34 research outputs found
PM2.5 chemical composition and health risks by inhalation near a chemical complex
Particulate matter (PM2.5) samples were collected in the vicinity of an industrial chemical pole and analysed for organic and elemental carbon (OC and EC), 47 trace elements and around 150 organic constituents. On average, OC and EC accounted for 25.2% and 11.4% of the PM2.5 mass, respectively. Organic compounds comprised polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, anhydrosugars, phenolics, aromatic ketones, glycerol derivatives, aliphatic alcohols, sterols, and carboxyl groups, including aromatic, carboxylic and dicarboxylic acids. Enrichment factors > 100 were obtained for Pb, Cd, Zn, Cu, Sn, B, Se, Bi, Sb and Mo, showing the contribution of industrial emissions and nearby major roads. Principal component analysis revealed that vehicle, industrial and biomass burning emissions accounted for 66%, 11% and 9%, respectively, of the total PM2.5-bound PAHs. Some of the detected organic constituents are likely associated with plasticiser ingredients and thermal stabilisers used in the manufacture of PVC and other plastics in the industrial complex. Photooxidation products of both anthropogenic (e.g., toluene) and biogenic (e.g., isoprene and pinenes) precursors were also observed. It was estimated that biomass burning accounted for 13.8% of the PM2.5 concentrations and that secondary OC represented 37.6% of the total OC. The lifetime cancer risk from inhalation exposure to PM2.5-bound PAHs was found to be negligible, but it exceeded the threshold of 10?6 for metal(loi)s, mainly due to Cr and As.3518-5DB7-75B0 | M?rio Tom?N/
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.publishe
Indoor air quality in two university sports facilities
In July 2012, an indoor/outdoor monitoring programme was undertaken in two university sports facilities: a fronton and a gymnasium. Comfort parameters (temperature, relative humidity, and CO2), CO and total volatile organic compounds (TVOCs) were continuously monitored. Concentrations of NO2, carbonyl compounds and individual VOCs were obtained, after passive sampling, by spectrophotometry, high-performance liquid chromatography and gas chromatography with flame ionisation detection, respectively. Low volume samplers were used to collect particulate matter (PM10). During the occupancy periods, the relative humidity values were within the comfort limits in both buildings, but frequent daytime temperatures over 30°C in the gymnasium make this indoor space rather uncomfortable. The minimum ventilation rates stipulated for acceptable indoor air quality were observed in both sports facilities. It was found that cleaning activities may have a large influence on the VOC levels. Acrolein was one of the most abundant carbonyl compounds, showing concentrations above the recommended limit. Formaldehyde was detected at levels lower than those commonly reported for other indoor environments. In the fronton, the PM10 concentrations obtained during the occupancy periods ranged between 38 and 43 μg/m3.Much higher levels, from 154 to 198 μg/m3, were registered in the gymnasium. Weekend average values lower than 20 μg/m3 were obtained in both sports facilities, which are comparable to the outdoor levels throughout the week. The high particle levels in the gym are mainly due to the climbing chalk and the constant process of resuspension.This study was partially funded by the Centre for Environmental and Marine Studies (CESAM) of the University of Aveiro and by the Spanish Ministry of Science and Innovation (Grant TEC2010-19241-C02-01). Ana Calvo acknowledges the postdoctoral grant SFRH/BPD/64810/2009 from the Portuguese Science Foundation (FCT).publishe
Indoor and outdoor air quality: a university cafeteria as a case study
A short but exhaustive air sampling campaign was conducted in a university cafeteria, an occupational environmental not yet studied. Carbonyls and volatile organic compounds were collected by passive diffusion samplers. Temperature, relative humidity, CO2, CO and particulate matter were continuously monitored indoors and outdoors. Simultaneous PM10 sampling with high and low volume instruments, equipped with quartz and Teflon filters, respectively, was performed during working hours and at night. The quartz filters were analysed for their carbonaceous content by a thermo-optical technique and organic constituents by GC-MS. Water-soluble ions and elements were analysed in the Teflon filters by ion chromatography and PIXE, respectively. Low air change rates (0.31–1.5 h−1) and infiltration factors of 0.14, for both PM2.5 and PM10, indicate poor ventilation conditions. Concentrations of both gaseous pollutants and particulate matter were much higher in the cafeteria than outdoors, showing strong variations throughout the day depending on occupancy and activities. The average concentration of indoor-generated PM10 was estimated to be 32 μg m−3. Organic compounds in PM10 included alkanes, PAHs, saccharides, phenolics, alcohols, acids, alkyl esters, triterpenoids, sterols, among others. The complex particle composition reveals the multiplicity of sources, formation reactions and removal processes, not yet fully known, and suggests the contribution from dust resuspension, abrasion and off-gassing of building materials, cooking emissions, tobacco smoke, and several consumer products. Many compounds are in the list of ingredients of personal care products, pesticides, plasticisers, flame retardants and psychoactive drugs. The inhalation cancer risks of metals and PAHs were found to be negligible.publishe
Impact of vacuum cleaning on indoor air quality
[EN] Vacuum cleaning can be a household source of particulate matter (PM) both from the vacuum motor and from settled dust resuspension. Despite the evidence of this contribution to PM levels indoors, the effect of this source on PM composition is still unknown. In this study, four vacuum cleaners (washable filter bag less, wet, bagged and HEPA filter equipped robot) were tested for the emission rate of particulate mass and number. The detailed PM chemical characterisation included organic and elemental carbon, metals and organic speciation. PM10 emission rates from bagged vacuum operation were much higher (207 ± 99.0 μg min−1) compared with the ones obtained from wet (86.1 ± 16.9 μg min−1) and washable filter bag less vacuums (75.4 ± 7.89 μg min−1). Particle (8–322 nm) number emission rates ranged from 5.29 × 1011 (washable filter bag less vacuum) to 21.2 × 1011 (wet vacuum) particles min−1. Ratios of peak to background levels indicate that vacuuming can elevate the ultrafine particle number concentrations by a factor ranging from 4 to 61. No increase in PM mass or number concentrations was observed during the HEPA filter equipped vacuum operation. The increase in copper and elemental carbon PM10 contents during vacuuming suggested motor emissions. Organic compounds in PM10 included alkanes, PAHs, saccharides, phenolics, alcohols, acids, among others. However, it was not possible to establish a relationship between these compounds and vacuuming due to the vast array of possible household sources. The cancer risks associated with metals and PAH inhalation were negligibleSIThe sampling campaign was partially supported by the Spanish Ministry of Economy and Competitiveness (Grant TEC2014-57821-R), the University of León (Programa Propio 2015/00054/001 and 2018/00203/001) and the AERORAIN Project (Ministry of Economy and Competitiveness, Grant CGL2014-52556-R, co-financed with European FEDER Funds). Other part of the monitoring campaign and the analytical determinations of this work were funded by the project “Chemical and toxicological SOurce PROfiling of particulate matter in urban air (SOPRO)”, POCI-01-0145-FEDER-029574, supported by FEDER, through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI), and by National Funds (OE), through FCT/MCTES. An acknowledgment is due to the Portuguese Foundation of Science and Technology (FCT) and to the POHP/FSE Funding Programme for the fellowships with the references SFRH/BD/117993/2016 and SFRH/BPD/123176/2016. Ana Vicente is subsidised by national funds (OE), through FCT, I.P., in the framework contract foreseen in the numbers 4, 5 and 6 of article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. Thanks are due, for the financial support to CESAM (UIDB/50017/2020+UIDP/50017/2020), to FCT/MEC through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. F. Oduber and C. Blanco-Alegre acknowledge the grants BES-2015-074473 and FPU16-05764 from the Spanish Ministry of Economy and Competitiveness and from the Ministry of Education, Culture and Sports, Spain, respectively
Organic compounds in PM2.5 emitted from fireplace and woodstove combustion of typical Portuguese wood species
The aim of this study is the further characterisation of PM2.5 emissions from the residential wood
combustion of common woods grown in Portugal. This new research extends to eight the number of
biomass fuels studied and tries to understand the differences that the burning appliance (fireplace versus
woodstove) and the combustion temperature (cold and hot start) have on emissions. Pinus pinaster
(Maritime pine), Eucalyptus globulus (eucalypt), Quercus suber (cork oak), Acacia longifolia (Golden
wattle), Quercus faginea (Portuguese oak), Olea europea (Olive), Quercus ilex rotundifolia (Holm oak) and
briquettes produced from forest biomass waste were used in the combustion tests. Determinations
included fine particle emission factors, carbonaceous content (OC and EC) by a thermaleoptical transmission
technique and detailed identification and quantification of organic compounds by gas chromatographyemass
spectrometry. Fine particle emission factors from the woodstove were lower than
those from the fireplace. For both combustion appliances, the OC/EC ratio was higher in “cold start” tests
(1.56 0.95 for woodstove and 2.03 1.34 for fireplace). These “cold start” OC/EC values were,
respectively, for the woodstove and the fireplace, 51% and 69% higher than those obtained in “hot start”
experiments. The chromatographically resolved organics included n-alkanes, n-alkenes, PAHs, n-alkanals,
ketones, n-alkanols, terpenoids, triterpenoids, phenolic compounds, phytosterols, alcohols, n-alkanoic
acids, n-di-acids, unsaturated acids and alkyl esters of acids. The smoke emission rate and composition
varied widely depending on fuel type, burning appliance and combustion temperature
Poluição fotoquímica na costa portuguesa
Doutoramento em Ciências Aplicadas ao AmbienteA zona costeira Portuguesa é uma região complexa que se encontra sob a
influência, quer de fenómenos naturais, como por exemplo as brisas costeiras,
quer da actividade humana. Os estudos anteriormente realizados na Europa e
os conhecimentos actuais apontam Portugal, particularmente a zona costeira
como uma área crítica onde se prevê que nos próximos anos seja difícil atingir
os objectivos de equilíbrio ambiental em relação aos efeitos da poluição
fotoquímica [Comissão Europeia, 2000]. Face a esta previsão, neste trabalho
desenvolveu-se um estudo sobre a qualidade do ar na zona costeira do Norte
de Portugal.
Numa primeira fase deste trabalho, no âmbito do Centro das Zonas Costeiras
e do Mar (CZCM), durante o Verão de 2001, realizou-se uma campanha
experimental simultaneamente em três locais com o objectivo de avaliar o
estado actual da qualidade do ar e o papel desempenhado pela circulação
atmosférica à mesoescala (brisas costeiras) na produção e distribuição dos
poluentes fotoquímicos e dos seus precursores. Assim, verificou-se que as
zonas rurais afastadas de fontes de emissão antropogénica no interior podem
apresentar um nível de poluição fotoqufmica superior relativamente às zonas
urbanas e suburbanas situadas no litoral. Confinnou-se ainda o papel
importante das brisas marítimas no transporte e produção dos poluentes
fotoquimicos. Por outro lado, a recirculação das massas de ar envelhecido
pode ter contribuição forte para o aumento de concentração de poluentes
atmosféricos à entrada da costa. A aplicação do modelo HYSPLIT (Hydrid
Single-Particle Lagrangian Integral Trajectory Model) mostrou que as
circulações à escala sinóptica também podem influenciar, quer a situação da
qualidade do ar, quer o desenvolvimento de brisas marítimas.
Durante o Verão de 2002, realizou-se uma campanha de medição das
concentrações de poluentes (Os e COVs) em altura, até 1000 m, utilizando-se
para este efeito um balão cativo, tendo sido adoptadas para amostragem em
altitude as técnicas de colheita e medição. Da análise dos perfis verticais de
ozono concluiu-se a existência de concentrações mais elevadas acima dos
100 - 300 m da altura, até ao topo de camada limite atmosférica. Os COVs, de
modo geral, apresentaram uma diminuição da sua concentração com a
altitude.
Por conseguinte, os dados experimentais obtidos durante a campanha CZCM-
2001 foram utilizados para a aplicação no modelo de transporte incluindo o
mecanismo fotoquímico detalhado MCM3. Constatou-se que os dados obtidos
através da simulação apresentaram uma boa concordância com os dados
observados. O presente estudo ainda englobou uma análise de sensibilidade
do modelo, tendo-se concluido que as concentrações iniciais de poluentes são
factores importantes e preponderantes na realização de uma simulação fiável.The coastal zone of Portugal is a complex region from the point view of air
quality control, being affected by natural phenomena, such as coastal breezes,
and by human activities. Previous studies performed in Europe and at national
level indicate Portugal, and particularly its coastal zone, as a critic region
regarding environmental equilibrium, under conditions of photochemical
pollution [European Commission, 2000]. It was based on this provision that the
study of air quality in the north coast zone of Portugal, presented in this thesis,
was carried out.
The first part of this work, sponsored by Coastal and Maritime Zone Centre
(CMZC), was developed during the summer period of 2001, and consisted of
an experimental campaign with simultaneous measurements of air quality
levels at three locations of the Portuguese coast oriented in-line with the
penetration of sea breezes. This study aimed at evaluating the present air
quality situation and the effect of mesoscale atmospheric circulation (coastal
breezes) on the production and distribution of photochemical pollutants and
their precursors. Thus, it was observed that in rural regions located inland, but
reached by sea breezes, the level of photochemical pollution is greater than in
urbane and sub-urbane more populated and industrialised locations near the
sea. Simultaneously, an important role of maritime breezes on the formation
and transport of photochemical pollutants have been confirmed.
It could be concluded that re-circulation of aged sea breeze polluted air,
transported from land to sea aloft, can contribute significantly to the increase of
air pollutant concentrations at coast entrance in each morning, during periods
of permanent sea breeze formation during summer. The application of the
HYSPLIT (Hybrid Single-Particle Lagrangian Integral Trajectory) model clearly
showed that atmospheric circulations on a synoptic scale could influence both,
air quality and the development of maritime breezes.
During a second summer campaign, in the summer of 2002, the vertical profiles
(up to 1000m altitude) of air pollutants (Oy, VOCs) were evaluated during sea
breeze periods, using a tethered balloon system. The analysis of vertical
profiles showed that ozone concentrations do not decrease with altitude and
that a good mixture of photochemical pollutants exists in the sea breeze
boundary layer. In some occasions, and principally during early morning,
concentrations of ozone at ground level can be lower that at altitudes above
100-300 m. In general, VOCs presented a different behaviour with
concentrations decreasing with altitude.
The experimental data obtained during the summer campaign CMZC-2001
were used as a database for the application in a chemically detailed
photochemical box model (Master Chemical Mechanism - MCM3). The
modelling results were in good agreement with experimental data. Additionally,
sensitivity analysis with MCM3 revealed that in the present experimental
conditions under sea breezes, the initial concentration of air pollutants is a
crucial factor influencing the production of ozone episodes in inland rural areas
Organic profiles of brake wear particles
Four brake pads were tested in a bench dynamometer under test cycles with different braking severities: i) two types of conventional brake pads (low steel 1 and 2), and ii) two types of non-asbestos organic brake pads (NAO 1 and 2) with non-ferrous materials. Wear particles (PM10) were analysed for total carbon by a thermo-optical method and then solvent-extracted and analysed by gas chromatography–mass spectrometry. In general, the test protocols with less braking and lower temperatures gave rise to much lower PM10 levels. Total carbon accounted for PM10 mass fractions in a wide range (5.07–75.4%), generally decreasing with the severity of the braking cycles. More than 150 organic compounds were quantified, comprising aliphatics, polycyclic aromatic hydrocarbons (PAHs), alcohols, several types of acids (alkanoic, alkenoic, diacids and others), glycol/glycerol derivatives, plasticisers, sugars, sterols and various phenolic constituents. Globally, larger amounts of most of these compounds were emitted by NAO 2 under the smoothest braking cycle. Several correlations between compounds with the same functional groups were established. No PAH with five or more benzenic rings was detected. The differences in composition and concentrations are discussed based not only on the characteristics of the braking circuits, but also on the diverse quantities and types of organic compounds used in the brake pad formulations.The authors are grateful to the BBVA foundation (Ayudas a Investigadores y Creadores Culturales 2016), the POHP/FSE programme and the Portuguese Foundation of Science and Technology (FCT) for funding the scholarship SFRH/BPD/123176/2016. Ana Vicente was subsidised by national funds (OE), through FCT, I.P., in the framework contract foreseen in the numbers 4, 5 and 6 of article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. An acknowledgment is also due for the support to CESAM (UIDB/50017/2020 + UIDP/50017/2020), to FCT/MCTES through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and COMPETE2020. Chemical analyses were supported by the “Chemical and toxicological SOurce PROfiling of particulate matter in urban air (SOPRO)”, POCI-01-0145-FEDER-029574, funded by FEDER, through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI), and by national funds (OE), through FCT/MCTES.Peer reviewe
Organic profiles of brake wear particles
Four brake pads were tested in a bench dynamometer under test cycles with different braking severities: i) two types of conventional brake pads (low steel 1 and 2), and ii) two types of non-asbestos organic brake pads (NAO 1 and 2) with non-ferrous materials. Wear particles (PM10) were analysed for total carbon by a thermo-optical method and then solvent-extracted and analysed by gas chromatography–mass spectrometry. In general, the test protocols with less braking and lower temperatures gave rise to much lower PM10 levels. Total carbon accounted for PM10 mass fractions in a wide range (5.07–75.4%), generally decreasing with the severity of the braking cycles. More than 150 organic compounds were quantified, comprising aliphatics, polycyclic aromatic hydrocarbons (PAHs), alcohols, several types of acids (alkanoic, alkenoic, diacids and others), glycol/glycerol derivatives, plasticisers, sugars, sterols and various phenolic constituents. Globally, larger amounts of most of these compounds were emitted by NAO 2 under the smoothest braking cycle. Several correlations between compounds with the same functional groups were established. No PAH with five or more benzenic rings was detected. The differences in composition and concentrations are discussed based not only on the characteristics of the braking circuits, but also on the diverse quantities and types of organic compounds used in the brake pad formulations.publishe