Nina Rosenkranz

Combustion of Hydrotreated Vegetable Oil and Jatropha Methyl Ester in a Heavy Duty Engine: Emissions and Bacterial Mutagenicity

Research on renewable fuels has to assess possible adverse health and ecological risks as well as conflicts with global food supply. This investigation compares the two newly developed biogenic diesel fuels hydrotreated vegetable oil (HVO) and jatropha methyl ester (JME) with fossil diesel fuel (DF) and rapeseed methyl ester (RME) for their emissions and bacterial mutagenic effects. Samples of exhaust constituents were compared after combustion in a Euro III heavy duty diesel engine. Regulated emissions were analyzed as well as particle size and number distributions, carbonyls, polycyclic aromatic hydrocarbons (PAHs), and bacterial mutagenicity of the exhausts. Combustion of RME and JME resulted in lower particulate matter (PM) compared to DF and HVO. Particle numbers were about 1 order of magnitude lower for RME and JME. However, nitrogen oxides (NOX) of RME and JME exceeded the Euro III limit value of 5.0 g/kWh, while HVO combustion produced the smallest amount of NOX. RME produced the lowest emissions of hydrocarbons (HC) and carbon monoxide (CO) followed by JME. Formaldehyde, acetaldehyde, acrolein, and several other carbonyls were found in the emissions of all investigated fuels. PAH emissions and mutagenicity of the exhausts were generally low, with HVO revealing the smallest number of mutations and lowest PAH emissions. Each fuel showed certain advantages or disadvantages. As proven before, both biodiesel fuels produced increased NOX emissions compared to DF. HVO showed significant toxicological advantages over all other fuels. Since jatropha oil is nonedible and grows in arid regions, JME may help to avoid conflicts with the food supply worldwide. Hydrogenated jatropha oil should now be investigated if it combines the benefits of both new fuels.

Prevalence of and relationship between rhinoconjunctivitis and lower airway diseases in compost workers with current or former exposure to organic dust.

INTRODUCTION AND OBJECTIVE The relationship between allergic rhinitis and allergic asthma is well characterized. However, it remains unknown whether an association exists between symptoms of upper and lower airway diseases and occupational bioaerosol exposure beyond the scope of allergy. MATERIALS AND METHODS The current cross-sectional study focuses on 190 current and 59 former compost workers exposed to bioaerosols. Work-related symptoms indicative of conjunctivitis, rhinitis and lower airway irritation were assessed and compared with 38 non-exposed control subjects. Allergic asthma was diagnosed using a calculated score, and chronic obstructive pulmonary disease (COPD) was spirometrically determined. RESULTS 12 current, 8 former and 5 non-exposed subjects were diagnosed with allergic asthma and excluded from further analysis. Multivariate logistic regression models suggested that cough and chronic bronchitis in current compost workers were associated with eye irritation (OR 2.75 (0.93-8.07); OR 7.22 (1.12-46.5)). Chronic bronchitis in former workers was strongly associated with work-related eye irritation (OR 38.6 (1.33->1000) and nose irritation (OR 25.0 (1.21-513)). CONCLUSIONS After excluding allergic asthmatics, there was no evidence that eye or nose irritation was due to an underlying atopic disease, but rather to non-allergic mucous membrane irritation syndrome. Therefore, the higher incidence of chronic bronchitis in former compost workers may reflect a chronic irritative process triggered by exposure to bioaerosols.

Kinetics of chemotaxis, cytokine, and chemokine release of NR8383 macrophages after exposure to inflammatory and inert granular insoluble particles

Accumulation of macrophages and neutrophil granulocytes in the lung are key events in the inflammatory response to inhaled particles. The present study aims at the time course of chemotaxis in vitro in response to the challenge of various biopersistent particles and its functional relation to the transcription of inflammatory mediators. NR8383 rat alveolar macrophages were challenged with particles of coarse quartz, barium sulfate, and nanosized silica for one, four, and 16h and with coarse and nanosized titanium dioxide particles (rutile and anatase) for 16h only. The cell supernatants were used to investigate the chemotaxis of unexposed NR8383 macrophages. The transcription of inflammatory mediators in cells exposed to quartz, silica, and barium sulfate was analyzed by quantitative real-time PCR. Challenge with quartz, silica, and rutile particles induced significant chemotaxis of unexposed NR8383 macrophages. Chemotaxis caused by quartz and silica was accompanied by an elevated transcription of CCL3, CCL4, CXCL1, CXCL3, and TNFα. Quartz exposure showed an earlier onset of both effects compared to the nanosized silica. The strength of this response roughly paralleled the cytotoxic effects. Barium sulfate and anatase did not induce chemotaxis and barium sulfate as well caused no elevated transcription. In conclusion, NR8383 macrophages respond to the challenge with inflammatory particles with the release of chemotactic compounds that act on unexposed macrophages. The kinetics of the response differs between the various particles.

Different Patterns in Changes of Exhaled Breath Condensate pH and Exhaled Nitric Oxide After Ozone Exposure

Study objective was the evaluation of pH in exhaled breath condensate (EBC-pH) and nitric oxide in exhaled breath (FeNO) as biomarkers of ozone induced inflammation. We recently demonstrated that an ozone exposure of 240 ppb is sufficient to reduce lung function indices. We enrolled ten healthy subjects exposed in an intermittent exercise protocol to ozone concentrations of 240 ppb and 40 ppb (sham exposure). EBC-pH and FeNO were assessed before (pre), immediately post (post), and 16 h after exposure (16 h). Findings are that compared to baseline, EBC-pH was significantly higher immediately after sham and ozone exposures, but not 16 h later. There was a negative net change in EBC-pH after adjusting for effects after sham exposure (net-ΔpHpost -0.38%, net-ΔpH16h -0.23%). Concerning FeNO, we observed no changes of values after sham exposure compared to baseline, but measured a significant lower net response at the end of exposure (net-ΔFeNOpost -17.5%) which was transient within 16 h (net-ΔFeNO16h -9.4%). We conclude that exercise known to enhance EBC-pH may compensate for EBC acidification associated with inflammation resulting in diminished change of this biomarker. Ozone imposes an oxidative burden and reactions between reactive oxygen species and NO might be an explanation for reduced FeNO levels.

Reproducibility of Sensitivity to Capsaicin Assessed by Single Breath Inhalation Methodology

The hallmark of sensory hyperreactivity is an enhanced capsaicin induced cough reflex. The cough reflex can be modified by activation of nociceptive (capsaicin-sensitive) nerve terminals. The aim of our study was to assess the influence of exposure to CO(2) concentrations up to 2.0 vol% on capsaicin induced cough reflex on four different occasions. Sixteen healthy volunteers were exposed to CO(2) concentrations of 0.5, 1.0, and 2.0 vol% for 4 h and to clean air in a repeated measures cross-over design. After exposure the capsaicin induced cough reflex was assessed by the single breath dose-response method according to ERS 2007 guidelines. After blank solutions, capsaicin doses (n=12, range 0.49 to 1000 μM) were administrated from a nebulizer combined with a provocation system (Masterscope, software APS version 5.02). Doses were doubled every minute and the concentration causing five or more coughs (C5) was fixed as the end point. The inter-individual C5 capsaicin responsiveness reflected a representative range (0.95-1000 μM). On an intra-individual basis, a good reproducibility could be demonstrated for four tests within 3 weeks. There was no influence of CO(2) challenge on the cough reflex. The first capsaicin test demonstrated a lower C5 threshold independent of the CO(2) concentration applied. In conclusion, assessing the capsaicin cough reflex by single breath inhalation is reliable. However, the at cough sensitivity might be overestimated at the first test occasion. Exposure to CO(2) in concentrations of up to 2.0 vol% has no effect on sensory reactivity.

Relationship of pulmonary function response to ozone exposure and capsaicin cough sensitivity.

Abstract Context: Challenge studies in humans have shown considerable interindividual variability in pulmonary impairment across ozone exposure. Objective: Since previous results suggested effect modulation by neural mechanism, we investigated sensory C-fiber reactivity in relationship to ozone-triggered response pattern. Methods: Cough reflex thresholds reflecting C-fiber sensitivity were evaluated by capsaicin single breath dose–response method. Capsaicin concentrations triggering, respectively, two and five or more coughs (C2, C5) were recorded. Sixteen healthy subjects were randomly exposed in an intermittent exercise protocol to ozone concentrations of 240 and 40 ppb (sham exposure). Ozone responsiveness was defined by a decrease in forced expiratory volume in 1 s (FEV1) of more than 5%. Results: Based on a dichotomous classification, subjects with enhanced reactivity to ozone had lower cough thresholds than non-responders (C2, p = 0.035; C5, p = 0.086). Over all, we could demonstrate relationships between capsaicin sensitivity and ozone-triggered changes in FEV1, peak expiratory flow and maximal expiratory flow at 50% vital capacity but not in specific airway resistance. Conclusion: Our results suggest that capsaicin challenge tests might be useful to characterize subjects with enhanced pulmonary function response towards inhalant irritants.

Regenerative Kraftstoffkonzepte für Plug-In-Hybrid-Fahrzeuge

Bei Plug-In-Hybrid-Fahrzeugen erlangt aufgrund moglicher langerer Verweilzeiten des Kraftstoffs im Tank die Alterungsproblematik eine grosere Relevanz. Dies ist insbesondere bei biodieselhaltigen Kraftstoffen der Fall, die eine kurzere Lagerstabilitat im Gegensatz zu fossilen Kraftstoffen aufweisen. Um dennoch Biodiesel als Kraftstoffkomponente langfristig einsetzen zu konnen, wurden verschiedene Fettalkohole und auch Tributylcitrat (TBC) als neuartige, stabilisierende Kraftstoffkomponenten getestet. Dabei wurde darauf geachtet, dass die neuen Kraftstoffformulierungen die Dieselkraftstoffnorm DIN EN 590 einhalten und somit als Drop-in- Kraftstoffe in den bestehenden Kraftstoffmarkt integriert werden konnen. Durch die Beimischung ausgewahlter Fettalkohole und TBC konnen Alterungsprodukte des Biodiesels in sehr unpolaren Kraftstoffen wie HVO (Hydrotreated Vegetable Oil) in Losung gehalten werden. Durch den Einsatz dieser Komponenten konnte ein Multikomponentenblend (REG50) definiert werden, der bei einem hohen regenerativen Anteil von bis zu 50 Vol.-% die Dieselkraftstoffnorm DIN EN 590 erfullt und mit den enthaltenen Losungsvermittleranteilen auch den gestiegenen Anforderungen von Plug-In-Hybrid- Fahrzeugen genugt. REG50 erwies sich bezuglich der Kraftstoff- und Emissionsparameter als unproblematisch beziehungsweise durch sehr gute Teilergebnisse als besonders geeignet.

Amylenes do not lead to bacterial mutagenicity in contrast to structurally related epoxides.

Amylenes are unsaturated hydrocarbons (C5H10), such as 1-pentene, 2-pentene, 2-methyl-but-1-en (3-methyl-1-butene), 2-methyl-but-2-en (isopentene), and 3-methyl-but-1-en. We investigated bacterial mutagenicity of 1-pentene, 2-pentene, and 3-methyl-but-1-en in the Ames test. 2-Pentene was investigated as racemate and as pure diastereomers. We included the methyltransferase deficient Salmonella Typhimurium strain YG7108 and the application of a gas-tight preincubation to reduce the risk of false negative results. 1,2-Epoxypentane which may arise from 1-pentene was used as positive control. None of the investigated amylenes showed mutagenic effects, whereas 1,2-epoxypentane was mutagenic exceeding 100 μg per plate. An exceptional high reverse mutation in the negative control plates in the experiments with 1,2-epoxypentane was obviously caused by evaporation into the incubator which was shown by placing the control plates in a separate apparatus. No differences were seen upon use of YG7108 and its parent strain TA1535. In conclusion, 1,2-epoxypentane is most probably not a substrate of the deleted bacterial methyltransferases. The comparison of the bacterial mutagenicity of the investigated amylenes and 1,2-epoxipentane suggests that epoxidation of amylenes in the S9-mix does not proceed effectively or is counterbalanced by detoxifying reactions. The assessment of mutagenic effects of short chained aliphatic epoxides can be underestimated due to the evaporation of these compounds.