Effects of Low Sulfur Fuel and a Catalyzed Particle Trap on the Composition and Toxicity of Diesel Emissions

In this study we compared a “baseline” condition of uncontrolled diesel engine exhaust (DEE) emissions generated with current (circa 2003) certification fuel to an emissions-reduction (ER) case with low sulfur fuel and a catalyzed particle trap. Lung toxicity assessments (resistance to respiratory viral infection, lung inflammation, and oxidative stress) were performed on mice (C57Bl/6) exposed by inhalation (6 hr/day for 7 days). The engine was operated identically (same engine load) in both cases, and the inhalation exposures were conducted at the same exhaust dilution rate. For baseline DEE, this dilution resulted in a particle mass (PM) concentration of approximately 200 μg/m(3) PM, whereas the ER reduced the PM and almost every other measured constituent [except nitrogen oxides (NO(x))] to near background levels in the exposure atmospheres. These measurements included PM, PM size distribution, PM composition (carbon, ions, elements), NO(x), carbon monoxide, speciated/total volatile hydrocarbons, and several classes of semi-volatile organic compounds. After exposure concluded, one group of mice was immediately sacrificed and assessed for inflammation and oxidative stress in lung homogenate. Another group of mice were intratracheally instilled with respiratory syncytial virus (RSV), and RSV lung clearance and inflammation was assessed 4 days later. Baseline DEE produced statistically significant biological effects for all measured parameters. The use of low sulfur fuel and a catalyzed trap either completely or nearly eliminated the effects

Effect of Operating and Sampling Conditions on the Exhaust Gas Composition of Small-Scale Power Generators

Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results

A study of the occurrence of HLA DR2 in 124 narcoleptics: clinical aspects

The authors examined HLA antigens in 124 narcoleptics. In addition to narcolepsy, 122 patients suffered also from cataplexy. The two patients without cataplexy suffered also from sleep paralysis and hypnagogic hallucinations. These two symptoms were also present in many of the other patients. HLA group DR2 was found in 120 patients including all six symptomatic cases. In four patients HLA DR2 was not present. Two of these were fully pronounced narcolepsy-cataplexy cases whereas the two other did not suffer from cataplexy. Since several other cases with negative DR2 have already been published it is necessary to admit the existence of DR2-negative narcolepsy, albeit very rare. Among 5 patients with isolated sleep paralysis HLA DR2 was present in one familial and 1 sporadic case. The authors further discuss some aspects of the classification of narcolepsies in the light of recent HLA studies as well as their delimitation from idiopathic hypersomnia

Fertilia: a European International Cooperation (INCO EU) project for monitoring trace elements in agricultural ecosystems

Background. A research project was financed starting in 1938 by the European Commission within the fourth Framework, involving International Cooperation (INCO EU) with Central European Countries. The project INCO Copernicus IC15-CT98-0124, acronym FERTILIA, addresses the relevance of trace metals for soil fertility. The participants come from four different countries: Italy, also acting as Coordinator, with the University of Parma, Department of Environmental Sciences, Division of Genetics and Environmental Biotechnology; Spain, with Consejo superior de Investigaciones Cientificas, Centre for the Biology of the Soil; Poland, with two partners, the Academy of Agriculture, Department of Microbiology and the University of Opole, Institute of Chemistry; finally, the Czech Republic, with the Academy of Sciences, Department of Environmental Analytical Chemistry. The participants bring together different expertise ranging from the analytical chemistry to soil microbiology up to plant genetic engineering and physic spectroscopy. The overall purpose of the three years project FERTILIA is to monitor the partitioning of trace elements in agricultural plants and vegetables grown on European soils subjected to different fertilisation regimes, taking into consideration all the biological, pedological and geochemical factors which can affect their form.Methods. Objectives and phases of the research are: determination of metal concentration in different sources of agricultural fertilisers (Action 1); physico-chemical analysis of metal concentration and aggregation in European soils (Action 2); analysis of metal content and partitioning ia different organisms taken from different levels of soil ecosystem (Action 3); morphological and functional effects of metals monitored with biomarkers microorganisms, invertebrates, and plants (Action 4); analysis of ecotoxicological and genotoxic effects of metals through the utilisation of model systems (Action 5); production and description of spatial models of soil ecosystems, by integrating geochemical and biological data within a Geographic Information System (GIS) (Action 6).Results. After the first year of research, Actions 1, 2, 3, and 4 reached a satisfactory set of experimental data. The last two actions are still in progress, because they require data from the first ones in order to be developed.Conclusions. Beside trying to show whether heavy metals can now in relevant amounts from fertilisers to soils and then to plants and soil microorganisms, this research project is trying to determine at which degree agricultural practices can modify soils metals content and the consequences this has on the crops quality