Probabilistic meta-analysis of risk from the exposure to Hg in artisanal gold mining communities in Colombia

Colombia is one of the largest per capita mercury polluters in the world as a consequence of its artisanal gold mining activities. The severity of this problem in terms of potential health effects was evaluated by means of a probabilistic risk assessment carried out in the twelve departments (or provinces) in Colombia with the largest gold production. The two exposure pathways included in the risk assessment were inhalation of elemental Hg vapors and ingestion of fish contaminated with methyl mercury. Exposure parameters for the adult population (especially rates of fish consumption) were obtained from nation-wide surveys and concentrations of Hg in air and of methyl-mercury in fish were gathered from previous scientific studies. Fish consumption varied between departments and ranged from 0 to 0.3 kg d?1. Average concentrations of total mercury in fish (70 data) ranged from 0.026 to 3.3 lg g?1. A total of 550 individual measurements of Hg in workshop air (ranging from menor queDL to 1 mg m?3) and 261 measurements of Hg in outdoor air (ranging from menor queDL to 0.652 mg m?3) were used to generate the probability distributions used as concentration terms in the calculation of risk. All but two of the distributions of Hazard Quotients (HQ) associated with ingestion of Hg-contaminated fish for the twelve regions evaluated presented median values higher than the threshold value of 1 and the 95th percentiles ranged from 4 to 90. In the case of exposure to Hg vapors, minimum values of HQ for the general population exceeded 1 in all the towns included in this study, and the HQs for miner-smelters burning the amalgam is two orders of magnitude higher, reaching values of 200 for the 95th percentile. Even acknowledging the conservative assumptions included in the risk assessment and the uncertainties associated with it, its results clearly reveal the exorbitant levels of risk endured not only by miner-smelters but also by the general population of artisanal gold mining communities in Colombia.

[ Pûtlā nav ćhûgā

Pīr Satgur Nūr].

Planeamento das condições operacionais do BOC-HG e UCA do Centro Hospitalar e Universitário de Coimbra EPE

No atual contexto de mudança, impõe-se como desafio das organizações a procura de uma maior economia, eficácia e eficiência das suas operações. Este projeto aborda e desenvolve o planeamento de cirurgias eletivas, em dois Blocos Operatórios do CHUC. Procura-se essencialmente uma melhor resposta, em termos estratégicos, para a redução das listas de espera para cirurgia, bem como a melhoria na eficiência do funcionamento dos serviços. Com este propósito procedeu-se ao levantamento bibliográfico, quer alusivo à integração destes Serviços Hospitalares, em normas e leis de referência nacional, regional e local, quer em conceitos na vertente da otimização/apoio à decisão. De seguida foi realizada uma análise contextual dos serviços em estudo, passando-se para a componente metodológica. Nesta, promoveu-se uma sequência de métodos, iniciando-se com recurso a questionários de forma a indagar sobre a opinião de critérios de otimização por parte dos intervenientes e agentes de suporte à decisão, seguindo-se de uma entrevista para recolha de parâmetros e ideias para um modelo de otimização, finalizando-se na conceção e adaptação do modelo. Os testes ao modelo mostraram bons resultados computacionais e revelaram-se adequados há realidade do bloco operatório. As abordagens propostas no presente projeto proporcionam ainda uma reflexão sobre os problemas de planeamento do Bloco Operatório e no seu desempenho global.

(Table 1) Age of sediments with anomalously high Hg concentrations in core BDP-98, Lake Baikal

Mercury distribution was examined in the sediments of Lake Baikal that were sampled within the scope of the Baikal Drilling International Project in 1996-1999. The Hg concentrations in the ancient sediments are close to those in the modern sediments with the exception of a few peak values, whose ages coincide with those of active volcanism in adjacent areas. Mercury was demonstrated to be contained in the sediments in the adsorbed Hg0 mode, predominantly in relation with organic matter. When the organic matter of the bottom sediments is decomposed in the course of lithification, Hg is retained in the sediments adsorbed on the residual organic matter, and the concentration of this element corresponds to its initial content in the bottom sediments during their accumulation. Mercury concentrations in lithologically distinct bottom sediments of Lake Baikal and its sediments as a whole depend on the climate. Sediments that were formed during warm periods of time contain more Hg than those produced during cold periods or glaciation. Periodical variations in the Hg concentrations in the bottom sediments of Lake Baikal reflect the variations in the contents of this element in the Earth's atmosphere in the Late Cenozoic, which were, in turn, controlled by the climatic variations on the planet and, thus, can be used for detailed reconstructions of variations in the average global temperature near the planet's surface.

Finanzas y política;

Mode of access: Internet.

Finanzas argentinas : estudios é ideas sobre nuestros empréstitos externos /

Includes "Fé de erratas."

Direct support and general support repair parts list (including depot maintenance allowances) : winch assembly (2590-753-8687, 2520-040-2112 HG-W2868D, and 2590-402-5200 w/cable level winder assembly).

Includes index.

Tierra de promision : descripción general de la república oriental del Uruguay : y su comercio, industrias, ganaderia, agricultura, finanzas, riquezas, educación y progresos en todas las manifestaciones de la actividad humana /

Mode of access: Internet.