Legacy and current use pesticides: environmental relevance to wildlife reservations.

ONDARZA P.M.; GOMES COSTA P.; SCENNA L.; MIGLIORANZA K.S.B.

Orlando, Florida

Congreso; 7th Society of Environmental Toxicology and Chemistry (SETAC) World Congress/SETAC North America 37th Annual Meeting; 2016

Society of Environmental Toxicology and Chemistry North America

Agricultural practices and wildlife reservations are sometime located very close and the impact of pesticide applied are of great concern to those ecosystems mainly on sensitive species. The southern area of the Atlantic Forest is located in Misiones province, in the northwestern of Argentina. Misiones has more than 50% of its surface covered by national and international reservations, such as the Iguazú falls (7 Wonders of Nature) and Yabotí MAB-UNESCO Reserve. Current-use and banned pesticides were measured in streamwater, suspended particulate matter (SPM) and bottom sediments (BS) in Acaraguá and Ramón rivers. These rivers are mainly used for direct consumption and domestic use by population. Samples were collected from upper, middle and lower sectors in each river, which run along agricultural lands passing through natural reservations. Endosulfans (a-, b- and sulfate), chlorothalonil, chlorpyrifos and trifularin were determined by GC-ECD. Pesticides more frequently detected were endosulfan and chlorpyrifos in water, SPM and BS, with high levels in streamwater (10-1700 ng/L) and the low in BS (0.2-1.3 ng/g dry wt). Chlorothalonil and trifluralin were only found in streamwater of Acaraguá (average 0.1 and 0.3 ng/L) and Ramón (average 10.4 and 0.5 ng/L) rivers. The a-/b-endosulfan ratios ranged from 3 to 10, showing a fresh application despite it was banned in 2013. Levels of endosulfan and chlorpyrifos in water were higher than the national limits for freshwater biota protection (≤7 ng/L a- + b-endosulfan) and ≤6 ng/L for chlorpyrifos. Moreover, the abundant precipitation in this area (>2000 mm/year) enhanced the availability of both pesticides, facilitated by its relative hydrophilicity. Therefore, endosulfan and chlorpyrifos occurrence deserve more attention, and monitoring programs are recommended in order to diminish their incorporation to aquatic biota and, consequently to human. This study reveals the impact of agricultural use on wildlife reservations, which would be vulnerable to runoff of current and legacy pesticides. Studies involving atmospheric transport of these contaminants are now developing in our laboratory in order to understand the pesticide dynamics in these environments.