Maurizio Manigrasso

Relevance of aerosol size spectrum analysis as support to qualitative source apportionment studies

This work presents a diagnostic methodology in support to source apportionment studies to identify remote and local pollution sources. It is based on the temporal analysis of both PM size distributions and PM size fraction correlation along with natural radioactivity measurements as index of Planetary Boundary Layer dynamic. A correlation drop is indicative of changing aerosol sources. When this observation is coupled with decreasing level of natural radioactivity and increasing aerosol concentration, be it coarse or fine, it is indicative of the inflow of remote polluted air masses. The methodology defines in which size range operates the contribution of remote pollution sources. It was applied to two PM10 pollution episodes: the first involved the advection of coarse PM, the second entailed the inflow of two air masses, one transporting coarse dust and the other fine PM. Dust models and backward trajectories analysis confirmed such results, indicating the air mass provenience.

Second-hand smoke generated by combustion and electronic smoking devices used in real scenarios: Ultrafine particle pollution and age-related dose assessment

Aerosol 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 3months to 21years of age using the multiple-path particle dosimetry (MPPD) model. Regardless of the smoking device, the highest doses were received by infants, which reached 9.88×108particles/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 100nm 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 1.60×108particles/kg bw, than those due to combustion devices. Dosimetry estimates were 50% to 110% higher for IQOS® than for e-cigarettes.

Local air pollution and long-range mass transport of atmospheric particulate matter: a comparative study of the temporal evolution of the aerosol size fractions.

Abstract Long–range transport of polluted air masses can significantly affect surface particulate matter levels. PM 10 and PM 2.5 daily-average ponderal values alone are not sufficient to investigate the occurrence of such phenomena and consequently do not give significant information for source apportionment. In this work, the analysis of aerosol size spectra and the study of the correlation of the fine and coarse modes of PM have been applied to individuate long–range transport episodes of polluted air masses. Dust-models and backward-trajectory analysis were supportive to local surface measurements of size distribution of PM in confirming the origins of remote sources of pollution. An application is discussed involving long range transport of desert dust over Italy that comparatively examined with a fine-PM pollution episode due to local sources. During the study, the atmospheric stability/unstability conditions were followed through the trend of the natural radioactivity considered as tracer of the Planetary Boundary Layer.

Temporal evolution of ultrafine particles and of alveolar deposited surface area from main indoor combustion and non-combustion sources in a model room

Aerosol 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 4.1×107particlescm-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 106particlescm-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 3.2×103μm2cm-3 for meat grilling without exhaust ventilation) and lowest for electric appliances (20-90μm2cm-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).

Pedestrians in Traffic Environments: Ultrafine Particle Respiratory Doses

Particulate 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.

Natural radioactivity as an easy and quick parameter for describing the dynamic of the Planetary Boundary Layer

This work describes a methodological approach based on natural radioactivity measurements aimed at interpreting air pollution episodes in urban air. The use of such parameters helps in the understanding of the temporal behaviors of seasonal primary (benzene and carbon monoxide) and secondary (nitrogen dioxide and ozone) pollutants. A comparison between the daily concentrations of primary and secondary pollutants and the natural radioactivity trends, considered as an index of the dynamic of the low atmospheric boundary layers, evidences that acute episodes of air pollution in downtown Rome occur in wintertime due to high atmospheric stability (primary pollution) and in summertime because of the strong diurnal atmospheric mixing (secondary pollution).

Deep investigation on inorganic fraction of atmospheric PM in Mediterranean area by neutron and photon activation analysis

BackgroundAnthropogenic activities introduce materials increasing levels of many dangerous substances for the environmental quality and being hazardous to human health. Major attention has been given to those elements able to alter the environment and endanger human health.The airborne particulate matter pollutant is considered one of the most difficult task in environmental chemistry for its complex composition and implications complicating notably the behavior comprehension. So, for investigating deeply the elemental composition we used two nuclear techniques, Neutron Activation Analysis and Photon Activation Analysis, characterized by high sensitivity, precision and accuracy. An important task has been devoted to the investigation of Quality Control (QC) and Quality Assurance (QA) of the methodology used in this study.This study was therefore extended as far back as possible in time (from 1965 until 2000) in order to analyze the trend of airborne concentration of pollutant elements in connection with the industrial and lifestyle growth during the entire period.ResultsAlmost all the elements may be attributed to long-range transport phenomena from other natural and/or anthropogenic sources: this behavior is common to all the periods studied even if a very light decreasing trend can be evidenced from 1970 to 2002. Finally, in order to investigate a retrospective study of elements in PM10 and their evolution in relationship with the natural or anthropogenic origins, we have investigated the Enrichment Factors. The study shows the EF trends for some elements in PM10 during four decades.ConclusionsThe two nuclear techniques have allowed to reach elevated sensibility/accuracy levels for determining elements at very low concentrations (trace and ultra-trace levels). The element concentrations determined in this study do not basically show a significant level of attention from a toxicological point of view.

Classification of an area as metallogenic province: environmental importance and problems

Abstract This paper proposes a new protocol to identify metallogenic provinces: about 30 elements along with the rare earths (Ce, Dy, Eu, La, Nd, Sm, Tb and Yb), Th and U in ores of the North-Latium have been investigated by INAA. Statistical procedures (enrichment factor, source discrimination and principal component analysis) had been employed to evaluate the enrichment in specific elements to investigate the possibility of an economic exploitation of some of them. Finally, the chondritic ratio of the rare earths compared to the MORB meteorite has been evaluated for determining the magma differentiation process and its effect.

Reaction Inhibition in the Control of Exothermic Runaway

A research program has been undertaken into the use of chemical inhibition techniques as a basis of safety for the control of exothermic runaway reaction hazards. The principal element of the research has been the design and running of a series of pilot scale trials at the Health and safety Laboratories into the inhibition of an uncontrolled polymerization of styrene have demonstrated the effectiveness of the injection of the inhibitor para tertiary butyl catechol at two different agitation speeds and under conditions immediately following agitation failure. Modeling of the experiments using a network-of-zones approach has shown some inadequacies with the reproduction of the pilot scale data, notably in the inability to simulate the jet mixing effects that dominate in small scale plant with the conditions employed. M The present modeling results do, however, underpredict the mixing efficiency, thereby leading to a more conservative design for the cases studied.

Second-hand aerosol from tobacco and electronic cigarettes: Evaluation of the smoker emission rates and doses and lung cancer risk of passive smokers and vapers.

Smoking activities still represent the main, and preventable, cause of lung cancer risk worldwide. For this reason, a number of studies were carried out to deepen and better characterize the emission of cigarette-generated mainstream aerosols in order to perform an a-priori evaluation of the particle doses and related lung cancer risks received by active smokers. On the contrary, a gap of knowledge still exists in evaluating the dose and risk received by passive smokers in indoor private micro-environments (e.g. homes). For this purpose, in the present paper, an experimental campaign was performed to evaluate the exposure to second-hand aerosol from conventional and electronic cigarettes and to estimate the consequent dose received by passive smokers/vapers and the related lung cancer risk. Measurements of exposure levels in terms of particle number, PM10 and black carbon concentrations, as well as particle size distributions, were performed in a naturally ventilated indoor environment during smoking activities of tobacco and electronic cigarettes. The particle emission rates of smokers and vapers, for the different aerosol metrics under investigation, were evaluated. Moreover, for a typical exposure scenario, the dose received by the passive smokers/vapers in a naturally ventilated indoor micro-environment was estimated through a Multiple-Path Particle Dosimetry (MPPD) model able to assess the particle dose received in the different tracts of the respiratory systems. Furthermore, on the basis of scientific literature data about mass fraction of carcinogenic compounds contained in cigarette-emitted particles (i.e. Heavy Metals, Benzo-a-pyrene and nitrosamines) and the estimated doses, the excess life cancer risk (ELCR) for passive smokers/vapers was evaluated. Cumulative respiratory doses for passive smokers were up to 15-fold higher than for passive vapers. The ELCR for second-hand smokers was five orders of magnitude larger than for second-hand vapers.