CONICET | Buscador de Institutos y Recursos Humanos

The aim of this study was to assess if the epiphyte Tillandsia bergeri is feasible to be used as a biomonitor ofpesticides in the air by comparing with the results of the artificial XAD-resin based passive air sampler (XADPAS). Biomonitors and XAD-PAS were deployed at 10 sites of Quequén Grande River watershed (Buenos Airesprovince, Argentina) during three exposure periods. Endosulfan was the main pesticide found in T. bergeri as wellas in XAD-PAS, even after the ban was in effect. Higher endosulfan levels were observed during pesticide application period in XAD-PAS, while T. bergeri showed a decreasing trend during this period. Chlorpyrifos concentrations were in the same order than endosulfan in XAD-PAS, while T. bergeri showed significantly lowerlevels. Concentrations of legacy pesticides (hexachlorocyclohexanes, chlordanes, dieldrin, heptachlors) registered a low contribution to total pesticides analyzed both in T. bergeri and XAD-PAS, reflecting the past use oforganochlorine pesticides in the region. Trifluralin showed the lowest concentrations in T. bergeri while XAD-PASexhibited a higher proportion in some sites. Even both samplers showed that endosulfan was the most frequentpesticide found, environmental processes such as volatilization and photodegradation, as well as biologicalprocesses in T. bergeri have probably occurred and therefore pesticides accumulation was altered. Results demonstrate the importance of taking into account the type of sampling media when analyzing atmosphericpesticide composition. Nevertheless, the use of T. bergeri and XAD-PAS allowed discriminating efficiently therelative contribution of currently used pesticides versus legacy pesticides to air pollution.

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