Fate of glyphosate in a Canadian forest watershed: Aquatic residues and off-target deposit assessment

Journal or Publishing Institution: Journal of Agricultural and Food Chemistry

Study: https://pubs.acs.org/doi/abs/10.1021/jf00094a045

Author(s): Feng, J.C., Thompson, D.G. and Reynolds, P.E.

Article Type: Peer Reviewed Study

Record ID: 678

Abstract: Glyphosate and AMPA residues in oversprayed and buffered streams were monitored following application of ROUNDUP (2.0 kg/ha) to 45 ha of a coastal British Columbia watershed. Maximum glyphosate residues (stream water, 162 pg/L; sediments, 6.80 pg/g dry mass; suspended sediments, C0.03 pg/L) were observed in two intentionally oversprayed tributaries, dissipating to <1 pg/L within 96 h postapplication. Buffered streams were characterized by very low glyphosate residue levels (2.4-3.2 pg/L in streamwater). Results of the off-target deposit assessment indicated CO.1% of applied glyphosate at 8 m from the spray boundary. Increases in residue levels were observed in relation to the first storm event postapplication. Ratios of maximum stream water concentrations of glyphosate observed in buffered and oversprayed tributaries relative to literature toxicity values indicated a substantial margin of safety under either operational or worst case scenarios.

Keywords: aerial application, Application, deposition, Glyphosate, Herbicides, residues, spraying, water, watersheds, catchment areas, weedicides, weedkillers, British Columbia, Canada, APEC countries, Commonwealth of Nations, Developed Countries, North America, America, OECD Countries

Citation: Feng, J.C., Thompson, D.G. and Reynolds, P.E., 1990. Fate of glyphosate in a Canadian forest watershed. 1. Aquatic residues and off-target deposit assessment. Journal of Agricultural and Food Chemistry, 38(4), pp.1110-1118.