Atmospheric fall-out of POPs (PCDD-Fs, PCBs, HCB, PAHs) around the industrial district of Porto Marghera, Italy.

In order to estimate the importance of atmospheric fall-out of persistent organic pollutants (POPs) around the industrial district of Porto Marghera, Italy, atmospheric depositions of POPs were collected using bulk samplers inside the Lagoon of Venice. Seventy-seven atmospheric deposition samples were collected monthly over a 12-month period (March 2003-March 2004) at seven sites located close to the industrial area of Porto Marghera. Samples were analysed by HRGC/HRMS for PCDD-Fs, PCBs, HCB and PAHs. Differences in mean daily fluxes of all organic pollutants between industrial, urban and lagoonal stations were clear, atmospheric depositions at industrial sites being higher than target values for dioxin deposition recommended by the EU strategy on dioxins, furans and polychlorobiphenyls. In order to calculate atmospheric loadings of POPs around the industrial district, we considered an area defined by a distance of 10 km from the hypothetical centre-point of the main sources of atmospheric emissions from Porto Marghera. The calculated loadings, compared with the previous estimates, show that annual loadings of POPs are 12, 510, 90 and 130 kg of PCDD-Fs, PCBs, HCB and PAHs, respectively, corresponding to 350-500 mg TEQ, thus indicating a slight decrease in PCBs and a great decrease in HCB with respect to 1998-99. The input coming from the atmosphere is of the same order of magnitude of that due to the watershed runoff and approximately one-half of the direct industrial discharges.