| Summary: |
Persistent Organic Pollutants (POPs) are an extended family, with high levels of stability, toxicity and persistence in all environment media and great mobility to the point of being extensively found in remote parts of the earth, eg. polar regions. They also accumulate in fatty tissues and present hydrophobic properties, with most POPs with high octanol-water partition coefficients (log Kow >5). Among the most prominent are 4 families - organochlorines (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polybrominated flame retardants (PBFRs). Obtaining knowledge regarding the chemistry, transport and environmental distribution of POPs is, therefore, essential to prevent and minimize the effects of their presence in the environment. Vegetation is a privileged matrix for the study of such contaminants, due to its omnipresence and lipophilic characteristics of some constituents, necessary to trap them and certify it as a reliable passive sampler, especially when dealing with airborne pollutants. Amongst the most studied such as moss, lichen and plant leaves, pine needles have been successfully applied to the detection of OCPs, PAHs and PCBs. However, to this day there is no information about their ability to detect PBFRs, hence being the perspective of biomonitoring these compounds undoubtedly innovative. This project aims to employ the most abundant pine species in Portugal - Pinus pinaster and Pinus pinea - as passive samplers to the monitoring of atmospheric contamination. Some important questions are expected to be answered: (i) how well do measurements of POPs in pine needles and bark represent environmental contamination? (ii) what kinds and at what levels can POPs be found in Portugal? (iii) is there a connection to local direct sources - industry, agriculture and/or incinerators - that can explain those levels or are there foreign sources? (iv) is there a direct relationship linking the levels of PO  |
Summary
Persistent Organic Pollutants (POPs) are an extended family, with high levels of stability, toxicity and persistence in all environment media and great mobility to the point of being extensively found in remote parts of the earth, eg. polar regions. They also accumulate in fatty tissues and present hydrophobic properties, with most POPs with high octanol-water partition coefficients (log Kow >5). Among the most prominent are 4 families - organochlorines (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polybrominated flame retardants (PBFRs). Obtaining knowledge regarding the chemistry, transport and environmental distribution of POPs is, therefore, essential to prevent and minimize the effects of their presence in the environment. Vegetation is a privileged matrix for the study of such contaminants, due to its omnipresence and lipophilic characteristics of some constituents, necessary to trap them and certify it as a reliable passive sampler, especially when dealing with airborne pollutants. Amongst the most studied such as moss, lichen and plant leaves, pine needles have been successfully applied to the detection of OCPs, PAHs and PCBs. However, to this day there is no information about their ability to detect PBFRs, hence being the perspective of biomonitoring these compounds undoubtedly innovative. This project aims to employ the most abundant pine species in Portugal - Pinus pinaster and Pinus pinea - as passive samplers to the monitoring of atmospheric contamination. Some important questions are expected to be answered: (i) how well do measurements of POPs in pine needles and bark represent environmental contamination? (ii) what kinds and at what levels can POPs be found in Portugal? (iii) is there a connection to local direct sources - industry, agriculture and/or incinerators - that can explain those levels or are there foreign sources? (iv) is there a direct relationship linking the levels of POPs, namely PAHs, to the occurrence of forest fires? In Portugal, quality control of these pollutants to such a large and diversified scale does not exist, and this project is an attempt to eliminate some of these faults. In 1979, Given the hypothesis of a correlation between atmospheric pollution and degradation of forests, several countries signed in Geneva, under the UN Economic Commission for Europe, the convention on Long Distance Trans-frontier Atmospheric Pollution, in order to investigate such phenomenon and study the measures to take to reduce or even stop its causes. Since then, several regulations regarding the Protection of Forests of the Community Against Atmospheric Pollution have been implemented and carried out. Portugal is involved since 1987, in the Pan-European Network for Sustainable Forest Management, when the sites of the 16x16 km sampling net were established on the field. The investigation carried out in some countries shows that, in many cases, the existence and the level of damage caused to forests cannot be explained neglecting its influence. Thus this project is perfectly integrated in those general conclusions, given the fact that it will complement the current evaluations of the vitality parameters of the forests with the information about the deposition of the semivolatile atmospheric pollutants. At an international level, this information will complement the one already existing in other countries, producing data for the evaluation of the world distribution and transport of these semivolatile micropollutants. |