Heavy Metal Burden Research Articles

Heavy metal burdens of public primary school children related to playground soils and classroom dusts in Ibadan North-West local government area, Nigeria.

Information about heavy metal burden of children in Nigeria related to playground soils and classroom dusts is lacking. Playground soil, classroom dust, blood and spot urine samples (n=253) were collected from 6 urban and 2 semi-rural public schools in Ibadan North-West, Nigeria. Samples were analysed for Pb, Cu, Zn, Fe and Mn. Mean blood Pb levels in urban area (male, 41.66±8.78μg/dl vs. female, 40.64±5.46μg/dl) were twice as high as those in semi-rural area (male, 19.71±3.73μg/dl vs. female, 20.65±2.26μg/dl). Concentrations of Pb, Cu, Zn, and Fe in soil and dust samples in the urban schools were between 2- to 4-fold greater than that of semi-rural schools. No correlation was observed between blood and dust metals. A positive correlation (r=0.168, p=0.008) was observed between blood Pb and playground soil Pb. Pb burden in the children might be from their schools' playgrounds and other yet unidentified sources.

Pilot study on the internal exposure to heavy metals of informal-level electronic waste workers in Agbogbloshie, Accra, Ghana.

Informal-level electronic waste (e-waste)-processing activities are performed at hotspots in developing countries such as India, China, and Ghana. These activities increase the ambient burden of heavy metals and contribute to the toxic exposure of the general population. However, few data exist on the internal exposure of populations involved in these informal activities and in close contact with fumes from the direct combustion of electronic waste products in these countries. Therefore, in a cross-sectional study design, we analyzed blood, urine, and hair samples from 75 e-waste workers residing in and/or working on a large e-waste recycling site in Agbogbloshie, Accra, Ghana, and compared the results against those of 40 individuals living in a suburb of Accra without direct exposure to e-waste recycling activities. A comparative analysis using the Mann-Whitney U test showed significantly higher median concentrations of blood lead (88.5 vs. 41.0μg/l, p<0.001), cadmium (0.12 vs. 0.10μg/gcrea, p=0.023), chromium (0.34 vs. 0.23μg/gcrea, p<0.001), and nickel (3.18 vs. 2.03μg/gcrea, p<0.001) in the urine of e-waste workers than those of controls. There was no difference in blood cadmium concentrations between the groups (0.51 vs. 0.57μg/l, p=0.215) or in urine mercury levels (0.18 vs. 0.18μg/gcrea, p=0.820). Hair mercury levels were higher in the controls than in the e-waste workers (0.43 vs. 0.72, p<0.001). We compared our data with those from European populations, specifically using the German reference values, and found that the internal concentrations of the participants exceeded the German reference values in 59.3 vs. 3.1% (e-waste workers vs. controls) for blood lead, 56.9 vs. 52.5% for urine nickel, 22.2 vs. 20.0% for urine chromium, and 17.8 vs. 62.2% for hair mercury. In particular, the high blood lead levels of up to several hundred micrograms per liter are a cause for concern because many of the workers in Agbogbloshie are children or adolescents who are in developmental stages and are at a particular risk for negative health effects. We conclude that exposure to some of the heavy metals tended to be a citywide phenomenon, but populations directly exposed to e-waste recycling are experiencing higher exposure levels and have concentration levels much higher than those of the general population and much higher than those found in European populations. To achieve environmental sustainability and to minimize the impact of e-waste-processing activities in developing countries, national authorities must formalize the rapidly growing informal-level e-waste management sector in these countries by deploying cleaner and easy-to-operate e-waste processing technologies.

Body burden of heavy metals among HIV high risk population in USA

ObjectiveHIV high risk population may face not only the threat of HIV infection but also a higher chance of exposure to environmental contaminants. However, no previous studies have examined the body burden of environmental pollutants including heavy metals among HIV high risk populations. The aim of this study was to investigate whether adults aged 20–59 years old at high risk of HIV infection have higher blood levels of heavy metals compared to those with low risk of HIV infection in United States. Material and methodsWe used the National Health and Nutrition Examination Survey (NHANES) 1999–2010 to compare exposures to heavy metals including cadmium, lead, and total mercury by HIV risk status. ResultsThe results showed that people at high risk of HIV had higher blood concentrations of all heavy metals compared to their counterparts with lower HIV risks. In multivariate linear regression models, HIV risk status was significantly associated with increased blood cadmium, lead, and total mercury after adjusting for age, sex, race, education, and poverty income ratio. ConclusionsOur study suggests that people at high risk of HIV have significantly higher body burden of heavy metals including cadmium, lead, and mercury compared to those with low risk of HIV. Further longitudinal study collecting more pollutants are warranted to determine the potential health effects of these elevated pollutants on both HIV-infected and HIV high-risk populations.

Allele Frequencies of the Single Nucleotide Polymorphisms Related to the Body Burden of Heavy Metals in the Korean Population and Their Ethnic Differences.

This study was performed to select single nucleotide polymorphisms (SNPs) related to the body burden of heavy metals in Koreans, to provide Korean allele frequencies of selected SNPs, and to assess the difference in allele frequencies with other ethnicities. The candidate-gene approach method and genome-wide association screening were used to select SNPs related to the body burden of heavy metals. Genotyping analysis of the final 192 SNPs selected was performed on 1,483 subjects using the VeraCode Goldengate assay. Allele frequencies differences and genetic differentiations between the Korean population and Chinese (CHB), Japanese (JPT), Caucasian (CEU), and African (YIR) populations were tested by Fisher’s exact test and fixation index (FST), respectively. The Korean population was genetically similar to the CHB and JPT populations (FST < 0.05, for all SNPs in both populations). However, a significant difference in the allele frequencies between the Korean and CEU and YIR populations were observed in 99 SNPs (60.7%) and 120 SNPs (73.6%), respectively. Ten (6.1%) and 26 (16.0%) SNPs had genetic differentiation (FST > 0.05) among the Korean-CEU and Korean-YIR comparisons, respectively. The SNP with the largest FST value between the Korean and African populations was cystathionine-β-synthase rs234709 (FST: KOR-YIR, 0.309; KOR-CEU, 0.064). Our study suggests that interethnic differences exist in SNPs associated with heavy metals of Koreans, and it should be considered in future studies that address ethnic differences in heavy-metal concentrations in the body and genetic susceptibility to the body burden of heavy metals.

Quick discrimination of heavy metal resistant bacterial populations using infrared spectroscopy coupled with chemometrics.

Lead and cadmium are frequently encountered heavy metals in industrially polluted areas. Many heavy metal resistant bacterial strains have a high biosorption capacity and thus are good candidates for the removal of toxic metals from the environment. However, as of yet there is no accurate method for discrimination of highly adaptive bacterial strains among the populations present in a given habitat. In this study, we aimed to find distinguishing molecular features of lead and cadmium resistant bacteria using Attenuated Total Reflectance-Fourier Transformed Infrared (ATR-FT-IR) spectroscopy and chemometric approaches. Our results demonstrated that both control and metal exposed E. coli and S. aureus strains could be successfully discriminated from each other using hierarchical cluster and principal component analysis methods. Moreover, we found that lead exposed bacterial strains could be successfully discriminated from cadmium exposed ones with a high heterogeneity value. These clear discriminations can be described by the ability of a bacterium to change its metabolism in terms of the content and structure of cellular macromolecules under heavy metal stress. In our case, cadmium and lead-induced genetic response systems in bacteria caused remarkable alterations in overall cellular metabolism. Bacteria deal with a heavy metal stress by altering nucleic acid methylations and lipid and protein synthesis. Heavy metal burden led to the development of relevant metabolic changes in proteins, lipids, and nucleic acids of the resistant bacteria described in this study. Our approach showed that infrared spectra obtained via ATR-FT-IR spectroscopy coupled with chemometric analysis can be utilized for rapid, low-cost, informative, reliable, and operator-independent discrimination of resistant bacterial populations.

A Study of the Possible Harmful Effects of Cosmetic Beauty Products on Human Health.

The origins of the usage of different substances in beauty, skin, body, hair, and nails care products can be found in ancient times. To achieve better quality and enhance their effects, some additives such as preservatives, stabilizers, mineral pigments, dye, and shine were added to these products. Some of these substances may also have allergic, irritating, and harmful effects on human health. The aim of this study was the optimization of the potentiometric stripping analysis (PSA) for the purpose of determining the content of heavy metals (lead, cadmium, zinc), in some commercial cosmetic beauty products (lipsticks, lip glosses, eye shadows, and henna hair dye). In addition, in order to monitor the potential adverse effects of henna dye on hair quality, as well as the total body burden of heavy metals (Pb, Cd), the paper analyzed hair samples before and after henna dye treatment. Beauty products used for cosmetic purposes can have adverse effects to human health due to the fact that they contain lead, a highly toxic metal. The lead content in the tested samples varied depending on the additives used along with the method of production. The cosmetic products that were analyzed in this study contained a certain amount of zinc, which is an essential element, although its content above the prescribed limit may lead to side effects. Highly toxic metal, cadmium, was not detected in the tested samples. The presence of these metals in cosmetic products certainly indicate that it is necessary to monitor and determinate the content of toxic heavy metals in these products, especially because they are in direct contact with skin or mucous membranes and are often used in daily life.

Monitoring of heavy metal burden in mute swan (Cygnus olor).

Concentrations of heavy metals (especially arsenic, cadmium, chromium, copper, mercury and lead) were measured in the contour (body) feathers of mute swans (Cygnus olor) and in its nutrients (fragile stonewort [Chara globularis], clasping leaf pondweed [Potamogeton perfoliatus], Eurasian watermilfoil [Myriophyllum spicatum], fennel pondweed [Potamogeton pectinatus]) to investigate the accumulation of metals during the food chain. The samples (17 feathers, 8 plants) were collected at Keszthely Bay of Lake Balaton, Hungary. Dry ashing procedure was used for preparing of sample and the heavy metal concentrations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Copper (10.24 ± 2.25 mg/kg) and lead (1.11 ± 1.23 mg/kg) were detected the highest level in feathers, generally, the other metals were mostly under the detection limit (0.5 mg/kg). However, the concentrations of the arsenic (3.17 ± 1.87 mg/kg), cadmium (2.41 ± 0.66 mg/kg) and lead (2.42 ± 0.89 mg/kg) in the plants were low but the chromium (198.27 ± 102.21 mg/kg) was detected in high concentration.

Heavy metal and trace element contents in edible muscle of three commercial fish species, and assessment of possible risks associated with their human consumption in Saudi Arabia

Three different highly consumed fish species from Al-Ahsa market, Saudi Arabia namely Spangled emporer (Lethriuns nebulosus), Red striped seabream (Pagrus major) and Black seabream (Spondyliosoma cantharus) were evaluated for their muscle contents of heavy metals (e.g., Cd and Pb) and trace elements (e.g., Cu, Zn, Fe and Mn). The possible risks associated with their human consumption were also studied. A total of 60 fresh fish samples comprising of 20 samples from each above mentioned fish were collected, and were subjected for determination of heavy metal and trace element contents by Atomic Absorption Spectrophotometry after Microwave Wet Digestion. The results showed that, accumulation patterns of the heavy metals and trace elements followed the order: Fe > Zn > Cu > Mn > Pb > Cd. There were variations among metal contents in the muscles of the three fish species; S. cantharus accumulated the highest levels of Cu, Zn and Mn, while the highest level of Fe could be detected in the muscles of P. major. The concentration of Cd and Pb remained comparable in the muscles of all three fish species. The calculated maximum daily intake (MDI) values were found as 0.0003, 0.0009, 0.0035, 0.0001, 0.0000, 0.0000 mg/day/person for Cu, Zn, Fe, Mn, Cd and Pb, respectively. Conclusively, the present study indicated that, fish muscles contain relatively less burden of heavy metals and trace elements, and no health problem can be raised from human consumption of the examined commercial fishes at Al-Ahsa market, Saudi Arabia.

The hooded crow (Corvus cornix) as an environmental bioindicator species of heavy metal contamination.

This study aims to examine the possible presence of lead and cadmium in the liver and kidneys of hooded crows (Corvus cornix). Liver and kidneys of hooded crow carcasses were collected in Province of Cuneo (Piedmont, Italy) in order to detect lead and cadmium content. Significant differences were found in lead and cadmium levels between areas of intensive cultivation versus areas where meadows are prevalent. Moreover, age greatly influenced the burden of heavy metals, while sex did not seem to affect the level of contamination. The source of contamination may be phosphate fertilizers used for intensive cultivation in the study area.

Detection and analysis of 12 heavy metals in blood and hair sample from a general population of Pearl River Delta area.

To detect the content of 12 heavy metals in blood and hair sample from a general population of Pearl River Delta area, and to analyze the influence of duration of residence, gender, age, smoking and drinking on the heavy metal content. Use inductively coupled plasma mass spectrometry to detect the content of 12 heavy metals lead (Pb), mercury (Hg), cadmium (Cd), aluminum (Al), arsenic (As), copper (Cu), chrome (Cr), manganese (Mn), nickel (Ni), zinc (Zn), tin (Sn) and antimony (Sb) in blood and hair samples of a total of 50 subjects from a general population, collected by multistage stratified cluster random sampling method. The geometric mean of heavy metal content in blood samples of general population (μg/L): blood aluminum 214.00; blood chrome 92.82; blood manganese 21.43; blood nickel 20.59; blood copper 0.67; blood zinc 11.50; blood arsenic 0.55; blood cadmium 2.45; blood tin 0.00; blood antimony 1.92; blood lead 158.84; and blood mercury 1.19. The geometric mean of heavy metal content in hair samples of general population (μg/g): hair aluminum is 84.65; hair chrome 0.00; hair manganese 2.44; hair nickel 0.61; hair copper 28.49; hair zinc 136.65; hair arsenic 0.75; hair cadmium 0.46; hair tin 1.04; hair antimony 0.05; hair lead 8.97; and hair mercury 0.69. Some heavy metals were correlated with duration of residence, gender, age, smoking and drinking. This was the first time that simultaneously detecting heavy metal content in blood and hair was used to analyze the internal heavy metal burden in resident population of Pearl River Delta area. These data can serve as reference for further research.

Effects of environmental levels of cadmium, lead and mercury on human renal function evaluated by structural equation modeling

A relationship between exposure to heavy metals, including lead and cadmium, and renal dysfunction has long been suggested. However, modeling of the potential additive, or synergistic, impact of metals on renal dysfunction has proven to be challenging. In these studies, we used structural equation modeling (SEM), to investigate the relationship between heavy metal burden (serum and urine levels of lead, cadmium and mercury) and renal function using data from the NHANES database. We were able to generate a model with goodness of fit indices consistent with a well-fitting model. This model demonstrated that lead and cadmium had a negative relationship with renal function, while mercury did not contribute to renal dysfunction. Interestingly, a linear relationship between lead and loss of renal function was observed, while the maximal impact of cadmium occurred at or above serum cadmium levels of 0.8μg/L. The interaction of lead and cadmium in loss of renal function was also observed in the model. These data highlight the use of SEM to model interaction between environmental contaminants and pathophysiology, which has important implications in mechanistic and regulatory toxicology.

The role of lead and cadmium in psychiatry.

Psychiatric disorders are associated with long-term disability and huge social and economic costs. The possible influence of heavy metals exposure on public health remains a matter of concern. A recurring research question that persisted among researchers in neuropsychiatry has been “are psychiatric patients more likely to have a high body burden of lead or other heavy metals?” This is an update account on the role of lead and cadmium in psychiatry. This review, which has employed search words like “lead and cadmium in psychiatry”, “lead and cadmium in schizophrenia”, “lead and cadmium in psychosis” in citation indices such as PubMed, Google Scholar, Scirus, and Scopus. A total of 415 articles were found; 60 fulfiled the inclusion criteria. Evidence-based information suggests that lead and cadmium may be involved in psychiatry. Should environmental lead and cadmium be implicated in the etiogenesis of psychiatry given the characteristic high environmental pollution in Sub Sahara Africa, it is worthwhile for toxicologists and scientists in Sub-Sahara Africa to investigate if lead and cadmium can become additional biomarkers in the diagnosis of psychiatric disorders.

Uptake of heavy metals by some edible vegetables irrigated using wastewater: a preliminary study in Accra, Ghana

The heavy metals (Fe, Zn, Pb, Ni, Cr, Co, and Cd) burden in wastewater, soil, and vegetable samples from a wastewater irrigated farm located at KorleBu, Accra has been investigated. Flame atomic absorption spectrometry after microwave digestion using a combination of HNO3, HCl, and H2O2 (for water), and HNO3 and HCl (for soil and vegetables). The mean concentrations (in milligrams per kilogram) of heavy metals in the soil samples were in the order of Fe (171 ± 5.22) > Zn (36.06 ± 4.54) > Pb (33.35 ± 35.62) > Ni (6.31 ± 8.15) > Cr (3.40 ± 3.63) > Co (1.36 ± 0.31) > Cd (0.43 ± 0.24), while the vegetables were in the order of Fe (183.11 ± 161.2) > Zn (5.38 ± 3.50) > Ni (3.52 ± 1.27) > Pb (2.49 ± 1.81) > Cr (1.46 ± 0.51) > Co (0.66 ± 0.25) > Cd (0.36 ± 0.15). The bioconcentration factors suggest environmental monitoring for the heavy metals as follows: Cd (0.828), Cr (0.431), Ni (0.558), Co (0.485), and Fe (1.067). Estimated daily intakes were very low for both children and adults except Fe (0.767mg/kg/day) in children. The population that consume vegetables from the study area were, however, estimated to be safe based on the results obtained from the health risk index, which were all < <1. The sodium absorption ratio according to FAO (1985) classifications indicate that the wastewater in the study area is unsuitable for irrigation purposes.

The transfer of heavy metals to barley plants from soils amended with sewage sludge with different heavy metal burdens

Purpose Our main aim objective was to evaluate the transfer of Cd, Cr, Cu, Ni, Pb and Zn to barley (Hordeum vulgare) grown in various soils previously amended with two sewage sludges containing different concentrations of heavy metals. This allowed us to examine the transfer of heavv metals to barley roots and shoots and the occurrence of restriction mechanisms as function of soil type and for different heavy metal concentration scenarios.

Gut microbiota limits heavy metals burden caused by chronic oral exposure

Environmental exposure to pollutants such as heavy metal(s) is responsible for various altered physiological functions which are detrimental for health. The gut microbiota is critical for intestinal homeostasis but its role on xenobiotic handling is not fully understood, especially when continuous sub-chronic exposure is addressed. We first confirmed the essential role of the intestinal microbiome to limit heavy metal body burden by using germ-free mice following 6-weeks oral exposure. Significant increases of cadmium and lead absorption and dissemination in blood and target organs were measured in germ-free mice when compared with conventional specific pathogen free (SPF) mice. Besides the “barrier” function of the luminal microbiota, this may involve specific host-genes such as metallothioneins, which are differentially expressed in the gastrointestinal tract of each group of mice. Considering genes relevant for divalent metal transporters and oxidative pathways, significant differences in basal gene expression were measured between control and germ-free mice. Moreover, the magnitude of induction of these genes upon stimulation by heavy metals varied greatly depending on the dose and type of metal as well as the microbial status of the animal. Collectively, these data illustrate the complex host-microbes interplay occurring with environmental pollutants inside the gut.

Heavy metal burdens of public primary school children in Ibadan north-west local government area, Nigeria related to playground soils and classroom dusts

Heavy metal burdens of public primary school children in Ibadan north-west local government area, Nigeria related to playground soils and classroom dusts

Heavy metals burden of Keenjhar Lake, District Thatta, Sindh, Pakistan

Detection of heavy metals (HMs) content from Keenjhar Lake water was carried out monthly from January to December, 2003. Zinc, chromium, copper, iron, manganese, nickel and cadmium were analyzed by dual mode of analytical methods flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry (FAAS and ETAAS) by multi element standard solution. The concentrations of zinc, chromium, copper, iron, manganese Nickel and cadmium were 1.4 to 104.3 μgL -1 , 1.28 to 4.9 μgL -1 , 0.6 to 7.3 μgL -1 , 2 to 45.6 μgL -1 , 0.2 to 6.7 μgL -1 , 3.54 to 39.5 μgL -1 and 1.0 to 4.3 μgL -1 , respectively. Zn 2+ , Cr + , Cu 2+ , Fe 2+ and Mn 2+ concentrations were recorded lower than those of permissible limits, whereas Ni + and Cd + were higher than those of permissible limits recommended by WHO (2004). Key words: Heavy metals, Keenjhar Lake, toxicity.

An investigation into the heavy metal burden of Akkulam–Veli Lake in south India

The heavy metal burden of Akkulam–Veli Lake, a shallow lake in southern part of India, is investigated through the analysis of surface sediments. The average concentrations of heavy metals such as lead, chromium, nickel, copper, zinc, cobalt, iron, and manganese were determined at selected stations. The degree of contamination of selected stations was evaluated using indices such as enrichment factor, contamination factor, and pollution load index and compared with sediment quality guidelines. Statistical analysis is carried out by correlation analysis and hierarchical clustering analysis to identify relatively homogeneous groups of cases. The results of this study indicate severe contamination at most of the stations selected. The degree of contamination of the lake could be rated as ‘moderate’ to ‘strong’. The average pollution load index shows progressive deterioration of sediment quality indicating ‘risk’ on the aquatic environment and ecosystems of the lake.

Water use efficiency and accumulation of trace elements in spinach (Spinacia oleracea L.) irrigated with municipal wastewater

The use of wastewater for irrigation is on the rise in developing countries like Pakistan, because of scarcity of good-quality irrigation water. Wastewaters contain plant nutrients that favor crop growth but leave a burden of heavy metals, which can enter the food chain, causing great concern. The present study was undertaken to investigate the effects of surface and subsurface wastewater irrigations on water use efficiency (WUE) and accumulation of trace elements (TE) in the shoots of spinach (Spinacia oleracea L.) grown on a soil column. Wastewater was applied at two levels based on daily pan evaporation (PE) (that is, 50 and 100%). Subsurface wastewater irrigation increased plant growth and WUE better than surface irrigation. Irrigation at 100% PE apparently reduced the WUE. However, WUE was enhanced by subsurface irrigation. Higher concentrations of TE were found in plants irrigated with 100% PE whether under surface or subsurface irrigation. Surface irrigation accumulated more TE in plants than subsurface irrigation. Slightly enhanced accumulation of TE was observed in the 2nd layer (30 to 60 cm) of the soil column under 100% surface irrigation. Subsurface irrigation gave higher concentrations of TE in the lower zone of the soil. Lower moisture was found in the top soil under both irrigation systems, but the middle soil layer had the highest electrical conductivity (EC). Irrigation with 100% PE increased EC more than 50% PE irrigation water. Surface irrigation with wastewater produced slightly greater pH than subsurface irrigation. Key words: Surface irrigation, subsurface irrigation, wastewater, spinach growth, trace elements.

Influence of Essential Trace Minerals and Micronutrient Insufficiencies on Harmful Metal Overload in a Mongolian Patient with Multiple Sclerosis

Parkinson's disease and other neurological disorders are prevalent in Mongolia. Our previous studies revealed a significant correlation of these diseases with high oxidative stress due to a high body burden of harmful metals, such as manganese, iron, lead, cadmium, and aluminum. This report describes a 37-year-old male Mongolian patient with multiple sclerosis and essential micronutrient deficiency. This patient demonstrated high oxidative stress, as shown by high urinary 8-hydroxy-2'-deoxyguanosine levels of 14.7 and 14.3 ng/mg creatinine (crea), although his hair levels of these toxic metals were markedly lower than other Mongolians. In addition, this patient was deficient not only in various essential minerals, including selenium, magnesium, copper, cobalt, vanadium, and nickel, but also in micronutrients such as vitamin B6, C, E, folic acid, niacin, and β-carotene. Furthermore, after taking 2,3-dimercaptosuccinic acid, a chelating agent, urinary excretion of lead, cadmium, manganese, aluminum, iron, copper, and lithium were increased 156-, 8.4-, 7.6-, 4.3-, 3.3-, 2.1-, and 2.1-fold, respectively. These results suggest that this patient suffered from a deficiency in micronutrients such as essential minerals and vitamins, which resulted in a disturbance in the ability to excrete harmful metals into the urine and hair. It is possible that a deficiency of micronutrients and a high burden of heavy metals play a role in the pathogenesis of multiple sclerosis. Nutritional treatment may be an effective approach to this disease.