The case for re-evaluating the upper limit value for selenium in drinking water in Europe
ABSTRACT Selenium is an essential trace element for life, which can be toxic for humans when intakes reach a certain amount. Therefore, since the margin between healthy intake and toxic intake is narrow, the selenium concentration of tap water is a parameter that must be monitored because of its potential for increased intake. The present work gives an overview of the different approaches used to calculate safe limits for selenium. As recommended by WHO, the guidelines for drinking water form the basis of national legislated standards for drinking water. Before setting a maximum acceptable level in drinking water, it is necessary to take into account the total intake of selenium in both food and beverage. The limit value of 10 microg l(-1) for drinking water laid down in the European regulations for all countries should be adapted depending on geographic area, as previously recommended by WHO.
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ABSTRACT: Results of recent epidemiologic studies suggest the need to reassess the safe upper limit in drinking water of selenium, a metalloid with both toxicological and nutritional properties. Observational and experimental human studies on health effects of organic selenium compounds consumed through diet or supplements, and of inorganic selenium consumed through drinking water, have shown that human toxicity may occur at much lower levels than previously surmised. Evidence indicates that the chemical form of selenium strongly influences its toxicity, and that its biological activity may differ in different species, emphasizing the importance of the few human studies on health effects of the specific selenium compounds found in drinking water. Epidemiologic studies that investigated the effects of selenate, an inorganic selenium species commonly found in drinking water, together with evidence of toxicity of inorganic selenium at low levels in from in vitro and animal studies, indicate that health risks may occur at exposures below the current European Union and World Health Organization upper limit and guideline of 10 and 40μg/l, respectively, and suggest reduction to 1μg/l in order to adequately protect human health. Although few drinking waters are currently known to have selenium concentrations exceeding this level, the public health importance of this issue should not be overlooked, and further epidemiologic research is critically needed in this area.Science of The Total Environment 12/2012; 443C:633-642. DOI:10.1016/j.scitotenv.2012.11.025 · 4.10 Impact Factor
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ABSTRACT: To assess the evidence regarding the efficacy and safety of intravenous fat emulsion (IFE) in the management of poisoned patients. We performed a systematic review of the literature with no time or language restriction. The electronic databases were searched from their inception until June 1, 2009 (Medline, EMBASE, ISI web of science, Biological abstract, LILACS, ChemIndex, Toxnet, and Proquest). We also examined the references of identified articles and the gray literature. The target interventions eligible for inclusion were administration of any IFE before, during, or after poisoning in human or animals. All types of studies were reviewed. Eligibility for inclusion and study quality scores, based on criteria by Jadad and the STROBE statement, were evaluated by independent investigators. The primary outcome was mortality. Secondary outcomes included neurologic, hemodynamic, and electrocardiographic variables, as well as adverse effects. Of the 938 publications identified by the search strategies, 74 met the inclusion criteria. We identified 23 animal trials, 50 human, and 1 animal case reports. Overall, the quality of evidence was weak and significant heterogeneity prevented data pooling. Available data suggest some benefits of IFE in bupivacaine, verapamil, chlorpromazine, and some tricyclic antidepressants and beta-blockers toxicity. No trial assessed the safety of IFE in the treatment of acute poisoning. The evidence for the efficacy of IFE in reducing mortality and improving hemodynamic, electrocardiographic, and neurological parameters in the poisoned patients is solely based on animal studies and human case reports. The safety of IFE has not been established.Clinical Toxicology 01/2010; 48(1):1-27. DOI:10.3109/15563650903544124 · 3.12 Impact Factor
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ABSTRACT: Jensen and Meckling (1976) argue that agency costs are not dependent on product market competition. However, elsewhere in the economics literature, theoretical analysis and empirical research have indicated that product market competition reduces agency costs by reducing the marginal cost of eliciting effort from agents. We investigate the relationship between product market competition and audit fee, as an example of agency cost. Taking advantage of a proprietary data set for Greek audit firms, we find that the audit fee and audit hours are inversely associated with client firm product market competition. We conclude that audit effort, as an agency cost, is reduced where competitive forces reduce the need for shareholders to bear the costs of monitoring agents.The British Accounting Review 06/2011; 43(2):112-119. DOI:10.1016/j.bar.2011.02.005