Results for most of the studied species presented a general declining
trend of Pb concentrations in each tissue as the Pb in the soils decreased.
Nevertheless, site 5 broke this trend, since the content of PbHCl in soil
samples at sites 3, 4 and 5 was not significantly different (Table 1)
while Pb accumulation in plants was significantly higher at site 5
This behavior suggests the effect of other factors influencing the uptake
rate at site 5, for both T. minuta and B. pilosa. Taking into account
soil physicochemical properties, organic matter content could be related
to Pb concentration in soils but was not appropriated to explain the