Serum concentrations of heavy metals in women with endometrial polyps.

Endometrial polyps are one of the common reasons of abnormal uterine bleeding in women. Industrialisation, urbanisation and increased air pollution cause increased heavy metal exposure. Heavy metals that have oestrogenic effects in human body are named as metalloestrogens. The aim of this study was to investigate the serum metalloestrogen levels such as copper (Cu), zinc (Zn), aluminium (Al), lead (Pb), nickel (Ni) and Cu/Zn ratio and their possible relationship with the occurrence of endometrial polyps. Eighty women with abnormal uterine bleeding were divided into two groups: 40 women diagnosed with endometrial polyp (study group) and 40 women without endometrial polyp (control group). Ages, body mass indices, smoking behaviours, drinking water choices, chronic diseases and intrauterine device histories were noted for all patients. Blood levels of Cu, Zn, Al, Pb, Ni and Cu/Zn ratio were analysed by inductively coupled plasma-mass spectrometry method for both groups. No statistically significant differences were observed in terms of serum median levels of Cu and Pb between the study and the control groups. The serum median levels of Zn, Ni and Al were found to be statistically lower in the study group when compared with the control group. The Cu/Zn ratio was statistically higher in the study group. High Cu/Zn ratio, as a biomarker of oxidative stress, suggests the role of oxidative stress in etiopathogenesis of endometrial polyps.IMPACT STATEMENTWhat is already known on this subject? Studies demonstrate that oestrogen and progesterone play an important role in pathogenesis of endometrial polyps. Inorganic heavy metal ions that bind and activate oestrogen receptors are referred to as 'metalloestrogens'. Apart from toxic effects, metalloestrogens have been linked to the aetiology of oestrogen-dependent diseases such as breast and endometrium cancer and endometriosis. However, serum levels of heavy metals were not investigated in a large group of endometrial polyp patients.What do the results of this study add? This is the first study investigating the serum levels of heavy metals in a large group of endometrial polyp patients. We did not observe any increased serum levels of heavy metals in endometrial polyp patients. Our results might suggest that oestrogenic heavy metal exposure has no role in the appearance of endometrial polyps. However, increased Cu/Zn ratio due to low serum levels zinc suggests oxidative stress might play a role in endometrial polyps.What are the implications of these findings for clinical practice and/or further research? Further research of heavy metals in endometrial polyps with simultaneous blood and tissue samples could show the precise effect of environmental exposure of metalloestrogens in aetiopathogenesis of endometrial polyps.

It's Time to Replace the Term "Heavy Metals" with "Potentially Toxic Elements" When Reporting Environmental Research.

Even if the Periodic Table of Chemical Elements is relatively well defined, some controversial terms are still in use. Indeed, the term "heavy metal" is a common term used for decades in the natural sciences, and even more in environmental sciences, particularly in studies of pollution impacts. As the use of the term appears to have increased, we highlight the relevance of the use of the term "Potentially Toxic Element(s)", which needs more explicit endorsement, and we illustrate the chemical elements that need to be considered.

Genotoxicity effects on Geophagus brasiliensis fish exposed to Doce River water after the environmental disaster in the city of Mariana, MG, Brazil / Efeitos da genotoxicidade em peixes da espécie Geophagus brasiliensis expostos a água do Rio Doce após o desastre ambiental na cidade de Marina, MG, Brasil

Abstract The Doce River basin has suffered the largest environmental accident ever occurred in Brazil with the influx of tailings from Fundão and Santarém, belonging to Samarco mining company, due to the disaster in Mariana. A spill between 50 and 60 million m3 of tailings was estimated by the company. According to Samarco, the wastewater was composed mainly of clay, silt and heavy metals like iron, copper and manganese. Thereby, the objective of the present study was evaluated the genotoxic damage in juvenile of Geophagus brasiliensis (Quoy e Gaimard, 1824) exposed to Doce river water before (DRWBA - Doce River water before acident) and after (DRWAA - Doce River water after acident) the influx of tailings from the Germano and Santarém Dam disasters in Mariana, MG, Brazil. For this, 24 individuals of the species G. brasiliensis (obtained on IFES/ALEGRE fish culture) were submitted to a bioassay with three treatments and eight replicates. The treatments were: 1) Control water (water from the urban water supply system, filtered with a 0.45 µm membrane), 2) DRBA and 3) DRAA. After 96 h, these fishes were anesthetized to remove blood for evaluation of genotoxic damage (micronucleus and comet). For the bioassay, a total of 80 L of The Doce River water were collected before the influx of tailings and after the influx and then submitted to metal quantification analysis. Fish exposed to DRWBA and DRWAA treatments showed a significant increase in both the number of erythrocyte micronuclei and the DNA damage index in relation to the control fish; however, they did not present any differences between the two treatments. The results demonstrate that the DRWBA treatment was already genotoxic for the fish, mainly due to dissolved Cu concentrations in the water. The DRWAA treatment probably presented genotoxicity due to the increase in the dissolved fraction and synergistic effects of several metals found in the tailings of the Mariana accident.

Resumo A bacia do Rio Doce sofreu o maior acidente ambiental com o influxo de rejeitos de Fundão e Santarém, pertencentes à empresa de mineração Samarco, devido ao desastre em Mariana. Um derramamento entre 50 e 60 milhões de m3 de rejeitos foi estimado pela empresa. De acordo com a Samarco, o rejeito despejado era composto principalmente de argila, silte e alguns metais pesados como ferro, cobre e manganês. Com isso, o presente estudo teve como objetivo avaliar os danos genotóxicos em juvenis de Geophagus brasilienses expostos a água do rio Doce antes (DRWAA - água do Rio Doce antes do acidente) e depois (DRWBA- água do Rio Doce depois do acidente) da chegada dos rejeitos do rompimento das barragens de Germano e Santarém em Mariana, MG, Brasil. Para isso, 24 indivíduos da espécie G. brasilienses (obtidos na piscicultura do IFES/ALEGRE) foram submetidos a um bioensaio com três tratamentos e oito réplicas. Os tratamentos eram: 1) Controle (com água do abastecimento urbano, filtrada com filtro analítico de 0,45 µm); 2) DRWBA e 3) DRWAA. Após um período de 96 h, esses peixes foram anestesiados para retirada de sangue para avaliação dos danos genotóxicos (micronúcleo e cometa). Para a realização do bioensaio, um total de 80 L de água do Rio Doce foram coletados antes da chegada dos rejeitos e outros 80 L foram coletados depois da chegada dos rejeitos e ambas foram submetidas a análises de quantificação de metal. Os peixes expostos ao DRWBA e ao DRWAA apresentaram um aumento significativo na quantidade de micronúcleos eritrocitários e no índice de danos do DNA em relação aos peixes controle, no entanto não apresentaram diferenças entre si. Os resultados obtidos demonstram que a DRWBA já era genotóxica para os peixes, principalmente, em função das concentrações de Cu dissolvido na água. A DRWAA apresentou genotixicidade, provavelmente, em função do aumento da fração dissolvida e do efeito sinérgico de diversos metais presentes nos rejeitos do acidente de Mariana.

Antioxidant Potential, Phytochemicals Composition, and Metal Contents of Datura alba.

This study investigated the phytochemical characteristics and antioxidant activity in leaves, roots, stem, flower, and seed parts of Datura alba (D. alba). The study also assessed the heavy metal (Cr, Mn, Zn, and Cu) accumulation in each part of the plant. Among the phytochemicals, alkaloids were found only in leaves while tannins, flavonoids, and phenols were present in all parts of the plant. For antioxidant activity, free radical scavenging assay for 2,2-diphenyl-1-picrylhydrazyl (DPPH) was performed using ascorbic acid as the standard. Higher activity was shown by stem extract in methanol and leaf extract in n-hexane, ethyl acetate, and chloroform. Furthermore, all the target heavy metals were detected in all plant sections with the highest concentration of Zn in leaves and Cu in stem, root, flower, and seed. Due to stronger antioxidant potential and phytochemical composition, D. alba could prove as valuable prospect in pharmaceutical formulations by taking part in the antioxidant defense system against generation of free radicals.

A quantitative analysis of chronic exposure of selected heavy metals in a model diet in a CKD hotspot in Sri Lanka.

BACKGROUND: Evidence of chronic low levels of exposure to heavy metals in Sri Lanka has emerged in a number of studies carried out in the recent past. The source and magnitude of such exposures have to be understood in order to assess the risk of adverse health effects of this exposure and to propose suitable public health interventions. METHODS: An assessment was carried out to quantify chronic exposure to cadmium, lead and arsenic through food in people living in an area in Sri Lanka, where prevalence of Chronic Kidney Disease of unknown origin (CKDu) is highest. First a dietary survey was carried out in the subjects to estimate the type and quantity of typical food items in order to estimate an average consumption. A model diet was formulated using this dietary consumption data; and this was thereafter used for estimation of chronic dietary exposure of selected contaminants. In parallel, the levels of contaminants of interest in the various identified food items: cadmium, lead and arsenic, were determined. RESULTS: Assuming the major route of intake is food, and based on the quantity and type of food items consumed, a 60 kg man is exposed to average doses of 83.7 µg cadmium, 924.1 µg lead, and 180.3 µg arsenic per week. The impact of chronic lead exposure was affirmed by a mean blood lead level of 3.0 µg/dL, with a maximum level of 8.8 µg/dL being observed in some cases. CONCLUSIONS: Chronic low dose exposure of lead from food appears to be a public health concern in the studied population. Cadmium exposure through food appears to be of concern also. However, arsenic exposure through food appears to be within safe limits. As there are numbers of possible adverse health outcomes that can be associated with such estimated exposures of heavy metals, public health interventions are warranted to limit the described harmful exposures. Advocacy on dietary patterns and agronomic practices to lower the contaminants identified are the two broad strategies suggested.

Genotoxicity effects on Geophagus brasiliensis fish exposed to Doce River water after the environmental disaster in the city of Mariana, MG, Brazil.

The Doce River basin has suffered the largest environmental accident ever occurred in Brazil with the influx of tailings from Fundão and Santarém, belonging to Samarco mining company, due to the disaster in Mariana. A spill between 50 and 60 million m3 of tailings was estimated by the company. According to Samarco, the wastewater was composed mainly of clay, silt and heavy metals like iron, copper and manganese. Thereby, the objective of the present study was evaluated the genotoxic damage in juvenile of Geophagus brasiliensis (Quoy e Gaimard, 1824) exposed to Doce river water before (DRWBA - Doce River water before acident) and after (DRWAA - Doce River water after acident) the influx of tailings from the Germano and Santarém Dam disasters in Mariana, MG, Brazil. For this, 24 individuals of the species G. brasiliensis (obtained on IFES/ALEGRE fish culture) were submitted to a bioassay with three treatments and eight replicates. The treatments were: 1) Control water (water from the urban water supply system, filtered with a 0.45 µm membrane), 2) DRBA and 3) DRAA. After 96 h, these fishes were anesthetized to remove blood for evaluation of genotoxic damage (micronucleus and comet). For the bioassay, a total of 80 L of The Doce River water were collected before the influx of tailings and after the influx and then submitted to metal quantification analysis. Fish exposed to DRWBA and DRWAA treatments showed a significant increase in both the number of erythrocyte micronuclei and the DNA damage index in relation to the control fish; however, they did not present any differences between the two treatments. The results demonstrate that the DRWBA treatment was already genotoxic for the fish, mainly due to dissolved Cu concentrations in the water. The DRWAA treatment probably presented genotoxicity due to the increase in the dissolved fraction and synergistic effects of several metals found in the tailings of the Mariana accident.

Environmental diagnosis of metals in streams near sugarcane cultivation areas: current and historical analysis in the central region of the State of São Paulo.

In Brazil, innumerable regions of native landcover have been removed and replaced by agricultural cultivation, especially of sugarcane. In this culture, the application of fertilizers containing metals has caused impacts on the water resources causing contamination of stream sediments and occasioning bioaccumulation of metals in aquatic invertebrates. In the year of 2006, an environmental diagnosis of metals in sediments of streams located near sugarcane cultivation areas and in streams located in preserved areas, was published. That study pointed to high concentrations of metals in stream sediments in agricultural areas. These streams have been monitored over the last 10 years conducting analyses of metals and monitoring possible changes in land use. In the present paper, a historical comparison of metals contamination in the sediments of the same streams is conducted, aiming to present a status of 10 years later, analyzing 5 metals (Zn, Cd, Mn, Cr and Fe) found in the sediments of 8 streams, five located in areas of sugarcane cultivation and three located in preserved areas. This study also shows that there is higher concentration of metals in the sediments of streams near sugarcane cultivation than in preserved areas. The temporal historical evaluation showed high concentrations of Cd in 2016 when compared to the year 2006 for streams near sugarcane cultivation.

Luteolin inhibits multi-heavy metal mixture-induced HL7702 cell apoptosis through downregulation of ROS-activated mitochondrial pathway.

With the rapid economic development in recent years, China is facing a great challenge due to heavy metal pollution. The heavy metals may enter the human body through ingestion of aqua products to cause great health risks. In the present study, the inhibitory effects of luteolin on the combined toxicity of multi-heavy metals (including zinc, manganese, lead, copper, cadmium, mercury, chromium and nickel) were investigated in HL7702 hepatocyte cells. An MTT assay demonstrated that 20 µM luteolin significantly alleviated the multi-heavy metal mixture-induced cell death and morphological changes. Furthermore, 20 µM luteolin significantly inhibited multi-heavy metal mixture-induced reactive oxygen species (ROS) generation, lipid peroxidation (malondialdehyde content) and caused a decrease in adenosine triphosphate levels in HL7702 cells. A JC-1 staining assay indicated that 20 µM luteolin inhibited the mitochondrial membrane potential-reducing effect of the multi-heavy metal mixture. Apoptotic assays revealed that the multi-heavy metal mixture induced HL7702 cell apoptosis in a dose-dependent manner, which was significantly inhibited by 20 µM luteolin. Western blot analysis indicated that addition of luteolin to the multi­heavy metal mixture significantly alleviated cytochrome c release from the mitochondria into the cytosol. In addition, 20 µM luteolin had a significant inhibitory effect on multi-heavy metal mixture-induced cleavage of caspase-9, caspase-3 and poly(adenosine diphosphate-ribose) polymerase-1 protein. Immunofluorescence staining demonstrated that addition of luteolin significantly alleviated caspase-3 cleavage induced by the multi-heavy metal mixture. The present results suggested luteolin exerts its inhibitory effects of on multi-heavy metal mixture induced cell apoptosis through downregulation of the ROS-activated mitochondrial pathway.

Chemical fractionation and mobility of traffic-related elements in road environments.

Due to considerable progress in exhaust control emission technology and extensive regulatory work regarding this issue, non-exhaust sources of air pollution have become a growing concern. This research involved studying three types of road environment samples such as road dust, sludge from storm drains and roadside soil collected from heavily congested and polluted cities in Poland (Krakow, Warszawa, Opole and Wroclaw). Particles below 20 µm were examined since it was previously estimated that this fine fraction of road dust is polluted mostly by metals derived from non-exhaust sources of pollution such as brake linings wear. Chemical analysis of all samples was combined with a fractionation study using BCR protocol. It was concluded that the finest fractions of road environment samples were significantly contaminated with all of the investigated metals, in particular with Zn, Cu, both well-known key tracers of brake and tire wear. In Warszawa, the pollution index for Zn was on average 15-18 times the background value, in Krakow 12 times, in Wroclaw 8-12 times and in Opole 6-9 times the background value. The pollution index for Cu was on average 6-14 times the background in Warszawa, 7-8 times in Krakow, 4-6 times in Wroclaw and in Opole 5 times the background value. Fractionation study revealed that mobility of examined metals decreases in that order: Zn (43-62%) > Cd (25-42%) > Ni (6-16%) > Cu (3-14%) > Pb (1-8%). It should, however, be noted that metals even when not mobile in the environment can become a serious health concern when ingested or inhaled.

[Levels of exposure to metals in population of Pechenga district of Murmansk region].

Serum levels of zincum, lead, nickel and mercury decrease in a row <>; average levels of manganese, cobalt, copper and arsenic are higher among females; in pregnant women serum levels of most metals are the lowest. If compared to the WHO. reference, levels of metals in whole blood demonstrated no excess in cobalt and cadmium, nearly absent - in arsenic, increased percentage of excess (but insignificant values) in copper and zincum, extremely high percentage of excess (and significant values) in manganese and nickel. Maximal manganese concentrations in blood reach 300 micrograms/I, those of nickel - 100 micrograms/I. Average blood concentrations of mercury in the examinees do not reach the most severe <> (S micrograms/1), and shares of men and women with blood concentrations of mercury over this limit are relatively small. Average blood concentrations of lead in the examinees do not reach lower allowable level (50 micrograms/1).

[The content of petroleum products, benzo(a)pyrene and heavy metals in soils of yamalnenets autonomous district and heavy metals in the hair of children].

The paper presents information about the content of benzo(a)pyrene in soil samples of petroleum products and the content of heavy metals (iron, copper, lead, arsenic, manganese, chromium, cadmium and mercury) in the soil and hair samples of children. Soil samples and hair were taken in October 2014 in the north-western part of the Yamal-Nenets Autonomous District. The values obtained were compared with the approximately permissible levels and maximum allowable concentrations adopted in the Russian Federation. Levels are determined compounds in the soil in general do not exceed the allowable concentrations. In hair samples there was noted marked exceeding of the recommended values for zinc, copper, chromium and iron 10%, 16.7%, 83.3% and 100% samples, respectively. The cause of the high iron content in the hair samples may be due to the quality of consumed water, which is characterized by low mineralization and high iron content. Increased chromium content of more than 80% of the hair samples can be caused, as in the case of iron, the quality of water consumed, but also a high proportion of local foods in the diet of people, rich by chromium. A conducted study on the state of the environment in the village, away from areas of hydrocarbon production, indicates to the low importance of anthropogenic impact.

Children's health risk assessment based on the content of toxic metals Pb, Cd, Cu and Zn in urban soil samples of Podgorica, Montenegro.

BACKGROUND/AIM: Due to their low tolerance to pollutants and hand-to-mouth pathways the health risk is very high in children's population. The aim of this study was to evaluate risk to children's health based on the content of heavy metals in urban soil samples from Podgorica, Montenegro. This study included the investigation of several toxic metals such as Pb, Cd, Cu and Zn in soil samples from public parks and playgrounds. METHODS: Sampling was conducted in a period October-November, 2012. Based on cluster analysis, soil samples were divided into two groups related to similarity of metal content at examinated locations: the group I--near by recreational or residential areas of the city, and the group II--near traffic roads. Concentration of toxic metals, in urban soil samples were determined by a graphite furnace atomic absorption spectrometry (Pb and Cd) and by inductively coupled plasma optical emission spectrometry technique after microwave digestion. Due to exposure to urban soil, non-cancerogenic index hazardous index (HI) for children was estimated using 95th percentile values of total metal concentration. The value of the total (ingestion, dermal and inhalation) HI is calculated for maximum, minimum and the average concentration of metals for children. RESULTS: Mean concentrations of Pb, Cd, Cu and Zn in the surface layer of the studied urban soils were 85.91 mg/kg, 2.8 mg/kg and 52.9 mg/kg and 112.5 mg/kg, respectively. Samples from group II showed higher metal content compared to group I. Urbanization and traffic are the main sources of pollution of the urban soils of Podgorica. Most of the samples (93.5%) had a high Pb content, 12.9% of the samples had a higher content of Cd, while Cu and Zn were within the limits prescribed by national legislation. At one location the level of security for lead is HI = 0.8 and very closed to maximum acceptable value of 1. It is probably the result of intensive traffic near by. CONCLUSION: All metals investigated showed relatively higher concentrations at sites that were close to industrial places and high ways. The mean concentrations of Pb and Zn and maximum concentrations of Pb, Cd, and Zn were higher than presented values in the National Regulation.

Chelation therapy and cardiovascular disease: connecting scientific silos to benefit cardiac patients.

Medical practitioners have treated atherosclerotic disease with chelation therapy for over 50 years. Lack of strong of evidence led conventional practitioners to abandon its use in the 1960s and 1970s. This relegated chelation therapy to complementary and alternative medicine practitioners, who reported good anecdotal results. Concurrently, the epidemiologic evidence linking xenobiotic metals with cardiovascular disease and mortality gradually accumulated, suggesting a plausible role for chelation therapy. On the basis of the continued use of chelation therapy without an evidence base, the National Institutes of Health released a Request for Applications for a definitive trial of chelation therapy. The Trial to Assess Chelation Therapy (TACT) was formulated as a 2 × 2 factorial randomized controlled trial of intravenous EDTA-based chelation vs. placebo and high-dose oral multivitamins and multiminerals vs. oral placebo. The composite primary endpoint was death, reinfarction, stroke, coronary revascularization, or hospitalization for angina. A total of 1708 post-MI patients who were 50 years or older with a creatinine of 2.0 or less were enrolled and received 55,222 infusions of disodium EDTA or placebo with a median follow-up of 55 months. Patients were on evidence-based post-MI medications including statins. EDTA proved to be safe. EDTA chelation therapy reduced cardiovascular events by 18%, with a 5-year number needed to treat (NNT) of 18. Prespecified subgroup analysis revealed a robust benefit in patients with diabetes mellitus with a 41% reduction in the primary endpoint (5-year NNT = 6.5), and a 43% 5-year relative risk reduction in all-cause mortality (5-year NNT = 12). The magnitude of benefit is such that it suggests urgency in replication and implementation, which could, due to the excellent safety record, occur simultaneously.

Speciation of heavy metals in River Rhine.

Chemical speciation of Zn, Cu, Ni, Cd and Pb in River Rhine was studied by measuring free ion concentration and distribution in nanoparticles, and by comparing the measurement with speciation modeling. Concentrations of free metal ions were determined in situ using Donnan Membrane Technique (DMT). The percentage of free over total (filtered) metal concentration is 52%, 33%, 2.6%, 0.48% and 0.12% for respectively Zn, Cd, Ni, Pb and Cu, i.e. the degree of metal complexation in the river is the lowest for Zn and the highest for Cu. Metals in 1-300 nm particles were analyzed using Asymmetric Flow Field Flow Fractionation (AsF-FFF), but the overall recovery is quite low. The nano-sized Cu detected is mainly associated with DOM of 1-5 nm, whereas Pb and Zn are dominantly associated with particles of iron hydroxides and clay of larger size (30-100 nm). Free ion concentrations calculated with the speciation modeling are in good agreement with the measurements, except for Pb. Based on the model, DOM-bound is the most important complexed form for Cu and Cd, whereas formation of (bi)carbonate and EDTA complexes are more important for Ni and Zn. Adsorption of Pb to DOM is probably overestimated by the model, whereas Pb adsorption to iron hydroxides is underestimated.

Distribution and chemical speciation of arsenic and heavy metals in highly contaminated waters used for health care purposes (Srebrenica, Bosnia and Herzegovina).

Determination of distribution and chemical speciation of arsenic and heavy metals in five acidic springs and in the receiving river near Srebrenica (Bosnia and Herzegovina) was carried out. These waters were used for centuries, and continue to be used, for health-care purposes. The composition and properties of all springs and the river water (after all inputs) resembled that of an acid mine drainage. Very low pH (<3.3), high sulphate concentration and extremely high contents of most of the measured elements (25) are found in all springs (e.g. arsenic and iron maximal concentration of 6.6 and 500 mg L(-1), respectively). Although of small discharge, spring waters caused the decrease of the receiving river pH (from 7.3 to 3.4) and the considerable increase of the concentrations of elements. The enrichment factor for the studied elements ranged from 1.2 for Sr up to 425 for As. In acidic spring waters, all elements were predominantly present in dissolved form. Elements associated to freshly-formed hydrous ferric oxide were prevailing in particulate forms only at the two most upstream sites in the river with pH>7. Geochemical speciation modelling (PHREEQC and WHAM-VI) revealed that As was mainly present as As(V), and Fe as Fe(III). Complexation of dissolved metals by organic matter was predicted to be significant only for the two river sites with neutral pH.

Effects of tree vegetation and waste amendments on the fractionation of Cr, Cu, Ni, Pb and Zn in polluted mine soils.

Soils at a depleted copper mine in Touro (Galicia, Spain) are physically and chemically degraded and have also polluted the surrounding area. Due to these environmental problems and the large area of these mine soils, the reclamation strategies carried out at Touro have consisted of planting trees (pine or eucalyptus), amending with waste material (sewage sludge and paper mill residues), or using both treatments. Tree planting has been carried out for 21 years and waste amending for 10. Two different zones were selected in the mine (the settling pond and mine tailing) in order to evaluate the effect of the different reclamation practices on the chemical fractions of Cr, Cu, Ni, Pb and Zn. The results showed that soils in the untreated sites were polluted by Cr and Cu. Planting pines and eucalyptus on mine soils decreased the concentration of these heavy metals in non-mobile soil fractions. Amendments also attenuated pollution by Cr and Cu as the wastes that were used had lower concentrations than the untreated mine soils. Planting trees increased Ni, Pb and Zn retention in the non-mobile fractions, preventing them from being leached into surrounding areas. However, caution should be exercised when adding organic wastes, as they can lead to increase concentrations of Ni, Pb and Zn and their phytoavailable form. The results also showed that changes in the chemical fractionation of heavy metals in soils was more influenced by the clay percentage and both dissolved and soil organic carbon (SOC and DOC) than by soil pH or cation exchange capacity.

Ranking ecological risks of multiple chemical stressors on amphibians.

Populations of amphibians have been declining worldwide since the late 1960s. Despite global concern, no studies have quantitatively assessed the major causes of this decline. In the present study, species sensitivity distributions (SSDs) were developed to analyze the sensitivity of anurans for ammonium, nitrate, heavy metals (cadmium, copper), pesticides (18 compounds), and acidification (pH) based on laboratory toxicity data. Ecological risk (ER) was calculated as the probability that a measured environmental concentration of a particular stressor in habitats where anurans were observed would exceed the toxic effect concentrations derived from the species sensitivity distributions. The assessment of ER was used to rank the stressors according to their potential risk to anurans based on a case study of Dutch freshwater bodies. The derived ERs revealed that threats to populations of anurans decreased in the sequence of pH, copper, diazinon, ammonium, and endosulfan. Other stressors studied were of minor importance. The method of deriving ER by combining field observation data and laboratory data provides insight into potential threats to species in their habitats and can be used to prioritize stressors, which is necessary to achieve effective management in amphibian conservation.

Characterization, leachability and valorization through combustion of residual chars from gasification of coals with pine.

This paper presents the study of the combustion of char residues produced during co-gasification of coal with pine with the aim of characterizing them for their potential use for energy. These residues are generally rich in carbon with the presence of other elements, with particular concern for heavy metals and pollutant precursors, depending on the original fuel used. The evaluation of environmental toxicity of the char residues was performed through application of different leaching tests (EN12457-2, US EPA-1311 TCLP and EA NEN 7371:2004). The results showed that the residues present quite low toxicity for some of pollutants. However, depending on the fuel used, possible presence of other pollutants may bring environmental risks. The utilization of these char residues for energy was in this study evaluated, by burning them as a first step pre-treatment prior to landfilling. The thermo-gravimetric analysis and ash fusibility studies revealed an adequate thermochemical behavior, without presenting any major operational risks. Fluidized bed combustion was applied to char residues. Above 700°C, very high carbon conversion ratios were obtained and it seemed that the thermal oxidation of char residues was easier than that of the coals. It was found that the char tendency for releasing SO(2) during its oxidation was lower than for the parent coal, while for NO(X) emissions, the trend was observed to increase NO(X) formation. However, for both pollutants the same control techniques might be applied during char combustion, as for coal. Furthermore, the leachability of ashes resulting from the combustion of char residues appeared to be lower than those produced from direct coal combustion.