| 1. |
- Dobric, Julia, et al.
(author)
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Physical activity changes the deposited fractions of particles in the respiratory tract of adults and children
- 2022
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In: ; , s. 45-45
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Conference paper (peer-reviewed)abstract
- Exposure to ambient air pollution can cause a numberof health problems and may be particularly dangerous to susceptible population groups such as children. Health effects caused by air pollution are criticallydependent on both the deposited fraction (DF) of the inhaled particles and in what region of the respiratory tract the deposition takes place. With increasing physical activity, the breathing pattern is altered and the airflow in the respiratory tract increase, this affects the DF and deposition site. In this study we investigated changes in DF at increasing physical activity for three population groups: ~5 and 10 year-old children, and adults.Our results indicate that the variation in total DF with physical activity is minor, but that the DF for the UFPs increase in the AI region at higher activity levels. This is important since the removal of particles in the AI region is not effective and UFPs are believed to pose a specific health risk. Therefore, activity patterns and DF of different population groups need to be considered when estimating particle dose and evaluating health risks.
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| 2. |
- Linell, Julia, et al.
(author)
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Alterations of particle deposition in the respiratory tract at increasing activity
- 2023
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Conference paper (other academic/artistic)abstract
- The deposited dose of particles in the respiratory tract is an important factor for understanding health effects of aerosol particles. It is a combination of the exposure, volume of inhaled air and particle deposition. At increasing activity the minute ventilation ( volume of breath x number of breaths ) increase . Little is known about if and how this affects the regional particle deposition.
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| 3. |
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| 4. |
- Linell, Julia, et al.
(author)
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Effects of breathing variables on modelled particle lung deposition at physical activity for children and adults
- 2023
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In: Air Quality, Atmosphere and Health. - : Springer Science and Business Media B.V.. - 1873-9318 .- 1873-9326.
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Journal article (peer-reviewed)abstract
- The respiratory tract deposited fraction (DF) is the link between exposure and health effects of airborne particles. Here, we investigate how breathing pattern alterations at increasing physical activity affect DF in different regions of the respiratory tract and compare DF between adults and children (5 and 10 years old). We performed a literature review on the alteration of tidal volume with minute ventilation at increasing physical activity and used the results to model the size resolved (0.001–10 µm) DF, primarily using the deposition models from NCRP and Yeh and Schum (1980), but also MPPD. We found a shift in the deposited size distribution with increasing physical activity—DF of ultrafine particles increased in the alveolar region and decreased in the other regions, while DF of coarser particles decreased in the alveolar region and increased in the extra-thoracic region. Children had a 10–20% higher DF of ultrafine particles in the alveolar region compared to adults. We also present parametrizations of the daily average size resolved (0.005–5 µm) DF, accounting for varying physical activity throughout the day and oral/nasal breathing. These can be applied to any size distribution to estimate deposited doses. We found that deposited mass and number doses were more than twice as high for 5-year-olds compared to adults when normalized for body weight, primarily caused by their higher weight normalized minute ventilation. This demonstrates the importance of studying children’s exposure to air pollution and not only rely on data from adults.
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