Laboratory methodologies for pesticide extraction from water were optimised for solid-phase extraction with SDB (Styrene-DivinylBenzene copolymer) disks, followed by gas chromatographic (GC) analysis of pesticides residues and confirmation by mass spectrometry (GC-MS).
The study of ground water exposure to pesticides continued in Ribatejo agricultural area and was also extended to Beira Litoral agricultural area which, according to previous analysis using DRASTIC index approach, was considered to have, in general, hydrogeological vulnerability. Therefore, it was performed a prospection of ground water contamination with pesticides in several agricultural ecosystems of Beira Litoral. It was also performed the study of pesticide residues dynamic in ground water along the year, in some wells of Beira Litoral and Ribatejo, where pesticides had been previously detected. Variation in residues levels in this compartment was observed, particularly as a consequence of agricultural practices such as pesticide treatments and irrigation.
In ground water collected in Ribatejo, in both irrigation wells and in wells for human consumption, residues of alachlor, atrazine, desethylatrazine, desisopropylatrazine, metolachlor, metribuzine and simazine were detected alone or in mixtures. On the other hand, in Beira Litoral, residues of atrazine, desethylatrazine, desisopropylatrazine, metolachlor and simazine were found. In both agricultural regions concentrations above 0.1mg/L of some herbicides and metabolites were quantified in several agricultural areas showing the impact of pesticide treatments in groundwater quality.
A research on leaching models is being performed in order to try to apply them to some Portuguese ecosystems.
Protecção das Plantas
e dos Produtos Agrícolas Armazenados