Auflistung nach Autor:in "Liu, L.-J. Sally"

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Characterization of source-specific air pollution exposure for a large population-based Swiss cohort (SAPALDIA)
(National Institute of Environmental Health Sciences, 2007) Liu, L.-J. Sally; Curjuric, Ivan; Keidel, Dirk; Heldstab, Jürg; Künzli, Nino; Bayer-Oglesby, Lucy; Ackermann-Liebrich, Ursula; Schindler, Christian
Background: Although the dispersion model approach has been used in some epidemiologic studies to examine health effects of traffic-specific air pollution, no study has evaluated the model predictions vigorously. Methods: We evaluated total and traffic-specific particulate matter < 10 and < 2.5 microm in aero-dynamic diameter (PM(10), PM(2.5)), nitrogren dioxide, and nitrogen oxide concentrations predicted by Gaussian dispersion models against fixed-site measurements at different locations, including traffic-impacted, urban-background, and alpine settings between and across cities. The model predictions were then used to estimate individual subjects' historical and cumulative exposures with a temporal trend model. Results: Modeled PM(10) and NO(2) predicted at least 55% and 72% of the variability of the measured PM(10) and NO(2), respectively. Traffic-specific pollution estimates correlated with the NO(x) measurements (R(2) >or=0.77) for background sites but not for traffic sites. Regional background PM(10) accounted for most PM(10) mass in all cities. Whereas traffic PM(10) accounted for < 20% of the total PM(10), it varied significantly within cities. The modeling error for PM(10) was similar within and between cities. Traffic NO(x) accounted for the majority of NO(x) mass in urban areas, whereas background NO(x) accounted for the majority of NO(x) in rural areas. The within-city NO(2) modeling error was larger than that between cities. Conclusions: The dispersion model predicted well the total PM(10), NO(x), and NO(2) and traffic-specific pollution at background sites. However, the model underpredicted traffic NO(x) and NO(2) at traffic sites and needs refinement to reflect local conditions. The dispersion model predictions for PM(10) are suitable for examining individual exposures and health effects within and between cities.
01A - Beitrag in wissenschaftlicher Zeitschrift
Reduced exposure to PM10 and attenuated age-related decline in lung function
(Massachusetts Medical Society, 2007) Downs, Sara H.; Schindler, Christian; Liu, L.-J. Sally; Keidel, Dirk; Bayer-Oglesby, Lucy; Brutsche, Martin H.; Gerbase, Margaret W.; Keller, Roland; Künzli, Nino; Leuenberger, Philippe; Probst-Hensch, Nicole M.; Tschopp, Jean-Marie; Zellweger, Jean-Pierre; Rochat, Thierry; Schwartz, Joel; Ackermann-Liebrich, Ursula
Background: Air pollution has been associated with impaired health, including reduced lung function in adults. Moving to cleaner areas has been shown to attenuate adverse effects of air pollution on lung function in children but not in adults. Methods: We conducted a prospective study of 9651 adults (18 to 60 years of age) randomly selected from population registries in 1990 and assessed in 1991, with 8047 participants reassessed in 2002. There was complete information on lung volumes and flows (e.g., forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], FEV1 as a percentage of FVC, and forced expiratory flow between 25 and 75% of the FVC [FEF25–75]), smoking habits, and spatially resolved concentrations of particulate matter that was less than 10 μm in aerodynamic diameter (PM10) from a validated dispersion model assigned to residential addresses for 4742 participants at both the 1991 and the 2002 assessments and in the intervening years. Results: Overall exposure to individual home outdoor PM10 declined over the 11-year follow-up period (median, −5.3 μg per cubic meter; interquartile range, −7.5 to −4.2). In mixed-model regression analyses, with adjustment for confounders, PM10 concentrations at baseline, and clustering within areas, there were significant negative associations between the decrease in PM10 and the rate of decline in FEV1 (P=0.045), FEV1 as a percentage of FVC (P=0.02), and FEF25–75 (P=0.001). The net effect of a decline of 10 μg of PM10 per cubic meter over an 11-year period was to reduce the annual rate of decline in FEV1 by 9% and of FEF25–75 by 16%. Cumulative exposure in the interval between the two examinations showed similar associations. Conclusions: Decreasing exposure to airborne particulates appears to attenuate the decline in lung function related to exposure to PM10. The effects are greater in tests reflecting small-airway function.
01A - Beitrag in wissenschaftlicher Zeitschrift