A Gent stacked filter unit sampler was used to collect air particulate matter (APM) in separate coarse (PM2.5–10) and fine (PM2.5) size fractions, at a sub-urban site in Lisbon, Portugal. The sampling was done during the year 2001 and two daily samples
were taken per week. The filters were analyzed for particulate mass by instrumental neutron activation analysis (INAA). The
chemical analysis of APM levels and the study of the atmospheric dynamics by back-trajectories showed that most of the PM2.5 and PM2.5–10 peaks events were associated with air masses transport from the Saharan desert. High mineral load in ambient particulate
matter levels were registered during the Saharan dust outbreaks. The accuracy of INAA to measure Fe, Sc and Sm was evaluated
by NIST filter standards, revealing results with an agreement of ± 10%. This method constituted an important tool to identify
Authors:S. Almeida, M. Freitas, M. Reis, and C. Pio
The analysis of airborne particulate matter (APM) by k0-NAA was assessed using: (1) BCR reference material (RM) simulated air-filters, (2) synthetic air-filters prepared by spiking blank filters with standard solutions, and (3) real APM filters. k0-INAA is a suitable technique for the analysis of APM, delivering accurate and precise results. However, the quality assessment of APM analysis appears to be a difficult task.
Authors:M. Freitas, S. Almeida, A. Pacheco, I. Dionísio, C. Repolho, A. Caseiro, C. Pio, and C. Alves
In 2006, elementary schools of inner-city Lisbon, Portugal were given questionnaires to identify respiratory problems. In
1,175 children aged 5–10 years, 27.7% reported rhinitis, 2.5% reported hay fever and 25.9% reported asthma symptoms. April
and August were the months with higher incidence of rhinitis, with a considerable difference nonetheless (10.5% and 2.3%,
respectively.). The former trends are addressed here by using meteorological data, PM2.5, and its elemental speciation. Mann-Whitney U-tests were applied to the data sets. Significantly higher values were found for humidity, K+, NH4+, Sb and Zn in April, and for temperature, Cl−, Mg2+ and Na+ in August. Commuter and heavy-duty traffic may contribute to rhinitis episodes.
Authors:S. Almeida, M. Freitas, C. Repolho, I. Dionísio, H. Dung, C. Pio, C. Alves, A. Caseiro, and A. Pacheco
Recent health studies evidence that epidemiological studies must be combined with accurate analyses of the physico-chemical
properties of the particles in order to determine the effects of atmospheric aerosols on human health. The project “Atmospheric
Aerosol Impacts on Human Health” focuses on the chemical characterization of PM2.5 aerosols with the aim to analyze the health
risks associated with exposure to aerosols and understand how their chemical composition contributes to the toxicity and human
health problems traditionally associated with fine particles. During one year, PM2.5 was collected daily, with a Partisol
sampler, in the centre of Lisbon. The aerosols were analyzed by Neutron Activation Analysis and Ion Chromatography in order
to determine their chemical composition. In parallel the clinical situation of students from the schools situated around the
sampler was followed. The incidence of asthma and rhinitis episodes was registered. Results showed that students were exposed
to PM2.5 concentrations that exceed the World Health Organization recommended levels. A marked sea influence in the aerosol
characteristics was identified by the use of air masses trajectories and by the concentrations of chloride, sodium and magnesium.
Authors:S. Almeida, M. Freitas, C. Repolho, I. Dionísio, H. Dung, A. Caseiro, C. Alves, C. Pio, and A. Pacheco
The goal of this research is to determine trends and sources of airborne particulates in the centre of Lisbon, by using speciated
particulate-matter data and back-trajectory analyses. Results showed that, in 2007, the annual PM2.5 concentration exceeded the World Health Organization recommended levels. PM2.5 diurnal variability and the ratio between weekdays’ and weekends’ concentrations indicated that traffic contributed highly
to decreasing air quality. Air back-trajectory analysis showed that maritime air mass transport had a significant role on
air quality in Lisbon, promoting the decrease of anthropogenic aerosol concentrations.
Authors:M. Freitas, I. Dionísio, D. Beasley, S. Almeida, H. Dung, C. Repolho, A. Pacheco, A. Caseiro, C. Pio, and C. Alves
The number of children reporting rhinitis by month is compared with air pollutant concentrations in Lisbon, where they live
and attend school. INAA, ionic exchange chromatography and data accessed through the internet were statistically processed
with the children rhinitis data. Association between rhinitis and atmospheric variables are processed using Spearman non-parametric
statistics and principal component analysis. It is pointed out that traffic, soil resuspension from traffic, meteorological
conditions, and industry air pollutants contribute to respiratory trends. Ir (Pt group), a vehicle catalyst, may have some
Authors:N. Canha, M. Freitas, M. Almeida-Silva, S. Almeida, H. Dung, I. Dionísio, J. Cardoso, C. Pio, A. Caseiro, T. Verburg, and H. Wolterbeek
One Plus Sequential Air Sampler—Partisol was placed in a small village (Foros de Arrão) in central Portugal to collect PM10 (particles with an aerodynamic diameter below 10 μm), during the winter period for 3 months (December 2009–March 2010). Particles
masses were gravimetrically determined and the filters were analyzed by instrumental neutron activation analysis to assess
their chemical composition. The water-soluble ion compositions of the collected particles were determined by Ion-exchange
Chromatography. Principal component analysis was applied to the data set of chemical elements and soluble ions to assess the
main sources of the air pollutants. The use of both analytical techniques provided information about elemental solubility,
such as for potassium, which was important to differentiate sources.