40 research outputs found
Polar organic marker compounds in atmospheric aerosol in the PoValley during the Supersito campaigns. Part 1: Low molecular weight carboxylic acids in cold seasons
No full textIn the framework of the“Supersito”project, three intensive experimental campaigns were conducted in
the Po Valley (Northern Italy) in cold seasons, such as late autumn, pre-winter and deep-winter, over
three years from 2011 to 2013. As a part of a study on polar marker compounds, including carboxylic
acids, sugar derivatives and lignin phenols, the present study reports a detailed discussion on the at-mospheric concentrations of 14 low molecular weight carboxylic acids, mainly dicarboxylic and oxo-hydroxy carboxylic acids, as relevant markers of primary and secondary organic aerosols.
PM2.5samples were collected in two monitoring sites, representing urban and rural background sta-tions. The high acid concentrations can be explained by the large human emission sources in the urbanized region, combined with
the stagnant atmospheric conditions during the cold seasons that accumulate the organic precursors and
accelerate the secondary atmospheric reactions.
The distribution profiles of the investigated markers suggest the dominant contributions of primary
anthropogenic sources, such as traffic, domestic heating and biomass burning. These results are
confirmed by comparison with additional emission tracers, such as anhydro-saccharides for biomass
burning and fatty acids originated from different anthropogenic sources. In addition, some secondary
constituents were detected in both sites, as produced by in situ photo-chemical reactions from both
biogenic (e.g. pinonic acid) and anthropogenic precursors (e.g. phthalic and adipic acids).
The impact of different sources from human activities was elucidated by investigating theweek pattern
of carboxylic and fattyacid concentrations. Theweekly trends of analytes during the warmer campaign may be related to emissions from motor vehicle traffic and industrial
activities. Otherwise, the random pattern of the markers suggests the prevalent contribution of primary
emissions from residential heating in the colder deep-winter
Identification of pathway-based toxicity in the BALB/c 3T3 cell model
No full textThe particulate matter represents one of the most complex environmental mixtures, whose effects on human health and environment vary according to particles characteristics and source of emissions. The present study describes an integrated approach, including in vitro tests and toxicogenomics, to highlight the effects of air particulate matter on toxicological relevant endpoints.
Air samples (PM2.5) were collected in summer and winter at different sites, representative of different levels of air pollution. Samples organic extracts were tested in the BALB/c 3T3 CTA at a dose range 1–12 m3. The effect of the exposure to the samples at a dose of 8 m3 on the whole-genome transcriptomic profile was also assessed.
All the collected samples induced dose-related toxic effects in the exposed cells. The modulated gene pathways confirmed that toxicity was related to sampling season and sampling site. The analysis of the KEGG’s pathways showed modulation of several gene networks related to oxidative stress and inflammation. Even if the samples did not induce cell transformation in the treated cells, gene pathways related to the onset of cancer were modulated as a consequence of the exposure.
This integrated approach could provide valuable information for predicting toxic risks in humans exposed to air pollution
Report on policy options for AQ and CC Deliverable 4.5 iSCAPE project
No full textThis report is the output of the work carried out in Task 4.3 of the iSCAPE
project, which addresses the efficacy of policy options to reduce air
quality in present and future climate taking into account also possible
behavioural change. The evaluation of the efficacy of policy options has
been conducted by reconstructing detailed air quality maps in three
iSCAPE cities, namely Bologna, Hasselt and Vantaa chosen as
representative of south, central and north Europe respectively. Following
a thorough validation of all numerical models used in present scenarios,
simulations have been conducted using downscaled climate projections
for the three cities. Changes in air quality in future climate have been
documented for several policy options allowing to extract
recommendations for the selected cities and easily extendable to other
European cities
A multi-year source apportionment of PM2.5 at multiple sites in the southern Po Valley (Italy)
No full textA source apportionment study was carried out at four sites in Emilia-Romagna region, southern Po Valley, one of the most critical regions in Europe in terms of atmospheric pollution. PM2.5 daily samples were collected during 4 years from April 2013 to October 2017 at one rural site (San Pietro Capofiume) and three urban background locations in the cities of Bologna, Rimini, Parma which show different features and are located in the central, coastal and inner part of the investigated region. Samples were analyzed to achieve a complete chemical characterization (carbon fractions, ions, and elements). A source apportionment analysis by Positive Matrix Factorization (PMF) was performed and 6 PM2.5 factors were identified at all sites but the rural one (where 5 out of 6 of them were detected); the factors were associated to traffic with dust resuspension, biomass burning, oil combustion/ship emission, mix anthropogenic (not found at the rural site), ammonium nitrate and ammonium sulfate with organics. Chemical profiles of factors were very similar among all the 4 sites, indicating that main pollution sources are basically the same at the 4 sites, while some differences emerged with regard to source contributions. Factors related to secondary components seem to explain almost 50% or even more of PM2.5 mass concentration in all seasons. Traffic and biomass burning are the most relevant contributors to PM2.5 in terms of primary components. A not negligible contribution of biomass burning results in Rimini during the summer, suggesting other possible sources of wood combustion, such as cooking or open burning of agricultural pruning bonfires. Agriculture is not singled out as a PMF factor, but a rough estimate based on ammonium concentrations and ammonia data from emission inventory indicates a contribution from this source of about 10% of PM2.5 mass, thus resulting the single productive activity with the highest impact on PM2.5 at the investigated sites. Back trajectory analysis points out the relevant extra-regional contributions of two factors; indeed, oil combustion/ship emission is related to long-range transport of air masses overpassing the Mediterranean sea and secondary sulfate from Eastern Europe countries occasionally impacts on the Po Valley
Field study of a soft X-ray aerosol neutralizer combined with electrostatic classifiers for nanoparticle size distribution measurements
No full textMost conventional aerosol neutralizers are based on radioactive sources, which are controlled by strict regulations restricting their handling, transport, and storage. The TSI 3087 soft X-ray (SXR) neutralizer circumvents these legal restrictions. The aim of the present work is to compare the performance of a standalone SXR aerosol neutralizer with that of conventional radioactive aerosol neutralizers based on85Kr (TSI 3077) and241Am (Grimm 5522) by performing field tests in a real environmental scenario. The results obtained when the SXR neutralizer was connected to a mobility particle sizer spectrometer (MPS), different from the device suggested by the manufacturer, were comparable with those obtained with the use of radioactive aerosol neutralizers. In changing the neutralizer, the particle number concentrations, measured with the MPS connected to the SXR neutralizer, almost remained within the 10% uncertainty bounds for the particle size interval 10–300 nm, when diffusion losses inside the SXR tube were considered. Based on our comparisons, the SXR neutralizer can be regarded as a standalone instrument that could solve the problems associated with legal restrictions on radioactive neutralizers and fulfil the need for a portable instrument for different field test purposes
Factors controlling the lung dose of road traffic-generated sub-micrometre aerosols from outdoor to indoor environments
No full textEstimates of lung dose of submicron particles in the human respiratory system play an essential role in assessing health outcomes of aerosol exposure. The objective of this study is to calculate the regional lung dose of traffic-generated particles by different metrics from exposure in outdoor and indoor environments, and to identify main factors determining the lung dose. Particle number size distributions were collected in both indoor and outdoor environments in two unoccupied apartments from 22nd February to 30th April 2012 in Bologna, Italy. The whole lung dose of outdoor aerosols by number, surface area and mass at a traffic site was 1.0 x 1010 particle/hour, 130 mm2/hour, and 1.9 µg/hour, respectively. A majority of particles by number and surface area was found to deposit in the alveolar region (65%). The physical properties of particles such as shape, hygroscopicity and density play an important role in the calculation of surface area and mass dose due to shifting the lung deposition curve. Particle number can predict well the regional dose by number, while PM2.5 and PM10 are good metrics for the prediction of surface area and mass dose. Good correlations between NOx and the surface areas and mass dose (r2 ~0.8) and number dose (r2 ~0.7) of submicron aerosols suggest that NOx may be a good indicator for predicting the health outcomes of traffic-generated aerosols. The doses of indoor submicrometre aerosols are less than those of outdoor aerosols by factors of 4.1 (for number), 2.7 (for surface area) and 2.1 (for mass). Due to traffic emissions, the lung dose of outdoor aerosols in the traffic area was much higher than that in the residential area by 5 times for number and surface area and 2 times for mass. A different exercise level (standing, walking, running, and cycling) has only a slight influence on the whole lung deposition fraction of submicron aerosols, but has a large effect on the dose due to the differences in ventilation rate
