Environmental assessment in an industrial area of Portugal

The region of Lisbon and south of Lisbon (Sado estuary) is densely industrialized, and, therefore, air pollution should be studied in a more detailed scale there. The topography of the Sado estuary region and the predominant wind direction from the northwest contribute to the influence in this region of the industries located in the north. The region selected includes a fuel-fired power station. Transplants of the lichen Parmelia sulcata Taylor were suspended in nylon bags within a rectangle 15 km wide and 25 km long on a grid 2.5 km x 2.5 km, centered in the power station. In each of the 47 sites, 2 sets of 4 transplants each were hung. Care was taken (1) in covering the two sets with a polyethylene roof to prevent leaching of elements in the lichen, (2) in building a hanging system that could rotate according to the wind direction, and (3) in orienting one set toward the wind and the other set opposite the wind. For a 1-yr period and every 3 mo, one transplant of each set is collected. In this work, the results of the first campaign (after 3 mo suspension) obtained by instrumental neutron activation analysis and proton-induced X-ray emission are shown. Some elemental contents are mapped and discussed.