Modeling Population Exposure to Ultrafine Particles in a Major Italian Urban Area

Average daily ultrafine particles (UFP) exposure of adult Milan subpopulations (defined on the basis of gender, and then for age, employment or educational status), in different exposure scenarios (typical working day in summer and winter) were simulated using a microenvironmental stochastic simulation model. The basic concept of this kind of model is that time-weighted average exposure is defined as the sum of partial microenvironmental exposures, which are determined by the product of UFP concentration and time spent in each microenvironment. In this work, environmental concentrations were derived from previous experimental studies that were based on microenvironmental measurements in the city of Milan by means of personal or individual monitoring, while time-activity patterns were derived from the EXPOLIS study. A significant difference was observed between the exposures experienced in winter (W: 28,415 pt/cm3) and summer (S: 19,558 pt/cm3). Furthermore, simulations showed a moderate difference between the total exposures experienced by women (S: 19,363 pt/cm3; W: 27,623 pt/cm3) and men (S: 18,806 pt/cm3; W: 27,897 pt/cm3). In addition, differences were found as a function of (I) age, (II) employment status and (III) educational level; accordingly, the highest total exposures resulted for (I) 55–59 years old people, (II) housewives and students and (III) people with higher educational level (more than 10 years of scholarity). Finally, significant differences were found between microenvironment-specific exposures

Quantification of asbestos and other mineral phase burden in necroscopic human lung tissues with a new method

Background: A large amount of studies on asbestos exposure reconstruction have been so far conducted digesting the lung tissues with appropriate reagents, separating the powder from the digestion liquid by filtration and analysing the residue by optical or electron microscopy. This analytical approach has good sensitivity but is not yet well standardized, the investigated portion is not representative of the bulk sample, the results are often characterized by lack of reproducibility and repeatability. Moreover, the numeric quantification of asbestos requires a time-consuming particle by particle analysis. Aim: to develop a new method for the complete quantitative characterization of asbestos and other mineral phases in human lung tissue. Methods: The new method is based on sodium hypochlorite digestion, separation and XRPD analysis. The XRPD approach needs moderate lung tissue amounts (at least 20 g of wet tissue), but allows to conduct a complete quantitative characterization of each crystalline phase in the sample giving bulk-representative results with good reproducibility, accuracy and precision. The detection limit of conventional XRPD was considerably improved by a novel instrumental setting and weight concentrations can be obtained, giving additional information to numeric ones, preferable in clinical and pathogenetic studies but probably not for the exposure reconstruction. Results: Among the analysed autoptic lung tissues, ten samples belonged to subjects occupationally exposed to asbestos and six were collected from urban area controls. Asbestos phases were detected in none of controls and in 5 of 10 occupationally exposed subjects (those with highest exposure history) indicating that this method is suitable for the reconstruction of medium and high asbestos exposures. It has been furthermore confirmed the mineral association found in previous studies: mainly composed by quartz, talc, clay minerals, micas, Fe-Al-Ti oxides and bio-minerals such Ca-phosphates, carbonates and oxalates

Personal exposure to airborne ultrafine particles in the urban area of Milan

The relevance of health effects related to ultrafine particles (UFPs; aerodynamic diameter < 100 nm) can be better evaluated using high-resolution strategies for measuring particle number concentrations. In this study, two different portable Condensation Particle Counters (CPCs) were used to measure personal exposure to UFPs in the central area of Milan for one week period during spring, with three sampling sessions per day. Experimental data were continuously collected along an established urban pathway, moving afoot or by different private and public means of transport. Correlation analysis between data measured by two CPCs was performed and general results showed a good agreement, especially at concentrations lower than 2 7105 particles /cm3. UFPs measures were divided on the basis of crossed environments or micro-environments, days of the week and day time (hours). The highest measured mean concentrations and data variability were observed during walking time and moving on motorized vehicles (bus and car), indicating that the highest exposure to UFPs can be reached near motorized traffic. The lowest exposures were observed in green areas and in office microenvironments. An appreciable difference between working and non-working days was observed. Concentration patterns and variation by days of the week and time periods appears related to time trends in traffic intensity

Monitoraggio ambientale dell\u2019esposizione a cromo: i risultati dello studio PPTP \u2013 Galvanica

Nell\u2019ambito dello studio PPTP-Galvanica della Regione Lombardia, sono state effettuate indagini di monitoraggio ambientale personali ed in postazione fissa (centro ambiente) al fine di caratterizzare l\u2019esposizione a particolato, ed in particolar modo a cromo esavalente, degli addetti alle attivit\ue0 di galvanica. Dall\u2019esame dei risultati emerge che, in condizione di corretto rispetto delle norme di igiene sul lavoro, le condizioni di processo e di protezione sono tali da assicurare il pi\uf9 ampio rispetto dei limiti previsti. In particolare il campione ha mostrato condizioni ottime nelle grosse realt\ue0 aziendali (dove \ue8 ormai in uso un sistema di lavorazione a \u201cciclo chiuso\u201d), molto buone nelle aziende di medie dimensioni e picchi pi\uf9 problematici di circa 40 \ub5m/m3 in quelle a conduzione famigliare (1 o 2 addetti). Ai fini della valutazione del rischio, non si pu\uf2 quindi escludere che situazioni di lavoro particolari possano portare ad un\u2019esposizione a cromo esavalente meritevole di maggiore attenzione

I valori limite per agenti chimici alla luce del Regolamento REACH

The European Regulation 1907/2006 (REACH - Registration, Evaluation, Authorization and Restriction of Chemicals) obliges manufacture companies and import chemicals to assess the risks arising from their use and to take the necessary measures to manage the risks identified. The Chemical Safety Report provides an accurate assessment of hazards to human health and the environment necessary to prepare an exposure scenario for the \u201cidentified uses\u201d of the substance. An exposure scenario is the set of conditions that describe how the substance is manufactured or used during its life cycle and how the manufacturer or importer controls, or recommends downstream users to control the \u2018exposure to humans and the environment. Firms therefore need specific skills. The spectrum of toxicological risk is extremely large, the information required in some cases are very complex and undoubtedly require a thorough knowledge in toxicology and environmental industry. The expertise and experience in toxicology of the occupational physician in this case may become useful in the environmental field as well as another familiar figure of relevant importance is the occupational hygienist who develop exposure scenarios for workers and their uses experience for the exposure scenarios for the consumer. It provides an obvious involvement of medical toxicologists and occupational hygienists for public tasks of control and inspection of chemical safety reports and, locally, even the accuracy of risk that arise from this

Fine and ultrafine particle levels determined during everyday activities : the PM-CARE project

Exposure to particle number (particles >0.02 \u3bcm in aerodynamic diameter, a.d.) and particle mass levels (PM0.5 , PM1 , PM2.5 and PM10) were determined on 82 non-smoking senior volunteers living in urban and suburban areas of Milan, during the warm and cold seasons of 2005-2006. Measuring devices, comprehending optical counters (6-channel OPC and CPC), a 4-stage cascade impactor, CO and O3 monitors and a NO2 passive sampler, were mounted on trolleys (25kg), especially equipped to provide 24h self-contained air monitoring. Subjects\u2019 activities were individually recorded on timetables, used also for clinical purposes (see Fanetti et al.). When required, outdoor transfers by car or afoot were assisted by project personnel. 24h-average particle number and mass (PM10) concentration means were 19.500 #/cm3 and 41.4 \ub5g/m3 in summer (1913 hours) and 26.600 #/cm3 and 62.0 \ub5g/m3 in winter (1894 hours), with a mean seasonal contribution of PM0.5 to PM10 of 54% and 68%, respectively. Data plots logged by particle counters were apportioned and separately examined according to the most common activities emerging from the timetable. Resulting particle number concentrations are here presented as the mean percent deviation from individual 24h-averaged levels, given as Activity: [a.d. 0.3\u20130.5 \ub5m] and [a.d. >0.02] (total hours monitored; number of subjects). Home at rest: -1% and -20% (1419; 76), Domestic activities: +6% and +7% (307; 75), Flame cooking: +14% and +97% (293; 72), Workplace activities: +18% and -10% (104; 12), Sleep: -7% and -51% (1170; 78), Moving by car: +46% and +141% (103; 81), Promenade: +52% and +27% (66; 32). With the exception of domestic and workplace activities, which could not be better specified, the results reported are indicative of human PM exposure pattern experienced in urban and suburban areas. Substantial increases of overall particle counts are associated with flame cooking and vehicle displacements, whereas PM0.5 levels seem to be mainly associated with outdoor sources

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc