The aim of this study was to determine soil properties influence on the heavy
metals sorption by vegetables which are used in the diet and possibilities
for prediction of their bioaccumulation by response surface methodology
(RSM). Lettuce was used as biosorbent, and cadmium (Cd) and lead (Pb) were
used as contaminants. Lettuce is grown on compost (previously contaminated
with different concentrations of Cd and Pb) which pH was adjusted with
different amounts of NPK fertilizers. The content of heavy metals was
determined by ICP-MS. Results showed that Cd content in lettuce was below the
toxic values, but Pb concentration was above allowable, which indicates that
limit value for Pb is not set in accordance with the food safety regulations.
It was found that the heavy metals accumulation in plants depends not only on
its content in the soil, but also on the plant affinity to the specific
metal, and the individual or the interactive effects of different soil
properties. Through the transfer factor it was found that lettuce has a much
higher affinity to Cd in relation to Pb. RSM has proved to be very good for
the examination of a large number of variables with a small number of
experiments.