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A knowledge of the total amount of trace metals is not enough to assess the environmental impact of polluted soils. For this reason, the determination of metal species in solution is important to evaluate their behavior in the environment and their mobilization capacity. Soils contaminated by Cu, Pb, Cd, and Zn found at Doñana National Park (Spain) were examined for total content. Sequential extraction schemes were used to determine the degree of pollution and to partition the trace elements in soils. The three areas studied (marshes, stabilized sand, and mine) have different contamination levels. The northern‐most marshes of Doñana National Park have the highest total levels of the four metals due to the influence of a mine located 40 km away. The stabilized sand was not polluted by the metals studied. The bioavailable fraction of Cd represents more than 50% of the total Cd found in soils, and this percentage is much greater than that of the other elements examined. Most of the Cu was present in the organic fraction, with only small amounts being associated with the crystalline Fe‐oxide fraction. Lead and Zn were associated mainly with the crystalline Fe‐oxide fraction, but the amount of Zn associated with the carbonates and amorphous Fe‐oxide fractions was also significant. The total amount of Cu, Pb, Cd, and Zn in the soils and their distribution in the five fractions depended on total metal contents, soil type, and soil properties (i.e., pH and percentage of sand, clay, organic matter, and carbonates). Mobility of soil metals were Cd > Zn > Pb > Cu.

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The impact of the spill from the mine in Aznalcollar (Seville, Spain) on waterfowl in the Doñana National Park is assessed. The concentrations of Cu, Pb, Cd, Zn nd As in the liver and eggs of 16 species of waterfowl found dead in the Park between April and November 1998 were determined. The highest levels were found for Zn, followed by Cu, Pb, Cd and As. The main parameters related to the accumulation of these elements in the waterfowl studied were species and trophic level. The other variables studied--distance from the spill, days of exposure, sex, size, and age--are important, although this depends on the element studied. Zn and Cu from the spill have entered the food chain of the aquatic birds studied, but Cd, Pb and As have not. There is currently no evidence to suggest that the trace element concentrations measured have reached toxic levels.

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A long history of urbanization and industrialization has affected trace elements in New York City (NYC) soils. Selected NYC pedons were analyzed by aqua regia microwave digestion and sequential chemical extraction as follows: water soluble (WS); exchangeable (EX); specifically sorbed/carbonate bound (SS/CAR); oxide-bound (OX); organic/sulfide bound (OM/S). Soils showed a range in properties (e.g., pH 3.9 to 7.4). Sum of total extractable (SUMTE) trace elements was higher in NYC parks compared to Bronx River watershed sites. NYC surface horizons showed higher total extractable (TE) levels compared to US non-anthropogenic soils. TE levels increased over 10 year in some of the relatively undisturbed and mostly wooded park sites. Surface horizons of park sites with long-term anthropogenic inputs showed elevated TE levels vs. subsurface horizons. Conversely, some Bronx River watershed soils showed increased concentrations with depth, reflective of their formation in a thick mantle of construction debris increasing with depth and intermingled with anthrotransported soil materials. Short-range variability was evident in primary pedons and satellite samples (e.g., Pb 253 ± 143 mg/kg). Long-range variability was indicated by PbTE (348 versus 156 mg/kg) and HgTE (1 versus 0.3 mg/kg) concentrations varying several-fold in the same soil but in different geographic locations. Relative predominance of fractions: RES (37 %) > SS/CAR (22 %) > OX (20 %) > OM/S (10 %) > EX (7 %) > WS (4 %). WS and EX fractions were greatest for Hg (7 %) and Cd (14 %), respectively. RES was predominant fraction for Co, Cr, Ni, and Zn (41 to 51 %); SS/CAR for Cd and Pb (40 and 63 %); OM/S for Cu and Hg (36 and 37 %); and OX for As (59 %).

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