Modification of an environmental surveillance program to monitor PCDD/Fs and metals around a municipal solid waste incinerator

Since the mid-90s, an environmental surveillance program has been on-going to provide information on the levels of PCDD/Fs and various metals in soil and vegetation samples collected in the vicinity of a municipal solid waste incinerator (MSWI) in Tarragona (Catalonia, Spain). However, the presence of other potential sources of pollution in the zone, such as traffic, forest fires, local industries, etc., makes hard to determine the impact concerning the MSWI. Therefore, in 2007 a change in the monitoring program was implemented by collecting additional ambient air samples through active and passive sampling devices. Mean PCDD/F levels in herbage and soil were 0.10 ng I-TEQ/kg dry weight (range: 0.05-0.17 ng I-TEQ/kg dw) and 0.64 ng I-TEQ/kg dw (range: 0.13-2.41 ng I-TEQ/kg dw), respectively. A significant reduction of the PCDD/F concentration in both monitors was observed with respect to our previous surveys. Air mean concentrations of PCDD/Fs were 12.04 and 15.21 fg WHO-TEQ/m(3) in 2007 and 2008, respectively, meaning a non-significant increase of 26%. In addition, a generalized increase of environmental metal levels with respect to our baseline study was not observed. The current concentrations of PCDD/Fs and metals in the vicinity of the MSWI of Tarragona are relatively low in comparison with other areas under the influence of emissions from waste incinerators. This indicates that the environmental impact of the MSWI of Tarragona is not significant. Moreover, the modification of the surveillance program has proven to be successful.