Authors:A. Marques, M. Freitas, M. Reis, H. Wolterbeek, and T. Verburg
Transplants of the epiphytic lichen Parmelia sulcata were suspended in nylon bags within a rectangle of 15 km wide and 25 km long on a grid 2.5 km'2.5 km in the Sado estuary region. The transplants were oriented towards the wind (F) and opposing the wind (T) and were collected after 3, 6 and 9 months of exposure. Samples were analyzed by INAA and PIXE. Source identification was made by Monte Carlo Target Transformation Factor Analysis (MCTTFA) using three different combinations of data (all data, F data and T data). Five factors were identified for all the combinations performed. For two factors, F and T differentiation was observed.
Authors:R. Jasan, T. Verburg, H. Wolterbeek, R. Plá, and M. Pignata
The lichen Ramalina celastri (Spreng.) Krog. & Swinsc. was used to study trace-element atmospheric pollution in Córdoba (Argentina). 38 samples from a 1999 campaign were analyzed by NAA and a number of physiological parameters was determined. In first-ever comparisons, no correlations were found between altitude, physiological parameters and determined elements, which allowed the full comparison of element data in lichen samples throughout the whole survey area. After the application of Monte Carlo assisted factor analysis to the elemental matrix, five source profiles were found and mapped. The attribution of the sources is discussed.
Authors:M. Farinha, S. Almeida, M. Freitas, T. Verburg, and H. Wolterbeek
Aerosol chemical composition data for PM2.5 and PM2.5–10 was acquired, in two sampling stations, at an industrialized area located in Sado Estuary. Two methods were used to have
an insight on the origin of the particles: the comparison between the measurements obtained in the two sampling stations and
the association between the wind direction and the element concentrations. Results showed that Ce, Fe, La, Sc, Sm, Na, Co
and Se were associated with non-local sources whereas As, K, Sb, Zn, Hg, Br, Cr, Hf and U had a local origin.
Authors:A. Marques, M. Freitas, H. Wolterbeek, and T. Verburg
Parmelia sulcata transplants were used in three different exposure systems, focused on three different influxes: free influx, horizontal influx
and vertical influx. The total element deposition and the precipitation volumes were found to be positively correlated for
Fe and Ni only. The element contents in lichen transplants and in total element deposition showed significant correlations
for Ca, Fe and Mn in the free influx system and for Na, Ni and V in the horizontal influx system. No significant positive
correlations were found for the vertical influx. The results indicate that, apart from response rates, the transplant positioning
systems may have effects on element-specific net accumulation.
Authors:M. Farinha, T. Verburg, M. Freitas, and H. Wolterbeek
Gent air samplers were used for air particulate matter sampling in Sado estuary area, separating fine and coarse fractions.
Three sampling sites were chosen (Palmela, Faralhão and Tróia), inside a 15 km × 25 km area at Setúba region, 50 km south
of Lisbon, Portugal. Transplants of Parmelia sulcata Taylor were suspended in nylon bags within the same area following a 2.5 km × 2.5 km grid, during the same period as the
aerosol collection. Both lichen transplants and filters were analysed by k0-INAA. This work compares MCTTFA results given by the two air pollution monitoring procedures. The main differences concern
a physiological factor in biomonitors and a better definition of traffic and re-suspension by aerosols.
Authors:A. Marques, M. Freitas, H. Wolterbeek, and T. Verburg
Parmelia sulcata transplants were positioned in three different exposure systems allowing three different influxes: free influx (Fi), horizontal
influx (Hi) and vertical influx (Vi). Results suggest the absence of any wind-directional effects on element accumulation
within Fi and Hi systems, but underline that differences in response may be observed in relation with the transplant set-up
systems. The Vi system generally shows poor results, while the performance of the Hi and Fi systems depends on the element
involved. Results were obtained for a specific lichen, and therefore are not necessarily representative for other lichens.
Authors:M. Freitas, M. Reis, L. Alves, H. Wolterbeek, T. Verburg, and M. Gouveia
During the months of July and August 1993 a lichen collection campaign was held in Portugal where about 250 samples were collected and analysed by thick target TIPIXE and INAA. Results for 44 different elements were obtained and a data base was built and subjected to Monte Carlo Aided Target Transform Factor Analysis (MCATTFA), a method developed at IRI (Delft). 10×10 km2 coast and 50×50 km2 far from coast sampling grids were used for collection. In this work we will present the results which were obtained based on a reduced data set of 36 elements measured by INAA. The results for 22 elements obtained by TTPIXE were published elsewhere. In this work we will also present the conclusions considering all the 44 elements determined by both techniques.
Authors:H. Wolterbeek, Z. Jeran, T. Verburg, J. de Goeij, and J. van Dam
Lichens, sampled around Chernobyl in 1990 and in Slovenia in 1992, were analyzed for radionuclides and elements, including Cs. Data were processed by Monte Carlo aided Target Transformation Factor (MCTTFA). The resulting factors indicate environmental accumulation routes. 40K : K and 210Pb : Pb ratios tested the procedure, showing fully mixed 40K and K, while for 210Pb and Pb the expected variability in specific radioactivity was confirmed. 137Cs showed a large factor-specific variability in 137Cs : Cs ratios. For the 1990 data, MCTTFA singled-out 137Cs in a separate factor, suggesting that the overall behavior of 137Cs cannot be derived from that of Cs: source (route)-related specific radioactivity makes that all individual transport-components should be taken into account.
Authors:R. Godinho, H. Wolterbeek, M. Pinheiro, L. Alves, T. Verburg, and M. Freitas
The elemental microdistributions of peripheral and central parts of the lichen Flavoparmelia caperata exposed to industrial pollution were analysed, in order to better understand the elements distribution patterns in relation
to the lichen constitution, thereby increasing our knowledge on uptake and release mechanisms. Nuclear microscopy techniques
were used to visualize elemental distributions in sample transepts and associate their concentrations to sample morphology.
The distribution data of the elements studied suggests there is biological regulation of internal concentrations. Considering
thallus parts, element-specific internal translocation should be taken into account as one more factor affecting lichen “memory
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.