Monitoring dioxins and furans near an old municipal solid waste incinerator: Temporal variation in vegetation

To determine the temporal variation in the levels of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in vegetation grown near an old municipal solid waste incinerator (Montcada, Barcelona, Spain), 24 herbage samples were collected at the same sampling points in which samples had been taken one year before. While in the previous survey PCDD/F concentrations ranged from 1.07 to 3.05 ng I-TEQ/kg (dry matter) (median value: 1.88 ng I-TEQ/kg, mean value: 1.92 ng I-TEQ/kg), in the current samples PCDD/F levels ranged from 0.75 to 1.95 ng I-TEQ/kg (dry matter) (median value: 1.27 ng I-TEQ/kg, mean value: 1.30 ng I-TEQ/kg). An individual comparison between PCDD/F concentrations in samples collected in both studies shows a decrease in all the sampling points with an average reduction of 32.3%. This reduction can be due to general abatement actions for PCDD/F emissions.