Glyphosate: maintenant la toxicologie trans-générationnelle

La lecture de cet article est intéressante. Ils suggèrent même que l'obésité soit due au Gly! Le tour de force c'est d'avoir passé cela dans Sci Reports. J'ai bien aimé les conséquences obstétricales (dystocies et autres) qui ne se verraient pas chez l'homme en raison des progrès de l'obstétrique... Bravo aux auteurs, joli coup.
Cet article s'inscrit donc dans la droite ligne de la récente vague d'études qui tentent de prouver quoi que ce soit en exposant les animaux à des doses extrêmement élevées de produits chimiques ou de médicaments ou de biocides et en attendant des effets pendant des générations. Est-ce juste? Oui dans une approche expérimentale. Est-ce applicable aux humains? J'en doute. Mais la stratégie consiste à en déduire que, comme nous sommes actuellement incapables de mesurer ces effets transgénérationnels, le principe de précaution doit nous amener à interdire ce produit chimique.

https://www.nature.com/articles/s41598-019-42860-0.pdf

As previously described76, female and male rats of an outbred strain Hsd: Sprague Dawley®™SD®™ (Harlan) at 70 to 100 days of age were fed ad lib with a standard rat diet and ad lib tap water. Timed-pregnant females on days 8 through 14 of gestation59 were administered daily intraperitoneal injections of glyphosate (25mg/kg BW/day dissolved in PBS) (Chem Service, Westchester PA) or dimethyl sulfoxide (DMSO) or Phosphate Buffered Saline (PBS), as previously described47. Twenty-five mg/kg for glyphosate is 0.4% of rat oral LD50 and 50% of the NOAEL and considering glyphosate rapid metabolism approximately twice the occupational exposure 3–5mg/kg per daily exposure10,77. There was a founder effect observed in the offspring of a specific male from the control population treated with PBS, manifesting as abnormally high rates (80–100%) of obesity in descendants, Supplemental Figure S7. Therefore, a portion of the original control colony was excluded from the study due to the obesity founder effects identified. These animals were replaced with offspring from DMSO-treated controls from a concurrent study. Disease phenotypes were compared from both DMSO lineage and PBS lineage controls, with no significant differences observed with histopathology evaluations between the two populations, Fig. 5 and Supplemental Figure S6. As previously described76, the gestating female rats treated were designated as the F0 generation. F1–F3 generation control and glyphosate lineages were housed in the same room and racks with lighting, food and water as previously described37,47,78. All experimental protocols for the procedures with rats were pre-approved by the Washington State University Animal Care and Use Committee (protocol IACUC # 6252). All methods were performed in accordance with the relevant guidelines and regulations.


Is it a scam?"Timed-pregnant females on days 8 through 14 of gestation59 were administered daily intraperitoneal injections of glyphosate (25mg/kg BW/day dissolved in PBS) (Chem Service, Westchester PA) or dimethyl sulfoxide (DMSO) or Phosphate Buffered Saline (PBS), as previously described47. "

In a woman of 60 kg, it is 1,5 g IP every day. It is the dose of pure Round-Up to eradicate weeds for 40sqm2 IP every day...
1liter or RU = 360g of glyphosate (https://www.monsanto-ag.co.uk/roundup/roundup-amenity/application-information/sprayers-and-water-volumes/).


But:

• Glyphosate is non-volatile.⁶ Absorption from inhalation exposure is not expected to be significant.¹⁴
• Questionnaires filled out by farm operators and eligible couples collected during the Ontario Farm Family Health Study suggested that there was an association between preconception exposure to pesticide products containing glyphosate and elevated risks of late spontaneous abortion.⁵⁶
• 56 reference: 
• Arbuckle, T. E.; Lin, Z.; Mery, L. S. An exploratory analysis of the effect of pesticide exposure on the risk of spontaneous abortion in an Ontario farm population. Environ. Health Perspect. 2001, 109 (8), 851-7.
• http://npic.orst.edu/factsheets/archive/glyphotech.html#references

So this paper is in the right line of the recent surge of studies which try to prove anything by exposing animals to ultra-high doses of chemicals or drugs or biocides and by waiting for generations for some effects.  Is it fair? Yes in an experimental approach. Is it applicable to humans? I doubt it. But the strategy is to infer that as we are unable at the present time to measure such trans-generational effects the precautionary principle must lead us to prohibit this chemical.