Observations of long-lived anthropogenic halocarbons at the high-Alpine site of Jungfraujoch (Switzerland) for assessment of trends and European sources.

Anthropogenic halocarbons, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), bromocarbons (halons) and long-lived chlorinated solvents have been measured continuously at the high-Alpine site of Jungfraujoch (Switzerland) since January 2000. Chloro- and bromo-containing halocarbons are responsible for the stratospheric ozone depletion and will be globally banned from usage within the next years. With the exception of the stable CFC-12 (CF2 Cl2), all major CFCs and chlorinated solvents show a negative trend in recent years in their background concentrations at Jungfraujoch. HCFCs, as their first-generation substitute, are still increasing with a few percent per year. However, the frequency and the strength of HCFCs pollution events, which are caused by regional European emissions, are already declining. This can be seen as a sign of the impending ban of these gases within the next years in Europe. On the other hand, HFCs as the second-generation substitutes, are increasing with relative rates of at least 10% per year (e.g. almost 5 ppt per year for HFC-134a). An allocation of European sources was attempted by combining measured concentrations with trajectories of air masses reaching the Jungfraujoch during pollution events. Potential source regions could be detected in Italy, France, Spain and Germany.

[Assessment of potential blood substitute solutions with oxygen-carrying properties and their possible uses]. / Zur Beteiligung potentieller Blut-Ersatzlösungen mit Sauerstoffträgereigenschaften den deren Einsatzmöglichkeiten.

Beside the necessary volume effect (isoosmotic and isooncotic solution) and the physiological bicarbonate concentration (prevention of dilution acidosis) a possible blood substitute with O2 carrier characteristics should enable an optimal O2 transport: Viscosity as low as possible and shear rate independent (Newtonian behavior), O2 concentration at the given O2 partial pressure at least 6 ml/dl, and mean capillary O2 partial pressure as high as possible. For the judgement of such a blood substitute, the so-called O2 supply index is recommended, i.e., O2 concentration times mean capillary O2 partial pressure divided by viscosity.