The objective of the current study was to estimate health risk indexes caused by the inhalation of particulate matter (PM) by adult males and children using data sampled in three European cities ...(Athens, Kuopio, Lisbon). Accordingly, the cancer risk (CR) and the hazard quotient (HQ) were estimated from particle-bound metal concentrations whilst the epidemiology-based excess risk (ER), the attributable fraction (AF), and the mortality cases were obtained due to exposure to PM10 and PM2.5. CR and HQ were estimated using two methodologies: the first methodology incorporated the particle-bound metal concentrations (As, Cd, Co, Cr, Mn, Ni, Pb) whereas the second methodology used the deposited dose rate of particle-bound metals in the respiratory tract. The indoor concentration accounts for 70% infiltration from outdoor air for the time activity periods allocated to indoor environments. HQ was lower than 1 and the cumulative CR was lower than the acceptable level (10−4), although individual CR for some metals exceeded the acceptable limit (10−6). In a lifetime the estimated number of attributable cancer cases was 74, 0.107, and 217 in Athens, Kuopio, and Lisbon, respectively. Excess risk-based mortality estimates (due to outdoor pollution) for fine particles were 3930, 44.1, and 2820 attributable deaths in Athens, Kuopio, and Lisbon, respectively.
The deposited dose in the human respiratory tract and its influencing factors were investigated for 8 urban/suburban locations within Greek cities. A dosimetry model (ExDoM2) was implemented assuming ...a 24-h exposure scenario to ambient PM
10
whereby regional deposition rates were obtained. Simulations were performed considering three cases (Sahara dust, cold, and warm periods) with seasonal and diurnal variations examining the relative sources and other influencing factors in each case. Health risk indexes such as the relative risk and attributable fraction were also estimated. Overall, higher daily deposited dose was obtained for all urban compared with suburban locations (
p
< 0.05) and for cold compared with the warm periods (252–820 μg for cold period and 300–686 μg for warm period) for all locations. This finding was associated with increased deposition rate on cold period during evening/night hours, as a result of significant heating emissions. Besides that, most of the urban locations showed relative comparable deposition rates during the day, compared with the daily mean, for the two periods (cold and warm), indicating that urban-associated sources such as exhaust emissions and road dust resuspension contribute similarly to the deposited dose irrespectively of the season. Finally, the highest deposited dose was obtained during Sahara dust events ranged from 1881 to 4648 μg.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The present study focused on the estimation of the personal dose of airborne particles using an exposure dose model (ExDoM2). Input data from three European cities (Athens, Kuopio, Lisbon) were ...selected to implement the model that calculates the deposited dose and retention of particles in the respiratory tract, the mass transferred to the oesophagus and the absorption to blood as well as the dose for five particle-bound metals. Model results showed that after one day exposure higher deposited dose in the respiratory tract was obtained for Lisbon as a direct consequence of the higher PM concentration measured in this city. Moreover, the activity profile and the physical characteristics of the exposed subject had strong impact on the estimated deposited dose. Thus, light activity corresponded to higher deposited dose compared to no activity as well as an adult male exhibited higher dose, both findings associated with increased inhalation rate. Regarding the internal dose for particle-bound metals higher dose for four out of the five metals was obtained in lungs followed by the muscles for As, the gastrointestinal tract for Cr, the other tissues for Mn, the intestines for Cd and finally for Pb higher dose was found in bones and blood.
Abstract
The objective of the current study was to develop a dosimetry model (ExDoM2) for calculating internal dose of specific particle-bound metals (As, Pb, Cd, Cr and Mn) in the human body. The ...ExDoM2 is a revised version of a respiratory tract model (ExDoM) incorporating a new particle clearance mechanism in the respiratory tract model and a Physiologically-Based PharmacoKinetic (PBPK) model. The revised respiratory tract model was used to calculate the deposition, clearance and retention of particles in the human respiratory tract and the mass transferred to the oesophagus (gastrointestinal tract) and blood. The PBPK module was used to analyze the distribution of metals (As, Pb, Cd, Cr and Mn) from the blood circulation system to other organs or tissues like liver, kidneys, heart, brain, muscle and bone. The model was applied to calculate the internal human dose for an adult Caucasian male exposed to particulate mass matter (PM), PMPb, PMCd, PMMn and PMCr in an urban area (Athens, Greece). The analysis showed that at the end of the exposure (one day exposure scenario) to PMPb, the major accumulation occurs in the bone, blood and muscle, whereas as regards PMCd the major accumulation occurs in the other tissues, like kidney and liver. In addition, for PMMn, the major accumulation occurs in the other tissues and lungs, whereas as regards PMCr the major accumulation occurs in the gastrointestinal (GI) tract and lungs. Therefore, ExDoM2 is an important feature in studying deposition of particles in the human body.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The objective of the current study was to determine the growth and deposition of hygroscopic aerosol particles in the human respiratory tract. A hygroscopic particle growth methodology was ...incorporated into an existing particle dosimetry model (Exposure Dose Model 2, ExDoM2) using the κ-Köhler theory, the International Commission on Radiological Protection (ICRP) formulation for hygroscopic growth and mathematical formulations for taking into account the residence time, the influence of hygroscopicity on the particle’s density, and hygroscopic growth at 99.5% relative humidity. In order to validate ExDoM2, the results of the model were compared with experimental total deposition data for NaCl particles. The incorporation of the hygroscopic growth resulted in predictions closer to the experimental data than to model results without the use of a hygroscopic model formulation. The hygroscopicity plays a more significant role in the lower regions (tracheobronchial (TB) and alveolar-interstitial (AI) regions) of the respiratory tract. In particular, the hygroscopicity of NaCl particles decreases the deposition in the AI region for particles in the size range 0.03 μm ≤ aerodynamic diameter (
d
ae
) ≤ 0.2 μm while for the size range 0.3 μm ≤
d
ae
≤ 3 μm, the hygroscopicity increases the deposition in the AI region. In addition, it is observed that the deposition of (NH
4
)
2
SO
4
and NH
4
NO
3
particles with
d
ae
≥ 0.30 μm is higher when the hygroscopic properties of the particles are taken into consideration. However, the particle deposition in the range 0.02 μm ≤
d
ae
≤ 0.25 μm is decreased due to hygroscopicity.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Investigation of pharmaceutical aerosol deposition in the human respiratory tract is an important topic because it enhances knowledge regarding the effective treatment of lung diseases. Herein, ...deposition in the human respiratory tract produced by the use of Dry Powder Inhalers (DPIs) was modeled for an adult male. A modified version of the model named Exposure Dose Model 2 (ExDoM2) was used where simulations incorporated both monodisperse and polydisperse aerosols. The impact of breath holding and mouthpiece diameter was also examined. The results revealed that the larger the aerodynamic diameter, the greater the deposition in the extrathoracic region. On the contrary, higher deposition of polydisperse particles in the tracheobronchial and alveolar-interstitial region was observed for particles with aerodynamic diameter 2–4 μm. In the extrathoracic region, deposition increased with a decrease in the mouthpiece diameter. However, its effect is negligible for particles approximately <1 μm in the tracheobronchial and alveolar-interstitial regions. For bigger particles, an increase in mouthpiece diameter resulted in an increase of the deposition. Similar findings were obtained for monodisperse particles. In addition, the results showed that breath holding increases the deposition in the lungs for all mouthpiece diameters and Mass Median Aerodynamic Diameters (MMADs), which confirms the medical recommendations of breath holding after inhalation of pharmaceutical aerosols through DPIs for more effective treatment of lung diseases. Finally, the user of the modified version of ExDoM2 has the capability to modify the parameters of the model for a more representative/realistic scenario. Future objectives include simulations that adopt the effect of particle properties (density and shape factor) and other parameters (such as the tidal volume), as well as simulations incorporating deposition using realistic input data (MMAD and standard deviation sg).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The daily deposited dose of bioaerosols and particle mass or number in the human respiratory tract using an exposure dose model (ExDoM2) was quantified in the present study. The dose was calculated ...for the extrathoracic (ET), tracheobronchial (TB), and alveolar-interstitial (AI) regions of the human respiratory tract. The calculations were performed for viable, cultivable airborne heterotrophic bacteria, mesophilic fast-growing fungi, and total coliforms at a municipal wastewater treatment plant (WWTP) located at a suburban area at a Mediterranean site. The human dose was determined using data from two locations at the WWTP which correspond to two different wastewater treatment stages (aerated grit chamber (indoor) and primary settling tanks (outdoor)) and one outdoor location at the urban background site. In addition, the model simulations were performed for two exposure periods (March to April and May to June 2008). Higher daily deposited dose in the total human respiratory tract was observed for heterotrophic bacteria at the aerated grit chamber, whereas lower values of heterotrophic bacteria were observed at the primary settling tanks. These findings were associated with the corresponding stage of wastewater treatment activities and may be valuable information for determining future dose–response relationships. In addition, higher daily deposited dose was determined in the ET region for the three categories of bioaerosols. Regarding PM
10
and PN
1
, the higher daily deposited dose received by a worker at the aerated grit chamber. Finally, the hazard quotients were estimated and the results showed that the non-carcinogenic effects can be ignored for bioaerosols and PM
10
except for workers present at aerated grit chamber. Regarding PM
2.5
, the non-carcinogenic effects are of concern and cannot be ignored for all cases.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This study investigated the suitability of outdoor particulate matter data obtained from a fixed monitoring station in estimating the personal deposited dose. Outdoor data were retrieved from a ...station located within the urban area of Lisbon and simulations were performed involving school children. Two scenarios were applied: one where only outdoor data were used assuming an outdoor exposure scenario, and a second one where an actual exposure scenario was adopted using the actual microenvironment during typical school days. Personal PM
and PM
dose (actual exposure scenario) was 23.4% and 20.2% higher than the ambient (outdoor exposure scenario) PM
and PM
doses, respectively. The incorporation of the hygroscopic growth in the calculations increased the ambient dose of PM
and PM
by 8.8% and 21.7%, respectively. Regression analysis between the ambient and personal dose showed no linearity with R
at 0.07 for PM
and 0.22 for PM
. On the other hand, linear regression between the ambient and school indoor dose showed no linearity (R
= 0.01) for PM
but moderate (R
= 0.48) for PM
. These results demonstrate that ambient data must be used with caution for the representativeness of a realistic personal dose of PM
while for PM
the ambient data cannot be used as a surrogate of a realistic personal dose of school children.
Exposure to wildfire smoke and dust can severely affect air quality and health. Although particulate matter (PM) levels and exposure are well-established metrics linking to health outcomes, they do ...not consider differences in particle toxicity or deposition location in the respiratory tract (RT). Usage of the oxidative potential (OP) exposure may further shape our understanding on how different pollution events impact health. Towards this goal, we estimate the aerosol deposition rates, OP and resulting OP deposition rates in the RT for a typical adult Caucasian male residing in Athens, Greece. We focus on a period when African dust (1–3 of August 2021) and severe wildfires at the northern part of the Attika peninsula and the Evia island, Greece (4–18 of August 2021) affected air quality in Athens. During these periods, the aerosol levels increased twofold leading to exceedances of the World Health Organization (WHO) 15(5) μg m−3 PM10 (PM2.5) air quality standard by almost 100 %. We show that the OP exposure is 1.5-times larger during the wildfire smoke events than during the dust intrusion, even if the latter was present in higher mass loads – because wildfire smoke has a higher specific OP than dust. This result carries two important implications: OP exposure should be synergistically used with other metrics - such as PM levels - to efficiently link aerosol exposure with the resulting health effects, and, certain sources of air pollution (in our case, exposure to biomass burning smoke) may need to be preferentially controlled, whenever possible, owing to their disproportionate contribution to OP exposure and ability to penetrate deeper into the human RT.
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•WHO PM10 and PM2.5 standards were exceeded on summer 2021 in Athens by almost 100% from dust intrusions and wildfires.•Exposure to biomass burning aerosol may have a stronger contribution than dust to OP and related health outcomes.•The largest OPDTTm is observed during times when the measuring site is not affected by either BB or dust emissions.•OP metrics provide a different view of pollution type importance, compared to results from aerosol mass deposition alone.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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