Massive airborne Endosulfan inputs related to intensive agriculture in Argentina's Pampa

In order to evaluate the impact of intensive agriculture on air quality in the most productive and populated Argentina's Pampas, a comprehensive assessment of airborne Endosulfan (∑Endo) was performed using polyurethane passive samplers deployed from 2010 to 2013 covering the critical period of Endosulfan restrictions at twenty nine sites in the Rural Pampa and Great Buenos Aires Metropolitan Area (GBA: Horticultural and Urban subareas). ∑Endo concentrations were very high and variable (0.01-63 ng m(-3)), exceeding worldwide reported maxima at Horticultural GBA and Rural Pampa with lowest values at Urban GBA (geometric means: 3.1, 1.1 and 0.53 ng m(-3), respectively). The composition was relatively fresh with strong predominance of Endo I (72 ± 18%) over Endo II (23 ± 15%) and Endo SO4 (5 ± 10%). Airborne ∑Endo was significantly correlated to annual soybean crop in Rural Pampa. ∑Endo concentrations showed a temporal pattern defined by consistent peaks enriched in Endo I during summer application periods, cold temperature minima with higher proportions of Endo SO4 and a general exponentially declining trend over time related to incipient control policies.