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- Bake, Björn, 1939, et al.
(författare)
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Exhaled Particles After a Standardized Breathing Maneuver
- 2017
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Ingår i: Journal of Aerosol Medicine and Pulmonary Drug Delivery. - : Mary Ann Liebert Inc. - 1941-2711 .- 1941-2703. ; 30:4, s. 267-273
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Tidskriftsartikel (refereegranskat)abstract
- Background: Particles in exhaled air (PEx) provide samples of respiratory tract lining fluid from small airways and offer a new opportunity to monitor pathological changes. The exhaled particles are produced by reopening of closed small airways and contain surfactant. The amount of PEx varies by orders of magnitude among subjects. A standardized breathing pattern reduces the variation, but it remains large and the reasons are unknown. The aim of the present study was to assess to what extent sex, age, body size, and spirometry results explain the interindividual variation of PEx among healthy middle-aged subjects. Methods: The PExA((R)) instrument was used to measure PEx in 126 healthy middle-aged nonsmoking subjects participating in the European Respiratory Community Health Survey (ERCS-III). The subjects performed a standardized breathing maneuver involving expiration to residual volume, a breath-hold of 3 seconds, a full inspiration, and then a full expiration into the PExA instrument. PEx number concentrations were expressed per exhalation and per exhaled liter. Age and anthropometric and spirometric variables were analyzed as potential predictors. Results: PEx/L was consistently and negatively associated to lung size-related variables and accordingly lower in men than in women. PEx/Exhalation was similar in women and men. Increasing age was associated with increasing PEx. Reference equations are presented based on age, weight, and spirometry variables and independent of sex. These predictors explained 28%-29% of the interindividual variation. Conclusions: The interindividual variation of PEx after a standardized breathing maneuver is large and the considered predictors explain a minor part only.
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| 2. |
- Carlsen, Hanne Krage, et al.
(författare)
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Indicators of residential traffic exposure: Modelled NOX, traffic proximity, and self-reported exposure in RHINE III
- 2017
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 167, s. 416-425
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have investigated associations between self-reported and modelled exposure to traffic pollution. The objective of this study was to examine correlations between self-reported traffic exposure and modelled (a) NOX and (b) traffic proximity in seven different northern European cities; Aarhus (Denmark), Bergen (Norway), Gothenburg, Umeå, and Uppsala (Sweden), Reykjavik (Iceland), and Tartu (Estonia). We analysed data from the RHINE III (Respiratory Health in Northern Europe, www.rhine.nu) cohorts of the seven study cities. Traffic proximity (distance to the nearest road with >10,000 vehicles per day) was calculated and vehicle exhaust (NOX) was modelled using dispersion models and land-use regression (LUR) data from 2011. Participants were asked a question about self-reported traffic intensity near bedroom window and another about traffic noise exposure at the residence. The data were analysed using rank correlation (Kendall's tau) and inter-rater agreement (Cohen's Kappa) between tertiles of modelled NOX and traffic proximity tertile and traffic proximity categories (0–150 metres (m), 150–200 m, >300 m) in each centre. Data on variables of interest were available for 50–99% of study participants per each cohort. Mean modelled NOX levels were between 6.5 and 16.0 μg/m3; median traffic intensity was between 303 and 10,750 m in each centre. In each centre, 7.7–18.7% of respondents reported exposure to high traffic intensity and 3.6–16.3% of respondents reported high exposure to traffic noise. Self-reported residential traffic exposure had low or no correlation with modelled exposure and traffic proximity in all centres, although results were statistically significant (tau = 0.057–0.305). Self-reported residential traffic noise correlated weakly (tau = 0.090–0.255), with modelled exposure in all centres except Reykjavik. Modelled NOX had the highest correlations between self-reported and modelled traffic exposure in five of seven centres, traffic noise exposure had the highest correlation with traffic proximity in tertiles in three centres. Self-reported exposure to high traffic intensity and traffic noise at each participant's residence had low or weak although statistically significant correlations with modelled vehicle exhaust pollution levels and traffic proximity. © 2017
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