| Resumo: |
Several pollutants are being monitored in forests, such as polycyclic aromatic hydrocarbons (PAHs) and other Persistent Organic Pollutants (POPs), but little attention has been paid yet to Emergent Pollutants (EPs) and their effect on forest vitality. There are two major categories of atmospheric EPs: known chemicals to industry and commerce, previously unrecognized as pollutants, and new chemicals introduced, such as drugs, pharmaceuticals or cosmetics, among others. Fragrances, polychlorinated paraffins, polybrominated diphenyl ethers (PBDEs) and perfluoroctanosulfonates (PFOS) may travel long-distance by atmospheric transport and therefore affect ecosystems far from their sources. Those compounds, except PBDEs, were never monitored for forest contamination, but being found in such distant and remote places as the Arctic they may also deposit on forests during their long-distance travelling. The impact of this effect is not known. LEPAE concluded the project PTDC/AGR-CFL/73156-2006, dedicated to use pine needles as passive samplers of atmospheric POPs. The project used the pan-European network on forest monitoring, managed by the Direcção Geral de Recursos Florestais as sampling base. Under its scope, it was possible to collect pine needles from Pinus pinaster and Pinus pinea trees in 29 different locations scattered throughout Portugal four times in a year (winter, spring, summer and autumn), totalling 339 samples. Results revealed levels of contamination between 75 and 1944 ng/g (dry weight) for the sum of 16 PAHs studied. Their average incidence is higher in industrial and urban areas, followed by the rural ones. There is a predominance of 3-ring and 4-ring PAHs, except for the case of remote areas, where naphthalene (2 rings) dominates. It was also concluded that P. pinaster needles had a superior entrapment capacity towards PAHs than P. pinea. Such evidence raises the issue of which is the affinity of different vegetation species towards the different poll  |
Resumo
Several pollutants are being monitored in forests, such as polycyclic aromatic hydrocarbons (PAHs) and other Persistent Organic Pollutants (POPs), but little attention has been paid yet to Emergent Pollutants (EPs) and their effect on forest vitality. There are two major categories of atmospheric EPs: known chemicals to industry and commerce, previously unrecognized as pollutants, and new chemicals introduced, such as drugs, pharmaceuticals or cosmetics, among others. Fragrances, polychlorinated paraffins, polybrominated diphenyl ethers (PBDEs) and perfluoroctanosulfonates (PFOS) may travel long-distance by atmospheric transport and therefore affect ecosystems far from their sources. Those compounds, except PBDEs, were never monitored for forest contamination, but being found in such distant and remote places as the Arctic they may also deposit on forests during their long-distance travelling. The impact of this effect is not known. LEPAE concluded the project PTDC/AGR-CFL/73156-2006, dedicated to use pine needles as passive samplers of atmospheric POPs. The project used the pan-European network on forest monitoring, managed by the Direcção Geral de Recursos Florestais as sampling base. Under its scope, it was possible to collect pine needles from Pinus pinaster and Pinus pinea trees in 29 different locations scattered throughout Portugal four times in a year (winter, spring, summer and autumn), totalling 339 samples. Results revealed levels of contamination between 75 and 1944 ng/g (dry weight) for the sum of 16 PAHs studied. Their average incidence is higher in industrial and urban areas, followed by the rural ones. There is a predominance of 3-ring and 4-ring PAHs, except for the case of remote areas, where naphthalene (2 rings) dominates. It was also concluded that P. pinaster needles had a superior entrapment capacity towards PAHs than P. pinea. Such evidence raises the issue of which is the affinity of different vegetation species towards the different pollutants. A preliminary study involving PAH molecular ratios defined that the potential emitting sources in Portugal are both petrogenic (emission from fossil fuels) and pyrogenic (combustions). In this Project, it is intended to use the same nation-wide sampling area, enlarging the monitoring scheme to three groups of semivolatile compounds, prone to be transported via atmosphere to regions far from its production sources - short-chain chloroparafins (SCCP C10-C13), perfluoroctanosulfonates (PFOS) and musks. The first two, derived from industrial activities, are included in the list of 33 priority compounds defined in the European Directive 2008/105/CE. The latter are found in the composition of several personal hygiene products, which due to their massive use tend to represent a medium-term potential hazard of environmental contamination. Some questions need to be answered by this project: What is the fate of one emergent contaminant adsorbed by pine trees? Is there any damage to the tree or does it suffer degradation? Is there any positive impact of climate change, once temperature increase and the intensification of solar radiation may induce thermodegradation and/or photolysis? The major goals of this proposal are: (i) a large monitoring scheme, concerning spatial and temporal distribution, aiming to obtain conclusions about the possible location of EPs' sources, (ii) a better comprehension of interfacial phenomena occurring in pine needles after the sorption of the contaminants (degradation, metabolisation by plant, etc) and (iii) conclusions about the influence of the contamination on vitality parameters of the forest. LEPAE is particularly prepared to face the proposed problem, profiting from the previous experience and the use of the same sampling scheme of a recently concluded project. Furthermore, a better comprehension of results may arise from the comparison of the different pollutants in different pine species, locations and time periods. |