar

Aquatic systems are extensively contaminated with heavy metals released due to anthropogenic activities. Mercury is one of toxic elements and its toxicity to humans has been established. The concern about mercuric pollution in the environments started with the incident of ‘Minamata’ in Japan in 1950’s. During the study period, flowing mercury electrode was used for the preparation of caustic at Travancore Cochin Chemicals Ltd (TCC), Eloor and effluents of small industries at Edayar were the sources of mercuric pollution. Surface water samples were collected from 1Km apart from TCC, near to Indian Rare Earth Ltd (IRE), Muttinakam and Mannamthuruth and fishes (male and female) were collected from this region with the help of local fishermen. This study implies the amount of mercury in aquatic system and its influence in different body components of three fishes. Total mercury content in both the samples analysed using cold vapour atomic absorption using Mercury Analyser MA-5840 and loss on mercury on heating processes (fishes) was decreased by the use of Bethge Apparatus. Fishes were Oreochromis mossambicus (Thilapia), Mugil cephalus (Mullet) and Arius arius (Cat fish) which were living in surface to near shore, middle of the river and bottom. The proximate composition (AOAC, 2000) of fishes showed that they were low fat (0.57-4.24%) with high protein content (18.4-21.96%). The total mercury content in surface water varied from 1.667- 3.334ng/ml and it was above tolerance level (1ng/ml) while in fishes followed the order A. arius&gt; M. cephalus&gt; O. mossambicus. Relatively higher concentrations of mercury were noticed in gut and liver than muscle, and also male fishes predominated over female. This study shows that mercury cycle in the habitat water did not influence to any hazardous level in these three fishes.

Effect of the stabilization process of sewage sludge on the mercury content of municipal sewage sludge

Sewage sludge, the amount of which is increasing every year, must be disposed of on the one hand, and on the other hand it makes a pretty good alternative fuel. However, due to the high mercury content of sewage sludge, its use for energy purposes requires further research. The effect of the technological process of sewage sludge treatment on the mercury content of this end product of wastewater treatment is not fully understood. Therefore, the present study examined 17 sewage sludges from municipal wastewater treatment plants in Lower Silesia for energy properties and mercury content before and after the following technological processes: autothermal aerobic stabilization at temperatures above 50 °C (ATSO), aerobic separated stabilization at effluent temperature (KTSO), separated digestion at ambient temperature (OKF) and separate digestion at 37 °C (WKF). The study showed that the mercury content ranged widely from 0.47 to 6.05 mg/kg Hg, indicating several times higher atmospheric emissions than when using conventional fuels. Among the sewage sludge samples tested, there were samples with very high mercury content, significantly different from the average mercury content of the sludge from the same process line. On this basis, it is concluded that the sewage sludge disposal process leads to the formation of significantly heterogeneous material.Sludge stabilization processes (ATSO, KTSO, OKF, and WKF) increase the mercury content of sewage sludge.

Involvement of Hg-bearing methane seeps in forming Ediacaran cap carbonate in South China

During the Cryogenian-Ediacaran transition, an extremely cold climate transitioned into a warm climate which was accompanied by the worldwide precipitation of cap carbonates showing striking negative carbonate carbon isotope (δ13Ccarb) anomalies. High mercury (Hg) contents up to 180 ppb have been reported from the Doushantuo cap carbonates, but the origin of Hg anomalies and its relationship with cap carbonate precipitation remain unclear. To address these issues, we measured Hg concentrations and isotopes along with total organic carbon (TOC) content and δ13Ccarb from the basal Ediacaran carbonates at the Jiulongwan section of western Hubei Province, South China. The results show that in laterally persistent intervals, Hg spikes (as high as 77 ppb) co-occur with decrease of Δ199Hg values (as low as 0.07‰), increase of δ202Hg values (−1.47‰), and conspicuous negative δ13Ccarb shifts (as low as ca. -17‰). Such Hg isotopic signature with high Hg concentration are comparable to those of natural gas hydrates and thus are ascribed to be an involvement of Hg-bearing methane seeps in precipitation of cap carbonate after melting of ice-sheets of the Marinoan glaciation (latest Cryogenian). Anaerobic oxidation of methane from hydrates via sulfate reduction may have produced bicarbonate (HCO3−), which was transformed into cap carbonate when combining with alkaline ions transported from continent to seawater via weathering process. This study provides the first evidence for Hg-bearing methane oxidation during cap carbonate precipitation.

Preliminary Study on Mercury and Lead in the Ambient Air of Metro Manila, the Philippines

Despite being acknowledged as an air pollutant, heavy metal contaminants in the atmosphere are not yet well studied in the Philippines. This study aims to assess the particulate matter, as well as mercury and lead concentration, in Metro Manila's ambient atmosphere. A one-hour sampling period was used to collect data at seven sampling stations using a respirable dust sampler with a flow rate of 1.4 m3/min. The mercury concentration was determined using cold vapor atomic absorption spectroscopy, whereas lead concentrations were measured using flame atomic absorption spectroscopy. Taguig had the highest level of total suspended particulates (TSP) at 524.07 μg/NCM, followed by Caloocan (459.92 μg/NCM) and Quezon City (434.50 μg/ NCM). Parañaque reported moderate particulate levels – recorded at 298.95, 291.69, and 347.36 μg/NCM, respectively. Valenzuela had the lowest TSP level at 263.85 μg/NCM. Results show that mercury concentrations were highest in the City of Manila with 0.09 μg/m3, followed by Valenzuela City with 0.009 μg/m3, against the lowest concentration in Taguig City and Quezon City with 0.001 μg/m3. However, based on the legal airborne permissible exposure from the Philippine Occupational Safety and Health Standards, the mercury concentration in the seven cities of Metro Manila did not exceed its 0.5 mg/m3 (50 μg/m3) limit. Furthermore, results revealed that atmospheric lead concentration in Metro Manila existed only in trace amounts (≤ limit of detection). The high concentration of mercury in the City of Manila could be attributed to its high population density combined with massive industrial, commercial, and transport activities. Monitoring the concentration of heavy metals in the atmosphere is critical for the development of effective strategies for reducing the negative impacts of these global pollutants.

Effects of legacy mining on mercury concentrations in conifer needles and mushrooms in northern Palatinate, Germany

Due to integrated pollution prevention and control measures and the reduced burning of coal, air concentrations of mercury (Hg0) are currently levelling off. In the future, however, evasion from land surfaces will probably reverse this trend. Reasons are the rising temperatures and the loss of forest cover caused by calamities, droughts, storms and wildfires. Plant leaves constitute an important matrix for the accumulation of gaseous mercury and uptake and re-volatilisation by plants depends on the species, the vitality and the age and morphology of leaf organs. It has been shown that older conifer needles show higher concentrations than young needles and Hg accumulation is increasing throughout the season.In present study, we collected branches from Norway Spruce (Picea abies) in a former cinnabar mining region in Northern Palatinate, where artisanal and small-scale mining left innumerable waste dumps. While mining, smelting and processing of the ores were terminated during WWII, high total mercury concentrations remained in the top soils locally, with presumably only small fractions being plant available. In the lab, up to seven needle age classes were analysed. 1000 needle weights increased with age and as expected, also the Hg concentrations were elevated in the older needles. Needle concentrations were higher than those reported from other national biomonitoring programs confirming the regional imprint from legacy mercury. To complement our biomonitoring study, we collected edible mushrooms in former mining areas. Hg concentrations in most samples exceeded the EU maximum residue levels (MRL), while only a few broke the existing cadmium and lead limits. Tolerable weekly intake (TWI) for inorganic mercury would be surpassed with the consumption of a small portion of mushrooms. Further studies should be performed on the outgassing of Hg from mine wastes and the incorporation of Hg in the local food web, including its methylation and biomagnification.

Highly Sensitive Whole-Cell Mercury Biosensors for Environmental Monitoring.

Whole-cell biosensors could serve as eco-friendly and cost-effective alternatives for detecting potentially toxic bioavailable heavy metals in aquatic environments. However, they often fail to meet practical requirements due to an insufficient limit of detection (LOD) and high background noise. In this study, we designed a synthetic genetic circuit specifically tailored for detecting ionic mercury, which we applied to environmental samples collected from artisanal gold mining sites in Peru. We developed two distinct versions of the biosensor, each utilizing a different reporter protein: a fluorescent biosensor (Mer-RFP) and a colorimetric biosensor (Mer-Blue). Mer-RFP enabled real-time monitoring of the culture's response to mercury samples using a plate reader, whereas Mer-Blue was analysed for colour accumulation at the endpoint using a specially designed, low-cost camera setup for harvested cell pellets. Both biosensors exhibited negligible baseline expression of their respective reporter proteins and responded specifically to HgBr2 in pure water. Mer-RFP demonstrated a linear detection range from 1 nM to 1 μM, whereas Mer-Blue showed a linear range from 2 nM to 125 nM. Our biosensors successfully detected a high concentration of ionic mercury in the reaction bucket where artisanal miners produce a mercury-gold amalgam. However, they did not detect ionic mercury in the water from active mining ponds, indicating a concentration lower than 3.2 nM Hg2+-a result consistent with chemical analysis quantitation. Furthermore, we discuss the potential of Mer-Blue as a practical and affordable monitoring tool, highlighting its stability, reliance on simple visual colorimetry, and the possibility of sensitivity expansion to organic mercury.

The capacity of Plectranthus sp. to perform phytoremediation on heavy metal mercury (Hg) in the tailing of gold processing industries

Sludge (tailing), a waste product of the amalgamation process used in the mining of gold, contains a high concentration of the heavy metal mercury (Hg). It is well known that mercury builds up in large quantities in Plectranthus sp. herbaceous plants in the Pancurendang Village Small-Scale Gold Mining area. The study intends to: 1) quantify the amounts of mercury present in plant organs and media tailing during phytoremediation treatment; 2) examine the mechanisms and capacities of plant phytoremediation using values of the Biological Accumulation Coefficient (BAC), Biological Concentration Factor (BCF), and Translocation Factor (TF); and 3) determine the impact of percentage variations in tailing and time on Plectranthus sp.’s capacity to accumulate mercury. On a lab scale, phytoremediation of tailings is done with concentrations of 0%, 30%, 50%, and 100%. Planting medium is combined with dried tailings. Pots are used for phytoremediation, and the residence times are 10, 20, and 30 days. With the use of a mercury analyzer, the amount of mercury present in plant media, roots, and shoots is determined. Using the BAC, BCF, and TF values, the mathematical calculation of phytoremediation ability is performed. Hg content ranged from 1.82 to 16.23 ppm in shoots and 5.15 to 37.19 ppm in roots. Throughout the course of treatment, the tailings Hg concentration varied between 13.18 and 220.05 ppm. Plectranthus sp. is categorized as a medium accumulator with a phytoextraction mechanism, according to the analysis’s findings. Hg phytomining is possible with Plectranthus sp., the TF value is 2.38. Within 10 days, Plectranthus sp. most effectively accumulates 50% Hg in tailings.

Fish Tissue Mercury in Lakes and the Moderating Effects of Selenium

Fish mercury concentrations result in fish consumption advisories. However, selenium : mercury molar ratios &gt;1 are protective to wildlife and humans. Therefore, we sampled total selenium (TSe) and total mercury (THg) concentrations and molar ratios in sport fish from 50 Idaho (ID) lakes &gt;20 ha and 67 northeastern USA (NE) lakes &gt;1 ha. Sample lakes were selected at random, to obtain unbiased estimates of mean fish tissue levels, with known confidence limits, for target populations of 95 ID lakes &gt;20 ha in surface area and 12,557 NE lakes &gt;1 ha. Bass and salmonids presented the greatest potential mercury toxicity risk to consumers based on their higher mercury content, desirability as game fish, and widespread distributions. Fish tissue THg exceeded safe consumption criteria in an estimated 20–80% of the lakes in the two regions and TSe exceeded safe consumption thresholds in an estimated 0–20% of the lakes in the two regions. However, the Se : Hg molar ratio was &gt;1 in an estimated 90–97% of fish tested from NE and ID lakes. Therefore, we concluded that Se levels in these systems are usually sufficient to limit disruption of selenoprotein activities by Hg, and that fish consumption advisories based on Hg alone are unnecessarily restrictive.

Association between Fish Consumption during Pregnancy and Maternal and Neonatal Outcomes: A Statistical Study in Southern Italy.

Background: This research aimed to evaluate the association between the monthly consumption of fish (differentiated by type) and both gestational and neonatal outcomes. Methods: Women who were admitted for delivery in the last 6 months of 2023 were prospectively included and divided according to type of fish consumed (based on DHA and mercury content) and frequency of consumption. Neonatal outcomes included weight, length, head circumference, and 1st and 5th minute Apgar scores. Maternal outcomes were threats of abortion, preterm birth, gestational diabetes and hypertension, cesarean section, and differential body mass index (BMI). Results: Small-size oily fish with high DHA and low mercury content (type B fish) consumption was positively associated with neonatal weight and head circumference, and less weight gain in pregnancy. It was also significantly associated with lower incidences of gestational diabetes and hypertension, and cesarean section. Correlation between differential BMI and monthly consumption of fish resulted in statistical significance, especially in type B fish consumers. Conclusions: The consumption of type B fish was significantly associated with increased neonatal weight and head circumference and better maternal outcomes.

NELL1 membranous nephropathy: clinical associations provide mechanistic clues.

Neural epidermal growth factor-like 1 (NELL1) membranous nephropathy (MN) is notable for its segmental deposit distribution, IgG1 dominant deposits, and comparatively high rate of spontaneous remission. It has been associated with a variety of exposures and secondary conditions, specifically use of thiol-containing medications - including lipoic acid, bucillamine, and tiopronin - as well as traditional indigenous medications (TIM) particularly those with high mercury content, and non-steroid anti-inflammatory drugs (NSAIDs). Malignancies, graft vs. host disease (GVHD), infection, and autoimmune conditions have also been associated with NELL1 MN. Herein, we provide a detailed summary of the clinicopathologic features of NELL1 and associations with underlying conditions, with a focus on treatment and outcomes. Rare cases of dual NELL1 and phospholipase A2 receptor (PLA2R) positive MN are reviewed. Genome-wide association study of NELL1, role of NELL1 in other physiologic and pathologic processes, and connection between NELL1 MN and malignancy with relevance of NELL1 tumor staining are examined. Finally, relationships and potential disease mechanisms of thiol- and mercury- associated NELL1 MN are discussed.

Assessment and Review of Heavy Metals Pollution in Sediments of the Mediterranean Sea

The impact of marine sediment pollution is crucial for the health of the seas, particularly in densely populated coastal areas worldwide. This study assesses the concentration and distribution of heavy metals in the marine sediments of the main regions of the Mediterranean Sea. The results underscore high concentrations of mercury (Hg), nickel (Ni), and copper (Cu), whereas chromium (Cr), zinc (Zn), cadmium (Cd), barium (Ba), and vanadium (V) exhibit moderate values. To assess the heavy metal results, sediment quality guidelines and pollution indices (Igeo and Geochemical Signal Type-GST) were employed, revealing a consistent trend of decreasing concentrations from the coastal zone to the open sea. Principal Component Analysis (PCA) emphasizes the significant roles of Cu, Zn, Ba, and Cr in sediment chemistry. The study suggests that the distribution patterns of heavy metals are linked to wastewater discharges in coastal areas, requiring effective management strategies to ensure the health of the Mediterranean Sea.

The non-selective Antarctic filter feeder Salpa thompsoni as a bioindicator of mercury origin

Hg is considered as the most toxic metal in the environment. Sources of Hg in the environment include burning fossil fuels, burning waste, and forest fires. The long residence time of the gaseous form in the atmosphere allows mercury to be transported over long distances. The pelagic tunicate Salpa thompsoni is an important component of the Antarctic environment. Over the past few decades an expansion of this species to the higher latitudes has been noted, mainly due to the ongoing climate change. The study material consisted of samples of S. thompsoni individuals, collected in the waters surrounding Elephant Island (Western Antarctic). Total mercury and five of its fractions were determined. Whole organisms were analyzed as well as internal organs: stomachs, muscle strips, and tunics. Obtained results showed that the highest concentrations of mercury in salps were observed in stomachs. With the Hg fraction results, it can be concluded that the main route of exposure of S. thompsoni to Hg is presumably absorption from the food—filtered organic and non-organic particles. Moreover, the process of transformation of simple soluble forms into organic forms of Hg in stomachs and intestines and its distribution to other tissues was observed.

Associations of five blood heavy metals with hepatitis B virus infection and immunity in adults: a cross-sectional study

BackgroundHeavy metal pollution has emerged as a significant concern for human health, prompting increased awareness of its potential adverse effects. While previous research has established a connection between heavy metals and liver function biomarkers, the specific relationship between heavy metals and HBV infection remains unexplored. This cross-sectional study aims to investigate the potential correlations between five blood heavy metals - lead, cadmium, mercury, manganese, and selenium - and the presence of HBsAg, HBsAb, and HBcAb in adults.MethodsThe study utilized data from NHANES 2007–2018. Participants were classified into four groups based on their infectious status, and the association between heavy metals and HBV infection was analyzed using multiple logistic regression and stratification analysis.ResultsA total of 8431 participants were included, with 5 436 classified as Susceptible, 1 765 as Vaccinated, 865 as Natural Infection, and 103 as Acute/Chronic HBV Infection. The Vaccinated group exhibited a lower mean age (34.52 ± 14.16 years) compared to the other groups. Statistically significant differences in heavy metal concentrations (except selenium) were observed among the groups (P < 0.001). After adjusting for covariates, lead was significantly associated with HBV infection (Q2: OR 2.37, 95%CI 1.04–5.39; Q3: OR 2.34, 95%CI 1.01–5.40), and positive trends were observed for high blood concentrations of mercury (Q4: OR 3.03, 95%CI 1.31–7.04) and manganese (Q4: OR 2.52, 95%CI 1.20–5.28). Furtherly, the presence of lead reduced the protection of HBsAb (Q2: OR 0.84, 95%CI 0.73–0.97; Q3: OR 0.77, 95%CI 0.66–0.90; Q4: OR 0.83, 95%CI 0.70–0.98). Subgroup analysis indicated that cadmium was associated with an increased risk of HBV infection in Asians (OR 1.36, 95%CI 1.03–1.78) and individuals with a BMI range of 25 to 30 (OR 1.60, 95%CI 1.17–2.18).ConclusionsThe study’s findings suggest a correlation between elevated blood Pb concentrations and reduced immunization rates against hepatitis B. Individuals with a positive HBsAg exhibit lower blood Se concentrations and higher blood Hg and Mn concentrations.

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.

Mercury distribution, exposure and risk in Poyang Lake and vicinity, China

Mercury (Hg), especially methylmercury (MeHg), which is highly neurotoxic, is a global pollutant that can affect human health because of its accumulation in aquatic products. Poyang Lake, an inland lake in China, has been significantly affected by human activity, yet there is limited understanding of local mercury contamination and potential exposure pathways to humans. In this study, we explored the risks of mercury exposure by sampling sediments, plants, and aquatic organisms in the lake and surrounding areas and analyzing total Hg (THg) and MeHg levels. Sediment sampling was conducted at the main lake, rivers, rice paddies, and fishponds. Two dominant species of plants and 15 species of aquatic organisms were sampled and analyzed. We assessed the characteristics of mercury in sediments using the geo-accumulation index (Igeo), mercury exposure using the biomagnification factor (BMF) and biota sediment accumulation factor (BSAF), and risks using thresholds for adverse effects. The highest THg concentrations (137.04 ± 44.3 ng g−1 dw) were detected in the main lake sediments, whereas the highest MeHg concentrations (0.47 ± 0.6 ng g−1 dw) were detected in fishpond sediments. Mercury accumulation in the main lake sediments could be assessed as contaminated (Igeo > 0: 81.6%). Yellow catfish had the highest mercury concentration (THg 770.69 ± 199.7 ng g−1 dw; MeHg 741.93 ± 168.8 ng g−1 dw). Piscivores were adversely affected by carnivorous fish (50.8%), but all fish concentrations did not exceed the food safety standards recommend by China and the WHO. The mercury exposure results revealed significant Hg biomagnification and enrichment (BMF >1: 94.55%; BSAFmax = 1218). Long-term monitoring of aquatic organisms is warranted.

Evaluation of mercury in skin lightening creams commonly used in Trinidad and Tobago and their associated health risk

Objectives: This study investigated the presence of mercury in commonly used over the counter skin-lightening creams available in Trinidad and Tobago. The objective of this study was to evaluate if skin-lightening creams commonly used in Trinidad and Tobago contained Mercury, and establish the health risks presented by these products. Methods: Nineteen skin-lightening creams were analysed using Cold Capor Atomic Absorption Spectrophotometry (CV-AAS). Margin of Safety (MoS) and Hazard Quotient (HQ) calculations were used to assess risk to users. Results: Of the nineteen creams assessed, sixteen contained high concentrations of mercury (0.294-14414.5 µg/g), only three creams had no mercury detected. 9 of the 19 samples contained levels of mercury that exceed the Minamata convention’s accepted limit of 1µg/g, with 3 samples exceeding 3800.000 µg/g. Risk assessments using MoS and HQ showed that 3 of the samples were unsafe for use and are considered hazardous. The study also revealed that many creams do contain mercury even if it did not constitute part of the product formulation. Conclusions: The data infers that some manufacturers do add mercury to their formulations while others are the victims of contaminated raw materials. MoS and HQ show that 21% of the samples were unsafe and 16% can be considered hazardous for human use. It is possible that with such levels of mercury in these products and the popularity of these products within the Caribbean Community and its diaspora, that there exists a significant amount of members with higher than acceptable mercury levels, with undiagnosed clinical symptoms.

Impact of Wastewater from Outfall of River on Bitter Gourd: Morphological and Biochemical Studies, Peptide Synthesis and Antioxidant Activity

River pollution poses a significant concern for the people of India who heavily rely on river water for daily needs. This study focuses on assessing the status of river pollution in West Bengal, India, with a particular emphasis on a major canal (N22° 39'08.75'' E88° 21'27.60'') near Dakhineswar New Jetty, known for its Kali Temple and frequent ritual activities. The region's dependence on river water is evident in daily life. Analysis of three consecutive years (2016-2018) reveals alarming levels of Total Coliform, reaching up to 8.18 x 106 MPN/100ml during the premonsoon season. Disturbingly high concentrations of Lead (0.069 mg/L) and Mercury (0.008 mg/L) are recorded. Average Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD) are 2.3 mg/L and 7.9 mg/L, respectively, during the premonsoon. The impact of wastewater on Bitter Gourd (Momordica charantia L.) manifests in detrimental changes to both morphological and biochemical parameters, including total chlorophyll and protein content. Low molecular weight peptide(s) (3.0-0.5 kDa) are extracted, purified, and analyzed through ion exchange resin column, ultra-filtration, and HPLC. HPLC analysis distinguishes the presence of peptides compared to the control, revealing adverse effects of wastewater. The antioxidant activity of low molecular weight peptide(s) is demonstrated through DPPH scavenging. Bioassays, such as the germination percentage of wastewater-treated Bitter Gourd seeds, indicate inhibition. The intensified impact of wastewater during the premonsoon season underscores the urgency of addressing river pollution in this region.