Number Concentrations and Modal Structure of Indoor/Outdoor Fine Particles in Four European Cities

Indoor/outdoor aerosol size distribution was measured in four European cities (Oslo-Norway, Prague-Czech Republic, Milan-Italy and Athens-Greece) during 2002 in order to examine the differences in the characteristics of the indoor/outdoor modal structure and to evaluate the effect of indoor sources to the aerosol size distributions. All the measurement sites were naturally ventilated and were occupied during the campaigns by permanent residents or for certain time periods by the technical staff responsible for the instrumentation. Outdoor particle number (PN) concentrations presented the higher values in Milan and Athens (median values 1.4 x 10(4) # cm(-3) and 2.9 x 10(4) # cm(-3) respectively) as a result of elevated outdoor emissions and led to correspondingly higher indoor values compared to Oslo and Prague. In absence of indoor activities, the indoor concentrations followed the fluctuations of the outdoor concentrations in all the measurement sites. Indoor activities (cooking, smoking, etc.) resulted in elevated indoor PN concentrations (maximum values ranging between 1.7 x 10(5) # cm(-3) and 3.2 x 10(5) # cm(-3)) and to I/O ratios higher than one. The I/O ratios were size dependant and for periods without indoor activities, they presented the lowest values for particles <50 nm (0.51 +/- 0.15) and the ratios increased with fine particle size (0.79 +/- 0.12 for particles between 100-200 nm). The analysis of the modal structure showed that the indoor aerosol size distribution characteristics differ from the outdoors under the effect of indoor sources. The percentage of unimodal size distributions increased during indoor emissions, compared to periods without indoor sources, along with the number concentration of Aitken mode particles, indicating emissions in specific size ranges according to the type of the indoor source.Peer reviewe

Characterizing Indoor Air Quality using microenvironmental models

In modern society people spent most of their time indoors. Therefore ,it is important to examine the exposure to pollutants found in indoor environments. Indoor pollutants are directly emitted from indoor sources or penetrate in the indoor environment from outdoors. Particles constitute a significant atmospheric pollutant, associated with various health effects, ranging from cough to lung cancer, depending on their size and chemical composition. Particles can enter the human body mainly through the respiratory system. An alternative way to the interior of the human body is through their deposition on the food that is consumed by people. A comprehensive microenvironmental model has been developed in the current thesis. The model can be used to describe indoor particle dynamics and it can be applied to estimate both particle mass concentrations and particle number concentrations. The model has been validated with experimental data collected during intensive measurements campaigns in three European cities (Oslo, Prague and Milan) and also with experimental data from laboratory experiments under well known environmental conditions. The model was combined with an algorithm suitable for determining the characteristics of the particle’s size distribution spectra. Furthermore, it was used to estimate the time dependent particles and mass emission rates from the indoor sources and the contribution of the outdoor environment to the indoor particle concentration. The conjunction of the two modelling tools with experimental data provided a comprehensive methodology for simulating indoor particles physical characteristics and estimating emissions rates. This methodology can be used to evaluate indoor air quality and identify potential threats on human health. Finally, the model was applied in the indoor environment of an industrial detergent facility in order to estimate the danger to the industry’s personnel due to their exposure in the emitted particles during the detergent production phase.Ο σύγχρονος άνθρωπος είναι αναγκασμένος να περνάει ένα μεγάλο μέρος του καθημερινού του χρόνου σε εσωτερικούς χώρους (σπίτι, γραφείο, αυτοκίνητο ή μέσα μαζικής μεταφοράς). Επομένως είναι σημαντικό να εξεταστεί η επιβάρυνση της υγείας του από ρύπους που εκπέμπονται ή εισέρχονται στο εσωτερικό περιβάλλον. Τα αιωρούμενα σωματίδια αποτελούν ένα σημαντικό ατμοσφαιρικό ρυπαντή με ποικίλες επιδράσεις στην καθημερινή ζωή των ανθρώπων. Τα αιωρούμενα σωματίδια μπορούν να εισέλθουν στον ανθρώπινο οργανισμό είτε μέσω της αναπνευστικής οδού, είτε μέσω της κατάπωσης τους από το στόμα (εναπόθεση στις τροφές) και να προκαλέσουν επιδράσεις στην υγεία από απλό βήχα μέχρι καρκίνο των πνευμόνων ανάλογα με το μέγεθος και τη χημική τους σύσταση. Στα πλαίσια της παρούσας διδακτορικής διατριβής αναπτύχθηκε μικροπεριβαλλοντικό μοντέλο που περιγράφει τη δυναμική των αιωρούμενων σωματιδίων σε εσωτερικούς χώρους. Το μοντέλο μπορεί να εφαρμοστεί για την εκτίμηση της συγκέντρωσης μάζας ή αριθμού αιωρούμενων σωματιδίων. Το μοντέλο αξιολογήθηκε με πειραματικά δεδομένα από εσωτερικούς χώρους τριών Ευρωπαϊκών πόλεων και πειραματικά δεδομένα που ελήφθησαν στο εργαστήριο κάτω από ελεγχόμενες συνθήκες. Στη συνέχεια σε συνδυασμό με υπάρχων εργαλείο εύρεσης χαρακτηριστικών φασματικής κατανομής πραγματοποιήθηκε μια ολοκληρωμένη μελέτη των φυσικών χαρακτηριστικών των αιωρούμενων σωματιδίων (φασματική κατανομή μεγέθους, συγκέντρωση σωματιδίων ανάλογα με το μέγεθος). Επίσης πραγματοποιήθηκε προσδιορισμός της ποσοτικής επίδρασης της εξωτερικής συγκέντρωσης και των εκπομπών από εσωτερικές πηγές στη συγκέντρωση αιωρούμενων σωματιδίων εσωτερικού χώρου. Επιπλέον υπολογίστηκαν χρονικά μεταβαλλόμενοι ρυθμοί εκπομπής από πηγές εσωτερικού χώρου και αναπτύχθηκε μια ολοκληρωμένη μεθοδολογία για τη μελέτη της ποιότητας του αέρα μέσω συνδυασμού πειραματικών μετρήσεων και μοντελοποίησης των δεδομένων. Τέλος το μοντέλο εφαρμόστηκε για την εκτίμηση της επικινδυνότητας των εκπομπών σε χώρους χημικής βιομηχανίας

Characterization of indoor air quality by using an indoor/outdoor microenvironmental model

Μη διαθέσιμη περίληψηNot available summarizationΠαρουσιάστηκε στο: Second ACCENT Symposiun Urbin

Indoor/Outdoor relationship of PM10, PM2.5, PM1 and NO2 at rural and urban domestic homes: A snapshot from Pakistan

Μη διαθέσιμη περίληψηNot available summarizationΠαρουσιάστηκε στο: Second ACCENT Symposiun Urbin

Impact assessement on organic materials in selected European museums

Μη διαθέσιμη περίληψηNot available summarizationΠαρουσιάστηκε στο: Indoor Air Quality Conferenc

Particle size characterization and emission rates during indoor activities in a house

Summarization: Characterization and emission rates of indoor aerosols have been of great interest. However, few studies have presented quantitative determinations of aerosol particle emissions during indoor activities. In the current study we presented and investigated the physical characteristics and size-fractionated emission rates of indoor aerosol particles during different activities in a house (naturally ventilated) located in Prague, Czech Republic. We utilized a multi-compartment and size-resolved indoor aerosol model (MC-SIAM) to investigate the indoor-to-outdoor relationship of aerosol particles and also to estimate their emission rates. When the windows and the main door were closed for several hours and there were minor indoor activities that did not produce significant amounts of aerosol particles, the particle number concentration showed similar levels at different indoor locations. As expected, the natural ventilation did not provide a controlled indoor-to-outdoor relationship of aerosol particles. As previous studies have emphasized, cooking and tobacco smoking activities are major sources indoors; the total particle number concentration was, respectively, as high as 1.8×105 and 3.6×104 cm−3 with emission rates around 380 and 36 cm−3 s−1. During intensive cooking activities the outdoor aerosol particle concentrations were also affected even though windows were closed. It seems that a simple model is not able to describe the fate of indoor aerosols within a multi-compartment construction; instead, a numerical and dynamic model with a multi-compartment approach is needed. Based on the indoor aerosol model simulations, the deposition rate was comparable to previous studies with friction velocity between 10–30 cm s−1 and surface area to volume ratio around 2.9–3.1 m−1. The penetration factor was equivalent to G3 filter standards and the ventilation rate varied between 0.6–1.2 h−1. Based on the emission rate analysis, aerosol particles produced during tobacco smoking and incense stick burning remain airborne for a longer time than cooking particles. It seems that aerosol particles emitted during tobacco smoking and incense stick burning undergo different processes; therefore, there is a need for a combined physical–chemical indoor aerosol model to better describe the evolution of indoor aerosol particles due to different activities.Παρουσιάστηκε στο: Atmospheric Environmen