GEOCHEMICAL ASSESSMENT OF THE POTENTIALLY TOXIC ELEMENTS BACKGROUND CONTENTS IN SOILS IN THE AREA OF THE SARALA GOLD ORE CLUSTER (THE REPUBLIC OF KHAKASSIA, RUSSIA)

We assessed the contents of Fe, Ni, Cu, Zn, As, Cr, Pb, Hg in soils of the residential settlements and surrounding areas exposed to anthropogenic load due to mining activities. The study object is located in the Kuznetsk Alatau (part of the Sarala gold ore cluster – SGOC), the village of Priiskovy and its tailings dump, the village of Ordzhonikidzevsky, the Republic of Khakassia). The background contents in the SGOC soils are the following: Fe 3.08–5.06 %, Ni 24.74–45.13 g/t, Cu 22.33–38.81 g/t, Zn 86.72–200 g/t, As 5.45–11.25 g/t, Cr 35.60–73.25 g/t, Pb 14.12–26.17 g/t, Hg 0.01–0.14 g/t. It was found that the background area has increased the natural contents of the studied elements. The soils sampled from the territory of the tailing dump are distinguished by the elevated element contents relative to the background values and especially by a sharp jump of the As and Zn contents (abnormal contents). The contents of all the elements examined in the soils of the territories in the vicinity of the tailing dump also exceed the background values of the SGOC with different proportions of cases and have the increased As, Cr, and Pb contents relative to the maximum permissible concentration of soils. Clustering of the data shows the presence of two clusters, which indicate the availability of the background and anomalous values associated with the technogenic impact of the mining industry in the study area of the Sarala gold ore cluster

SEQUENTIAL EXTRACTION OF SUBSTANCES WITH KNOWN Au SPECIATION – AN EXPERIMENTAL DATA

A study has been conducted on the features of distriburion of Au among the fractions of a 7-step sequential extraction procedure using model substances that are similar in composition to natural organic matter from the dispersion train of sulfide tailings. Use has been made of model substances with known Au speciations: bulk native gold, nanoscale native gold, Au-containing pyrite, humic acids, and Fe(III) oxides/hydroxides, which served as the basis for preparing mixtures with low-Au filler substances (quartz, limestone, humic acids, Fe(III) oxides/hydroxides).It has been stated that several Au species are leached in one fraction during sequential extraction. Nanoscale Au0 and gold bound to the organic matter are leached together in easily oxidizable (organic) fraction; gold bound to Fe(III) compounds and Au complexes chemisorbed on the surface of other minerals (sulfides, aluminosilicates) are leached in reducible (hydroxides) fraction; "invisible" gold in sulfides, nanoscale Au0 and, partially, >1 μm-seized bulk Au0 are leached in hardly oxidizable (sulfidic) fraction. Bulk native gold is leached predominantly in residual fraction. Mobile species are Au bound to water-soluble organic compounds and complexes of ionic Au desorbed from the surface of minerals

ГЕОХИМИЧЕСКАЯ ОЦЕНКА ФОНОВЫХ СОДЕРЖАНИЙ ПОТЕНЦИАЛЬНО ТОКСИЧНЫХ ЭЛЕМЕНТОВ В ПОЧВАХ В РАЙОНЕ САРАЛИНСКОГО ЗОЛОТОРУДНОГО УЗЛА (РЕСПУБЛИКА ХАКАСИЯ, РОССИЯ)

We assessed the contents of Fe, Ni, Cu, Zn, As, Cr, Pb, Hg in soils of the residential settlements and surrounding areas exposed to anthropogenic load due to mining activities. The study object is located in the Kuznetsk Alatau (part of the Sarala gold ore cluster – SGOC), the village of Priiskovy and its tailings dump, the village of Ordzhonikidzevsky, the Republic of Khakassia). The background contents in the SGOC soils are the following: Fe 3.08–5.06 %, Ni 24.74–45.13 g/t, Cu 22.33–38.81 g/t, Zn 86.72–200 g/t, As 5.45–11.25 g/t, Cr 35.60–73.25 g/t, Pb 14.12–26.17 g/t, Hg 0.01–0.14 g/t. It was found that the background area has increased the natural contents of the studied elements. The soils sampled from the territory of the tailing dump are distinguished by the elevated element contents relative to the background values and especially by a sharp jump of the As and Zn contents (abnormal contents). The contents of all the elements examined in the soils of the territories in the vicinity of the tailing dump also exceed the background values of the SGOC with different proportions of cases and have the increased As, Cr, and Pb contents relative to the maximum permissible concentration of soils. Clustering of the data shows the presence of two clusters, which indicate the availability of the background and anomalous values associated with the technogenic impact of the mining industry in the study area of the Sarala gold ore cluster.Проведена оценка содержаний Fe, Ni, Cu, Zn, As, Cr, Pb, Hg в почвах жилых поселков и окружающих территорий, подверженных техногенной нагрузке за счет горно-добывающей деятельности. Объект расположен на территории Кузнецкого Алатау (часть Саралинского золоторудного узла (СЗУ), пос. Приисковый и хвостохранилища пос. Орджоникидзевский, Республика Хакасия). Фоновые содержания в почвах СЗУ составляют: Fe 3.08–5.06 %, Ni 24.74–45.13 г/т, Cu 22.33–38.81 г/т, Zn 86.72–200 г/т, As 5.45–11.25 г/т, Cr 35.60–73.25 г/т, Pb 14.12–26.17 г/т, Hg 0.01–0.14 г/т. Зафиксировано, что фоновый участок имеет повышенные природные содержания исследуемых элементов. Почвы на территории хвостохранилища выделяются повышенными содержаниями элементов относительно фоновых значений и особенно резким скачком содержаний As и Zn (аномальные содержания). Содержания элементов в почвах территорий вблизи хвостохранилища также превышают фоновые значения СЗУ с разной долей случаев и имеют повышенные содержания As, Cr и Pb относительно предельно допустимых концентраций почв. Кластеризация данных показывает наличие двух кластеров, отражающих присутствие фоновых и аномальных значений, связанных с техногенным влиянием горно-добывающей промышленности на изученном участке Саралинского золоторудного узла

ЭКСПЕРИМЕНТАЛЬНЫЕ ДАННЫЕ ПО СТУПЕНЧАТОМУ ВЫЩЕЛАЧИВАНИЮ ВЕЩЕСТВ С ИЗВЕСТНЫМИ ФОРМАМИ НАХОЖДЕНИЯ Au

A study has been conducted on the features of distriburion of Au among the fractions of a 7-step sequential extraction procedure using model substances that are similar in composition to natural organic matter from the dispersion train of sulfide tailings. Use has been made of model substances with known Au speciations: bulk native gold, nanoscale native gold, Au-containing pyrite, humic acids, and Fe(III) oxides/hydroxides, which served as the basis for preparing mixtures with low-Au filler substances (quartz, limestone, humic acids, Fe(III) oxides/hydroxides).It has been stated that several Au species are leached in one fraction during sequential extraction. Nanoscale Au0 and gold bound to the organic matter are leached together in easily oxidizable (organic) fraction; gold bound to Fe(III) compounds and Au complexes chemisorbed on the surface of other minerals (sulfides, aluminosilicates) are leached in reducible (hydroxides) fraction; "invisible" gold in sulfides, nanoscale Au0 and, partially, >1 μm-seized bulk Au0 are leached in hardly oxidizable (sulfidic) fraction. Bulk native gold is leached predominantly in residual fraction. Mobile species are Au bound to water-soluble organic compounds and complexes of ionic Au desorbed from the surface of minerals.Изучены особенности распределения Au по фракциям 7-ступенчатой методики выщелачивания с применением модельных веществ, приближенных по составу к природным образцам из ореола рассеяния сульфидных хвостохранилищ. Применялись модельные вещества с известными формами нахождения Au: крупное самородное золото, наноразмерное самородное золото, Au-содержащие пирит, гуминовые кислоты и оксиды/гидроксиды Fe(III). На их основе были приготовлены смеси с веществами-наполнителями с низкими содержаниями Au (кварц, известняк, гуминовые кислоты, оксиды/гидроксиды Fe(III)).Установлено, что при ступенчатом выщелачивании наблюдается совместное извлечение нескольких форм золота в одной фракции. Наноразмерное Au0 и золото, связанное с органическим веществом, совместно извлекаются в легкоокисляемой (органической) фракции; золото, связанное с соединениями Fe(III), и комплексы Au, хемосорбированные на поверхности других минералов (сульфиды, алюмосиликаты), – в восстанавливаемой (гидроксидной) фракции; «невидимое» золото в сульфидах, наноразмерное и, частично, крупное (с размером частиц >1 мкм) Au0 – в трудноокисляемой (сульфидной) фракции. Крупное Au0 извлекается преимущественно в остаточной фракции. Мобильные формы элемента представляют собой Au, связанное с легкорастворимыми органическими соединениями, и комплексы ионного Au, десорбированные с поверхности минералов

Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers

Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infection with multiple infection routes likely to be functional in sheep, definitive evidence for or against transmission from ewe to her developing fetus has been difficult to achieve. In addition the very early literature on maternal transmission of scrapie in sheep was compromised by lack of knowledge of the role of the PRNP (prion protein) gene in control of susceptibility to scrapie. In this study we experimentally infected pregnant ewes of known PRNP genotype with a distinctive scrapie strain (SSBP/1) and looked for evidence of transmission of SSBP/1 to the offspring. The sheep were from the NPU Cheviot flock, which has endemic natural scrapie from which SSBP/1 can be differentiated on the basis of histology, genetics of disease incidence and strain typing bioassay in mice. We used embryo transfer techniques to allow sheep fetuses of scrapie-susceptible PRNP genotypes to develop in a range of scrapie-resistant and susceptible recipient mothers and challenged the recipients with SSBP/1. Scrapie clinical disease, caused by both natural scrapie and SSBP/1, occurred in the progeny but evidence (including mouse strain typing) of SSBP/1 infection was found only in lambs born to fully susceptible recipient mothers. Progeny were not protected from transmission of natural scrapie or SSBP/1 by washing of embryos to International Embryo Transfer Society standards or by caesarean derivation and complete separation from their birth mothers. Our results strongly suggest that pre-natal (in utero) transmission of scrapie may have occurred in these sheep

Mercury species in solid matter of dispersion of the Ursk tailing dispersion train (Ursk village, Kemerovo region, Russia)

Mercury species are highly toxic, and methylmercury is the most dangerous for environment and biota. The purpose of this study is to evaluate the distribution of mercury speciations (HgX2 (were X is O, SO24-, Cl and et al.), CH3Hg+, HgS) in diffuse halation high-sulfide waste of piles at the Ursk massive sulfide ore deposits which are being mined since the 1940s. To determine the mercury speciation, the method of thermal analysis with atomic absorption spectrometry as detector was applied

Mercury species in solid matter of dispersion of the Ursk tailing dispersion train (Ursk village, Kemerovo region, Russia)

Mercury species are highly toxic, and methylmercury is the most dangerous for environment and biota. The purpose of this study is to evaluate the distribution of mercury speciations (HgX2 (were X is O, SO24-, Cl and et al.), CH3Hg+, HgS) in diffuse halation high-sulfide waste of piles at the Ursk massive sulfide ore deposits which are being mined since the 1940s. To determine the mercury speciation, the method of thermal analysis with atomic absorption spectrometry as detector was applied

Изучение состава минералов Hg в природно-техногенных системах

Mercury speciation and the composition of mercury phases in natural and mining-related environments is studied by the thermal release analysis combined with electrothermal atomic absorption spectroscopy (TA-ET-AAS), as well as scanning electron microscopy with energy-dispersive X-ray microanalysis (SEM-EDS). The analyses are applied to laboratory-made samples bearing mercury selenide and to field samples from sites known for relatively high natural or industrially induced Hg background. They are, namely, material from the dispersion train of the Ursk sulfide tailings (Ursk Village, Kemerovo region) and debris precipitated from snow sampled in the Kurai mercury zone (Aktash Village, Gorny Altai). The TA-ET-AAS method works well in discrimination and identification of Hg sulfide and Hg selenide provided that the samples contain sufficient amounts of both compounds, but the sum HgS + HgSe can be determined at any contents of the two compounds. The presence of both mercury sulfide and mercury selenide in the samples has been confirmed by SEM-EDS microanalysis. The temperature ranges for the mercury species (Hg2+; HgS+HgSe mixture; mercury bound with organic matter (Hg-OM), including CH3Hg+) are identical in the laboratory and field samples. Therefore, the suggested approach can ensure fast and reliable detection of Hg phases in rocks exposed to supergene alterationДля изучения состава минералов ртути в природных и техногенных объектах предложен подход, сочетающий метод термического анализа с электротермическим атомно-абсорбционным детектированием (ТА-ЭТА-ААС) и сканирующую электронную микроскопию (СЭМ ЭДС). Исследования проводили с использованием модельного образца, содержащего селенид ртути, а также образцов, отобранных на объектах, характеризующихся повышенным природным и техногенным геохимическим фоном ртути, а именно: вещества потока рассеяния хвостохранилища Ново-Урского месторождения (п. Урск, Кемеровская область) и твердого осадка снега Курайской ртутной зоны (п. Акташ, Горный Алтай). Показано, что применение метода ТА-ЭТА-ААС для разделения и идентификации сульфида и селенида ртути возможно при значительных содержаниях обоих соединений в исследуемых образцах, т. е. при сравнительно небольших разбавлениях, однако при этом определение суммы HgS и HgSe возможно при любых содержаниях данных форм. Присутствие обеих форм подтверждается данными СЭМ ЭДС. Показано, что интервалы температурных выходов изучаемых форм ртути (Hg2+; смесь HgS/HgSe; Hg-OM (форма, связанная с органическим веществом, в том числе CH3Hg+)) в модельных и реальных образцах совпадают. На основании чего можно полагать, что предложенный подход может быть с успехом применен для быстрой и надежной идентификации минералов ртути в гипергенных условия