Human Heavy Metal Research Articles

Assessment of ecological and public health risks associated with heavy metals on farmland in Wonosobo Regency, Indonesia

The deposition of metallic substances on farmland is of critical importance owing to its possible detrimental impacts on the surroundings and human wellness. Heavy metals can adversely affect the physicochemical properties of soil and plant health. Prolonged exposure to heavy metals in humans can lead to both carcinogenic and non-carcinogenic effects. The present research intended to determine the dispersion condition of toxic metals on cropland and assess the attendant environmental and health dangers in the Wonosobo Regency. This study used a soil sample survey encompassing 312 soil sampling sites. The completed analyses comprise geographical analysis, index of geo-accumulation (IG), contamination index (CI), Nemerow comprehensive contamination index (NCCI), risk analysis, and health risk analysis. The research findings reveal that cadmium material is the primary contributor to contamination from heavy metals in farmland in Wonosobo Regency, as shown by IG analysis. The CI and environmental hazards assessments suggest considerable pollution levels. Kids are more prone to illnesses than adults due to their daily intake amount, so it is necessary to pay more attention to the daily intake sources in children to minimize exposure to heavy metals.

A dual-ligand lanthanide-based metal-organic framework for highly selective and sensitive colorimetric detection of Fe2.

Accumulation of heavy metals in humans and mammals causes health problems due to their abundance as transition metal ions. Iron (Fe2+) serves significantly in numerous biological processes as a heavy metal ion. In this study, we have designed and prepared a metal-organic framework (MOF) utilizing a one-step solvothermal process, incorporating a dual-ligand combination of terephthalic acid (H2BDC) and α,α',α''-tert-pyridine (TPY) with Eu3+ as the metal node. For this MOF, we termed it Eu-BDC/TPY. Eu-BDC/TPY has superior selectivity over other metal cations. It provides an accurate, sensitive, broad linear range colorimetric method for detecting Fe2+ in a concentration range of 1-50 μM with a modest limit of detection (0.33 μM). Eu-BDC/TPY detects the absence of Fe2+ quickly (within 5 seconds), which is very valuable in practical applications. In addition, the results can be used to create a digital image colorimetric card (DIC) using colorimetric software, enabling instantaneous detection of Fe2+ concentration using a smartphone.

A combined method for human health risk area identification of heavy metals in urban environments

Multi-medium heavy metals pollution is a crucial pathway to destroy the urban environmental resources cycle. In this study, Nanjing of China, a typical mega city, was taken as the study area. Compared with other cities or countries, Cr, Cu and Zn in human nails and hair in the study area have higher concentration characteristics, while Cd and Pb have lower concentration characteristics. By combining the health risk status of heavy metals in soil and dustfall, the spatial clustering characteristics of heavy metals in soil dustfall and the concentration information of heavy metals in humans in the study area, a potential toxic risk area identification method based on soil-dustfall-human (SDB-HR) was established. Through Monte Carlo analysis, it’s found that the risk of Zn and Cr in soil-dustfall to human health is relatively high, with the probability of carcinogenesis reaching 51.2 % and 50.2 %, respectively. By the proposed method, different levels of heavy metal risk areas in urban environments can be more reasonably and effectively identified, which will provide important technical and theoretical support for the precise management of heavy metals in urban environments.

Metal Ions, Metal Chelators and Metal Chelating Assay as Antioxidant Method

Heavy metals are essential for a wide range of biological processes, including the growth and reproduction of cells, synthesis of biomolecules, many enzymatic reactions, and the body’s immunity, but their excessive intake is harmful. Specifically, they cause oxidative stress (OS) and generate free radicals and reactive oxygen species (ROS) in metabolism. In addition, the accumulation of heavy metals in humans can cause serious damage to different organs, especially respiratory, nervous and reproductive and digestive systems. Biologically, metal chelation therapy is often used to treat metal toxicity. This process occurs through the interaction between the ligand and a central metal atom, forming a complex ring-like structure. After metals are chelated with appropriate chelating agents, their damage in metabolism can be prevented and efficiently removed from the body. On the other hand, heavy metals, including Zn, Fe and Cu, are necessary for the suitable functioning of different proteins including enzymes in metabolism. However, when the same metals accumulate at levels higher than the optimum level, they can easily become toxic and have harmful effects toward biomolecules. In this case, it induces the formation of ROS and nitrogen species (RNS) resulting in peroxidation of biological molecules such as lipids in the plasma membrane. Antioxidants have an increasing interest in many fields due to their protective effects, especially in food and pharmaceutical products. Screening of antioxidant properties of compounds needs appropriate methods including metal chelating assay. In this study, a general approach to the bonding and chelating properties of metals is described. For this purpose, the basic principles and chemical principles of metal chelation methods, both in vivo and in vitro, are outlined and discussed. Hence, in the main sections of this review, the descriptions related to metal ions, metal chelating, antioxidants, importance of metal chelating in biological system and definitions of metal chelating assays as widely used methods to determine antioxidant ability of compounds are provided. In addition, some chemical properties, technical and critical details of the used chelation methods are given.

Assessment of some heavy metals in crude oil workers from Kurdistan Region, northern Iraq.

Heavy metal pollution in the environment has gained interest in the past few decades, as it has been found to accumulate in soil and water, as well as in the human body. Heavy metals present a serious health risk to humans when the concentration level and exposure time are increased. Although they have been extensively studied in the environment and food, little is known regarding their occurrence in the Kurdistan Region of northern Iraq. To fill this gap, we investigated the occurrence of some metals and heavy metals, namely aluminium (Al), barium (Ba), mercury (Hg), manganese (Mn), lead (Pb), vanadium (V) and zinc (Zn), in the blood of crude oil workers (40 men) who have worked in crude oil fields for at least 3 years-exposed group. In addition, a control group of 40 men was selected who have never worked or been close to crude oil fields. There is a significant correlation of metal concentrations between exposed and control groups, especially for Al, Ba, Hg, Mn and V (significant for all metals). Even though the correlation for Pb and Zn was weak, the concentrations were higher by 2-folds in the exposed group compared to the control group. Thus, the exposure caused an increase in the concentration of heavy metals by at least 1-fold in the blood of the exposed group compared to the control group. The environmental and ecotoxicological relevance of heavy metals in humans and the environment in areas with industrial activities have yet to be assessed.

Exposure assessment and safe intake guidelines for heavy metals in consumed fishery products in the Republic of Korea.

Heavy metals in food are non-intentional pollutants such as lead (Pb), cadmium (Cd), and mercury (Hg). Pb, a neurotoxic substance, is classified as a possible carcinogen for humans (group 2B) by the International Agency for Research on Cancer (IARC) under the World Health Organization (WHO). Cd, a substance that causes kidney damage, is classified as a substance that causes human cancer (group 1). In this study, inductively coupled plasma atomic emission spectrometry (ICP-AES) and a mercury analyzer (MA) were used to identify the concentrations of heavy metals (Pb, Cd, Hg) in fishery products and to assess the effects of chronic human exposure to heavy metals via fisheries consumption. Food consumption data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES 2010-2015), and the mean exposure concentrations for Pb, Cd, and Hg were 0.0067μg/kgbw/day, 1.1277μg/kgbw/month, and 0.0872μg/kgbw/week, respectively. Exposures to Pb, Cd, and Hg using the 95th percentile of the consumption data were 0.0183μg/kgbw/day, 4.0230μg/kgbw/month, and 0.2268μg/kgbw/week, respectively, corresponding to 3, 16, and 6% of the human exposure safety standard. Safe guidelines for the intake of fishery products are proposed to reduce the exposure to and accumulation of heavy metals in humans.

Astaxanthin as Potential Antioxidant Agent Protects from Accumulation of Heavy-metals in Brain

يتعرض البشر بشكل متزايد للمعادن الثقيلة من الغذاء والماء والدواء واللقاحات ومستحضرات التجميل. يتم ترسب سمية المعادن الثقيلة في البشر لفترة و التي ترتبط بعلاقات سببية محتملة بين عبء الجسم الثقيلة المعادن الثقيلة وعدد من الاضطرابات العصبية بما في ذلك مرض الزهايمر، باركنسون واضطرابات التوحد. هدفت هذه الدراسة إلى تقييم الخصائص المضادة للأكسدة لأستازانتين (أستا) لتحديد تأثير قدرة أستا التي تعطى عن طريق الفم لتقييم تراكم وسمية المعادن الثقيلة في دماغ الفئران. كما أنها تقيم ضد الإجهاد التأكسدي الناجم عن بيروكسيد الهيدروجين والخصائص المحتملة المضادة للأكسدة من أستا مع مقارنة التأثيرية من 5٪ و 10٪ من أستا في زيادة الانزيمات إعادة التدوير الجلوتاثيون (أكسدة غس). وقد لوحظ تغير كبير في زيادة الانزيمات الجلوتاثيون إعادة تدوير (غكس أكسدة) من الفئران وأظهرت تأثير وقائي ضد تراكم الألومنيوم (آل) في أنسجة المخ الفئران. وأظهرت نتائج هذه الدراسة في الجسم الحي أن أستا 10٪ يكون أكثر ارتباطا في تراكم وسمية الالمونيوم في الدماغ.

The Adverse Effects of Heavy Metals with and without Noise Exposure on the Human Peripheral and Central Auditory System: A Literature Review.

Exposure to some chemicals in the workplace can lead to occupational chemical-induced hearing loss. Attention has mainly focused on the adverse auditory effects of solvents. However, other chemicals such as heavy metals have been also identified as ototoxic agents. The aim of this work was to review the current scientific knowledge about the adverse auditory effects of heavy metal exposure with and without co-exposure to noise in humans. PubMed and Medline were accessed to find suitable articles. A total of 49 articles met the inclusion criteria. Results from the review showed that no evidence about the ototoxic effects in humans of manganese is available. Contradictory results have been found for arsenic, lead and mercury as well as for the possible interaction between heavy metals and noise. All studies found in this review have found that exposure to cadmium and mixtures of heavy metals induce auditory dysfunction. Most of the studies investigating the adverse auditory effects of heavy metals in humans have investigated human populations exposed to lead. Some of these studies suggest peripheral and central auditory dysfunction induced by lead exposure. It is concluded that further evidence from human studies about the adverse auditory effects of heavy metal exposure is still required. Despite this issue, audiologists and other hearing health care professionals should be aware of the possible auditory effects of heavy metals.

Concentrations of Heavy Metals in Hair and Nails of Young Pakistanis: Correlation with Dietary Elements

Hair and nail samples from young Pakistani adults were separately analyzed for quantification of Cd, Cr, Cu, Ni, Pb, and Zn concentrations. The concentrations of these metals were also analyzed in commonly consumed local foods to evaluate potential correlation of hair and nail concentrations with diet. Pearson correlation coefficients ranged from 0.349 to 0.999, demonstrating diet to be a significant contributor for accumulation of heavy metals in humans.

Chelating effect of leek (Allium tuberosum Rottler ex Sprengel) containing chlorophyll on Cd, Pb, and As

Effect of leek (Chinese chive) on bioaccessibility of arsenic (As), cadmium (Cd), and lead (Pb) was determined in comparison with sodium copper chlorophyllin (SCC) using in vitro digestion model. Leek (0, 6, 12, 60, and 120 mg) and SCC (0, 1, 5, 10, and 50 mg) were digested with equal concentration (10 ppm) of As, Cd, and Pb. Concentration of each heavy metal in aqueous phase following in vitro digestion was measured using an inductively coupled plasma optical emission spectrometer. Changes in absorbance spectra of chlorophyll extracted from leek and SCC by heavy metals were measured at 0, 1, 2, and 3 h after mixing. Results showed that the concentration of each heavy metal in aqueous phase decreased with increasing amounts of leek and SCC. At the highest level of leek (120 mg), the concentrations of As, Cd, and Pb decreased to 93.9, 87.1, and 58.2%, respectively. Absorbance of chlorophyll drastically decreased after 1 h of mixing with each As, Cd, and Pb, and no difference in the absorbance was observed after 2 and 3 h. This result indicates that mixing chlorophyll extracted from leek with each heavy metal for 1 h was sufficient for chelating As, Cd, and Pb ions. On the other hand, SCC and each heavy metal showed a decreasing pattern of absorbance without any significant difference for 3 h, indicating that chlorophyll from leek was more effective than SCC, a commercial grade chlorophyll derivative, in chelating As, Cd, and Pb. Results showed leek reduces heavy metals in humans.

Bioaccumulation of Heavy Metals in Fish Species Collected From Former Tin Mining Catchment

This study has been carried out to determine the accumulation of heavy metals (arsenic, copper, lead, tin and zinc) in fish samples collected from former tin mining catchment. Total eight types of fish family having fifteen different species are identified. Cyperinidae is the most abundant family with eight different species found in the catchment. Fish samples were analysed by using inductively coupled plasma optical emission spectrophotometer ICP-OES. The accuracy of method is validated by certified reference material. The highest level of arsenic was observed in Hampala macrolepidota while Osteochilus hasselti shows the least. For Copper concentrations, the maximum was obtained in Mastacembelus armatus and the minimum in Oxyeleotris marmorata. High levels of lead, tin and zinc were found in the Rasbora elegans, Trichogaster trichopterus, Oxyeleotris marmorata respectively while Macrobrachium resenbergii,Mastacembelus armatus, Rasbora elegans had the least concentrations. The sequence of order of the heavy metals measured was Sn > Pb >Zn > Cu> As, respectively. The results showed elevated levels of tin, led and zinc in all the fish samples although copper and arsenic were available in relatively low concentration in the most samples. Sn, Pb, and Zn concentration in the samples were greater than Malaysia food act permissible levels. Hazard index 1 suggests the probability of adverse health effects. Although the heavy metals anal ysed in the catchment did not pose any immediate health risk to humans but due to thebioaccumulation and magnification of these heavy metals in humans, it is essential to safeguard levels of the metals in the environment.

English

Significant number of occupations are present in our society which involves metal pollution. These small operational occupations which are always neglected by governments and other occupational health services are another major factor of metal flow in urban soil. The local auto body refinishing shops are one of these occupations. Workers, soil, plants, air and all environments around these shops are continually exposed by their organic solvents, dust, noise and metal pigments. In the present study, 36 top soil samples including controls were collected from 26 different auto body refinishing shops of the metropolitan city, Karachi. The soil samples were digested by EPA method 3050. The metal contents Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn were analyzed by Atomic Absorption Spectrometery (AAS). The results showed that metal contents in soil samples around auto body shops were mainly contaminated due to the exposure of metal pigments. The silent increase in metal concentration in soil samples may contribute to the accumulation of heavy metals in humans and livestocks through soils and plants which will grow in these areas. The statistical methods of analysis were also applied to find out the t-values, p-values and correlation parameters. The Principal Component Analysis (PCA) was also applied to increase the significance of results. Keywords : Metal pollution, occupational health services, heavy metals, livestock

Monitoring exposure to heavy metals among children in Lake Victoria, Kenya: Environmental and fish matrix

This study used hair and nails to biomonitor heavy metals (Pb, Cd, Cr and Cu) from geological source and exposure through regular fish consumption among children in Lake Victoria, Kenya. Concentration of Pb and Cu in water reflected anthropogenic pathways, while Cd and Cr reflected accumulation from the catchment basin. Higher concentration of heavy metals in the nails samples than the hair samples suggested longer term exposure. The estimated intake of Cd and Cr from fish in one site associated with high concentration of the metals from geological source was appreciably above the respective recommended daily allowance, signifying possible health risks to humans. Significant correlations between Pb, Cd and Cu in hair, nails and heavy metals from fish consumed suggested fish consumption as possible pathway of heavy metals in humans. Possible health risks from heavy metals were likely due to consumption of higher quantities of fish and from geological basins.

Heavy Metals Modulate Glutamatergic System in Human Platelets

Research strategies have been developed to characterize parameters in peripheral tissues that might easily be measured in humans as surrogate markers of damage, dysfunction or interactions involving neural targets of toxicants. The similarities between platelet and neuron may even be clinically important, as a number of biochemical markers show parallel changes in the central nervous system (CNS) and platelets. The purpose of our research was to investigate the effect of Hg(2+), Pb(2+) and Cd(2+) on the [(3)H]-glutamate binding and [(3)H]-glutamate uptake in human platelets. The involvement of oxidative stress in the modulation of glutamatergic system induced by heavy metals was also investigated. The present study clearly demonstrates that Hg(2+), Cd(2+), and Pb(2+) inhibited [(3)H]-glutamate uptake in human platelets. Hg(2+) inhibited [(3)H]-glutamate binding, while Cd(2+) and Pb(2+) stimulated [(3)H]-glutamate binding in human platelets. Hg(2+), Cd(2+) and Pb(2+) increased lipid peroxidation levels and reactive oxygen species (ROS) measurement in platelets. The present limited results could suggest that glutamatergic system may be used as a potential biomarker for neurotoxic action of heavy metals in humans.