Internal dose of particles in the elderly—modeling based on aerosol measurements
The paper presents an integrated methodology that combines experimental and modeling techniques and links exposure to airborne particulate matter (PM) with internal dose in the respiratory system and burden in adjacent tissues over a period of time. The methodology is used to estimate doses in the respiratory systems of elders that reside in 10 elderly care centers (ECCs) in the metropolitan area of Lisbon. Measurements of PM were performed in the ECCs and combined with a time-budget survey for the occupants. This information served as input to the first model that estimated particle doses in the different regions of the respiratory tract of the elderly, and then a second model was used to calculate particle build-up in the alveolar region, the interstitium and the hilar lymph nodes of the elders over a 5-year exposure period. It was found that in 5 years of continuous exposure to the average particle concentration measured over all ECCs, 258 mg of all particles are deposited on the surface of the alveoli of which 79.6% are cleared, 18.8% are retained in the alveolar region, 1.5% translocate to the hilar lymph nodes, and 0.1% are transferred to the interstitium.
KeywordsElders Particulate matter Model Deposition Human respiratory tract Clearance
The study would not be possible without the assistance of the Câmara Municipal de Loures, by Dr. Luzia Sousa and Dr. Beatriz Reis. C2TN/IST authors gratefully acknowledge the FCT support through the UID/Multi/04349/2013 project.
We gratefully acknowledge Fundação para a Ciência e Tecnologia (FCT) for funding M. Almeida-Silva PhD fellowship (SFRH/BD/69700/2010) and S.M. Almeida contract (IF/01078/2013).
- Eurostat (2003) DAI-EPT results analysis. http://en.eustat.es/elementos/ele0003200/ti_2003_Time_Budget_Survey_Results_analysis/inf0003219_i.pdf
- Eurostat (2006) Christel Aliaga, How is the time of the women and men distributed in Europe? http://epp.eurostat.ec.europa.eu/cache/ITY_OFFPUB/KS-NK-06-004/EN/KS-NK-06-004-EN.PDF
- ICRP (1994) Human respiratory tract model for radiological protection. Annals of the ICRP. ICRP Publication 66, 24(1-3). ISBN 0 08 041154 1Google Scholar
- ILO, UNep, WHO (2000) Environmental health criteria 214: human exposure assessmentGoogle Scholar
- Kreyling WG, Möller W, Semmler-Behnke M, Oberdörster G (2007) Paricle dosimetry: Deposition and clearance from the respiratory tract and translocation towards extra-pulmonary sites. In Donaldson K, Borm P (eds) Particle toxicology, Chap. 3. CRC Press, Taylor & Francis, New York, pp 47–74Google Scholar
- National Academy of Science (NAS) (1991) Human exposure assessment for airborne pollutants, advances and opportunities. National Academy Press, Washington, DCGoogle Scholar
- Pilou M, Mavrofrydi O, Housiadas C, Eleftheriadis K, Papazafiri P (2013) Computational modeling as part of alternative testing strategies in the respiratory and cardiovascular systems: inhaled nanoparticle dose modelling based on representative aerosol measurements and corresponding toxicological analysis. Nanotoxicology 9(Suppl 1):106–115Google Scholar
- Pilou M, Mavrofrydi O, Housiadas C, Eleftheriadis K, Papazafiri P (2015) Computational modeling as part of alternative testing strategies in the respiratory and cardiovascular systems: inhaled nanoparticle dose modeling based on representative aerosol measurements and corresponding toxicological analysis. https://doi.org/10.1007/s11356-018-2661-3 Nanotoxicology 7(s): 113–122
- Portaria 353-A/2013 de 4 de Dezembro. https://dre.pt/application/dir/pdf1sdip/2013/12/23501/0000200009.pdf
- Tena AF, Clarà PC (2012) Deposition of inhaled particles in the lungs. Arch Bronconeumol 48(7):240–246Google Scholar
- Tran L, Kuempel E (2007) Biologically based lung dosimetry and exposure-dose-response models for poorly soluble inhaled particles. In: Donaldson K, Born P (eds) Particle toxicology. CRC Press, New York, pp 351–386Google Scholar
- Weibel ER (1963) Morphometry of the human lung. Springer Verlag, Berlin-Göttingen-HeidelbergGoogle Scholar