Clara cell protein as a biomarker for ozone-induced lung injury in humans

Exposure to ozone (O3) impairs lung function, induces airway inflammation and alters epithelial permeability. Whilst impaired lung function and neutrophilia have been observed at relatively low concentrations, altered lung epithelial permeability is only seen after high-dose challenges. The appearance of Clara cell protein (CC16) in serum has been proposed as a sensitive marker of lung epithelial injury. Here, the use of CC16 as an injury biomarker was evaluated under a controlled exposure to O3 and the relationship between this marker of lung injury and early lung function decrements was investigated. Subjects (n=22) were exposed on two separate occasions to 0.2 parts per million O3 and filtered air for 2 h. Blood samples were drawn and lung function assessed at 2 h pre-exposure, immediately before and immediately after exposure as well as 2 and 4 h postexposure. O3 increased CC16 serum concentrations at 2 h (12.0+/-4.5 versus 8.4+/-3.1 microg x L(-1)) and 4 h postexposure (11.7+/-5.0 versus 7.9+/-2.6 microg x L(-1)) compared with air concentrations. Archived samples from O3 studies utilising the same design indicated that this increase was sustained for up to 6 h postexposure (9.1+/-2.6 versus 7.1+/-1.7 microg x L(-1)) with concentrations returning to baseline by 18 h (7.7+/-2.9 versus 6.6+/-1.7 microg x L(-1)). In these studies, the increased plasma CC16 concentration was noted in the absence of increases in traditional markers of epithelial permeability. No association was observed between increased CC16 concentrations and lung function changes. To conclude, Clara cell protein represents a sensitive and noninvasive biomarker for ozone-induced lung epithelial damage that may have important uses in assessing the health effects of air pollutants in future epidemiological and field studies

Assessing ozone exposure for epidemiological studies in Malmo and Umea, Sweden

Ground level ozone [ozone] is considered a harmful air pollutant but there is a knowledge gap regarding its long term health effects. The main aim of this study is to develop local Land Use Regression [LUR] models that can be used to study long term health effects of ozone. The specific aim is to develop spatial LUR models for two Swedish cities, Umea and Malmo, as well as a temporal model for Malmo in order to assess ozone exposure for long term epidemiological studies. For the spatial model we measured ozone, using Ogawa passive samplers, as weekly averages at 40 sites in each study area, during three seasons. This data was then inserted in the LUR-model with data on traffic, land use, population density and altitude to develop explanatory models of ozone variation. To develop the temporal model for Malmo, hourly ozone data was aggregated into daily means for two measurement stations in Malmo and one in a rural area outside Malmo. Using regression analyses we inserted meteorological variables into different temporal models and the one that performed best for all three stations was chosen. For Malmo the LUR-model had an adjusted model R-2 of 0.40 and cross validation R-2 of 0.17. For Umea the model had an adjusted model R-2 of 0.67 and cross validation adjusted R-2 of 0.48. When restricting the model to only including measuring sites from urban areas, the Malmo model had adjusted model R-2 of 0.51 (cross validation adjusted R-2 0.33) and the Umea model had adjusted model R-2 of 0.81 (validation adjusted R-2 of 0.73). The temporal model had adjusted model R-2 0.54 and 0.61 for the two Malmo sites, the cross validation adjusted R-2 was 0.42. In conclusion, we can with moderate accuracy, at least for Umea, predict the spatial variability, and in Malmo the temporal variability in ozone variation. (C) 2014 The Authors. Published by Elsevier Ltd

The Po River Delta (North Italy) Indoor Epidemiological Study: Home Characteristics, Indoor Pollutants, and Subjects' Daily Activity Pattern

A total of 140 homes in the Po River Delta area of North Italy (near Venice) were monitored during summer and winter to measure the concentration of nitrogen dioxide (NO2), and respirable suspended particulate matter (RSP, < 2.5 mu m). In this paper, the findings on home characteristics, daily activity pattern of occupants, and residential indoor air quality are described. Our study confirms that people spend the greater part of their daily lives indoors (84%), especially at home (64%). The concentration of monitored pollutants was greater in winter than in summer. The highest levels of NO2 were found in the kitchens. Significantly higher indoor NO2 levels were found in the houses with gas-furnace heating and/or with gas water heater located inside the home. RSP was significantly higher in homes where tobacco smoking took place, and was significantly related to the number of cigarettes smoked. A significant relationship between NO2 indoor concentrations and RSP values in both seasons was found. (C) Indoor Air (1998)