Spatial and temporal distribution of Persistent Organic Pollutants and current use pesticides in the atmosphere of Argentinean Patagonia.

XAD-based passive air samplers (PAS) were used to evaluate organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and some current use pesticides (chlorotalonil, trifluralin and dichlofluanid) in the atmosphere of Argentinian Patagonia. The PAS were deployed for 12 months during three consecutive years along a longitudinal (Rio Negro watershed) and a latitudinal (Patagonian coast) transect. Endosulfan, trifluralin and DDT-related substances were the most prevalent pesticides in the Rio Negro watershed, an intensive agricultural basin, consistent with ongoing use of endosulfan at the time of sampling. Concentrations of industrial contaminants were low (mean 25 pg/m3 and 1.9 pg/m3 for Σ38 PCBs, and Σ5PBDEs, respectively) and similar among sites. However, along the Patagonian coast, air concentrations of total contaminants were highly variable (14-400 pg/m3) with highest values recorded at Bahia Blanca, an important industrial area that is also downwind of the most intensively agriculturally used area of Argentina. Contaminant levels decreased toward the south, with the exception of the southernmost sampling site (Rio Gallegos) where a slight increase of total pollutant levels was observed, mainly due to the lower chlorinated PCB congeners. Interannual variability was small, although the last year tended to have slightly higher levels for different contaminant groups at most sampling sites. This large-scale spatial atmospheric monitoring of POPs and some CUPs in the South of Argentina highlights the important and continuing role of rural and urban areas as emission sources of these chemicals.

Assessment of Argentinean Patagonia pollution: PBDEs, OCPs and PCBs in different matrices from the Río Negro basin.

This work reports the occurrence and distribution of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in soil, sediment, suspended particle matter (SPM), streamwater and macrophytes, along the Río Negro basin, Argentinean Patagonia. The clear predominance of OCPs among all matrices indicates the impact of agriculture on the watershed. The highest levels were found for pp'-DDE which represented up to 95% in agricultural soils (42.0-1.27x10(3) ng/g d.w) from the Upper Valley (upstream), where long and historical intensive fruit cultures have been settled and represent a hot spot of legacy pesticides for the environment. The insecticide endosulfan, currently in use, was also found in all matrices. Levels ranged between 0.3 and 708.0 ng/g d.w, being the highest concentrations those of SPM from the Middle Valley, just before the delta area, where pesticides would be retained leading to lower concentrations as was observed downstream. PCB (#153, 138, 110, 101) and PBDE (BDE-47) levels were directly related with the presence of hydroelectric power plants, dams and dumping sites, mainly settled in the Upper Valley (0.8 ng/g and 15.1 ng/g d.w for PBDEs and PCBs, respectively). Although there was a decreasing gradient of these pollutant concentrations through the river flow, downstream urban areas enhanced PCB concentrations in the aquatic environment. More efforts and monitoring programs are highly required to control and reduce soil erosion in order to prevent the availability of forbidden pollutants in the environment.