Search Results (134)

Artisanal small-scale gold mining (ASGM) is the largest source of global mercury (Hg) emissions. This study investigated Hg contamination in water, soil, sediment, fish, and cassava plants around ASGM sites in Gunung Pongkor, West Java, Indonesia. Hg concentration ranged from 0.06 to 4.49 µg/L in water; 0.420 to 144 mg/kg dw in soil; 0.920 to 150 mg/kg dw in sediment; 0.259 to 1.23 mg/kg dw in fish; 0.097 to 5.09 mg/kg dw in cassava root; and 0.350 to 8.84 mg/kg dw in cassava leaf. Geo-accumulation index (Igeo) analysis revealed moderate to heavy soil contamination upstream, likely due to direct ASGM input. In contrast, sediment Igeo values indicated heavy contamination downstream, suggesting Hg transport and sedimentation. Bioconcentration factors (BCFs) in fish were predominantly high in downstream and midstream areas, indicating enhanced Hg bioavailability. Bioaccumulation factors (BAFs) in cassava were higher in upstream areas. Health risk assessment, based on the Hazard Quotient (HQ) and Hazard Index (HI), identified ingestion as the primary exposure route, with children exhibiting significantly higher risks than adults. These findings highlight the significant Hg contamination associated with ASGM in Gunung Pongkor and emphasize the need for targeted mitigation strategies to protect human and environmental health. Full article

The administration of nutraceutical substances to fish diet can help to control disease outbreaks in aquaculture practices, thereby promoting sustainability and food safety. In particular, some substances have the potential to alleviate the effects of trace metals toxicity in fish also by reducing metal accumulation in tissues. This study evaluates, for the first time, the effect of nutraceutical substances on bioaccumulation mechanisms of mercury (Hg) in tissues and organs of farmed gilthead seabream (Sparus aurata) by mesocosm experimentation. The kinetics of bioaccumulation in muscle, gills, gut, liver and kidney and the detoxification efficiency were also assessed. Fish were fed with three different diets: a commercial diet used as control (CD); a diet enriched with short chain fatty acids (SCFA) and extract of Castanea sativa (D1); a diet enriched with yeast Saccharomyces cerevisiae and extract of Schinopsis balansae (D2). All groups were exposed to sub-lethal concentrations of mercury. After 20 days of exposure, mercury levels in different organs and tissues clearly revealed the effectiveness of yeast and plant extracts in limiting the metal bioaccumulation in fish fed with D2 through mercury absorption and then elimination by feces. In contrast, the D1 seems to not reduce the Hg bioaccumulation in fish tissues. This can be attributed to the high affinity of SCFA for mercury, leading to the formation of organometallic compounds absorbed by the fish tissues. This mechanism potentially counteracts the efficiency of tannins contained in the extract plant on mercury removal. This study clearly demonstrates that the use of diets enriched with yeast and/or plant extracts rich in tannins are a useful bioremediation strategy to reduce trace metals bioaccumulation in farmed fish, thus preserving their health status from intoxication, their commercial values, and consequently the health of consumers. Full article

In 2019, an unusual mortality event (UME) affected bottlenose dolphins (Tursiops truncatus) in the Mississippi Sound (MSS) following an extended dual opening of the Bonnet Carré Spillway (BCS), which prevents flooding in New Orleans. This resulted in low salinity, skin lesions, and electrolyte imbalances in dolphins. Additionally, the influx likely altered the MSS’s environmental chemical composition, including levels of heavy metals and metalloids; thus, we quantified heavy metals, metalloids, and essential elements in the tissues of dolphins that stranded in the MSS before and after the 2019 UME. We hypothesized that levels of heavy metals and metalloids (such as mercury (Hg), arsenic (As), lead (Pb), and cadmium (Cd)) would not show significant changes post-UME. Indeed, we found no major changes associated with the UME in most metals; sodium (Na) and magnesium (Mg) levels were lower in several tissues after 2019, which correlated with the average yearly salinity measured from the MSS. Toxic metals and metalloids were detectable with some changes over time; however, the selenium (Se):Hg molar ratio increased in some tissues post-2019. Additionally, we confirmed that Hg can bioaccumulate, with positive correlations between Hg levels and dolphin size as assessed by straight length. Overall, our findings indicate that freshwater incursions into the MSS can alter dolphin exposure to essential and toxic elements. Full article

Amazonian parrots (Psittacidae) are essential to ecosystem balance. Already vulnerable to habitat fragmentation and weak environmental regulations, they are now increasingly threatened by heavy metal contamination. This review synthesizes evidence on the sources, transgenerational bioaccumulation, and physiological impacts of metals such as mercury (Hg), lead (Pb), cadmium (Cd), zinc (Zn), and arsenic (As) in these birds. Anthropogenic activities, including illegal gold mining, agricultural intensification, and urban expansion, release metals that biomagnify along food webs. Parrots, as long-lived, high-trophic consumers, accumulate metals in vital tissues, leading to severe neurotoxic effects, immunosuppression, reproductive failure, and reduced survival. Furthermore, maternal transfer of contaminants to eggs exacerbates genetic erosion and threatens population viability. While biomonitoring tools and habitat restoration have been proposed, current strategies are insufficient against the synergistic pressures of pollution and climate change. Addressing heavy metal exposure is critical to conserving Amazonian biodiversity and safe-guarding ecosystem services. Future efforts should prioritize multidisciplinary predictive models, bioremediation actions, and the strengthening of international environmental governance to ensure the survival of these sentinel species. Full article

Heavy metals are naturally occurring elements that have numerous applications in industries, agriculture, and other sectors, leading to their widespread distribution in the environment. The constant emission of heavy metals into the environment raises concerns about their impact and harmful effects on living organisms, including human health. Key threats arise from exposure to heavy metals such as lead, cadmium, mercury, and arsenic, all of which are classified as carcinogens. Chronic exposure and bioaccumulation of these metals can result in toxic effects on various body systems, including the female reproductive system. Notably, heavy metals can induce oxidative stress, generate excessive reactive oxygen species, and impair antioxidant defense systems. These metals may also lead to DNA damage, enzyme inactivation, and epigenetic modifications, ultimately disrupting critical cellular processes such as growth, proliferation, differentiation, repair, and apoptosis. Furthermore, some heavy metals can mimic endogenous estrogens, interact with estrogen receptors, and cause hormonal disruptions, a mechanism particularly relevant to the pathogenesis of female-related cancers. Despite significant advances, many gaps remain in our understanding of the molecular mechanisms by which heavy metals contribute to cancer development. Addressing these gaps could facilitate the development of more effective strategies for the prevention and treatment of female cancers. This review highlights the potential effects of heavy metals on molecular pathways in female cancers, suggesting several mechanisms of cancer development. Full article

Heavy metal and pesticide contaminations represent significant environmental and health hazards to humans and animals. Toxic heavy metals such as lead (Pb), cadmium (Cd), mercury (Hg), and copper (Cu) persist in the environment, bioaccumulating in beverages and food products from both natural and anthropogenic sources. Traditional remediation techniques, such as chemical precipitation and ion exchange, are effective but often costly and challenging to apply at a large scale. In recent years, grape pomace—a winemaking by-product rich in bioactive compounds—has emerged as a promising, low-cost biosorbent for the removal of such pollutants. Its high adsorption capacity, environmental friendliness, and availability make it a strong candidate for water and food decontamination processes. This study evaluates grape pomace and its biochar as sustainable biosorbents for heavy metal removal from water and soil, examining their adsorption efficiency, adsorption mechanisms, environmental benefits, advantages, limitations, and perspectives for future industrial-scale applications. Full article

Soil contamination with heavy metals poses a significant risk to human health and ecological systems through multiple exposure pathways: direct ingestion of crops, dermal contact with polluted soil, and bioaccumulation within the food chain. This study analyses eleven composite soils, each collected in triplicate from different sites in Iași County, four of which are designated Natura 2000 protected areas (Mârzești Forest, Plopi Lake—Belcești, Moldova Delta, and Valea lui David). The assessment includes measurements of soil humidity by the gravimetric method, pH, and organic matter content, examined in relation to heavy metal concentrations due to their well-established interdependencies. For heavy metal determination, energy-dispersive X-ray spectroscopy (EDS) using an EDAX system (AMETEK Inc., Berwyn, PA, USA) and X-ray fluorescence spectrometry (XRFS) with a Vanta 4 analyser (Olympus, Waltham, MA, USA) were employed. Additionally, scanning electron microscopy (SEM) with a Quanta 450 microscope (FEI, Thermo Scientific, Hillsboro, OR, USA) was used primarily for informational purposes and to provide a broader perspective. In the case of chromium, 45.45% of the samples exceeded the permissible levels, with concentrations ranging from 106 mg/kg to 186 mg/kg, the highest value being nearly twice the alert threshold. Notably, not all protected areas maintain contaminant levels within safe limits. The sample from the Mârzești Forest protected site revealed considerably raised concentrations of mercury, arsenic, and lead, exceeding the alert thresholds (1 mg/kg—mercury, 15 mg/kg—arsenic, and 50 mg/kg—lead) established through Order no. 756/1997 issued by the Minister of Water, Forests, and Environmental Protection from Romania. On the other hand, the sample from Podu Iloaiei, an area with intensive agricultural activity, shows contamination with mercury and cadmium, highlighting significant anthropogenic pollution. The findings of this study are expected to raise public awareness regarding soil pollution levels, particularly in densely populated regions and protected ecological zones. Moreover, the results provide a scientific basis for policymakers and relevant authorities to implement targeted measures to manage soil contamination and ensure long-term environmental sustainability. Full article

The growing incidence of breast cancer over time suggests that environmental factors might contribute to the underlying causes of the disease. Mercury, a toxic metal classified as a Substance of Very High Concern, accumulates in the body through contaminated food, air, water, and soil, raising concerns about its role in tumor biology. The main aim of this study was to identify the possible associations between in situ mercury bioaccumulation and the molecular features of breast cancer. To achieve this, a total of 26 breast cancer cases were analyzed using an integrated approach that combined DNA and RNA sequencing, histological analysis, and inductively coupled plasma mass spectrometry (ICP-MS) to assess mercury bioaccumulation. Mercury was detected in 72% of the cases. A significant positive correlation was found between mercury bioaccumulation and CXCR4 expression in breast cancer tissues. Bioinformatic analysis further revealed that CXCR4 expression was significantly higher in metastatic tissues compared to primary tumors. These findings suggest that mercury accumulation may influence tumor biology through the CXCR4-CXCL12 signaling pathway, highlighting a potential mechanism by which mercury contributes to breast cancer progression. Full article

Mercury (Hg) is a naturally occurring element, but atmospheric Hg has increased due to human activities since the industrial revolution. When deposited in aquatic environments, atmospheric Hg can be converted to methyl mercury (MeHg), which bioaccumulates in ecosystems and can cause neurologic and endocrine disruption in high quantities. While higher atmospheric Hg levels do not always translate to higher contamination in wildlife, museum specimens over the past 2 centuries have documented an increase in species that feed at higher trophic levels. Increased exposure to pollutants presents an additional threat to fish and wildlife populations already facing habitat loss or degradation due to global change. Additionally, Hg cycling and bioaccumulation are primarily driven by geophysical, ecological, and biogeochemical processes in the environment, all of which may be modulated by climate change. In this review, we begin by describing where, when, and how the Hg cycle may be altered by climate change and how this may impact wildlife exposure to MeHg. Next, we summarize the already observed physiological effects of increased MeHg exposure to wildlife and identify future climate change vulnerabilities. We illustrate the implications for wildlife managers through a case study and conclude by suggesting key areas for management action to mitigate harmful effects and conserve wildlife and habitats amid global change. Full article

Mercury (Hg) poses significant risks to human health, the environment, and plant physiology, with its effects influenced by chemical form, concentration, exposure route, and organism vulnerability. This study evaluates the physiological impacts of Hg on Handroanthus impetiginosus (Ipê Roxo) seedlings through SPAD index measurements, chlorophyll fluorescence analysis, and Hg quantification in plant tissues. Four-month-old seedlings were exposed for eight days to distilled water containing Hg at 0, 1, 3, 5, and 7 mg L⁻¹. The SPAD index decreased by 28.17% at 3, 5, and 7 mg L⁻¹, indicating reduced photosynthetic capacity. Chlorophyll a fluorescence analysis revealed a 50.58% decline in maximum efficiency (Fv/Fm) and a 58.33% reduction in quantum yield (ΦPSII) at 7 mg L⁻¹, along with an 83.04% increase in non-photochemical quenching (qn), suggesting oxidative stress and PSII damage. Transpiration decreased by 26.7% at 1 mg L⁻¹ and by 55% at 3, 5, and 7 mg L⁻¹, correlating with Hg levels and leaf senescence. Absorption, translocation, bioconcentration, and bioaccumulation factors varied among treatments. Hg accumulated mainly in stems (40.23 μg g⁻¹), followed by roots (0.77 μg g⁻¹) and leaves (2.69 μg g⁻¹), with limited translocation to leaves. These findings highlight Hg’s harmful effects on H. impetiginosus, an ecologically and commercially valuable species, addressing a gap in research on its Hg tolerance and phytoremediation potential. Full article

Background: Gaseous elemental mercury (Hg⁰ or GEM) is an atmospheric form of mercury (Hg)—a toxic heavy metal—that is naturally released in volcanic environments. Research with wild mice demonstrates that chronic exposure to a hydrothermal volcanic environment leads to the bioaccumulation of Hg in the lungs, but also in both the central (CNS) and peripheric (PNS) nervous systems, with marked indications of neurotoxicity. Studies addressing human exposure to volcanogenic Hg⁰ are scarce, hence its risks are still unknown. This study aims to evaluate the level of exposure to Hg⁰ in children living in a volcanically active environment. Methodology and main findings: Two groups of school-aged children (from 6 to 9 years old) were part of this study: one with children inhabiting a hydrothermal area (exposed group) and another with children inhabiting an area without volcanic activity (non-exposed group). Hair samples were collected from each individual for Hg level analysis. It was found that the levels of Hg in the hair of exposed children were 4.2 times higher than in that of non-exposed children (≈1797.84 ± 454.92 ppb vs. 430.69 ± 66.43 ppb, respectively). Conclusion: Given the vast health risks Hg poses, the need to monitor the health of populations inhabiting volcanically active areas is highlighted. Because little is known about the fate, modifications, and effects of Hg⁰ in the human body, particularly regarding its effects on the nervous system in children, the development of further research within the scope is strongly encouraged. Full article

Total mercury pollution in oolong tea garden soils was comprehensively investigated in this study. Soil samples were collected from 146 villages in a famous oolong tea production area. The total mercury content in the soils ranged from 0.025 to 0.296 mg/kg, with a median of 0.105 mg/kg. According to the Soil Accumulation Index Method, 67.81% of samples were pollution-free, 31.51% had pollution levels from none to moderate, and 0.68% were moderately polluted. The PMF model revealed that natural geochemical processes were the main mercury source, contributing 72.4%, with some from transportation, coal combustion, and industrial activities. Most values were below the HQ threshold, suggesting low non-carcinogenic risk from mercury in most soils. Further research is needed to understand mercury’s bioaccumulation in tea leaves and assess short- and long-term exposure risks for a better understanding of its long-term impacts on the tea industry and human health. Full article

The Colombian Caribbean faces environmental challenges due to urbanization, industrialization, and maritime activities, which introduce pollutants such as heavy metals, hydrocarbons, and microplastics into aquatic ecosystems. Perna viridis (Asian green mussel), an invasive species that has been established in Cartagena Bay since 2009, exhibits potential bioaccumulation capacity, making it a promising biomonitor. This study assessed the concentrations of mercury (Hg), cadmium (Cd), lead (Pb), and selenium (Se) in P. viridis across two key sites—a port area at the Cartagena Bay (CB) and Virgen marsh (VM) in Colombia—from 2020 to 2023. Seasonal variations driven by La Niña and El Niño phenomena significantly influenced metal concentrations, with transitional periods modulating pollutant accumulation. The levels of trace metals in soft tissue of P. viridis (dry weight) ranged from 0.0003 to 0.0039 µg/g (Cd), 0.04 to 0.21 µg/g (Hg), 0.05 to 1.18 µg/g (Pb), and 0.0029 to 0.0103 µg/g (Se). In suspended particulate matter (SPM), Cd ranged from 0.07 to 0.33 µg/g; Pb ranged from 4.94 to 25.66 µg/g; and Hg ranged from 0.18 to 1.20 µg/g. Results revealed differences in metal concentrations between sites and seasons, highlighting the role of environmental and anthropogenic factors in pollutant distribution. The findings confirm P. viridis as an effective biomonitor of complex pollution scenarios in Cartagena Bay. However, its invasive status highlights ecological risks to be addressed, such as interaction with native bivalves and benthic community structures. These results emphasize the need for ongoing monitoring efforts to mitigate pollution and preserve marine biodiversity in the Colombian Caribbean. Full article

This study assessed environmental metal and metalloids (TE) levels using hair of Apodemus sylvaticus as a non-lethal biomonitor. TE decreased as follows: Zn > Al > Fe > Cu > Pb > Cr > Ni > Mn > Cd > Se > As > Hg; TE widely distributed in soils as Zn, Al, Fe, and Cu, are more abundant than those of ecotoxicological interest, such as Cd, Se, As and Hg. Cd, Pb, Cu, and Cr concentrations are highly variable, while Zn, Fe, and Mn are less variable. TE in hair are below the threshold levels in soil and decrease the same way in both sexes. Concentrations in soil and hair are significantly related, and their level can be modulated both by homeostatic control of essential metals and absorbance from the soil by keratin. Slight differences in Ni and Cr can be related to the differing behaviour of males and females during reproduction. A scarce tendency toward mercury bioaccumulation has been observed in both sex and age classes; from an ecological point of view, these data suggest that the species is a primary consumer, feeding more on the leaves and seeds than on small invertebrates. Full article

The shorthorn sculpin (Myoxocephalus scorpius) is considered a suitable sentinel species for marine pollution in the Arctic due to its ecology and stationary habits. To evaluate its role as a bioindicator for potential natural and anthropic impacts on the marine ecosystem of the Kongsfjorden (Svalbard, Norwegian Arctic), 33 female and male specimens of shorthorn sculpins were collected in July 2018 in proximity of the Ny-Ålesund international research facility and analyzed for the content of 25 major and trace elements and methylmercury (MeHg) in the muscle, liver, gonads, and gills by using spectroscopic techniques. Most elements had their maximum average concentrations in the gills (Al, Cr, Fe, Mn, Na, Ni, Pb, Se, Si, Sr, and V), while the livers featured higher contents of some toxic and heavy metals (As, Cd, Cu, Mo, and Zn). The muscle was characterized by high contents of Ca, K, and Mg, while Ba, Co, and P were mostly concentrated in the gonads. The gonads presented higher concentrations of Cr, K, Mg, Ni, P, and V for the males and Co, Cu, Fe, Mn, and Se for the females. Both the total Hg and MeHg concentrations in the muscle correlated with the fish size, indicating bioaccumulation, although high Se/Hg molar ratios (11.0 ± 2.2) suggested a low toxic potential of mercury. Full article