Authors:M. C. Freitas, A. M. G. Pacheco, and E. Ferreira
The present study aims the identification and quantification of trace elements in samples of honey from the Azores and the
Portuguese mainland. Elemental concentrations were determined for Al, Br, Cl, Cs, Cu, Eu, Fe, K, Mg, Mn, Na, Rb, Sb, and Zn.
Some of these elements are essential dietary nutrients for humans. The essential elements, K and to a lesser extent Na and
Cl were the most abundant in the honey samples. However, overall, the elemental content was very low, inferior to the recommended
allowances for daily dietary intake (DDI), with the exception of Na whose concentration exceeded that of the recommended DDI.
The results of the present investigation and data reported for other countries compare well. The honeys correlate much better
when they are from Azores or from Portugal mainland, however, some good correlations were found between honeys from the islands
and the mainland. The color of the honey, which depends of the flower-source, could have a role in the differences and similarities
between the different honeys as suggested by the cluster analysis of the data. The correlation between honey, soil, tree bark
and lichens, all collected in Azores, was poor.
Authors:M. C. Freitas, M. M. Farinha, A. M. G. Pacheco, M. G. Ventura, S. M. Almeida, and M. A. Reis
Selenium is determined by instrumental neutron activation analysis (INAA), based on measurement of the long-lived 75Se nuclide. In the urban and industrialized areas of Portugal selenium contents have been found of the order of of 0.5-1 ng/m3 in PM10 and PM2.5, according to the data collected since 1994. From November 12, 2001 and for not more than 3 months, the Se contents in PM10 and PM2.5 increased by a factor of 1000 in the northern area of Lisbon. More than other nutrients, selenium illustrates the dichotomy between essentiality and toxicity. There is no legislation on Se for ambient air and on indoor ambient point threshold limit values (US and Germany legislation), were 100 times higher than the abnormal values found that winter. The increase was also visible for mercury although not to such an extent. Attempts were made to understand the trend, going into a study of the emission sources located in the area using both INAA and PIXE. It was concluded that the observation occurred due to abnormal meteorological wind direction, which pushed the pollutants towards the populated area, when usually they flow into the Tagus estuary.
Authors:M. C. Freitas, A. M. G. Pacheco, B. J. Vieira, and A. F. Rodrigues
Within an extensive survey of lower and higher plants in the Azores' Terceira and Santa Maria islands, this study is focused
on the evaluation of ectohydric bryophytes and bark from Cryptomeria japonica as an alternative to epiphytic lichens for air-monitoring purposes. Neutron activation analysis (k0-NAA) has been applied to all field samples for elemental determinations. Judging from the present results, and since the
islands embody most features of the whole archipelago, bryophytes do not appear as an option for further campaigns in the
Azores, due to scanty supply and relatively poor performance as biomonitors. On the other hand, comparisons of bark with lichens
collected at the same sites seem fairly good, and elements are enriched in bark to an even greater extent than in lichens.
All things considered - including material availability and ecological concern - bark stands for a sensible choice for biomonitoring
in the Azores.