Heat in Germany: Health risks and preventive measures

BACKGROUND: Climate change has already led to a significant temperature increase in Germany. The average temperature in the past decade was approximately 2°C above the pre-industrial level and eight of the ten hottest summers since the beginning of systematic weather records in 1881 were recorded in the last 30 years. METHODS: Based on a selective literature search and authors' own results, the article summarises the current state of knowledge on heat and its health impacts for Germany, addresses adaptation measures, and gives an outlook on implementation and research questions. RESULTS: Heat can aggravate pre-existing conditions such as diseases of the cardiovascular system, the respiratory tract, or the kidneys and trigger potentially harmful side effects for numerous medications. A significant increase in mortality is regularly observed during heat events. Previous approaches to mitigate the health impact of high temperatures include, for example, the heat alerts of the German Meteorological Service and recommendations for the preparation of heat-health action plans. CONCLUSIONS: Evidence on health impacts of heat and awareness of the need for heat-related health protection have grown in recent years, but there is still a need for further action and research

Electrical Mobility Measurements of Fine-Particle Formation during Chamber Studies of Atmospheric Photochemical Reactions

New approaches have been applied to electrical mobility measurement of ultrafine aerosol particles in smog chamber studies of secondary aerosol formation. With several mobility classifiers operating in parallel, rapid new particle formation was followed in the photochemical oxidation of dimethyl disulfide. When foreign particles were present before reaction was initiated, multiple bursts of nucleation and oscillations in the concentrations of 3.4-nm particles were observed. Later experiments used the scanning electrical mobility spectrometer to make high-resolution particle size distribution measurements. With this measurement method, the rapid growth of nuclei from their initial appearance at 10-nm size was followed in hydrocarbon/NO_x and hydrocarbon/NO_x/SO_2 reactions. Again, multiple bursts of nucleation were observed in some experiments, and insights were gained into particle growth mechanisms

Correlative cross-sectional characterization of nitrided, carburized and shot-peened steels: synchrotron micro-X-ray diffraction analysis of stress, microstructure and phase gradients

Mechanical properties of case modified steels depend decisively on the near-surface gradientsof residual stresses, microstructures, phases and chemical composition, which aregenerated by the empirically well-established case-hardening techniques. Currently,however, to obtain the correlation between near-surface structureeproperty gradients,applied hardening process parameters and steels’ overall performance is a very challengingtask. In this work, high-energy synchrotron cross-sectional X-ray diffraction(CSmicroXRD) using a pencil beam cross-section of 20 500 mm2 and complementaryanalytical techniques are used to characterize the surface-to-bulk gradient of (i) a plasmanitrided steel W300, (ii) a carburized case hardening steel (grade 18CrNiMo7-6) and (iii) ashot-peened high strength steel, type 300M. CSmicroXRD analysis reveals complex gradientsof martensite and austenite phases, residual stresses in both phases, crystallographictexture and the evolution of diffraction peak broadening with a spatial resolution of~20 mm. These parameters are correlated with the gradients of hardness, morphologymicrostructureand with the changes in N and C concentrations and/or retainedaustenite formation/depletion in all three model samples. Finally, the correlative microanalyticsapproach indicates the complexity of near surface structure-property relationshipsas well as the importance of innovative cross-sectional characterization, whichallows for assessing gradual near-surface physical and/or chemical changes accompanyingthermo-chemical and mechanical surface treatment

Smog chamber studies of aerosol formation in atmospheric mixtures

During a joint experiment of the Department of Chemical Engineering (California Institute of Technology) and the Institute of Experimental Physics (University of Vienna), measurements have been performed to study the dynamics of particle inception in photochemical smog. The goal of this study was to obtain an understanding of the fundamental mechanisms in the formation of organic aerosols during atmospheric photochemical reactions. This paper presents results with new approaches to mobility analysis for aerosol-measurements that have been performed to trace the dynamics of ultrafine aerosol particles in smog chamber experiments

Sensitivity of CCN spectra on chemical and physical properties of aerosol: A case study from the Amazon Basin

Organic material, about half of which is water soluble, constitutes nearly 80% of the wet-season aerosol mass in the Amazon Basin, while soluble inorganic salts (predominantly ammonium bisulfate) represent about 15%. A detailed analysis of number distributions and the size-dependent chemical composition of the aerosol indicates that, in principle, the sulfate fraction could account for most of the cloud condensation nuclei (CCN) activity. Uncertainty about the chemical speciation of the water-soluble organic component precludes a rigorous analysis of its contribution to nucleation activity. Within reasonable assumptions, we can, however, predict a similar contribution of the organic component to CCN activity as that from sulfate. Because of the nonlinear dependence of droplet nucleation behavior on solute amount, the nucleation activity cannot be attributed uniquely to the inorganic or organic fractions. The role of water-soluble organic compounds as surfactants, however, may be significant (especially in the case of biomass-burning aerosol) and more field measurements are needed to quantify their effects on the surface tension of ambient aerosols. The parametric dependence of the CCN spectra on the physical and chemical properties of the aerosol show that the number distribution, soluble content of the aerosol, and surface tension effects all play an important role in determining CCN spectra