Global pesticide budget

We conducted a global study to analyze the distribution and fate of pesticides in agricultural areas, extending to rivers and oceans. We used the full capabilities of BRTSim v.5.0b integrating information on land use and weather patterns, to examine 92 significant agricultural pesticides as of 2015. We specifically focused on 144 major global catchments using a detailed georeferenced grid, and we run two simulations, one for the land budget and the other, receiving information from the first, for the river budget. 

We found that in 2015, of the 0.94 Tg of pesticides applied, 82% were biologically degraded, 10% remained in the soil, and 7.2% reached below the root zone. Rivers received 0.73 gigagrams (Gg) of pesticides, with a discharge rate ranging from 10 to over 100 kilograms per year per kilometer. Only 1.1% of these pesticides were degraded in rivers, with unsafe levels of pesticides (>1 μg per liter) detected in over 13,000 kilometers of river length. Annually, 0.71 Gg of pesticides reached the oceans. Herbicides were the most common residue in both soil and river outlets. 

More details in PUBLICATIONS.