Work in Hypoxic Conditions-Consensus Statement of the Medical Commission of the Union Internationale des Associations d'Alpinisme (UIAA MedCom)

Objectives: The Commission gives recommendations on how to provide health and safety for employees in different kinds of low oxygen atmospheres. So far, no recommendations exist that take into account the several factors we have outlined in this report. Methods: The health and safety recommendations of several countries were analysed for their strength and deficiencies. The scientific literature was checked (Medline, etc.) and evaluated for relevance of the topic. Typical situations of work in hypoxia were defined and their specific risks described. Specific recommendations are provided for any of these situations. Results: We defined four main groups with some subgroups (main risk in brackets): short exposure (pressure change), limited exposure (acute altitude disease), expatriates (chronic altitude disease), and high-altitude populations (re-entry pulmonary oedema). For healthy unacclimatized persons, an acute but limited exposure down to 13% O2 does not cause a health risk. Employees should be advised to leave hypoxic areas for any break, if possible. Detailed advice is given for any other situation and pre-existing diseases. Conclusions: If the specific risk of the respective type of hypoxia is taken into account, a pragmatic approach to provide health and safety for employees is possible. In contrast to other occupational exposures, a repeated exposure as often as possible is of benefit as it causes partial acclimatization. The consensus statement was approved by written consent in lieu of a meeting in July 200

Trace element composition of aqueous extracts of some diatomite and lydite samples from Karelia

Актуальность исследования обусловлена необходимостью получения достоверной информации об элементном составе водных экстрактов диатомитов и лидитов. В настоящее время диатомиты используются в различных отраслях промышленности, в том числе медицинской и фармацевтической. Однако детального изучения состава их водных экстрактов практически не проводилось. Цель: изучить микроэлементный состав водных экстрактов нескольких образцов диатомитов и лидитов. Объекты: три образца диатомитов и два образца лидитов территории Республики Карелия. Методика: лабораторный эксперимент, водная экстракция, масс-спектрометрия с индуктивно-связанной плазмой (ICP MS). Результаты. Изучен элементный состав водных экстрактов нескольких образцов диатомитов и лидитов территории Республики Карелия методом ICP MS. Во всех исследованных экстрактах образцов диатомитов и лидитов преобладающими элементами являются Mg, Na, Ca, K и Al (до нескольких тысяч мкг/л). Экстракты образцов диатомитов имеют однородный состав. Максимальные содержания в них других, наиболее значимых, элементов составляли: P - до 650, Fe - до 1700 (образец № 1) и Mn - до 3300 (образец № 3) мкг/л. Концентрации в диапазоне от 10 до 100 мкг/л характерны для ряда элементов (Li, B, Ti, Cr, Co, Ni, Cu, Zn, Sr, Y, Zr и Ba) в экстрактах всех образцов диатомитов. Экстракты образцов диатомитов № 1 и 2 имели максимальные концентрации легких редкоземельных элементов (РЗЭ): Nd (до 247), Ce (до 230), La (до 156 мкг/л). Химический состав экстрактов образцов лидитов заметно отличался, как между собой, так и от экстрактов диатомитов. Кислая среда (рН 4,5-4,6) экстракта образца № 4 способствовала накоплению ряда элементов: Ni, Sr, Be, Mn, U, Tl, и особенно V, Co, Cu, Zn, Y, Ba. В то же время в экстракте образца № 5 в слабощелочных условиях (рН 7,4-7,5) наблюдались максимальные концентрации Mo, W, Zr, Hf. В исследованных экстрактах образцах диатомитов и лидита № 4 концентрации Al, Mn, Fe, Co, Ni, Cu, Zn превышали значения предельно допустимых концентраций (ПДК) рыбохозяйственных водоемов. Водные экстракты образцов диатомитов показали значительное содержание элементов, которые могут оказать влияние на формирование состава маломинерализованных карельских вод. При этом содержание ряда полезных для развития растений микроэлементов (Ca, Mg, К, Р, Cu, Zn, V, Mn, Sr, Y, Zr) предполагает возможность их использования как «мягких» удобрений (или добавок к минеральным удобрениям).The relevance of the research consists in the necessity to obtain reliable information on microelemental composition of aqueous extracts of diatomite and lydite. Currently, diatomites are expected to be widely used in medical, pharmaceutical and food industries, but a detailed study of their composition has not been conducted. The main aim of the research is to investigate the trace element composition of aqueous extracts of several samples of diatomite and lydite using ICP MS analytic method. The objects: three samples of diatomite and two samples of lydite from Karelia (North-West of Russia). Methods: grinding samples of diatomite and lydite infused with deionized water at room conditions. Assays of aqueous extracts of the studied samples were centrifuged and analyzed by ICP MS after 1, 3 and 10 days. Results. The authors present the results of 54 chemical elements identification in water extracts of diatomite and lydite using ICP MS. In all water extracts Mg, Na, Ca, K and Al (up to several thousand µg/l) are the predominant elements. Extracts of diatomite samples have a more homogeneous composition. The most important elements were: P - 650, Fe - 1700 (sample no. 1) and Mn - up to 3300 (sample no. 3) µg/L. Concentrations in the range from 10 to 100 µg/l are typical for a number of elements (Li, B, Ti, Cr, Co, Ni, Cu, Zn, Sr, Y, Zr and Ba) of all diatomite samples. Extracts of diatomite samples no. 1 and 2 had a maximum concentration of light REE: Nd (up to 247 µg/l), Ce (up to 230 µg/l), La (up to 156 µg/l). Chemical composition of extracts of lydite was differed markedly, both among themselves and from diatomites. Acidic medium (pH 4,5-4,6) of an aqueous extract of the sample lydite no. 4 contributed to accumulation of a number of elements Sr, Mn, U and, especially, Be, Fe, Co, Ni, Cu, Zn, Y, Ba, Tl. At the same time, maximum concentrations of V, Mo, W, Zr, Hf were observed in the extract of sample no. 5 under slightly alkaline conditions (pH 7,4-7,5). We noted an excess of permissible limits of fishery water bodies for Al and Mn in all samples. The excess of the «normal» maximum permissible concentrations have also shown the transition elements (Fe, Co, Ni, Cu, Zn) in extracts of diatomite and sample lydite no. 4, as well as V and Mo in the sample lydite no. 5. The study of aqueous extracts of diatomite and lydites showed that diatomite and lydites under certain conditions can have a significant impact on composition of low-mineralized waters in the territory of Karelia. At the same time, the presence of useful elements for the plant growth (Mg, Ca, K, Cu, Zn, V, Mn, Sr, Y, Zr) gives the possibility of their use as a «soft» fertilizers (or additives to mineral fertilizers)