1,721,108 research outputs found
Aerosol deposition doses in the human respiratory tree of electronic cigarette smokers
No full textAerosols from eight e-cigarettes at different nicotine levels and flavoring were characterized as particle number size distributions in the range 5.6-560 nm by FMPS and CPC. Results were used to provide dosimetry estimates applying the MMPD model. Particle number concentrations varied between 3.26 Ã 109 and 4.09 Ã 109 part cm-3 for e-liquids without nicotine and between 5.08 Ã 109 and 5.29 Ã 109 part cm-3 for e-liquids with nicotine. No flavor effects were detected on particle concentration data. Particle size distributions were unimodal with modes between 107-165 nm and 165-255 nm, for number and volume metrics, respectively. Averagely, 6.25 Ã 1010 particles were deposited in respiratory tree after a single puff. Highest deposition densities and mean layer thickness of e-cigarette liquid on the lung epithelium were estimated at lobar bronchi. Our study shows that e-cigarette aerosol is source of high particle dose in respiratory system, from 23% to 35% of the daily dose of a no-smoking individual
Where do ultrafine particles and nano-sized particles come from?
No full textThis paper presents an overview of the literature studies on the sources of ultrafine particles (UFPs), nanomaterials (NMs), and nanoparticles (NPs) occurring in indoor (occupational and residential) and outdoor environments. Information on the relevant emission factors, particle concentrations, size, and compositions is provided, and health relevance of UFPs and NPs is discussed. Particular attention is focused on the fraction of particles that upon inhalation deposit on the olfactory bulb, because these particles can possibly translocate to brain and their possible role in neurodegenerative diseases is an important issue emerging in the recent literature
Benchmark study on fine-mode aerosol in a big urban area and relevant doses deposited in the human respiratory tract
No full textIt is well-known that the health effects of PM increase as particle size decreases: particularly, great
concern has risen on the role of UltraFine Particles (UFPs). Starting from the knowledge that the main
fraction of atmospheric aerosol in Rome is characterized by significant levels of PM2.5 (almost 75% of
PM10 fraction is PM2.5), the paper is focused on submicron particles in such great urban area. The daytime/
nighttime, work-/weekdays and cold/hot seasonal trends of submicron particles will be investigated
and discussed along with NOx and total PAH drifts demonstrating the primary origin of UFPs from
combustion processes. Furthermore, moving from these data, the total dose of submicron particles
deposited in the respiratory system (i.e., head, tracheobronchial and alveolar regions in different lung
lobes) has been estimated. Dosimeter estimates were performed with the Multiple-Path Particle
Dosimetry model (MPPD v.2.1). The paper discusses the aerosol doses deposited in the respiratory system
of individuals exposed in proximity of traffic. During traffic peak hours, about 6.6 1010 particles are
deposited into the respiratory system. Such dose is almost entirely made of UFPs. According to the
greater dose estimated, right lung lobes are expected to be more susceptible to respiratory pathologies
than left lobes
Temporal evolution of ultrafine particles and of alveolar deposited surface area from main indoor combustion and non-combustion sources in a model room
No full textAerosol number size distributions, PM mass concentrations, alveolar deposited surface areas (ADSAs) and VOC concentrations were measured in a model room when aerosol was emitted by sources frequently encountered in indoor environments. Both combustion and non-combustion sources were considered. The most intense aerosol emission occurred when combustion sources were active (as high as 4.1×10(7)particlescm(-3) for two meat grilling sessions; the first with exhaust ventilation, the second without). An intense spike generation of nucleation particles occurred when appliances equipped with brush electric motors were operating (as high as 10(6)particlescm(-3) on switching on an electric drill). Average UFP increments over the background value were highest for electric appliances (5-12%) and lowest for combustion sources (as low as -24% for tobacco cigarette smoke). In contrast, average increments in ADSA were highest for combustion sources (as high as 3.2×10(3)μm(2)cm(-3) for meat grilling without exhaust ventilation) and lowest for electric appliances (20-90μm(2)cm(-3)). The health relevance of such particles is associated to their ability to penetrate cellular structures and elicit inflammatory effects mediated through oxidative stress in a way dependent on their surface area. The highest VOC concentrations were measured (PID probe) for cigarette smoke (8ppm) and spray air freshener (10ppm). The highest PM mass concentration (PM1) was measured for citronella candle burning (as high as 7.6mgm(-3))
Second-hand smoke generated by combustion and electronic smoking devices used in real scenarios: ultrafine particle pollution and age-related dose assessment
Full text linkAerosol measurements were carried out in a model room where both combustion (conventional and hand-rolled
cigarettes, a cigar and tobacco pipe) and non-combustion (e-cigarette and IQOS®) devices were smoked. The data
were used to estimate the dose of particles deposited in the respiratory systems of individuals from 3 months to
21 years of age using the multiple-path particle dosimetry (MPPD) model. Regardless of the smoking device, the
highest doses were received by infants, which reached 9.88 ×108 particles/kg bw during a cigar smoking
session. Moreover, 60% to 80% of the particles deposited in the head region of a 3-month-old infant were smaller
than 100 nm and could be translocated to the brain via the olfactory bulb. The doses due to second-hand smoke
from electronic devices were significantly lower, below 1.60 ×108 particles/kg bw, than those due to combustion
devices. Dosimetry estimates were 50% to 110% higher for IQOS® than for e-cigarettes
Sensitive multiresidue method by HS-SPME/GC-MS for 10 volatile organic compounds in urine matrix: a new tool for biomonitoring studies on children
No full textA HS-SPME method coupled with GC-MS analysis
has been developed for simultaneously measuring the concentration
of 10 volatile organic compounds (VOCs) (benzene,
toluene, ethylbenzene, o-, m-, and p-xylene, methyl tertbutyl
ether, ethyl tert-butyl ether, 2-methyl-2-butyl methyl
ether, and diisopropyl ether) in urine matrix as a biomonitoring
tool for populations at low levels of exposure to such
VOCs. These compounds, potentially toxic for human health,
are common contaminants of both outdoor and indoor air, as
they are released by autovehicular traffic; some of them are
also present in environmental tobacco smoke (ETS). Thus, the
exposure to these pollutants cannot be neglected and should
be assessed. The low limits of detection and quantification
(LODs and LOQs <6.5 and 7.5 ng L–1, respectively) and the
high reproducibility (CVs <4 %) make the developed method
suited for biomonitoring populations exposed at low levels
such as children. Further, the method is cost-effective and
low in time-consumption; therefore, it is useful for investigating
large populations. It has been applied to children exposed
to traffic pollution and/or ETS; the relevant results are reported,
and the relevant implications are discussed
Ultrafine particles in domestic environments: regional doses deposited in the human respiratory system
No full textBased on aerosol measurements carried out in a test room, particle regional respiratory doses have been estimated for both combustion and non-combustion aerosol sources currently encountered in domestic environments. The general population chronically receives doses that, pooled together, are well above those due to urban outdoor pollution. At the end of each source operation, from 75% to 99% and from 27% to 93% of these doses are due to ultrafine particle, respectively on particle number and surface area metrics. Depending on the source, the pattern of exposure may be, for very short time laps, very intense (up to 8.0 × 109particles s−1) and involve a fraction of particles with mode at about 10 nm. For appliance operated by brush electric motors, this mode is the major one and is due to the generation of copper nanoparticles. The health relevance of such particles deserves particular attention due to their possible translocation to the brain and in the light of the associations between copper ions and Alzheimer's disease, proposed by several studies
Pedestrians in traffic environments: ultrafine particle respiratory doses
Full text linkParticulate matter has recently received more attention than other pollutants. PM10 and PM2.5 have been primarily monitored, whereas scientists are focusing their studies on finer granulometric sizes due both to their high number concentration and their high penetration efficiency into the respiratory system. The purpose of this study is to investigate the population exposure to UltraFine Particles (UFP, submicrons in general) in outdoor environments. The particle number
doses deposited into the respiratory system have been compared between healthy individuals and persons affected by Chronic Obstructive Pulmonary Disease (COPD). Measurements were performed by means of Dust Track and Nanoscan analyzers. Forty minute walking trails through areas with
different traffic densities in downtown Rome have been considered. Furthermore, particle respiratory doses have been estimated for persons waiting at a bus stop, near a traffic light, or along a high-traffic road, as currently occurs in a big city. Large differences have been observed between workdays and weekdays: on workdays, UFP number concentrations are much higher due to the strong contribution of vehicular exhausts. COPD-affected individuals receive greater doses than healthy individuals due to their higher respiratory rate
The water supply of Rome: an “almost” unique case
No full textThe trace element composition of water intended for human consumption plays an important role for
public health. Water is a significant source of potentially
toxic and essential elements; it can provide the body by
both direct recruitment and/or influencing the element
concentration in agriculture, livestock products and food
industry. The present study examines the concentrations of
a great number of elements in the drinking waters distributed in the territory of Rome, whose water supply
mainly comes from spring waters. 20 samples drawn from
municipal potable facilities in Rome were analyzed by
Instrumental Neutron Activation Analysis. The neutron
irradiations were performed in the pneumatic channel and
in the rotating rack of ENEA’s Triga Mark II reactor at
1.3 9 1013 and 2.6 9 1012 n cm-2 s
-1
, respectively. In
total, 38 elements were determined in each sample. The
results evidence that all the studied elements for all the
aqueducts resulted well below the limits posed by the
regulations on water for human consumption. Besides,
considering the elements not regulated, the monitored
waters resulted safe from a toxicological point of view, and
adequate from nutritional aims. In addition, it was also
evidenced that the elemental composition resulted quite
similar to that of uncontaminated natural water. Finally, a
statistical approach evidences that the elemental behavior
of the monitored waters is mainly determined by geochemical factor
Tocols and fatty acids as markers of the origin of vegetable oils and fats in bakery products
No full textThis study reports an approach combining the use of tocols and fatty acids as variables to separate different bakery products with respect to the oil/fat used as ingredients. The tocol and fatty acid profiles were investigated in 12 biscuits prepared with different fats/oils. Based on different profiles, principal component analysis (PCA) was used to classify samples according to their fat/oil ingredients. The PCA found three components that are able to explain approximately 71% of total variance, and it proved useful in characterizing products. The tested approach was validated on 33 commercial bakery products prepared with different fats/oils to verify the information mentioned
on food labels
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