Heavy Metals Soil Pollution in Some Urban Location from Romania - Highway and Urban Environment - page 325

heavy metal abundance global values, recorded in urban soils of these localities,
including heavy metals from parks soils and those from industrial enclosures [1] .

Cd, Pb and Zn Total Content Fractions

Although sequential extraction with different conventional reagents of those three
heavy metals have resulted in percentage values closer from one soil to another,
these percentages represent parts of very different total heavy metal contents,
expressed in mg/kg. Thus, for the lead case, 29% of lead is associated with
exchangeable components of a 34.5 mg/kg total lead content in Bucharest urban
soils, while the same lead exchangeable fraction from Baia Mare soils, about 34%
from total content, correspond to 270 mg/kg lead (Fig. 2 ). A very similar situation
was found in the zinc case, when closer percentage values of the exchangeable
content (34% in Bucharest soil and 36% in Baia Mare soil), in fact correspond to
very contrasting values expressed in 56.1 and 212.0 mg/kg, respectively.
Analysis of the heavy metal concentrations in Baia Mare soil solution showed
that it contained up to 12% Cd, 7% Pb and 9% Zn. These percentage values cor-
respond to heavy metal contents expressed in mg/kg about: 0.19 Cd, 55.6 Pb and
53.0 Zn. In urban soils situated lengthways the main streets in Bucharest and Iassy,
similar calculations (mg/kg) result in 0.17 Cd, 7.1 Pb, and 11.5 Zn respectively.

Fig. 2 Fraction percentage of Cd, Pb and Zn total contents from superior horizons of urban soils
situated lengthways of the main streets of Bucharest, Iassy and Baia Mare