Both laboratory and in-forest studies show that glyphosate does not accumulate in muscle tissues of animals, but is rapidly excreted in urine and feces. Therefore, the Pest Management Regulatory Agency (PMRA) is not concerned about human consumption of wild game that has lived in treatment areas.
Based on laboratory studies, glyphosate does not bioaccumulate in tissues and is known to be rapidly excreted in the urine and feces of experimental animals even when exposed at very high experimental dose levels (Williams et al. 2000). Newton et al. (1984) reported that mammalian herbivores, carnivores and omnivores had visceral and body contents at or below observed levels in ground cover and litter and that residues were largely associated with the viscera (presumably largely in the digestive tract) and that other non-visceral body parts contained residues less than 0.5 ppm in all cases. Couture et al. (1995), summarizing results of studies conducted in Quebec, reported no detectable glyphosate residues in meat or liver of hares, moose or deer (1 sample only) collected in the hunting season (2 months after treatment), despite measureable residues in stomach contents, urine and feces of these animals. One of 19 kidney samples taken from hare contained a measureable level (0.208 ppm) of glyphosate.
Launtenschlager has reported results of a study, which investigated residues of glyphosate in moose meat from an area, which had been treated approximately two months before sampling. The authors reported that glyphosate residues were detected in only one sample out of 31 tested and that this single positive finding was likely the result of contamination.
Glyphosate forestry products are also used in agricultural settings, and it is therefore expected that the exposure to glyphosate from food products (i.e., fruits and vegetables from direct treatment with glyphosate) or animal commodities such as meat, milk and eggs (derived from livestock animals exposed to glyphosate -treated feed) will cover potential exposure from inadvertent residues in moose following a forestry use. The potential inadvertent exposure from consumption of moose meat is therefore not of concern.
In April 2015, the PMRA released their latest review of glyphosate and declared that the weight of evidence indicates that glyphosate does not present unacceptable risk to human health. The full PMRA glyphosate review can be found here or please visit here for a summary version of the full PMRA review.
RA Lautenschlager. Effects of conifer release with herbicides on moose: Browse production, habitat use and residues in meat. ALCES Vol 28 (1992) pp 215 – 222.