Metal Burden Research Articles

Impacts of trace metals on Ascaris sp., endoparasites of greater cane rat, Thryonomis swinderianus (Temmincks, 1827), in the tropical rainforests of Odo Ona Kekere, Oluyole Local Government of Ibadan, Oyo State, Nigeria

BackgroundSamples of hunted greater cane rat (Thryonomis swinderianus) were collected from Oluwo Market, Epe and Odo Ona Kekere in Oluyole Local Government Area Ibadan, Nigeria. Trace metals such as zinc, cadmium, vanadium, barium, nickel, copper, lead, cobalt, chromium, and manganese were determined in the liver, intestine, and endoparasites of T. swinderianus and the associated implications on the lipid profile, and antioxidant biomarkers were investigated.ResultsThe study showed that the enteric parasites of the greater cane rat accumulated barium and zinc at a higher level than the host rat. This may be an ecotoxicological concern as the concentrations may exceed the acceptable limits in the near future if the rate of accumulation continues without remediation. The histopathological standpoint evidences indicate that the tissue alterations appear to be higher with increase in trace metal concentrations in tissues analyzed. The tissue alterations also commensurate with the intensity of the parasitic infections. Suspected cellular damage in the parasites evidenced by the high levels of cholesterol and low-lipid lipoproteins was characterized by the outstanding upregulation of SOD in the parasites above the levels detected in the liver and intestine of the greater cane rat. Furthermore, this investigation revealed that the accumulation of barium and zinc may be implicated in the oxidative stress tendencies observed in the parasites which is an early warning for the protection of the host. At the fairly higher concentrations, toxicity of these metals characterized by the oxidative stress in the parasite may be tremendous enough to eliminate the parasite and reduce their abundance in the host rats. The deleterious impact of the multi-stress conditions in the natural habitat was evident in this study. The significantly highest concentrations of zinc and barium in the parasites than the intestines and liver of the greater cane rat may partly be implicated in the outstandingly higher cholesterol and low-lipid lipoproteins indicate dyslipidemia, which results from cellular damage due to stress. Results showed that the levels of MDA in the investigated tissues were fairly stable, the upregulated SOD in the tissues of the parasite may mitigate the parasitic infection in the host.ConclusionThis study has demonstrated an empirical prognosis on the deleterious accumulation of barium and zinc. The results have also indicated the possibility of controlling the parasitic infection in the greater cane rat using the metal burden in the tissues of the rat to its advantage. The report has provided useful information by identifying the actual metals of concern and the associated early warning signals which necessitates proactive decisions toward sustainable conservation of the greater cane rat.

Microplastic Pollution in the Inlet and Outlet Networks of Rawa Jombor Reservoir: Accumulation in Aquatic Fauna, Interactions with Heavy Metals, and Health Risk Assessment

Streams are regarded as a pathway for spreading microplastics from land to various aquatic systems. The contamination of streams connected to the Rawa Jombor Reservoir may increase microplastic concentrations in the reservoir. The water coming out of the reservoir carries microplastics that spread out into the stream networks around the reservoir. Heavy metals have a high affinity for microplastics, increasing metal burdens on the surface of microplastics. The transfer of microplastics along the food chain leads to the possibility of increased adverse effects on organisms, mainly top predators. This research evaluated the accumulation and characterization of microplastics in water, sediment, and aquatic fauna (zooplankton, benthos, and fish); interactions with heavy metals (Pb, Cu, Cd, and Zn); and health risk assessment. Microplastics were collected from six sampling locations. The density, type of polymers, and color of microplastics were analyzed, as well as heavy metal concentrations on the surface of microplastics and a health risk assessment. The results showed microplastic contamination at a moderate level. The accumulation of microplastics in aquatic fauna showed the same pattern as microplastics in the environment. Microplastic concentrations in aquatic fauna showed an increase through trophic transfer and indications of biomagnification. Heavy metals were adsorbed on the surface of microplastics in high concentrations. Based on the health risk assessment, microplastic contamination of fish at the inlet and outlet of the Rawa Jombor Reservoir is still safe, but further monitoring is needed because of the possible long-term health hazards that may arise.

The effects of sea turtle and other marine megafauna consumption in northeastern Madagascar

ABSTRACT Sea turtles are essential to the health of marine ecosystems, yet nearly 90% are threatened with extinction. The unsustainable consumption of sea turtles contributes to their global decline. Because sea turtle meat is also high in heavy metals, the monitoring of sea turtle consumption is a priority for both marine conservation and public health. Despite this, sea turtle consumption was understudied along Madagascar’s eastern coastline. We used structured interviews (collected over nine years) in northeastern Madagascar to study the rural consumption of sea turtles and other marine megafauna (including dolphins, whales, and dugongs). Sea turtle consumption is increasing in the southwest Indian Ocean. Over 80% of households ate a mean of 1.47 kg of sea turtle meat per year over the prior decade. The vast majority of sea turtle meat was purchased. Households which were more financially and nutritionally secure ate significantly more sea turtle meat. Sea turtle meat did not provide a significant source of nutrients to insecure households. Thus, its elimination from the diet would be unlikely to economically or nutritionally harm consumers. In fact, sea turtle meat contributed significantly to heavy metal burdens within communities and reducing consumption is a key step toward ensuring both adequate public and environmental health. Social marketing campaigns on the content and effects of heavy metals in sea turtle meat paired with increased heavy metal testing of children and pregnant women, may benefit both local communities and marine conservation.

Human Body Burden of Heavy Metals and Health Consequences of Pb Exposure in Guiyu, an E-Waste Recycling Town in China.

Guiyu accommodates millions of tons of e-waste from overseas and domestic sources each year and is notorious for its e-waste dismantling industry. As a consequence, Guiyu has been described as “the world’s most toxic place” and “junk town”. Informal e-waste recycling activities have caused severe pollution to the local environment and are associated with extensive health problems to the residents. This review provides updated insights on the body burden of heavy metals derived from e-waste and health outcomes resulted from lead (Pb) exposure. The review identified that Guiyu has been highly contaminated by heavy metals, especially Pb. Excessive exposure to Pb has been associated with multi-system and long-term effects in neonates and children, covering nervous, cardiovascular, adaptive immune, and hematologic systems as well as chromosome and DNA damage. Our review indicates strong associations that emphasize the need to develop strong regulations for prevention of exposure and health consequences in Guiyu and similar sites around the world.

Assessment of foliar dusts metals burden as indicators of heavy metals contamination in Kano metropolis, Nigeria

ABSTRACT Plants have been used as biological filters by taking advantage of their capacity to remove dust and heavy metals from the air, which make them effective biomonitors to detect the presence of these metals even at trace levels. The present study was aimed to assess the levels of heavy metal in foliar dust of some selected urban trees along the roadside in Sauna Kawaji, Magwan, Kwanar Ganduje, and Nassarawa GRA of Kano Metropolis. From each sample site, leaf samples of neem trees (Azadirachta indica) were randomly collected along the roadside. The leaves were processed, digested and analysed by atomic absorption spectrometry. From the results, site variation showed that Zinc, Manganese, and Cadmium had the highest levels of 0.019, 0.137 and 0.0039 mg/L at Magwan and Kwanar Ganduje, respectively. In the evening hours, zinc, manganese and cadmium had the highest levels of 0.022, 0.140, and 0.002 mg/L at Magwan, Sauna Kawaji and Kwanar Ganduje, respectively. However, lead was not detected in all samples. Manganese was found to be the highest from all sampling sites, while cadmium had the least. However, the levels of the analysed metals were below the permissible limits of WHO and EPA. Therefore, foliar dust contained heavy metals in relative amount, which might be a cause of concern for environmental issues and could serve in environmental monitoring.

Spatial distribution and composition of mine dispersed trace metals in residential soil and house dust: Implications for exposure assessment and human health

Trace metal exposure from environmental sources remains a persistent global problem, particularly in communities residing adjacent to metal extraction and processing industries. This study examines front yard soil and house dust from 62 residences throughout the Australian Ag–Pb–Zn mining city of Broken Hill to better understand spatial variability in metal distributions, compositions and exposures across an industrially polluted urban environment. X-ray fluorescence analysis of paired soil/dust samples indicated that geomean concentrations (mg/kg) of Cu (32/113), Zn (996/1852), As (24/34) and Pb (408/587) were higher in house dust while Ti (4239/3660) and Mn (1895/1101) were higher in outdoor soil. Ore associated metals and metalloids (Mn, Zn, As, Pb) in soil and house dust were positively correlated and declined in concentration away from mining areas, the primary source of metalliferous emissions in Broken Hill. The rate of decline was not equivalent between soil and house dust, with the indoor/outdoor concentration ratio increasing with distance from mining areas for Zn/Pb (geomean = 1.25/1.05 (<1 km); 2.14/1.52 (1–2 km); 2.54/2.04 (>2 km)). House dust and Broken Hill ore Pb isotopic compositions (206Pb/207Pb; 208Pb/207Pb) were more similar in homes nearest to mining areas than those further away (geomean apportioned ore Pb = 88% (<1 km); 76% (1–2 km); 66% (>2 km)), reflecting spatial shifts in the balance of sources contributing to indoor contamination. Incorporation of house dust Pb reduced overestimation of IEUBK modelled blood Pb concentrations compared to when only soil Pb was used. These findings demonstrate that even in contexts where the source and environmental burden of metals are relatively apparent, geochemical relationships and exposures between outdoor and indoor environments are not always predictable, nor easily disaggregated.

Assessment of Heavy Metals in Mine Soil and Tailings from Jos, Nigeria

Jos is a mining town in Nigeria; mining activities has been going on in the area for more than a 100 years. Although, the mining and other related activities have brought about economic, social growth and infrastructural development in the area. Unfortunately, mining activities has been linked to the enhance in the level of heavy metals in the soil and other geological formations in the environment. To ascertain the heavy metals (HM) burden in the soil due to tin mining activities at Rayfield-Du area of Jos, HM concentrations were evaluated in soil samples collected from the mine site. The HM concentrations in the soils were evaluated using the Energy Dispersive X-ray Florescence (EDXRF) spectrometer system. The analysis of eight HM (Cr, Co, Ni, Cu, Zn, As, Cd, and Pb) concentrations showed that they are above the Nigerian reference level except for Co and Ni. The pollution and ecological risk indices of the HM concentrations were classified as low for the mine soils.

Central Nervous System (CNS)-Derived Extracellular Vesicles (EVs) as Novel Biomarkers for Environmental Exposure and Disease Progression in ALS

BACKGROUND AND AIM: Metal exposure is linked to amyotrophic lateral sclerosis (ALS) but biomarkers of central nervous system (CNS) metal burden are lacking. Here, we tested the use of blood-isolated CNS-derived extracellular vesicles (EVs) as biomarkers of metal exposure and disease progression in ALS. Specifically, we examined whether: 1) cultured brain cells can eliminate metals via EV release, 2) metal levels in ALS patient blood-isolated CNS-EVs predict metal load in their brain and spinal cord, and 3) differences in CNS-EV metal levels are associated with ALS disease progression (ongoing). METHODS: Metal levels were measured by ICP-MS. Cultured astrocytes were treated with 2.5µM Mn or As for 3 or 7 days. Released EVs were isolated by ultracentrifugation. In a pilot of N = 7 National ALS Registry patients, we measured metal levels in blood, CNS-EVs, spinal cord, and cortex to assess their correlations. CNS-EVs of neuronal (L1CAM) and astrocyte (GLAST) origin were enriched via immunoprecipitation. In 97 ALS patients at two disease stages, GLAST-EVs were immunopurified from blood and analyzed for Cu, Pb, Hg, Al, Mn, Cd, and Fe levels. Linear models are being employed to examine associations between changes in CNS-EV metal levels and ALS Functional Rating Scale progression. RESULTS:Mn and As levels in treated astrocyte EVs increased over time, whereas these metals were not detected in control cells. Circulating GLAST-EV metal load was overall more predictive of spinal cord and cortex metal levels than total blood or L1CAM-EV metal levels. Hg and Cd were not detected in ALS patient GLAST-EV samples, while geometric means of Cu, Pb, Al, Mn, and Fe decreased between the two timepoints. CONCLUSIONS:Preliminary evidence suggests that peripheral GLAST-EVs metal levels may reflect internal CNS metal exposure and that metal regulation via CNS-EVs weakens over time. The association of GLAST-EVs with ALS disease progression deserves further exploration. KEYWORDS: Heavy metals, Exposures, Biomarkers of exposure, Neurodegenerative outcomes, ALS, Extracellular vesicles

Residential Proximity to Metal-Containing Superfund Sites and Toenail Metal Concentrations in a Nationwide Study of US Women

BACKGROUND AND AIM: Superfund sites in the United States contain hazardous substances, including toxic metals, which could potentially expose those living nearby. However, it is unclear whether residential proximity to sites may increase body burden of toxic metals. We aimed to evaluate the association between residential proximity to metal-containing Superfund sites and toenail metal concentrations. METHODS: Metal concentrations (aluminum, antimony, arsenic, cadmium, and lead, ng/g) were measured in toenail clippings collected between 2003-2009 in 2,998 women with a family history of breast cancer. Residential proximity to Superfund sites was measured by living ≤5 or 10 miles of a site (yes/no), site density (sites/mile^2) and an inverse-weighted sum distance measure (sites/mile). Linear regression was used to estimate the difference in toenail metal concentrations and 95% confidence intervals (CIs) per unit change in residential proximity measures (β). We evaluated whether associations varied by race/ethnicity. RESULTS:Women who lived closer to, or had a higher residential density of, Superfund sites reporting contamination of lead or antimony had higher toenail concentrations of the corresponding metals. For example, living ≤5-miles of a lead site was associated with 0.37 ng/g higher lead concentrations (95% CI: 0.18-0.57), and an increase in 1 additional lead-containing site/mile^2 was associated with 2.9 ng/g higher lead concentrations (95% CI: 1.8-4.0). Negligible associations were observed for sites containing arsenic or aluminum for any distance metric. For cadmium, associations were only evident in non-Hispanic Black women living near Superfund sites (N=744) but not non-Hispanic White women (N=2,244, e.g., living ≤5-miles of a cadmium site, βNon-Hispanic Black= 0.69, CI: 0.37-1.0; βNon-Hispanic white = -0.04, CI: -0.3-0.23; p-heterogeneity=0.02). CONCLUSIONS:Increased residential proximity to Superfund sites was associated with higher toenail concentrations of certain metals. Results for cadmium suggest important racial/ethnic differences in exposure that warrant follow-up for potential issues of environmental justice. KEYWORDS: chemical exposures, hazardous waste, heavy metals

Comparison of metal burden in different muscle tissues of Great cormorant (Phalacrocorax carbo)

Concentrations of 12 metals (As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb and Zn) were examined in the pectoral and thigh muscle of great cormorants (Phalacrocorax carbo). The samples were collected from Central Tisza-Jászság Nature Conservation Area in Hungary. The tissue samples were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The aim of the study was to examine the impacts of heavy metal pollution on the water birds, determine the concentrations of the abovementioned metals in the different muscle tissues of these wetland birds, and provide the basic materials for monitoring the environmental pollution. Among the investigated elements/metals, the detected concentrations of As, Ba, Cd, Co, Cr, Mo and Ni were below the detection limit. Higher concentration of Cu, Hg, Mn and Pb was measured in the pectoral muscle compared to the thigh muscle, but only in the case of Cu and Mn were found significant differences between the tissues. In the case of the Zn concentration, the higher value was detected in the thigh muscle. There were no statistical differences between males and females in either metal concentrations.

Metal exposure and biomarker levels among e-cigarette users in Spain

The use of electronic cigarettes (e-cigarettes) has increased due to the belief that they are healthier than tobacco cigarettes. E-cigarettes contain a metallic heating coil (composed of Ni, Cr, Al and other metals) to heat a solution (commonly called e-liquid) and convert it into an aerosol. This aerosol is inhaled (vaped) by the users who can be potentially exposed to a wide variety of metals. We investigated the possible transfer of metals from the coil to the e-liquid and the generated aerosol, and how the exposure to this aerosol can increase metal body burden in e-cigarette users. We recruited 75 e-cigarette users (50 who only vaped and 25 dual users who vaped and smoked) and 25 controls who neither vaped nor smoked. E-liquid samples before (dispenser e-liquid) and after (tank e-liquid) being added to their devices were collected. Aerosol samples were collected using a condensation method. All participants provided urine and hair samples. All samples were analyzed for metals by ICP-MS. We observed higher metal concentrations in the aerosol and tank e-liquid (in contact with the coil) compared to the dispenser e-liquid (before contact with the coil). The median concentrations for some of the metals with the most remarkable increases in aerosol and tank e-liquid vs. dispenser e-liquid were 36.90 and 62.73 vs. 18.29 μg/kg for Al; 6.71 and 28.97 vs. 0.98 μg/kg for Cr; 91.39 and 414.47 vs. 1.64 μg/kg for Ni; 738.99 and 744.24 vs. 16.56 μg/kg for Zn; and 10.17 and 22.31 vs. 0.88 μg/kg for Pb. We also found detectable and potentially high concentrations of other metals such as Mn, Cu, Sb and Sn. In urine, increases in the median levels (μg/g creatinine) in vapers/duals vs. controls were observed for some metals, including Cr (0.34/0.28 vs. 0.20), Cu (1.72/2.36 vs. 1.46), Sn (0.26/0.31 vs. 0.18) and Pb (0.39/0.44 vs. 0.22). In hair, there were no differences in metal concentrations among the three groups. In conclusion, e-cigarettes are likely a source of metals such as Cr, Cu, Ni, Pb or Sn. These metals come from the device, likely the heating resistance, as their concentrations were low in the dispenser e-liquid and higher in the aerosol and the e-liquid left in the tank. Although the exposure to e-cigarette aerosol can have an influence in the body burden of metals, aerosol metal levels were not clearly associated with metal levels in biological samples such as urine or hair in e-cigarette users in this study.

Effect of Baking Methods Types on Residues of Heavy Metals in the Different Breads Produced with Wheat Flour in Iran: A Case Study of Mashhad

Food contamination with heavy metals is the main concern for human health that increases globally. Bread wheat is one of the most important grain products for human consumption. The aim of the study is to examine the effect of baking methods on residues of heavy metals in the different breads produced with wheat flour in Mashhad, Iran. A total of 180 samples of different breads produced in 90 bakery shops in Mashhad was analyzed for some heavy metals (Fe, Cr, Cu, Zn, Pb, Hg, Co, As, Al, V, Cd, and Ni) by inductively coupled plasma-optical emission spectrometry (ICP-OES). Results showed that the average concentration of Fe, Al, Zn, Cu, and Cd in some bread samples were significantly (p<0.05) different between traditional and industrial baking processes. The average concentrations of the entire test of Fe (46.35±39.78 mg.kg-1), Cr (0.28±0.33 mg.kg-1), Al (3.49±1.89 mg.kg-1), and As (0.479±0.229 mg.kg-1) were higher than the current corresponding safety limit in all type of bread. The results obtained indicated that the government requires implementing more remediation or intervention to control and mitigating the contamination burden of heavy metals in traditional bread in the study area to reduce its associated risks for human health.

Risk assessment of the anthropogenic activities (quarrying) and heavy metal profile in mining environment.

The need to generate internal revenue by most individuals and government in Nigeria has led to the establishment of quarries in different parts of Ebonyi state of Nigeria. This study was aimed at determining the risk associated with the heavy metal burden in the state. Soil samples from the quarrying environments designated as MS1, MS2, and MS3 were analyzed for the metal profile using inductively coupled plasma optical emission spectrometry (ICP-OES). The result showed that the mean concentration of metals which is a representation of the whole sites showed a higher concentration of Ca (40.065 ± 1.011ppm), Mg (12.450 ± 8.815ppm), K (16.631 ± 14.670ppm), and Mn (19.539 ± 3.225ppm) while Na (1.326 ± 0.117ppm) was low. The heavy metal profile showed Pb (0.120 ± 0.027ppm), Fe (27.718 ± 1.523ppm), Zn (2.227 ± 0.570ppm), Cu (6.267 ± 1.402ppm), Ni (1.856 ± 0.472ppm), Mo (1.758 ± 0.258ppm), Cd (0.023 ± 0.006ppm), Cr (0.037 ± 0.011ppm), etc. Hg was found to be below detectable limit while the Cs was not radioactive. The mean values were found to be lower than the permissible limit of each metal. The pollution index (PI) was calculated for the different sites, and the result reveals that MS3 (0.0426) had a higher PI when compared to MS1 (0.0341) and MS2 (0.0317). Therefore, the PI of the sites showed MS3 > MS1 > MS2. These results showed that the environment is still as safe as PI < 1. The geoaccumulation index also showed a safe environment since its values were less than 0 which means that the environment is practically uncontaminated. Other risk determining parameters showed that the three locations were still within a safe level. Although the results of the study have shown a safe environment, it is still necessary to keep close monitoring of the heavy metal profile of the environment, since these metals can bioaccumulate in living tissues with time.

Seasonal Speciation Study of Heavy Metals Content in Well Water of Some Chicken Farms in Osun State, Southwestern Nigeria

Heavy metals are native to various soils, dusts, air, sediments, water and plant constituent in various means and these relations quantify their mobility and availability. In this manuscript, the seasonal differences in contents of arsenic, cadmium, copper, iron, lead and zinc in well water within the proximity of three main chicken farms in Osun State, were studied to ascertain the ecological impacts of the chicken farming on the well water sources. Water samples taken for eight months were assayed for pH, conductivity, total dissolved solids, alkalinity and speciation of heavy metal contents utilizing standard techniques. A column filled up with Amberlite XAD-16 resin was utilized for the quantification of metals bound to humic substances and free metal ions in the water samples. The samples were assayed for their heavy metal content utilizing Flame Atomic Absorption Spectrophotometer. Quality assurance techniques involved blank determination, recovery analysis and calibration of standards. Descriptive and inferential statistics were used for data interpretations. The content ranges of the metals were: 0.0110–0.0878, 0.0130–0.0900, 0.1124–0.5196, 17.0563-59.4264, 0.021-0.2283 and 3.0420–21.1450 µg/mL for As, Cd, Cu, Fe, Pb and Zn, respectively. With the exception of Cu, the content ranges of all the other metals were present to be exceeded the international standards and acceptable level for drinkable water. The speciation analyzes signified that Fe and Zn were present primarily in the particulate phase, As and Cu were predominant in the humic substances phase, while Cd, Fe, Pb and Zn mainly found in the free metal ions. The free metal ions phase of Cd, Fe, Pb and Zn were found to be bio-available, and thus, could present health risks to humans and poultry bird. The contents found from the control site signified that the chicken farm activities might have impacted the well water with high heavy metal burdens.

Cytotoxic effects of wildfire ashes: In-vitro responses of skin cells

Wildfires are a complex environmental problem worldwide. The ashes produced during the fire bear metals and PAHs with high toxicity and environmental persistence. These are mobilized into downhill waterbodies, where they can impair water quality and human health. In this context, the present study aimed at assessing the toxicity of mimicked wildfire runoff to human skin cells, providing a first view on the human health hazardous potential of such matrices. Human keratinocytes (HaCaT) were exposed to aqueous extracts of ashes (AEA) prepared from ash deposited in the soil after wildfires burned a pine or a eucalypt forest stand. Cytotoxicity (MTT assay) and changes in cell cycle dynamics (flow cytometry) were assessed. Cell viability decreased with increasing concentrations of AEA, regardless of the ash source, the extracts preparation method (filtered or unfiltered to address the dissolved or the total fractions of contaminants, respectively) or the exposure period (24 and 48 h). The cells growth was also negatively affected by the tested AEA matrices, as evidenced by a deceleration of the progress through the cell cycle, namely from phase G0/G1 to G2. The cytotoxicity of AEA could be related to particulate and dissolved metal content, but the particles themselves may directly affect the cell membrane. Eucalypt ash was apparently more cytotoxic than pine ash due to differential ash metal burden and mobility to the water phase. The deceleration of the cell cycle can be explained by the attempt of cells to repair metal-induced DNA damage, while if this checkpoint and repair pathways are not well coordinated by metal interference, genomic instability may occur. Globally, our results trigger public health concerns since the burnt areas frequently stand in slopes of watershed that serve as recreation sites and sources of drinking water, thus promoting human exposure to wildfire-driven contamination.

Assessment of non-carcinogenic health risk of heavy metal pollution: evidences from coal mining region of eastern India.

Various developmental projects and economic actions such as mining, industries, urban expansion, and agricultural activities contribute toxic heavy metals into the soils and it adversely affects to human health and broadly the environment. For the scientific study (coal mining region of Eastern India) around 120 soil samples were collected from top (0 - 20 cm) and subsurface soil (20 - 50 cm) of coal mining, semi mining and non mining type of land use sites to assess ten heavy metals applying standard methods and indices for the assessment of pollution load and human health risk. Statistical analysis clearly indicated that Fe, Mn, Zr are the most dominantly distributed in the study region. Coefficient of variance (CV)showed that there was very less variation in the metal values among samples of any particular landuse site. Correlation coefficient (0.05% level of significance) depicts that metals were very strongly correlated with each other in every site of Neturia block. Igeo (Geo- accumulation index) values of Fe and As indicated moderate to low pollution in the topsoil of study area. It is because of their regional background value. Enrichment Factor (EF) also showed thatcontamination of Fe ismainly supplied by natural factors (EF < 2)i.e., weathering of parent rock in all over the study area. All other heavy metals indicated their anthropogenic sources (EF > 2)on top and subsurface soil both of three landuse site. Degree of contamination (Cdeg), modified degree of contamination (mCdeg), contamination factor (CF) and pollution load index (PLI) clearly suggest that topsoil of coal mining sites is most polluted than two other sites. Subsurface soil of mining sites also indicated comparatively higher pollution load than subsoil of semi mining or non mining sites. PLI values have been classified into four groups i.e., high pollution (> 6), medium pollution (6 -3), low pollution (3 - 1) and no pollution (< 1) zone. There was no PLI value < 1 in topsoil of the study area. But subsurface soil of non mining site indicated no pollution to the soil. Spatial mapping using Inverse Distance Weightage (IDW) on Arc GIS 10.4 software showed clear variation of metal concentration and pollution load to the top and subsoil of the study area. Human health risk of non - carcinogenic typeisdue to heavy metals intake of topsoil through three exposure pathwaywhich indicates the health risk of HI dermal> HI ingestion> HI inhalation for both the adult and children. Mean values of total HI showed that children are more prone to health risk in comparison with adult. There was no soil sample that exceeds its HI values > 1 for adults and thus no obvious health risk was found from soil heavy metals for adults.On the other hand, topsoil of mining sites indicated HI values >1;therefore, children are prone to health risk in this site. The present investigation suggests that coal mining region is highly polluted by their heavy metal burden on soil. Industrial and semi urban areas of semi mining region are also affected by heavy metal dust to its soil. Agricultural activities in non-mining region indicated lower pollution than other landuse sites. Remedial measures are highly needed to control heavy metal pollution of different landuse sites at colliery region to sustain environmental quality and human health as well. Modern scientific technologies and public awareness should be very useful on this way.

Multi-metal effluent removal by Centella asiatica (L) Urban: Prospects in phytoremediation

The search for an efficient plant for simultaneous extraction of ten trace elements from industrial effluent has lead us to Centella asiatica , a native species, known for medicinal properties. After 28-d of trial, it could effectively lower toxic metals such as Cd (14%–54%), Cr (2%–43%), Cu (18%–81%), Pb (35%–90%), Ni (13%–59%) and Zn (20%–81%) from test solutions that comprised of the effluent from a pulp and paper mill that was appropriately diluted with 30% Hoagland’s solution The plant demonstrated favourable attributes such as augmentation of key antioxidant enzymes (SOD, CAT, APX and GPX) for combating oxidative stress. Plants showed improved growth and worked well in the lowest effluent dose (25%, v/v). Scanning electron microscopy along with energy dispersive X-ray microanalysis of the root showed the localization of all the trace elements, Pb (weight %, 11–28) and Cd (weight %, 3.1–6.8) peaks indicated that adsorbed metals predominantly remained in the root at 75% and 100% (v/v) exposures. The phytoremediation trials were validated by bioassays in Clarias batrachus reared in phytoremediated effluents; fish showed lower metal burden, most toxic trace metals were within the safe levels, which was suggestive of the accomplishment of phytoremediation and utilities for bio-monitoring purposes. • Centella asiatica simultaneously extracted 10 trace elements from effluent. • Decrement in the level of trace elements were registered from effluent after trials. • Plants showed improved growth and worked well in the lowest effluent dose. • Plant combated oxidative stress by augmented production of key antioxidant enzymes. • Success of remediation trials were validated by bioassays in a catfish.

Indoor particulate matter and blood heavy metals in housewives: A repeated measured study

BackgroundParticulate matter (PM) less than 2.5 μm in diameter and 10 μm (PM10) contains heavy metals, but whether exposure to PM is significantly associated with the burden of heavy metal exposure in the population is unknown. We investigated the association between exposure to PM and blood concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in Korean housewives. Materials & MethodsFrom July 2017 to January 2020, we recruited 115 housewives in Ulsan, Republic of Korea. After excluding participants with missing information, we finally included 88 Korean housewives in our study. We measured the concentrations of indoor PM using a gravimetric method 24 h before blood sampling and the concentrations of Cd, Pb, and Hg in blood, twice at a 1-year interval. We used a linear mixed effect model to estimate the associations between indoor PM and blood heavy metals. ResultsExposure to PM10 was significantly associated with blood concentrations of Cd among Korean housewives. A 10 μg/m3 increase of PM10 the previous day was associated with a 2.8% (95% confidence interval (CI) = 1.1%, 4.6%) and a 1.5% (95% CI = −0.1%, 3.1%) increase in blood concentrations of Cd and Pb in the linear mixed effect model, respectively. ConclusionThere was a significant association between indoor PM exposure and blood Cd concentrations among Korean housewives. This result suggests that the body burden of heavy metals is significantly associated with air pollution.

Low-Level Cadmium Exposure and Atherosclerosis.

Cadmium has been recognized as a potential risk factor for cardiovascular disease (CVD). We present a review of cadmium toxicity, its effect on cellular activities, and a summary of reported association between environmental cadmium exposure and CVD. We also discuss the possible therapeutic benefit of cadmium chelation. Experimental data suggest that cadmium affects several signaling pathways which may lead to endothelial dysfunction and vascular tissue damage, promoting atherosclerosis. This is further supported by epidemiological studies that have shown an association of even low-level cadmium exposure with an increased risk of clinical cardiovascular events. The Trial to Assess Chelation Therapy (TACT) provided inferential evidence for the cardiovascular benefit of treating toxic metal burden. However, at the present time, there is no direct evidence, but suggestive findings from clinical trials indicating that removal of cadmium from body stores may be associated with improved cardiovascular outcomes. An evolving body of evidence supports environmental cadmium exposure as a pro-atherosclerosis risk factor in CVD; however, the mechanisms for the proatherogenic effect of cadmium are still not completely understood. Further studies in translational toxicology are needed to fill the knowledge gaps regarding the molecular mechanisms of cadmium toxicity and the promotion of atherosclerosis.

Low-Level Metal Contamination and Chelation in Cardiovascular Disease-A Ripe Area for Toxicology Research.

Cardiovascular disease remains the leading cause of death worldwide. In spite of cardiovascular prevention, there is residual risk not explicable by traditional risk factors. Metal contamination even at levels previously considered safe in humans may be a potential risk factor for atherosclerosis. This review examines evidence that 2 metals, lead, and cadmium, demonstrate sufficient toxicological and epidemiologic evidence to attribute causality for atherosclerotic disease. Basic science suggests that both metals have profound adverse effects on the human cardiovascular system, resulting in endothelial dysfunction, an increase in inflammatory markers, and reactive oxygen species, all of which are proatherosclerotic. Epidemiological studies have shown both metals to have an association with cardiovascular disease, such as peripheral arterial disease, ischemic heart disease, and cardiovascular mortality. This review also examines edetate disodium-based chelation as a possible pharmacotherapy to reduce metal burden in patients with a history of cardiovascular disease and thus potentially reduce cardiovascular events.