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Most of Africa's illegal mining operations are conducted in rural areas, but along the Red Sea coast, they primarily occur in the Eastern Desert, where they are regarded as the major source of revenue. Soil samples were collected and examined at an illegal gold mining site in the far south of Egypt's Eastern Desert to determine the toxicity levels of eight heavy metals for pollution load index (PLI), Igeo, and health (Au, Ag, As, Hg, Ni, Cr, Zn, and Pb). The methodology used in this study was categorized into fieldwork with restricted rules within the visit, soil samples collected from the field, chemical analyses for heavy metals, and statistical analyses by applying six equations to define the environmental status of the study area. It was found that the PLI increases contamination as an environmental risk grade, Igeo, reaches grade 6, which is highly contaminated, and the average hazard index (HI) for the individual elements is high (>0.01). The health risk assessment results for Ni and Cr showed that oral intake was the main mode of exposure to heavy metals in the tailings of illegal mines. In addition, the average levels of As, Hg, Cr, Ni, Pb, and Zn were higher than the equivalent background levels for soils. Thus, adult cancer risk (CR) exceeds the permissible level of 10−4. The illicit mining activities in the Eastern Desert also resulted in heavy metal contamination with substantial noncarcinogenic hazards for As and Zn, necessitating urgent remediation. [ABSTRACT FROM AUTHOR]

This study investigated the impact of soil type, pH, and geographical locations on the accumulation of arsenic (As), lead (Pb), and cadmium (Cd) in rice grains cultivated in Ghana. One hundred rice farms for the sampling of rice grains and soil were selected from two regions in Ghana—Volta and Oti. The concentrations of As, Pb, and Cd were analyzed using ICP-OES. Speciation modeling and multivariate statistics were employed to ascertain the relations among measured parameters. The results showed significant variations in soil-As, Pb, and Cd levels across different soil types and pH ranges, with the highest soil-As and Cd found in alkaline vertisols. For soil-As and Cd, the vertisols with a pH more than 7.0 exhibited the highest mean concentration of As (2.51 ± 0.932 mgkg-1) and Cd (1.00 ± 0.244 mgkg−1) whereas for soil-Pb, the luvisols of soil types with a pH less than 6.0 exhibited the highest mean concentration of Pb (4.91 ± 1.540 mgkg−1). Grain As, Pb, and Cd also varied across soil types and pH levels. In regards to grain-As, the vertisols soil type, with a pH less than 6.0, shows the highest mean concentration of grain As, at 0.238 ± 0.107 mgkg−1. Furthermore, vertisols soil types with a pH level less than 6.0 showed the highest mean concentration of grain Cd, averaging at 0.231 ± 0.068 mgkg−1 while luvisols, with a pH less than 6.0, exhibited the highest mean concentration of grain Pb at 0.713 ± 0.099 mgkg−1. Speciation modeling indicated increased bioavailability of grains Cd2+ and Pb2+ ions in acidic conditions. A significant interaction was found between soil-Cd and pH, affecting grain-As uptake. The average concentrations of soil As, Pb, and Cd aligned with international standards. Generally, the carcinogenic metals detected in grain samples collected from the Volta region are higher than that of the Oti region but the differences are insignificant, and this may be attributed to geographical differences and anthropogenic activities. About 51% of the study area showed a hazard risk associated with grain metal levels, although, no carcinogenic risks were recognized. This study highlights the complex soil-plant interactions governing metal bioaccumulation and emphasizes the need for tailored strategies to minimize metal transfer into grains. [ABSTRACT FROM AUTHOR]

The rivers are severely contaminated by human activities due to its massive outflow and industrial effluents. Three economically significant fish species Sperata seenghala, Wallago attu, and Cyprinus carpio from the river water were selected for the assessment of heavy metals (HMs). The edible part of the collected fish from the river sampling sites were analyzed to determine the metal concentrations and potential health risks to humans. The Atomic Absorption Spectroscopy (AAS) technique was used to measure HMs including lead (Pb), chromium (Cr), and copper (Cu) for both water and fish samples. Order of HMs in the fish was found as Pb > Cd > Cr. Levels of HMs in all species were found higher than the European Commission (EC) recommended acceptable levels. The metal pollution index (MPI) indicates that W. attu and S. seenghala, two highly consumed fish species, have accumulated HMs in higher concentrations. Wallago attu has the highest bioaccumulation factor (BAF) for both Pb and Cd permissible levels. For adult and children, the Hazard Index (HI) and Targeted Hazard Quotient (THQ) values were less than 1, which indicated that there would be no non-carcinogenic health consequences. Carcinogenic risk (CR) exposure to Pb, Cd, and Cr for all consumers was found to be higher than the permitted limit (10−6-10−4), while children were found more vulnerable than adults in terms of CR values. The study findings identified several sources of contaminants in the area, including agricultural waste, lubricant usage, and electroplating material production dumping near into the river water. Based on the results of the analysis, metal concentrations exceeded the thresholds for carcinogenic health risks, indicating that fish from the area are generally unsafe to consume. Therefore, immediate action must be taken to reduce or prevent the discharge of contaminants into the river. Additionally, regular monitoring of the river's water quality should be conducted to control the contamination of water.

Heavy metal pollution in agricultural soil is a threat to people's health and sustainable development. However, there is currently no nationwide health risk assessment in China. In this study, we performed a preliminary assessment of heavy metals in agricultural soils of the Chinese mainland, and found obvious carcinogenic risks (total lifetime carcinogenic risk (TLCR) > 1 × 10–5). A similar spatial distribution pattern was found in soil heavy metal and the mortality of esophagus and stomach cancers. Combining the potential carcinogenic risk assessed by LCR for individual heavy metal with Pearson correlation, Geographical Detector (q statistic > 0.75 for TLCR, p < 0.05), and redundancy analysis (RDA), it was found that long-term exposure and intake route of heavy metals exceeding the maximum safety threshold (Health Canada standard) may induce digestive system (esophagus, stomach, liver, and colorectum) cancers in rural populations. Through Partial Least Squares Path Model (PLS-PM), it was also revealed that the LCR of heavy metals was closely related to the soil environmental background (path coefficients = 0.82), which in turn was affected by factors such as economic development and pollution discharge. The current research results highlight the potential carcinogenic risk to the digestive system associated with low-dose and long-term exposure to heavy metals in agricultural soils, and policymakers should propose countermeasures and solutions according to the local conditions. [ABSTRACT FROM AUTHOR]

Landfill area is one of developing countries' most common anthropogenically contaminated sites. The pressure of urbanization has led to increased waste generation in major cities, commonly deposited in landfills; hence, heavy metals contaminations are closer to the human environment than ever. The study assessed the environmental risk of Arsenic (As), Cadmium (Cd), Zinc (Zn), Manganese (Mn), Copper (Cu), Colbat (Co), Cranium (Cr), Nickel (Ni), and Lead (Pb) in an abandoned landfill system and health-related risk using United State Environmental Protection Agency model. The Concentration of the elements descended as follows; Mn > Zn > Cr > Pb > Cu > Ni > Co > As > Cd and exceeded the WHO permissible limit. The Enrichment factor (EF) and potential ecological risk (ER) indicated no enrichment and low risk for all the elements except Cd (3.67, 426), with moderate enrichment and very high ecological risk. The hazard index (HI) value of the elements indicated no significant risk of non-carcinogenic effect for both Adults and Children except for Mn in Children with a value of 1.69 × 100; however, the HI value of the elements descended as; Co > Mn > Zn > As > Cd > Cu > Pb > Ni > Cr for adult and Mn > Cd > Co > Cr > As > Zn > Pb > Cu > Ni for children. The total carcinogenic risk (TCR) value of the toxic metals descended as Ni > Cd > Cr > As > Pb for both adults and Children, while the metals showed no carcinogenic to acceptable risk to humans. The Principal Component Analysis (PCA) indicated that the metals have similar sources and distribution which could be both lithogenic and anthropogenic influenced. Engaging the environment through sustainable practices will ensure efficient waste disposal and management.

One of the consequences of landfill systems is the emission of leachate, which is capable of causing contamination of the surrounding environment, including groundwater. Considering three major abandoned landfills in an urban area in Nigeria, the potential environmental pollution due to leachate generated from landfills and human health risk assessment of nearby groundwater were examined using laboratory standards (APHA 2012). The result revealed that the landfills' leachate pollution index (LPI) is 18.84, 19.57, and 19.66, indicating potential pollution of the environment, including groundwater and soil. Conformity of groundwater indicated that Arsenic (Ar-0.0001), Cadmium (Cd-0.002), Zinc (Zn-0.02), Barium (Ba-0.03), Manganese (Mn-0.05), Copper (Cu-0.02, 0.012), Chromium (Cr-0.006, 0.007), and Cobalt (Co-0.03, 0.015) are within the WHO permissible limit while Nickel (Ni-0.06) and Lead (Pb-0.05) exceeded the permissible limit. Using the USEPA model for human health risk assessment, the Total Hazard quotient (THQ) for ingestion and derma exposure indicated that the heavy metals have ≤1 across the three landfills, indicating that the exposed population experience no significant health risk. The THQ trended as Cd>Co>Zn>Ba>Mn>Cu>Cr>Ni>As>Pb for children across all the landfills. The estimation for Total Carcinogenic Risk (TCR) for carcinogenic metals (As, Cd, Cr, Ni, and Pb) from various landfill indicated no carcinogenic risk (TCR

The occurrence of some carcinogenic metals; Cu, Ni, Pb and Cd was investigated in sediment samples collected from 12 stations at Great Bitter and Timsah lakes. In the same time, two of the most famous edible bivalve species (Ruditapes decussatus and Paratapes undulatus) live buried in these sediments were chosen for measuring the same metals within their edible tissues in order to investigate the permissibility limits for human consumption. The bio-available forms of these metals were measured in the bulk sediments and the finest fractions (Ø3, Ø4 and Ø5) and in the edible tissues (flesh) of the selected bivalve individuals using a flame atomic absorption spectrophotometer (AAS). The finest fraction (Ø5) recorded the highest averages of most carcinogenic metals at Great Bitter and Timsah lakes with significant occurrences of Cd at both lakes. Carcinogenic Cd in the edible tissues of P. undulates and R. decussatus showed neglected low contents at the Great Bitter and Timsah lakes in spite of its very high contents in the surrounding sediment layer. Ni, Cu, and Pb averages in the edible tissues of P. undulates at the Great Bitter lake were 1.32, 0.23 and 0.37 μg/g wet wt. respectively. The averages of Ni, Cu and Pb in R. decussatus at Timsah Lake, were; 1.30, 0.24 and 0.95 μg/g wet wt. and in P. undulates were; 0.79, 0.14, and 1.15 μg/g wet wt. respectively. Bio-sediment accumulation factor (BSAF) in the different bivalve species at the Great Bitter and Timsah lakes were much lower than unity (<<<1.0) indicating that the bivalves tend to accumulate their needs only from the surrounding environment. Finally, the investigated metals in the edible tissues of the different bivalve species are within the permissible safe limits for human consumption except for Pb that exceeds these limits and showed a slight hazard to health risk. [ABSTRACT FROM AUTHOR]

• Green and efficient adsorbent, CeO 2 NPs were synthesized by azadirachta indica leaf extracts. • CeO 2 NPs exhibits good characterization attributes and efficient for Cr and d removal from wastewater. • Kinetic modeling, isotherm models were suitable for chemisorption of NPs for the removal of these metals. • The green CeO 2 NPs have a potential adsorbent for Cr and Cd removal from wastewater. Chromium and cadmium are two hazardous heavy metals that are known carcinogens and can cause a range of health problems as well as changes in the regular functioning of the environment. Green nanotechnology has sparked a lot of attention in recent years as a potential solution to heavy metal concerns. Because of their unique chemical, physical, and biological properties that make them favorable for a wide range of uses, application of cerium oxide nanoparticles (CeO 2 NPs) has gained in popularity. CeO 2 NPs have a larger surface area than larger particles, leading in improved biochemical reactivity, catalytic activity, and environmental effectiveness. In this study, CeO 2 NPs were made from green procedure by the use of plant extract from Azadirachta indica. The stat of the art techniques were utilized to study the physical characteristics of the synthesized CeO 2 NPs. These nanoparticles were utilized as bio-sorbents to extract chromium (Cr) and cadmium (Cd) ions from wastewater. In standard testing conditions, the CeO 2 nanoparticles exhibited high removal efficiency, removing 93% of Cr within approximately 15 min of contact time, and achieving 89% removal of Cd. To acquire the best results for industrial-scale applications and to simplicity the reuse of these heavy metals, exact experimental conditions that improve the absorbance efficiency must be identified. Despite the fact that nanoparticles have demonstrated great efficiency and selectivity in extracting and recovering chromium from wastewater, further study is needed to optimize their production and performance for industrial-scale applications. [ABSTRACT FROM AUTHOR]

Highlights • The study provides the reference values for thirteen trace elements in the urine of the Italian general population. • No Italian data are currently available for establishing urinary reference values for a large number of elements. • Six different laboratories carried out the analysis after interlaboratory control tests were performed on urinary samples. • The results have been reported in micrograms/L and in micrograms/g creatinine. • To evaluate the modification of urinary metals over time a larger number of subjects should be enrolled for biomonitoring. Abstract The purpose of this study of the Italian Society of Reference Values (SIVR) was to provide the reference values for metals in the urine of the Italian general population. Thirteen sampling centres situated in the north, centre and south of Italy took part in this project. Each sampling centre selected 20 adult subjects. The sample was made up of 120 male and 140 female non-smokers or smokers who had abandoned the habit at least 5 years previously, aged between 18 and 60 years. Urine samples were obtained from the same subjects in June and again in November of the same year. During collection of these two samples, we administered an ad hoc questionnaire designed to assess factors that might influence exposure and the results of the study such as personal characteristics, occupational or extra-occupational activities, dietary habits, the presence of dental fillings containing amalgam, the frequency and mode of exposure to passive smoking and exhaust gases of motor vehicles (traffic). Therefore, the urinary levels of thirteen trace elements (Be, Cd, Co, Cr, Cu, In, Mn, Ni, Pb, Pt, Sb, Tl and V) were determined by Inductively Coupled Plasma Mass Spectrometry. The concentrations obtained (95th percentile) are in μg/L: 0.034, 0.900, 2.24, 0.600, 24.0, 0.013, 1.53, 4.44, 2.64, 0.022, 0.095, 0.759 and 0.855 for Be, Cd, Co, Cr, Cu, In, Mn, Ni, Pb, Pt, Sb, Tl and V, respectively. Further studies with a larger number of subjects are needed in order to continue the biomonitoring of the Italian general population and to monitor the modified levels over time. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the concentration of PM2.5 particles, potential sources, and determination of health risk assessment of heavy metals in various parts of composting facilities of Tehran’s Kahrizak. A total of 60 PM2.5 particle samples were collected every 3 days from January to March 2016. To analyze the heavy metals, inductively coupled plasma atomic emission spectroscopy (ICP-AES) was applied. SEM-EDX analysis indicated that metals of Al, Si, Mg, Na, Au, S, Ca, K, and Co were dominant in the structure of particles. The concentration of PM2.5 was found to be the highest in the final processing site (c), followed by primary processing site (a) and the aerated site (b). The mean concentrations of Al and Fe in all sampling sites of a, b, and c were 7.46 ± 2.73, 1.48 ± 0.59, 24.30 ± 8.23 μg/m3 and 4.97 ± 2.83, 1.33 ± 0.48, 16.48 ± 7.36, respectively. The enrichment factor order of the trace elements was as follows: Cd > As > Pb > Zn > Cu > V > Cr > Ni > Mn > Fe > Al, with the highest EF value exceeding 10,000 for Cd at the a site. For all sampling sites in composting facilities, the cancer risk was more than > 1 × 10−4 as posed by the total of five carcinogenic metals (Pb, Cr, As, Ni, and Cd), indicating that risk factors were not negligible. [ABSTRACT FROM AUTHOR]

This paper presents a detailed study on the indoor air pollution in the Jokahng Temple at Tibet Plateau, and its implication to human health. The mean concentrations of PM 1.0 and PM 2.5 were 435.0 ± 309.5 and 483.0 ± 284.9 μg/m 3 , respectively. The PM 2.5 concentration exceeded the National Ambient Air Quality Standard (75 μg/m 3 ) by 6.4 times. The size-segregated aerosols displayed a bimodal distribution. One peak was observed in the fine mode (0.4–2.1 μm) and the other peak appeared in the coarse mode (2.1–9.0 μm). The concentration of the total size-resolved PM was 794.3 ± 84.9 μg/m 3 . The mass fraction of coarse particles shared by 41.1%, apparently higher than that reported at low altitudes, probably due to incomplete combustion at Tibet Plateau with hypoxic atmospheric environment. The total concentration of polycyclic aromatic hydrocarbons (PAHs) was 331.2 ± 60.3 ng/m 3 , in which the concentration of benzo(a)pyrene (BaP) was 18.5 ± 4.3 ng/m 3 , over ten times higher than the maximum permissible risk value of 1 ng/m 3 on account of carcinogenic potency of particulate PAHs through inhalation. PAHs exhibited a trimodal distribution, of which two peaks were observed in the fine mode and one peak in the coarse mode. With the aromatic rings increasing, the peak intensity increased in the fine mode. Na, Ca, Al, Mg and K dominated the elemental mass profiles, and metals displayed a bimodal distribution with a dominant peak in the coarse range. The total PAH deposition flux was 123.6 and 53.1 ng/h for adults and children, respectively. Coarse particles contributed most deposition flux in the head region, while fine particles contribute most deposition flux in the alveolar region. The increment lifetime cancer risk (ILCR) of PAHs ranaged at 10 −5 -10 −4 , indicating potential cancer risk to human health. The total deposition flux of metals was estimated at 1.4–13.2 ng/h. With the size increasing, deposition flux increased in the head region while decreased in the alveolar region. The highest ILCR of Cr and Ni were 4.9 × 10 −5 and 1.5 × 10 −6 , respectively, exceeding the permissible risk of 10 −6 . The hazard quotient (HQ) of Fe (10 −5 -10 −4 ) and Zn (10 −6 -10 −5 ) were much lower than the safe level of 1.0, and thus they were not considered as a health concern. [ABSTRACT FROM AUTHOR]

The concentrations of heavy metals (Cr, Cd, Ni, and Pb) were investigated in sediment and cyprinid fish (Capoeta razii) from Telar River, Iran in spring, summer, and autumn. Mean concentration of metals in fish and sediment over the seasonal sampling was as follows: Cr > Ni > Pb > Cd. Metal deposition in sediment was higher than their bioaccumulation in fish tissue. Unlike sedimentary metals, the tissue-content of Pb and Cr varied seasonally. Enrichment Factor (EF) values of Cr and Ni showed partial enrichment, implicating the role of anthropogenic inputs, while Pb was derived from natural weathering. When considering Pollution Load Index (PLI), an uneven temporal and spatial distribution of contamination was observed in sediment with moderate contamination level in spring and summer and no pollution in autumn. Tissue-contents of Pb, Cr, and Cd were below permissible limits while a higher risk level of Ni was noted for human consumption. • The order of mean metal concentration in fish and sediment was Cr > Ni > Pb > Cd. • Unlike sedimentary metals, the tissue content of Pb and Cr varied seasonally. • Cr and Ni originated from anthropogenic inputs. • Tissue contents of Ni showed a dangerous level for human consumption. • Sediment was moderately polluted in spring and summer, but not polluted in autumn. [ABSTRACT FROM AUTHOR]

Analysis of occupational exposure to welding fumes is based on determination of inhalable and respirable fractions of dust and its chemical components. Such measurement does not reflect the actual exposure because it does not include significant parameters related to particle sizes, especially the ultrafine. The study was aimed at investigating exposure to welding fumes containing metals and fine and ultrafine particles. The studies were carried out at two metal industry plants during stainless steel and mild steel welding. Stationary samples of welding fumes were collected for evaluation of morphology and structure of fluids, using scanning electron microscope (SEM) and energy dispersive spectrometry (EDS). Individual samples were collected from welders inhalable breathing zones to determine the concentration of iron (Fe), manganese (Mn), nickel (Ni), chromium (Cr + 6 and Cr + 3 ) and their compounds in inhalable and respirable fractions, using flame absorption atomic spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) techniques. The results indicate that stainless steel welders were capable of producing fumes containing carcinogenic and neurotoxic metals with concentrations exceeding Limit Values (LV). [ABSTRACT FROM AUTHOR]

Objective: To examine maternal and fetal exposure levels to four carcinogenic metals, arsenic (As), cadmium (Cd), nickel (Ni), and beryllium (Be), and to investigate their environmental influences. Methods: Metal concentrations in maternal and umbilical cord blood were measured by inductively coupled plasma-mass spectrometry (ICP-MS). Environmental factors that might play a role in exposure were analyzed using Mann-Whitney nonparametric U-tests and multiple linear regression. Results: The concentrations of As, Cd, and Ni in umbilical cord blood (5.41, 0.87, and 139.54 μg/L) were significantly lower than those in maternal blood (6.91, 1.93, and 165.93 μg/L). There were significant positive correlations between the maternal and cord concentrations of each carcinogen. Our results showed that: (i) exposures to potentially harmful occupational factors during pregnancy were associated with high levels of maternal As, Cd, and Ni; (ii) living close to major transportation routes (<500 m) or exposure to second-hand smoke during pregnancy increased the maternal Cd levels and (iii) living close to industrial chimneys induced high maternal Ni levels. Multiple linear regression analysis showed that these environmental factors remained significant in models of the influences of these four carcinogens. Conclusion: Both mothers and fetuses had been exposed to As, Cd, Ni, and Be. The increased levels of these carcinogens in pregnant women were associated with some detrimental environmental factors, such as occupational exposure, contact with second-hand smoke and living close to major transportation routes or industrial chimneys. [Copyright &y& Elsevier]

Mechanisms of carcinogenicity are discussed for metals and their compounds, classified as carcinogenic to humans or considered to be carcinogenic to humans: arsenic, antimony, beryllium, cadmium, chromium, cobalt, lead, nickel and vanadium. Physicochemical properties govern uptake, intracellular distribution and binding of metal compounds. Interactions with proteins (e.g., with zinc finger structures) appear to be more relevant for metal carcinogenicity than binding to DNA. In general, metal genotoxicity is caused by indirect mechanisms. In spite of diverse physicochemical properties of metal compounds, three predominant mechanisms emerge: (1) interference with cellular redox regulation and induction of oxidative stress, which may cause oxidative DNA damage or trigger signaling cascades leading to stimulation of cell growth; (2) inhibition of major DNA repair systems resulting in genomic instability and accumulation of critical mutations; (3) deregulation of cell proliferation by induction of signaling pathways or inactivation of growth controls such as tumor suppressor genes. In addition, specific metal compounds exhibit unique mechanisms such as interruption of cell–cell adhesion by cadmium, direct DNA binding of trivalent chromium, and interaction of vanadate with phosphate binding sites of protein phosphatases. [ABSTRACT FROM AUTHOR]

Abstract: Epidemiological and experimental animal data indicate that exposure to both metals and metalloid species exacerbates the risk of human diseases, particularly cancers. Vascular endothelial growth factor (VEGF), which performs a primary function in both tumor progression and angiogenesis, is up-regulated due to exposure to an array of carcinogenic metals, but the mechanisms responsible for the metal activation remain somewhat poorly understood. Recently, we demonstrated that AMP-activated protein kinase (AMPK), which acts as an energy sensor, providing metabolic adaptation effects under ATP-deprived conditions, is critical for the expression of VEGF under oxygen- and glucose-deprived conditions. As carcinogenic metals are potent VEGF expression inducers, we hypothesized that AMPK would also play a crucial role in metal-induced VEGF expression. Here, we present evidence that carcinogenic metals such as arsenite, vanadate, and cobalt, induce AMPK activation and VEGF expression via several different mechanisms, and that AMPK is able to regulate the expression of VEGF mRNA in a hypoxia-inducible factor-1-dependent or -independent manner, depending on the metal applied. We also attempted to characterize the relevant signal transduction pathways in metal-induced VEGF expression and AMPK activation, as well as the role of reactive oxygen species within this context. Overall, our data suggest that AMPK is a critical regulatory component in metal-induced VEGF expression, which further implies its intrinsic involvement in metal-induced carcinogenesis. [Copyright &y& Elsevier]

Six metals and/or their compounds have been recognized as carcinogens: arsenic, beryllium, cadmium, chromium, cobalt and nickel. With the exception of arsenic, the main rote of exposure is inhalation and the main target organ is the lung. Arsenic is exceptional because it also produces tumors of skin and lung after oral uptake. With the exception of hexavalent chromium, carcinogenic metals are weak mutagens, if at all, and their mechanisms of carcinogenicity are still far from clear. A general feature of arsenic, cadmium, cobalt and nickel is their property to enhance the mutagenicity and carcinogenicity of directly acting genotoxic agents. These properties can be interpreted in terms of the ability of these metals to inhibit the repair of damaged DNA. However, because carcinogenic metals cause tumor development in experimental animals even under exclusion of further carcinogens, other mechanisms have to be envisaged, too. Evidence will be discussed that carcinogenic metal compounds alter patterns of gene expression leading to stimulated cell proliferation, either by activation of early genes (proto-oncogenes) or by interference with genes downregulating cell growth. Special reference will be devoted to the effects of cadmium and arsenic on gene expression, which have been studied extensively. Possible implications for occupational safety and health will be discussed. [Copyright &y& Elsevier]

T he goal of the study wasto evaluate the usefulness of metallothionein mRNA, anti-5- hydroxymethyl-2'-deoxyuridine antibodies titres (anti-HMdU Ab), and 8-hydroxydeoxyguanosine (8OHdG) in urine as markers of the biologically active dose after exposure to airborne cadmium and nickel in human studies. Exposed persons (n = 38) were chosen from workers involved in the production and assembly, chemistry, and maintenance departments of a nickel-cadmium battery factory in Poland. Controls ( n = 52) were chosen from administration personnel at the factory. Biological samples from workers were collected twice: once in the summer, after a month of vacation, and again in the winter, after 3 months of regular working activity within the plant. Controls were recruited during the second phase of the study. When exposure groups were defined on the basis of ambient air cadmium measurements, we found a two-fold increase in mean metallothionein mRNA values in the highest exposure group (air cadmium above 1000 g m-3) and a positive correlation of metallothionein mRNA with blood cadmium levels ( r = 0 46, p < 0 008). Future studies can be designed to investigate further the interand intra-subject component of the variability and the possibility of the existence of M T gene polymorphisms, determining different responses and susceptibilities to cadmium exposure. We did not find any difference in the mean values of anti-HMdU Ab titres and 8OHdG in urine in any of the exposure groups analysed. Nickel exposure appeared to have greater impact on anti-HMdU Ab titres than cadmium. [ABSTRACT FROM AUTHOR]

The fine particulate matter (PM 2.5) was collected at academic campus of Indian Institute of Technology, Delhi, India from January–December 2017. The PM 2.5 samples were analysed for carcinogenic (Cd, Cr, As, Ni, and Pb) and non-carcinogenic (V, Cu, Zn, Fe) trace metals and their elicited effects on carcinoma epithelial cell line A549. Toxicological testing was done with ELISA kit. Same analyses were repeated for standard reference material (NIST-1648a) represents urban particulate matter. The student-t test and spearman correlation were used for data analysis. The seasonality in PM 2.5 mass concentration and chemical composition showed effect on biological outcomes. The PM 2.5 in post-monsoon and winter had higher amount of trace metals compared to mass collected in pre-monsoon and monsoon. Following the trend in PM mass concentration significantly (p < 0.5) lower cell viability was observed in post-monsoon and winter compared to other two seasons. NIST UPM 1648(a) samples always had higher cytotoxicity compared to ambient PM 2.5 Delhi sample. Strong association of Chromium, Nickel, Cadmium, and Zinc was observed with cell viability and reactive oxygen species (ROS) production. In winter IL-6, IL-8 production were 2.8 and 3 times higher than values observed in post-monsoon and 53 and 9 times higher than control. In winter season trace metals As, Cu, Fe, in pre-monsoon Cr, Ni, As, Pb, V, and Fe, in post-monsoon Cd and V strongly correlated with ROS generation. ROS production in winter and pre-monsoon seasons found to be 2.6 and 1.3 times higher than extremely polluted post-monsoon season which had 2 to 3 times higher PM 2.5 concentration compared to winter and pre-monsoon. The result clearly indicated that the presence of Fe in winter and pre-monsoon seasons catalysed the ROS production, probably O H ˙ radical caused high cytokines production which influenced the cell viability reduction, while in post-monsoon PM majorly composed of Pb, As, Fe and Cu and affected by photochemical smog formation showed significant association between ROS production with cell viability. Overall, in Delhi most toxic seasons for respiratory system are winter and post-monsoon and safest season is monsoon. Image 1 • Delhi, India is one of the most polluted cities in the world with PM 2.5 concentration of 209 μg/m³. • Few studies to do cyto-toxicity analysis in Indian scenario with PM 2.5. • One yearlong study, incorporating four Indian seasons towards cytotoxicity. • Cell-Viability, Reactive Oxygen Species generation & Pro-inflammatory cytokine production check in lung cell line. • Role of Delhi s PM 2.5 concentration and composition in toxicity. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are the carcinogenic component of carbonaceous aerosols and the toxicity of PAHs depends on their molecular structure. PM 2.5 -bound PAHs concentration, their isomeric ratios and health impacts during wintertime (fog and non-fog episodes) are assessed at two heavily polluted sites (Allahabad and Kanpur) in central IGP (Indo-Gangetic plains) to better understand the spatial-temporal variability of PAHs as well as identification of their major sources. The highest contribution to PAH loading is reported from indeno (1,2,3-c,d) pyrene, benzo(g,h,i) perylene, benzo (b,j) fluoranthene and benzo (a) pyrene at the two sites during studied winter campaigns. Significantly higher contribution from 6-ring PAHs to total PAH concentration at Allahabad has been observed as compared to Kanpur. Moreover, lower PAHs concentration observed during dense fog episodes can be attributed to wet scavenging of aerosols by fog droplets. Isomeric ratios of PAHs indicated significant contribution from diesel engine exhaust at Allahabad and gasoline combustion at Kanpur. Substantial contribution from coal combustion and biomass burning emissions during wintertime over these sites was also observed. Estimation of health risk due to PAHs indicate potential health hazard to adults as well as children at both the sites. Furthermore, health risk observed due to carcinogenic metals (Cr(VI), Cd, Ni, As) and PAHs is nearly twice at Allahabad as compared to Kanpur. Diesel exhaust emissions (a dominant source of Cd and PAHs) appeared to be responsible for increased cancer risk at Allahabad. Whereas, higher Cr(VI) and PAHs concentration in the ambient aerosol is aggravating cancer risk at Kanpur. • High molecular weight PAHs are major contributors to total PAH loading. • PAHs concentration observed is lower during dense fog episodes. • Dominant source is diesel emission at Allahabad and gasoline combustion at Kanpur. • Health risk due to metals and PAHs is ~2 times higher at Allahabad than Kanpur. • Cd at Allahabad and Cr(VI) at Kanpur are the major cancer risk causing factors. [ABSTRACT FROM AUTHOR]

The photovoltaic (PV) technology is one of the fastest growing renewable and environmental friendly sources of electricity. However, this huge deployment rate is associated with generation of end-of-life (EoL) PV waste containing particularly, carcinogenic metals, once their operation phase ends. This study attempted to address this upcoming waste issue by systematically reviewing about 300 review/theoretical/case/research papers/books/patents published between 2000 and 2018. The information was compiled and synthesized on: (i) initial metal concentration/content (IMC) for silicon-PV, amorphous-PV, CIGS and CdTe PVs; ii) statistical characterisation and distribution of compiled IMCs; iii) leached metal concentrations (mg/l) from various PVs in water-based leaching solutions, as per standard waste characterisation methods, in acid leaching and landfill matrix; iv) metal leaching rate constants (LRC) by fitting exponential model on reported plots of leached metal concentration values versus time using the GetData software; v) feasible application of compiled IMC and LRC data for: a) Leachate Pollution Index (LPI) determination of an MSW landfill dumped with solar-PV waste, b) human health risk assessment (HHRA) for exposure to lead leached from solar PV waste in an MSW landfill; vi) data/knowledge gaps from literature review and highlight the required future research actions. The range of IMC values for top three solar PV-associated carcinogens, arsenic, cadmium and lead (% weight) were obtained to be: 0.00–0.001, 0.0001–19.84, and 0.003–5.09, respectively. Further, the range of LRC of solar PV-associated leached arsenic, cadmium and lead were obtained to be (per day): 0.00–0.129, 0.001–0.031, and 0.003–0.041, respectively. Leaching of Cd, Pb and Se from PVs have been mostly studied in acidic conditions (pH 3.0–6.5), whereas, fate of solar PVs in landfill conditions was not observed to be studied much. The estimation of contribution of solar PV in leachate pollution potential of an existing MSW landfill at T 90 values (i.e., time required for 90% leaching of metals) showed an increase of 5.15% in pollution potential of landfill if landfill were to be dumped with EoL PV waste as well. HHRA for exposure to groundwater contaminated with leachate from a landfill dumped with lead containing solar PV waste did not pose any significant risk, however, the carcinogenic effects due to other metals under this scenario cannot be neglected. Out of 85 studies selected for content analysis, only 2.39% of them investigated the fate of PVs in landfill stimulating conditions. To address the fate of EoL solar waste and reduce uncertainty in present work, following future research actions need to be initiated: (i) conduct experimental studies to obtain data on metal leaching under realistic dumping scenarios and landfill conditions (intact solar panels with bigger size in MSW landfill); (ii) revise the expression of LPI for including solar PV-based LPI with critical parameters, like carcinogenic metals (cadmium); (iii) investigate suitability of existing standard hazardous waste characterizing methods (TCLP or WET) for PV waste. Image 1 • Presentation of research trends of end-of-life –related solar photovoltaic studies from year 2000 to 2018. • Estimation of initial concentrations of metals present in solar photovoltaics. • Estimation of leaching rate constant of metals leached from dumped end-of-life solar PVs. • Estimating solar PV-associated leachate pollution index and its contribution in leachate contamination potential of a MSW landfill. • Human health risk assessment due to exposures of leached carcinogenic metals from dumped solar PVs. [ABSTRACT FROM AUTHOR]