Margarita Evtyugina

Outdoor/indoor air quality in primary schools in Lisbon: a preliminary study

Simultaneous measurements of outdoor and indoor pollution were performed at three schools in Lisbon. Volatile organic compounds (VOCs), formaldehyde and NO2 were passively monitored over a two-week period. Bacterial and fungal colony-forming units and comfort parameters were also monitored at classrooms and playgrounds. The highest indoor levels of CO2 (2666 μg/m3), NO2 (40.3 μg/m3), VOCs (10.3 μg/m3), formaldehyde (1.03 μg/m3) and bioaerosols (1634 CFU/m3), and some indoor/outdoor ratios greater than unity, suggest that indoor sources and building conditions might have negative effects on air indoors. Increasing ventilation rates and use of low-emission materials would contribute towards improving indoor air quality.

Emission of trace gases and organic components in smoke particles from a wildfire in a mixed-evergreen forest in Portugal

On May 2009, both the gas and particulate fractions of smoke from a wildfire in Sever do Vouga, central Portugal, were sampled. Total hydrocarbons and carbon oxides (CO(2) and CO) were measured using automatic analysers with flame ionisation and non-dispersive infrared detectors, respectively. Fine (PM(2.5)) and coarse (PM(2.5-10)) particles from the smoke plume were analysed by a thermal-optical transmission technique to determine the elemental and organic carbon (EC and OC) content. Subsequently, the particle samples were solvent extracted and fractionated by vacuum flash chromatography into different classes of organic compounds. The detailed organic speciation was performed by gas chromatography-mass spectrometry. The CO, CO(2) and total hydrocarbon emission factors (g kg(-1) dry fuel) were 170 ± 83, 1485 ± 147, and 9.8 ± 0.90, respectively. It was observed that the particulate matter and OC emissions are significantly enhanced under smouldering fire conditions. The aerosol emissions were dominated by fine particles whose mass was mainly composed of organic constituents, such as degradation products from biopolymers (e.g. levoglucosan from cellulose, methoxyphenols from lignin). The compound classes also included homologous series (n-alkanes, n-alkenes, n-alkanoic acids and n-alkanols), monosaccharide derivatives from cellulose, steroid and terpenoid biomarkers, and polycyclic aromatic hydrocarbons (PAHs). The most abundant PAH was retene. Even carbon number homologs of monoglycerides were identified for the first time as biomarkers in biomass burning aerosols.

Factores de risco e prevalência de asma e rinite em crianças em idade escolar em Lisboa

AIMS A cross-sectional study was carried out with the objective of identifying nutrition habits and housing conditions as risk factors for respiratory problems in schoolchildren in Lisbon. MATERIAL AND METHODS Between October and December 2008, parents of 900 students of the basic schools of Lisbon were invited to answer a questionnaire of the International Study of Asthma and Allergies in Childhood Program (ISAAC). The response rate was 40%. Logistic regression was used in the analysis of results. RESULTS The prevalence of asthma, allergic rhinitis and wheeze was 5.6%, 43.0% and 43.3%, respectively. Risk factors independently associated with asthma were wheezing attacks, and dry cough at night not related to common cold in the last 12 months. Wheezing crises were found to affect children daily activities. Risk factors for wheeze were hay fever and the presence of a pet at home. A risk factor for rhinitis was cough at night. The frequent consumption of egg was also associated with increased risk of rhinitis. CONCLUSION Contrarily to asthma, the prevalence of allergic rhinitis and wheeze increased in comparison with previous ISAAC studies. Wheezing attacks were associated with asthma and hay fever was identified as a risk factor of manifesting wheezing symptoms. Having pets at home was pointed out as a significant risk factor for rhinitis, but not smoking exposure, mould, plush toys, diet (except egg consumption), breastfeeding or other conditions.

Could houseplants improve indoor air quality in schools

Previous studies performed by the National Aeronautics Space Administration (NASA) indicated that plants and associated soil microorganisms may be used to reduce indoor pollutant levels. This study investigated the ability of plants to improve indoor air quality in schools. A 9-wk intensive monitoring campaign of indoor and outdoor air pollution was carried out in 2011 in a primary school of Aveiro, Portugal. Measurements included temperature, carbon dioxide (CO2), carbon monoxide (CO), concentrations of volatile organic compounds (VOC), carbonyls, and particulate matter (PM10) without and with plants in a classroom. PM10 samples were analyzed for the water-soluble inorganic ions, as well for carbonaceous fractions. After 6 potted plants were hung from the ceiling, the mean CO2 concentration decreased from 2004 to 1121 ppm. The total VOC average concentrations in the indoor air during periods of occupancy without and with the presence of potted plants were, respectively, 933 and 249 μg/m3. The daily PM10 levels in the classroom during the occupancy periods were always higher than those outdoors. The presence of potted plants likely favored a decrease of approximately 30% in PM10 concentrations. Our findings corroborate the results of NASA studies suggesting that plants might improve indoor air and make interior breathing spaces healthier.

New polyoxometalate-functionalized cellulosic fibre/silica hybrids for environmental applications

Cellulosic fibre/silica hybrid materials functionalized with Keggin-type polyoxometalates ([PV2Mo10O40]5−, [PVMo11O40]4−, ([PMo12O40]3− or [PW12O40]3−) were prepared by a sol–gel method at room temperature. The novel materials are composed of ca. 56 wt% of polysaccharides, ca. 37 wt% of propylamine-modified silica, 2 wt% of polyoxometalate, and 5% of hydration water. The silica network of these hybrids exhibits relatively high degree of condensation being distributed mainly on the surface of the cellulosic fibres as a dense film. The functionalization of silica with polyoxometalates via electrostatic interactions with protonated propylamino groups of modified silica was unambiguously confirmed. Despite their high silica content cellulose/silica hybrids retained basic cellulosic pulp properties—supramolecular and fibrous structure, porosity, relatively low density, etc. The novel bio-based material functionalized with 2% of [PVMo11O40]4− shows particularly high activity towards the oxidation of volatile organic compounds (VOCs) present in urban air thus anticipating future environmental applications.

Risk factors and prevalence of asthma and rhinitis among primary school children in Lisbon

Abstract Aims A cross-sectional study was carried out with the objective of identifying nutrition habits and housing conditions as risk factors for respiratory problems in schoolchildren in Lisbon. Material and methods Between October and December 2008, parents of 900 students of the elementary schools of Lisbon were invited to answer a questionnaire of the International Study of Asthma and Allergies in Childhood Program (ISAAC). The response rate was 40 %. Logistic regression was used in the analysis of results. Results The prevalence of asthma, allergic rhinitis and wheeze was 5.6 %, 43.0 % and 43.3 %, respectively. Risk factors independently associated with asthma were wheezing attacks, and dry cough at night not related to common cold in the last 12 months. Wheezing crises were found to affect children daily activities. Risk factors for wheeze were hay fever and the presence of a pet at home. A risk factor for rhinitis was cough at night. The frequent consumption of egg was also associated with increased risk of rhinitis. Conclusion Contrarily to asthma, the prevalence of allergic rhinitis and wheeze increased in comparison with previous ISAAC studies. Wheezing attacks were associated with asthma and hay fever was identified as a risk factor of manifesting wheezing symptoms. Having pets at home was pointed out as a significant risk factor for rhinitis, but not smoking exposure, mould, plush toys, diet (except egg consumption), breastfeeding or other conditions.

Detailed chemical analysis of regional-scale air pollution in western Portugal using an adapted version of MCM v3.1.

A version of the Master Chemical Mechanism (MCM) v3.1, refined on the basis of recent chamber evaluations, has been incorporated into a Photochemical Trajectory Model (PTM) and applied to the simulation of boundary layer photochemistry in the Portuguese west coast region. Comparison of modelled concentrations of ozone and a number of other species (NO(x) and selected hydrocarbons and organic oxygenates) was carried out, using data from three connected sites on two case study days when well-defined sea breeze conditions were established. The ozone concentrations obtained through the application of the PTM are a good approximation to the measured values, the average difference being ca. 15%, indicating that the model was acceptable for evaluation of the details of the chemical processing. The detailed chemistry is examined, allowing conclusions to be drawn concerning chemical interferences in the measurements of NO(2), and in relation to the sensitivity of ozone formation to changes in ambient temperature. Three important, and comparable, contributions to the temperature sensitivity are identified and quantified, namely (i) an effect of increasing biogenic emissions with temperature; (ii) an effect of increasing ambient water vapour concentration with temperature, and its influence on radical production; and (iii) an increase in VOC oxidation chain lengths resulting from the temperature-dependence of the kinetic parameters, particularly in relation to the stability of PAN and its higher analogues. The sensitivity of the simulations to the refinements implemented into MCM v3.1 are also presented and discussed.

Chemical profiling of PM 10 from urban road dust

Road dust resuspension is one of the main sources of particulate matter with impacts on air quality, health and climate. With the aim of characterising the thoracic fraction, a portable resuspension chamber was used to collect road dust from five main roads in Oporto and an urban tunnel in Braga, north of Portugal. The PM10 samples were analysed for: i) carbonates by acidification and quantification of the evolved CO2, ii) carbonaceous content (OC and EC) by a thermo-optical technique, iii) elemental composition by ICP-MS and ICP-AES after acid digestion, and iv) organic speciation by GC-MS. Dust loadings of 0.48±0.39mgPM10m-2 were obtained for asphalt paved roads. A much higher mean value was achieved in a cobbled pavement (50mgPM10m-2). In general, carbonates were not detected in PM10. OC and EC accounted for PM10 mass fractions up to 11% and 5%, respectively. Metal oxides accounted for 29±7.5% of the PM10 mass from the asphalt paved roads and 73% in samples from the cobbled street. Crustal and anthropogenic elements, associated with tyre and brake wear, dominated the inorganic fraction. PM10 comprised hundreds of organic constituents, including hopanoids, n-alkanes and other aliphatics, polycyclic aromatic hydrocarbons (PAH), alcohols, sterols, various types of acids, glycerol derivatives, lactones, sugars and derivatives, phenolic compounds and plasticizers. In samples from the cobbled street, these organic classes represented only 439μgg-1PM10, while for other pavements mass fractions up to 65mgg-1PM10 were obtained. Except for the cobbled street, on average, about 40% of the analysed organic fraction was composed of plasticizers. Although the risk via inhalation of PAH was found to be insignificant, the PM10 from some roads can contribute to an estimated excess of 332 to 2183 per million new cancer cases in adults exposed via ingestion and dermal contact.

Characterization of Exhaust Emissions from A EURO 5 Light Passenger Vehicle Using Biodiesel Blends

The authors have performed experiments using a EURO 5 light passenger vehicle, operated over the New European Driving Cycle (NEDC). Fuel blends containing 7% (B7) and 20% (B20) of biodiesel (84% soyabean/16% palm) in petroleum-based diesel were tested and compared with a diesel fuel (B0). The exhaust gases emissions were assessed for NO, NO₂, SO₂ and volatile organic compounds (VOC), including a speciation analysis of VOC. The experiment reveals that biodiesel blends improve the combustion efficiency, NO and SO₂ emissions, and increasing NO₂ and total VOC emissions. The VOC speciation analysis suggests that the type and fraction of VOC existent in exhausted gases is fuel dependent, changing their presence and concentrations according to the fuel used. Additionally, the concentration of the three main VOC species in exhaust gases from B0 (benzene, toluene and octane) decrease 60-80% if a B20 blend is used. This experimental study contributes to a better characterization of the emission factors of EURO 5 light passenger vehicles using diesel/biodiesel blends and to a better understanding of the impact of the use of biodiesel blends on pollutant emissions.

Mapping anthropogenic and natural volatile organic compounds around Estarreja Chemical Industrial Complex

In the region of Estarreja, since the middle of century XX has settled one of the largest complexes of basic chemical industries in Portugal. During the 80s of the last century, the air quality started to be monitored in this region, but only the classic pollutants were addressed. This region never was submitted to a VOC survey, a group of compounds together NOx with a strong impact in ozone production at surface level. Every year ozone exceedances are observed in this region. Adding to this environmental problem, volatile organic compounds include several compounds with negative human health effects, like aromatic compounds. Due to a complexity of sources, industrial, traffic, agriculture and natural, that can drive air quality in the region, field campaigns were planned involving VOCs and NO2 measurements with passive tubes. A set of passive tubes were distributed for 32 sampling locations in an area of ~100 km 2 . Radiello passive tubes and Palmes type tubes were used for VOCs and NO2 concentration measurements respectively. Four sampling campaigns with a weekly duration were performed between March and June 2012. The values obtained show that toluene was the VOC (C5 to C12), which in general, showed higher concentrations in all campaigns. The highest concentrations of many VOCs like BTEX, and NO2 were observed close to the vicinity of the industrial complex. The high ratio of toluene/benzene pinpoint a heavy influence by emissions from industry, even the ratio of xylene/benzene suggests that this region is also influenced by transport of pollutants from other regions. The high correlations between the xylenes and ethylbenzene in the entire area indicate a single emission source, most likely vehicular emissions, in opposition to what is