Environmental Quality in Urban Allotment Gardens: Atmospheric Deposition, Soil, Water and Vegetable Assessment at LISBON City

Abstract

The purpose of this study was to analyze the quality of atmospheric deposition, soil, vadose zone water, and plant species in several Urban Allotment Gardens (UAG) in the city of Lisbon, and to correlate its nature and characteristics with their location within the city pressures and with the farming practices, comparing results with similar studies elsewhere. Twenty one metals or metalloids (Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Sb, Se, Ta, V, Zn) and 16 PAHs (acenaphthene, acenaphthylene, anthracene, fluorene, phenanthrene, naphthalene, benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[g,h,i]perylene, chrysene, dibenzo[a,h]anthracene, fluoranthene, indeno[1,2,3-c,d]pyrene), pyrene) were analyzed in the atmospheric deposition, and some of these elements/compounds were further analyzed in soils, water, and vegetables. Results show a wide range of concentrations in the city resulting from different soil types and contamination sources. Indexes based on ratios of selected PAHs suggest pyrogenic origins for the PAHs. Metals and metalloids have both anthropogenic and petrogenic origins, the latter mainly for soils with vulcanic origin. Despite the fact that concentrations in soils and waters have exceeded the recommended values in some areas, the lettuce and cabbage rarely presented contamination, with the measured metal values generally under legislated limits, where this exist.