Impact of endocrine-disrupting compounds (EDCs) on female reproductive health

Evidence is accumulating that environmental chemicals (ECs) including endocrine-disrupting compounds (EDCs) can alter female reproductive development, fertility and onset of menopause. While not as clearly defined as in the male, this set of abnormalities may constitute an Ovarian Dysgenesis Syndrome with at least some origins of the syndrome arising during foetal development. ECs/EDCs have been shown to affect trophoblast and placental function, the female hypothalamo-pituitary-gonadal axis, onset of puberty and adult ovarian function. The effects of ECs/EDCs are complex, not least because it is emerging that low-level, 'real-life' mixtures of ECs/EDCs may carry significant biological potency. In addition, there is evidence that ECs/EDCs can alter the epigenome in a sexually dimorphic manner, which may lead to changes in the germ line and perhaps even to transgenerational effects. This review summarises the evidence for EC, including EDC, involvement in female reproductive dysfunction, it highlights potential mechanisms of EC action in the female and emphasises the need for further research into EC effects on female development and reproductive function

Increases in mercury emissions from desert soils in response to rainfall and irrigation

As part of an international Hg flux intercomparison at the Steamboat Springs, Nevada, geothermal area, several dynamic soil flux chambers and micrometeorological gradient systems were operated over desert soils in early September 1997. A series of unanticipated convective rain cells impacted the site with the first rainfall in ∼90 days, and the initial 4-cm rainfall increased soil moisture from ∼0.01 to 0.06% (vol/vol). Several chambers were operating prior to the events, and two were deployed over wet soils following rainfall. Rainfall resulted in an immediate and steep rise in ambient air Hg concentrations and soil Hg emissions which persisted for 12–24 hours. Fluxes increased most quickly and to a greater degree over the wettest soils, and the rate of increase was related to chamber design and flushing rate. The flux response was also apparent in the micrometeorological data. In general, soil emissions increased by an order of magnitude following the rain, and reached levels ∼6 times above those at the same time the previous day. These fluxes were significantly correlated with temperature, radiation, humidity, wind speed, and soil moisture. After drying for ∼40 hours, selected soil plots were manually irrigated with low-Hg-distilled water. Mercury emissions responded similarly across the three treated sites, uniformly increasing from ∼60 ng m⁻² h⁻¹ pretreatment to ∼650 ng m⁻² h⁻¹ posttreatment, which was a factor of ∼6 higher than adjacent control soils. Possible causes of the increases in flux include soil gas displacement, desorption of Hg° by water molecules, and desorption of Hg(II) and subsequent reduction in solution. The kinetics of the flux response, combined with local soil and climatic conditions, suggest that Hg emissions were responding primarily to soil moisture and solar radiation. These data have interesting implications for the role of changing regional climates on biogeochemical cycling of Hg.10 page(s

Systemeigenschaften von Nickel-Metallhydrid-Batterien in bipolarer Bauweise Abschlussbericht

The report summarizes the results of a research project into the properties of bipolar nickel metal hydride batteries. Various investigations have been analyzed to discuss th behavior of these high power storage systems. In addition to the discharge characteristics, the performance during cycling and charging methods have been in focus of the investigation. Stacks of 12 and 36 V have been built and used for the investigations. One of the major achievements was the manufacturing of a complete battery of 310 V for bench tests. Results emphasize that nickel metal hydride batteries are good candidates for use in hybrid vehicles. (orig.)Das Projekt beinhaltete den Aufbau und die Untersuchung der Betriebsweise von Nickel-Metallhydridbatterien in bipolarer Stackbauweise. Es wurden zahlreiche Untersuchungen durchgefuehrt, die das Verhalten solcher Module als Hochleistungsspeicher beschreiben. Neben der Untersuchung der Belastbarkeit, des Verhaltens beim Zyklisieren als Hybridbatterie standen vor allem die Techniken des Ladens im Mittelpunkt der Untersuchungen. Als Messobjekte wurden Stacks mit Spannungen von 12 und 36 V eingesetzt. Im Verlauf des Projektes gelang es eine bipolare Batterie einer Nennspannung von 310 V aus Modulen aufzubauen. Die Ergebnisse belegen, dass Nickel-Metallhydridbatterien in bipolarer Bauweise aussichtsreich fuer den Einsatz in Hybridfahrzeugen sind. (orig.)SIGLEAvailable from TIB Hannover: F02B11 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman