Probing functional groups at the gas-aerosol interface using heterogeneous titration reactions: a tool for predicting aerosol health effects?

The complex chemical and physical nature of combustion and secondary organic aerosols (SOAs) in general precludes the complete characterization of both bulk and interfacial components. The bulk composition reveals the history of the growth process and therefore the source region, whereas the interface controls--to a large extent--the interaction with gases, biological membranes, and solid supports. We summarize the development of a soft interrogation technique, using heterogeneous chemistry, for the interfacial functional groups of selected probe gases [N(CH(3))(3), NH(2)OH, CF(3)COOH, HCl, O(3), NO(2)] of different reactivity. The technique reveals the identity and density of surface functional groups. Examples include acidic and basic sites, olefinic and polycyclic aromatic hydrocarbon (PAH) sites, and partially and completely oxidized surface sites. We report on the surface composition and oxidation states of laboratory-generated aerosols and of aerosols sampled in several bus depots. In the latter case, the biomarker 8-hydroxy-2'-deoxyguanosine, signaling oxidative stress caused by aerosol exposure, was isolated. The increase in biomarker levels over a working day is correlated with the surface density N(i)(O3) of olefinic and/or PAH sites obtained from O(3) uptakes as well as with the initial uptake coefficient, γ(0), of five probe gases used in the field. This correlation with γ(0) suggests the idea of competing pathways occurring at the interface of the aerosol particles between the generation of reactive oxygen species (ROS) responsible for oxidative stress and cellular antioxidants.

Deposition rates of sidestream tobacco smoke particles in an experimental chamber

The natural dissipation rates of sidestream smoke (SS) particles dispersed in a chamber were studied from the standpoint of a static atmosphere and were expressed as half-lives of residence in the air. The half-lives for particles less than 0.3 micron, 0.3-0.5 micron and 0.5-1 micron were found to be 25.5, 12.8 and 4.9 h, respectively. Total particulate matter (TPM) decreases by half after 6.2 h. Other data on diluted SS in the indoor air were also reported.

'Herbal' but potentially hazardous: an analysis of the constituents and smoke emissions of tobacco-free waterpipe products and the air quality in the cafes where they are served

BACKGROUND: There are limited data on the composition and smoke emissions of 'herbal' shisha products and the air quality of establishments where they are smoked. METHODS: Three studies of 'herbal' shisha were conducted: (1) samples of 'herbal' shisha products were chemically analysed; (2) 'herbal' and tobacco shisha were burned in a waterpipe smoking machine and main and sidestream smoke analysed by standard methods and (3) the air quality of six waterpipe cafes was assessed by measurement of CO, particulate and nicotine vapour content. RESULTS: We found considerable variation in heavy metal content between the three products sampled, one being particularly high in lead, chromium, nickel and arsenic. A similar pattern emerged for polycyclic aromatic hydrocarbons. Smoke emission analyses indicated that toxic byproducts produced by the combustion of 'herbal' shisha were equivalent or greater than those produced by tobacco shisha. The results of our air quality assessment demonstrated that mean PM2.5 levels and CO content were significantly higher in waterpipe establishments compared to a casino where cigarette smoking was permitted. Nicotine vapour was detected in one of the waterpipe cafes. CONCLUSIONS: 'Herbal' shisha products tested contained toxic trace metals and PAHs levels equivalent to, or in excess of, that found in cigarettes. Their mainstream and sidestream smoke emissions contained carcinogens equivalent to, or in excess of, those of tobacco products. The content of the air in the waterpipe cafes tested was potentially hazardous. These data, in aggregate, suggest that smoking 'herbal' shisha may well be dangerous to health.

Sellu- ja paperiteollisuuden haitallisimmat ilmapäästöt

Diplomityössä luotiin katsaus sellu- ja paperiteollisuuden haitallisimpiin ilmapäästöihin ja ilmapäästömäärien kehitykseen Suomessa 1990-luvun alusta nykypäivään. Työssä tutustuttiin sellu- ja paperiteollisuuden ilmapäästöjä rajoittavan lainsäädännön ajankohtaisiin asioihin Suomessa ja Euroopan Unionissa, sekä tarkasteltiin nykyisen lainsäädännön perustana olleita ilmastosopimuksia eli kansainvälisen ilmastopolitiikan syntyä ja kehittymistä. Työssä on myös selvitetty ilman osuutta paperinvalmistuksessa, tutustuttu ilmapäästöjen rajoittamismenetelmiin ja eri mittausmenetelmiin ilmapäästöjen toteamiseksi. Työn puitteissa suoritettiin mittalaitetestejä eri paperitehtailla. Haitallisimpia ja määrällisesti suurimpia ilmapäästöjä sellu- ja paperiteollisuudessa ovat typen ja rikin oksidit, pelkistyneet rikkiyhdisteet, hiukkaset, haihtuvat orgaaniset yhdisteet (VOC) ja hiilidioksidi. Ilmapäästömäärät Suomessa ovat typenoksideja lukuun ottamatta olleet laskussa 1990-luvun alusta nykypäivään. Tärkein kasvihuonekaasu on hiilidioksidi, jonka määrää rajoitetaan Kioton sopimuksessa. Vuoden 2002 aikana selvinneekin, mikä on Kioton sopimuksen vaikutus Suomen metsäteollisuuteen. Päästömittauksia tarvitaan lainsäädännön raja-arvojen toteamiseksi, mittauksia suorittavat sertifioidut päästömittauslaboratoriot. Suoritetuissa mittalaitetesteissä havaittiin mittalaitteiden soveltuvuudessa kosteiden paperiprosessin poistokaasujen määrittämiseen suuria eroja.

Lentotuhkan fraktiointi sähkösuodattimella ja Ion Blast -menetelmällä

Diplomityö on osa YTI-tutkimuskeskuksessa vuosina 2002 - 2004 toteutettavaa Jätekompostit rakeiksi tuhkaseostuksella -käyttöarvon parantaminen -projektia. Työssä tutkittiin Etelä-Savon Energia Oy:n Pursialan voimalaitoksen lentotuhkan fraktioimista voimalaitoksen nykyisellä 3-kenttäisellä sähkösuodattimella ja pilot-mittakaavaisella Ion Blast -koelaitteistolla. Sähkösuodattimen koeajojen aikana muuteltiin sen ajotapaa mm. CBO -suhteen ja maksimijänniteasetuksen avulla. Ion Blast -koelaitteistolla tutkittiin mahdollisuuksia voimalaitoksen lentotuhkan puhdistamiseksi raskasmetalleista. Lentotuhkan hyötykäyttöä vaikeuttaa sen raskasmetallipitoisuuksien suuri vaihtelu. Ongelmallisin raskasmetalli puuperäisessä lentotuhkassa on kadmium, jonka lannoitelainsäädännön raja-arvo on tällä hetkellä 3 mg/kg. Sähkösuodattimella tehtyjen fraktiointikokeiden perusteella voidaan todeta raskasmetallipitoisuuksien olevan pienimmillään sähkösuodattimen 1-kentässä ja suurimmillaan 3-kentässä. Tämä johtuu siitä, että 1-kenttään kerääntyy hiukkaskooltaan suurimmat lentotuhkahiukkaset ja 3-kentässä on mukana enemmän pienhiukkasia sisältävää tuhkaa. Lannoitteeksi menevän tuhkan Cd-pitoisuutta voidaan vähentää parhaimmillaan jopa 70 % sähkösuodattimella fraktioimalla. Muiden raskasmetallien pitoisuudet eivät vähene aivan yhtä paljon. Sähkösuodattimella voidaan tulosten perusteella fraktioida lentotuhkaa. Sähkösuodattimella ei kuitenkaan voida varmasti saavuttaa alle 3 mg/kg Cd-pitoisuuksia polttoaineen laadunvaihtelun vuoksi. Ion Blast -koelaitteiston tulokset tukevat sähkösuodattimella tehtyjä kokeita. Erottimen jännitteen kasvaessa raskasmetalleja sisältävien hiukkasten erotusaste kasvaa. Ion Blast -laitteistolla tehdyissä kokeissa myös Cd-pitoisuus oli korkeimmillaan pienimmän raeluokan hiukkasissa ja laski sitten raeluokan suurentuessa. Ion Blast -laitteisto ei kuitenkaan sellaisenaan ole hyvä fraktiointiin. Se on liian tehokas, jolloin se puhdistaa tehokkaasti myös raskasmetalleja sisältävät pienhiukkaset. Jos laitetta aiotaan käyttää fraktiointiin, tulisi sen rakennetta muuttaa.

Impact of open-ocean convection on particle fluxes and sediment dynamics in the deep margin of the Gulf of Lions.

Abstract. The deep outer margin of the Gulf of Lions and the adjacent basin, in the western Mediterranean Sea, are regularly impacted by open-ocean convection, a major hydrodynamic event responsible for the ventilation of the deep water in the western Mediterranean Basin. However, the impact of open-ocean convection on the flux and transport of particulate matter remains poorly understood. The variability of water mass properties (i.e., temperature and salinity), currents, and particle fluxes were monitored between September 2007 and April 2009 at five instrumented mooring lines deployed between 2050 and 2350-m depth in the deepest continental margin and adjacent basin. Four of the lines followed a NW-SE transect, while the fifth one was located on a sediment wave field to the west. The results of the main, central line SC2350 ("LION") located at 42 02.50 N, 4 410 E, at 2350-m depth, show that open-ocean convection reached midwater depth ( 1000-m depth) during winter 2007-2008, and reached the seabed ( 2350-m depth) during winter 2008-2009. Horizontal currents were unusually strong with speeds up to 39 cm s−1 during winter 2008-2009. The measurements at all 5 different locations indicate that mid-depth and near-bottom currents and particle fluxes gave relatively consistent values of similar magnitude across the study area except during winter 2008-2009, when near-bottom fluxes abruptly increased by one to two orders of magnitude. Particulate organic carbon contents, which generally vary between 3 and 5 %, were abnormally low ( 1 %) during winter 2008-2009 and approached those observed in surface sediments (0.6 %). Turbidity profiles made in the region demonstrated the existence of a bottom nepheloid layer, several hundred meters thick, and related to the resuspension of bottom sediments. These observations support the view that open-ocean deep convection events in the Gulf of Lions can cause significant remobilization of sediments in the deep outer margin and the basin, with a subsequent alteration of the seabed likely impacting the functioning of the deep-sea ecosystem.

Oxidative potential of particles in different occupational environments: a pilot study

The oxidative potential (OP) of particulate matter has been proposed as a toxicologically relevant metric. This concept is already frequently used for hazard characterization of ambient particles but it is still seldom applied in the occupational field. The objective of this study was to assess the OP in two different types of workplaces and to investigate the relationship between the OP and the physicochemical characteristics of the collected particles. At a toll station, at the entrance of a tunnel ('Tunnel' site), and at three different mechanical yards ('Depot' sites), we assessed particle mass (PM4 and PM2.5 and size distribution), number and surface area, organic and elemental carbon, polycyclic aromatic hydrocarbon (PAH), and four quinones as well as iron and copper concentration. The OP was determined directly on filters without extraction by using the dithiothreitol assay (DTT assay-OP(DTT)). The averaged mass concentration of respirable particles (PM4) at the Tunnel site was about twice the one at the Depot sites (173±103 and 90±36 µg m(-3), respectively), whereas the OP(DTT) was practically identical for all the sites (10.6±7.2 pmol DTT min(-1) μg(-1) at the Tunnel site; 10.4±4.6 pmol DTT min(-1) μg(-1) at the Depot sites). The OP(DTT) of PM4 was mostly present on the smallest PM2.5 fraction (OP(DTT) PM2.5: 10.2±8.1 pmol DTT min(-1) μg(-1); OP(DTT) PM4: 10.5±5.8 pmol DTT min(-1) μg(-1) for all sites), suggesting the presence of redox inactive components in the PM2.5-4 fraction. Although the reactivity was similar at the Tunnel and Depot sites irrespective of the metric chosen (OP(DTT) µg(-1) or OP(DTT) m(-3)), the chemicals associated with OP(DTT) were different between the two types of workplaces. The organic carbon, quinones, and/or metal content (Fe, Cu) were strongly associated with the DTT reactivity at the Tunnel site whereas only Fe and PAH were associated (positively and negatively, respectively) with this reactivity at the Depot sites. These results demonstrate the feasibility of measuring of the OP(DTT) in occupational environments and suggest that the particulate OP(DTT) is integrative of different physicochemical properties. This parameter could be a potentially useful exposure proxy for investigating particle exposure-related oxidative stress and its consequences. Further research is needed mostly to demonstrate the association of OP(DTT) with relevant oxidative endpoints in humans exposed to particles.

The environmental effects of changing speed limits: a quantile regression approach

Two speed management policies were implemented in the metropolitan area of Barcelona aimed at reducing air pollution concentration levels. In 2008, the maximum speed limit was reduced to 80 km/h and, in 2009, a variable speed system was introduced on some metropolitan motorways. This paper evaluates whether such policies have been successful in promoting cleaner air, not only in terms of mean pollutant levels but also during high and low pollution episodes. We use a quantile regression approach for fixed effect panel data. We find that the variable speed system improves air quality with regard to the two pollutants considered here, being most effective when nitrogen oxide levels are not too low and when particulate matter concentrations are below extremely high levels. However, reducing the maximum speed limit from 120/100 km/h to 80 km/h has no effect – or even a slightly increasing effect –on the two pollutants, depending on the pollution scenario. Length: 32 pages

Avaliação de poluição do ar por chumbo particulado: uma abordagem geoquímica

High lead concentrations up to 5478 mg kg-1 were detected in dry atmospheric precipitations in Rio Grande city and adjacent area. Lead anomalies cover up to 30% of the study area. Lead concentration measurement in dry atmospheric precipitation and suspended particulate matter provides a possibility to detect concentrations above lead threshold in the air. The most impacted areas are fishermen's villages. The most possible source of lead in the air is uncontrolled sub industrial activity of local population

Estudo de aerossóis atmosféricos e aplicação de modelos numéricos

The main purpose of the present work is to study the concentration of atmospheric particles (PM10 and PM2.5) in the Candiota (RS) region using HV PM10 and dichotomous samplers. Four sampling sites at a distance of 50 km from the emission source were selected: Aceguá, Aeroporto, 8 de Agosto and Pedras Altas. Samples were collected from December 2000 to December 2001. The values obtained with the ISCST (Industrial Source Complex Term) model and with the samplers were compared on January 21st, April 5th, July 14th, August 1st, and October 13th 2001, and are representative of frontal systems occurring in the study area.

Aerossóis atmosféricos: perspectiva histórica, fontes, processos químicos de formação e composição orgânica

This work starts with a historical perspective of the social and scientific progress related to the understanding of the atmospheric aerosol. Its origin, physical, chemical and optical characteristics, as well as its environmental behaviour are described, retracing the evolution of the concepts related to this subject over the last centuries. The main sources that contribute to atmospheric particulate matter and the modern understanding of its formation processes and constitution, focusing on the chemical pathways leading to it and on its organic components are presented. This discussion is complemented with recent evaluations of the quantities emitted by primary, secondary, biogenic and anthropogenic sources and the effects due to accumulation or dispersion of aerosols, justifying the chemical and environmental interest they engender.

Determinação de manganês em material particulado atmosférico de ambientes de trabalho utilizando eletrodo de diamante dopado com boro e voltametria de onda quadrada com redissolução catódica

A boron-doped diamond electrode is used for determination of Mn(II) in atmospheric particulate matter by square wave cathodic stripping voltammetry. The analytical curve was linear for Mn(II) concentrations between 5.0 and 37.5 µg L-1, with quantification limit of 3.6 µg L-1. The precision was evaluated by the relative standard deviation, with values between 5.1% and 9.3%. The electrode is free of adsorption, minimizing memory effects. Samples collected in the workplace atmosphere of a foundry had Mn(II) concentrations between 0.4 and 4 µg m-3. No significant differences were observed between the proposed method and inductively coupled plasma optical emission spectroscopy.

Case-Crossover Analysis of Air Pollution Health Effects: A Systematic Review of Methodology and Application

Case-crossover is one of the most used designs for analyzing the health-related effects of air pollution. Nevertheless, no one has reviewed its application and methodology in this context. Objective: We conducted a systematic review of case-crossover (CCO) designs used to study the relationship between air pollution and morbidity and mortality, from the standpoint of methodology and application.Data sources and extraction: A search was made of the MEDLINE and EMBASE databases.Reports were classified as methodologic or applied. From the latter, the following information was extracted: author, study location, year, type of population (general or patients), dependent variable(s), independent variable(s), type of CCO design, and whether effect modification was analyzed for variables at the individual level. Data synthesis: The review covered 105 reports that fulfilled the inclusion criteria. Of these, 24 addressed methodological aspects, and the remainder involved the design’s application. In the methodological reports, the designs that yielded the best results in simulation were symmetric bidirectional CCO and time-stratified CCO. Furthermore, we observed an increase across time in the use of certain CCO designs, mainly symmetric bidirectional and time-stratified CCO. The dependent variables most frequently analyzed were those relating to hospital morbidity; the pollutants most often studied were those linked to particulate matter. Among the CCO-application reports, 13.6% studied effect modification for variables at the individual level.Conclusions: The use of CCO designs has undergone considerable growth; the most widely used designs were those that yielded better results in simulation studies: symmetric bidirectional and time-stratified CCO. However, the advantages of CCO as a method of analysis of variables at the individual level are put to little use

Is Microtox R toxicity related to potentially harmful algae proliferation in Mediterranean salt marshes?

Mediterranean salt marshes are ecosystems that are highly influenced by sea changes and freshwater inputs from runoff. In these ecosystems, toxic and non-toxic algae blooms often produce large and unpredictable biomasses of phytoplankton. The Microtox R test has been described as a successful, quick method for detecting toxicity in various phytoplankton taxa. Ourstudy sought to test the efficiency of Microtox R in detecting toxic HAB in Mediterranean salt marshes. The results showed that the Microtox R test was able to detect toxic substances in the particulate matter of several lagoons in the Empordà salt marshes. This Microtox R toxicity coincided with periods when potentially harmful cyanobacteria, dinoflagellates andhaptophytes had a high biomass. The results suggest that potentially harmful phytoplankton cannot be ruled out as a source of Microtox R

Composição elementar do material particulado presente no aerossol atmosférico do município de Sete Lagoas, Minas Gerais

The main objective of this study was the identification of sources generating particulate matter in the atmospheric aerosols of Sete Lagoas, Minas Gerais. The measurement of the mineral composition was accomplished by X-ray diffractometry and the elemental concentration by neutron activation analysis. The results showed that Al, Cl, Cu, Fe, K, Mg and Na are the predominant chemical elements in the total suspended particles (TPS). The presence of Na, Ba, Cl, Cu, Eu, Fe and Sm in those particles with aerodynamic diameter smaller than 10 µm (PM10), indicates that soil dust and ceramic and pig iron industries are the main sources of air quality degradation in the region.