Browsing by Autor "Tom Harner"

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Air monitoring of new and legacy POPs in the Group of Latin America and Caribbean (GRULAC) region
(Elsevier BV, 2018) Cassandra Rauert; Tom Harner; Jasmin K. Schuster; Anita Eng; Gilberto Fillmann; Luisa E. Castillo; Oscar Fentanes; Martı́n Villa Ibarra; Karina S.B. Miglioranza; Isabel Moreno
Altitudinal and Seasonal Variations of Persistent Organic Pollutants in the Bolivian Andes Mountains
(American Chemical Society, 2008) Victor H. Estellano; Karla Pozo; Tom Harner; Margot Franken; Mauricio Zaballa
Polyurethane foam disk passive air samplers were deployed over four periods of approximately 3 months along an altitudinal gradient (1820, 2600, 4650, and 5200 masl) on the east side of the Andean mountain range in Bolivia. The purpose of the study was to assess the gas-phase concentration and the altitudinal and seasonal trends of organochlorine pesticides and polychlorinated biphenyls (PCBs). Target compounds that were regularly detected included alpha- and gamma-hexachlorocyclohexane (HCH), endosulfans, and select PCB congeners. Endosulfans and HCH concentrations increased with altitude. Enrichment factors (concentration at the highest altitude divided by concentration at the lowest altitude) ranged from 10 to 20 for HCHs and 3 to 10 for endosulfans. Air parcel back trajectory analysis indicated that, in general, the high-altitude sites were exposed to a larger airshed and hence susceptible to long-range atmospheric transport from more distant regions. Seasonal differences were also observed with SigmaHCH concentrations peaking during periods 2 and 3 (March-September 2005). Airsheds (derived from the analysis of back trajectories) for periods 2 and 3 were less oriented along the Andes range (mountain air) with greater input from coastal regions. Endosulfans peaked during periods 1 and 2 (February-June 2005) and also exhibited the highest air concentrations of the target compounds, reaching approximately 1500 pg/m3 at the two highest elevation sites. PCB air concentrations at all sites were generally typical of global background values (<12 pg/m3) and showed no increase with altitude. This is the first study to measure air concentrations of persistent organic pollutants (POPs) in Bolivia and one of only a few studies to investigate altitudinal gradients of POPs.
Atmospheric Concentrations of New Persistent Organic Pollutants and Emerging Chemicals of Concern in the Group of Latin America and Caribbean (GRULAC) Region
(American Chemical Society, 2018) Cassandra Rauert; Tom Harner; Jasmin K. Schuster; Anita Eng; Gilberto Fillmann; Luisa E. Castillo; Oscar Fentanes; Martı́n Villa Ibarra; Karina S.B. Miglioranza; Isabel Moreno
A special initiative was run by the Global Atmospheric Passive Sampling (GAPS) Network to provide atmospheric data on a range of emerging chemicals of concern and candidate and new persistent organic pollutants in the Group of Latin America and Caribbean (GRULAC) region. Regional-scale data for a range of flame retardants (FRs) including polybrominated diphenyl ethers (PBDEs), organophosphate esters (OPEs), and a range of alternative FRs (novel FRs) are reported over 2 years of sampling with low detection frequencies of the novel FRs. Atmospheric concentrations of the OPEs were an order of magnitude higher than all other FRs, with similar profiles at all sites. Regional-scale background concentrations of the poly- and perfluoroalkyl substances (PFAS), including the neutral PFAS (n-PFAS) and perfluoroalkyl acids (PFAAs), and the volatile methyl siloxanes (VMS) are also reported. Ethyl perfluorooctane sulfonamide (EtFOSA) was detected at highly elevated concentrations in Brazil and Colombia, in line with the use of the pesticide sulfluramid in this region. Similar concentrations of the perfluoroalkyl sulfonates (PFAS) were detected throughout the GRULAC region regardless of location type, and the VMS concentrations in air increased with the population density of sampling locations. This is the first report of atmospheric concentrations of the PFAAs and VMS from this region.
Concentración de Contaminantes Orgánicos Persistentes (COPs) en un gradiente altitudinal durante las estaciones de verano y otoño en la cara oriental de la cordillera Real de los Andes, Bolivia
(2011) Victor H. Estellano; Tom Harner; Karla Pozo; Mauricio Zaballa Romero; Margot Franken
Los Contaminantes Organicos Persistentes (COPs) son compuestos organoclorados de origen natural o antropogenico, toxicos, resistentes a la degradacion fotolitica, quimica y biologica, que presentan una elevada persistencia en el medio ambiente, biomagnificandose y bioacumulandose. Producen efectos toxicos en el sistema reproductor, sistema endocrino, desarrollo de malformaciones y llegan a afectar algunas funciones inmunologicas de animales y vegetales. Estos compuestos son capaces de viajar largas distancias principalmente adheridos al material particulado de las masas de aire, migrando mediante procesos de evaporacion y redeposicion desde zonas calidas a regiones frias, resultando en una amplia distribucion, incluso encontrandose en regiones remotas donde nunca han sido utilizados i.e., zonas polares y regiones de altas montanas. Por lo que, es importante conocer sus concentraciones en la atmosfera asi como su transporte. En Bolivia se eligieron cuatro estaciones en la cara oriental de la cordillera de los Andes que representan un perfil altitudinal, desde los 1.820 hasta los 5.200 m.s.n.m., instalandose muestreadores pasivos utilizando esponjas de poliuretano (PUF) realizando un monitoreo continuo de cada tres meses durante las estaciones de verano y otono del 2005. Los filtros fueron analizados por cromatografia de gases acoplada a un espectrometro de masas y analizados para 19 pesticidas organoclorados. Los resultados obtenidos muestran que los compuestos con las concentraciones mas altas fueron Endosulfan I y II, 3- HCH (lindano) y a-HCH, observando ademas una correlacion entre la concentracion de pesticidas y la altitud del sitio de muestreo. Endosulfan I fue el compuesto que presento las concentraciones mas altas, con una rango de 115 pg/m3 en el punto mas bajo (1820 msnm), hasta 1156 pg/m3 en el punto mas alto (5.198 m.s.n.m.) mostrando un correlacion entre la concentracion de los pesticidas y el aumento de altitud (r2=0,90 p<0,05). De esta forma podemos decir que existe una correlacion entre la concentracion de los pesticidas y el aumento de la altitud.
Towards a regional passive air sampling network and strategy for new POPs in the GRULAC region: Perspectives from the GAPS Network and first results for organophosphorus flame retardants
(Elsevier BV, 2016) Cassandra Rauert; Tom Harner; Jasmin K. Schuster; Karen Quinto; Gilberto Fillmann; Luisa E. Castillo; Oscar Fentanes; Martı́n Villa Ibarra; Karina S.B. Miglioranza; Isabel Moreno