Glyphosate has been extended for use in the uk as part of brexit, but it's still regulated and although cancer concerns are (for now) dismissed until further evaluation, it's effects as a strong irritant for eyes and lungs are still in place (https://www.britishagriculturebureau.co.uk/updates-and-information/glyphosate-state-of-play/ ). This assessment/extension will be re-evaluated in 2025. ( https://www.hse.gov.uk/pesticides/using-pesticides/general/glyphosate-faqs.htm ) ( code of practice from the hse: https://www.hse.gov.uk/pesticides/using-pesticides/codes-of-practice/index.htm . Code that regulates use of hazardous substances https://www.hse.gov.uk/coshh/industry/agriculture.htm )
Arguments in favour are based mostly in either incomplete, inconclusive or blatantly false data/scientific research. (i.e. https://www.nfus.org.uk/glyphosate.aspx) Another common argument is the un approval, but this is limited and with lots of caveats ( https://theecologist.org/2016/may/17/no-un-has-not-given-glyphosate-clean-bill-health ) also, due a revision that will likely overturn it.
There is also actual research on how the regulatiory process itself is also failing when it comes to glyphosate ,which casts even further doubt on it's safety and explains how persistent it is. ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9229215/ )
It has documented damaging effects (just glyphosate, not even getting into the non-active ingredients), for mammals (https://www.pan-uk.org/glyphosate/ ):
"Studies have found that glyphosate-based herbicides can interfere with various organs and biochemical pathways in mammals. Genotoxicity and endocrine disruption also lead to chronic health and developmental effects. It causes imbalances in gut bacteria and some studies have found that glyphosate appears to accumulate in human cells. At low concentrations it damages liver, kidney and skin cells and long term effects include cancer, infertility, pregnancy problems, birth defects and respiratory diseases. Read more about the effects of pesticides on our health here (https://www.pan-uk.org/health-effects-of-pesticides/)."
health effects in respiratory systems are documented and not withdrawn from even the UN evaluation.
https://pubmed.ncbi.nlm.nih.gov/35963408/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5381985/
( https://www.beyondpesticides.org/resources/pesticide-induced-diseases-database/asthma )
https://globaljournals.org/GJMR_Volume21/2-Environmental-Exposure-to-Glyphosate.pdf
there is also ongoing research on those same pesticides being the root of the current epidemiologic boom of allergies https://www.allergyamulet.com/blog/2017/5/30/is-monsanto-giving-us-food-allergies
It also has a severe impact in biodiversity and ecosystems, water ( https://pubmed.ncbi.nlm.nih.gov/30223108/ ), disease spread, soil fertility , soil quality and the reproduction and genetic chain of insects, worms and bees (and from polen other plants).
https://pubmed.ncbi.nlm.nih.gov/36531643/ https://www.theguardian.com/environment/2022/jun/02/glyphosate-weedkiller-damages-wild-bumblebee-colonies https://setac.onlinelibrary.wiley.com/doi/10.1002/etc.5442
https://cropwatch.unl.edu/2017/new-research-quantifies-dispersal-glyphosate-resistance-trait-through-pollen-mediated-gene-flow
It can even affect seeds https://www.jstor.org/stable/4046620
https://www.jstor.org/stable/4046816 https://www.frontiersin.org/articles/10.3389/fpls.2021.698202/full
"Glyphosate has direct and indirect effects on the environment. Indirect impacts on birds and other animals occur due to the wiping out of weeds and wild flowers, destroying habitats and food supplies. Glyphosate is water soluble and has had significant effects on species that underpin the entire aquatic food chain with amphibians being particularly vulnerable.
It upsets the balance of microbial communities in soil, increasing the numbers of some microorganisms and decreasing others, impacting on soil fertility. It has caused an upsurge in some crop diseases in no-till agriculture by stimulating the growth of a number of fungal pathogens. It also binds micro-nutrients in the soil causing deficiencies in plants.
Glyphosate has also been found to have adverse effects on earthworms, beneficial insects and bees. Read more about the effects of pesticides on our environment here ( https://www.pan-uk.org/our-environment/ )."
Less documented but still worrying, is the transport by binding to polen and dust, which has been ignored in just about every single evaluation of it's environmental impacts (https://phys.org/news/2021-10-re-approval-glyphosate-large-aerial-dispersal.html). Another overlooked propagation vector is through compost and waste disposal https://www.rhs.org.uk/prevention-protection/weedkiller-damage This also makes the pesticide LESS effective https://onlinelibrary.wiley.com/doi/abs/10.1111/wre.12413 and more damaging https://pubmed.ncbi.nlm.nih.gov/36746112/ https://www.sciencedirect.com/science/article/abs/pii/S0269749116313860
It also propagates through the food chain even after processing the grains/raw crops, as per https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/824814/expert-committee-pesticide-residues-food-annual-report-2018.pdf . The values are within the legal limits, but those limits are highly debated and the levels are on the high end. Also worth noting those levels only apply to "normal" foods. Organic foods are forbidden altogether to use or contain ANY level of glyphosate. https://www.legislation.gov.uk/uksi/1999/3483/made
It's also not needed for weed control in most scenarios and there are numerous projects both against it's use (i.e. banning it within councils (https://www.pan-uk.org/where-are-we-with-a-national-ban-on-urban-pesticides-in-the-uk/) , and proving it's possible (https://www.earthisland.org/journal/index.php/magazine/entry/nontoxic-rewilding/) Trials in the uk are also promising https://media.reading.gov.uk/news/council-trials-weed-control-alternatives
Because of it's impacts in the full scale ecosystems and potential risks to human health , it should never be used for rewilding, nor anywhere near acuifers, dusty and/or windy locations or where foods are grown. There simply isn't a way of containing solid pesticides like glyphosate to the application area with no drift or cross contamination of soil, acuifers and surrounding areas, up to several kilometers.
There is a high chance it will be either forbidden or highly regulated in the future, so it's also risky to engage from a risk management perspective, as when it's banned alternatives would need to be put in place, and tested, in much shorter timescales that may make it unfeasible.
further sources and risk evaluations/metastudies: https://extension.psu.edu/glyphosate-roundup-understanding-risks-to-human-health https://www.sciencedirect.com/science/article/pii/S2667010021001281 https://www.mcgowanhood.com/2017/08/15/safe-application-roundup-weed-killer-experts-believe-not/ https://vjel.vermontlaw.edu/moving-away-glyphosate-environmental-health-effects-potential-alternatives https://www.jstor.org/stable/3987621