Eco Hvar

In view of the increasing knowledge about the harm which glyphosate can cause, the shared acronym can seem appropriate. Concerns have been voiced by scientists and environmentalists over the safety of GBHs. Much has been written about their possible and known risks. Worries have been multiplying over the years since glyphosate was first introduced in 1974. In 2001, the Pesticide Action Network (UK) published a report highlighting the discrepancies between the manufacturer's claims for the herbicide and its real effects (1). Since then, much more has been observed in practice, and a lot of research has been done, all of it pointing in the same direction, that glyphosate is damaging to humans and the environment (2). In 2009 a report by the Pesticide Action Network Asia and the Pacific (PANAP) put forward a comprehensive review of the areas of concern, and suggested practical ways of improving the situation (3). In the last several years, scientists have been proving not only that glyphosate-based herbicides can be harmful, but also the mechanisms by which they cause harm.

For more details, please refer to our listing of scientific works in peer-reviewed journals relating to glyphosate and its risks. The list is updated regularly.

Approvals given on unscientific grounds

It is surprising how many supposed experts deny that there is any scientific evidence that herbicides are dangerous. On the contrary, there is plenty, published in a wide variety of respected peer-reviewed journals. I found no evidence that any of it had been properly considered when approval was sought for the pesticides. In fact, approval for glyphosate herbicide use has been given primarily on the basis of laboratory experiments on animals, experiments which were almost exclusively carried out by or on behalf of the agrochemical companies themselves, and which have mostly remained unpublished. There are hundreds of these unpublished studies.

Later reviews by responsible bodies, such as the 2004 World Health Organization document produced in response to concerns about the high levels of glyphosate residues found in groundwater in Denmark and Greenland, and the report submitted to the EU by rapporteur state Germany in 2014 have largely focussed on whether the protocols for the studies carried out by the agrochemical companies were followed correctly. Reviewing those protocols has been done many times over the past few years. It evades the issues of concern. It is not a guarantee of pesticide safety, and does nothing towards reassuring the public that safety measures are at the forefront of official policies regarding these herbicides.

The effects of glyphosate-based herbicides vary according to specific conditions. In some places, glyphosate-related problems have shown up without room for doubt. This happened, for instance in Sri Lanka, which in 2014, became the first country to ban the sale of Roundup following publication of a report linking glyphosate to chronic kidney disease in rice-producing areas of the country (4). Disappointingly, the ban was not total. Following representations from the plantation lobby, which claimed to rely heavily on herbicides rather than using manual labour, the ban was restricted to those areas where chronic kidney disease was manifestly prevalent.

'Safe limits' in the human food chain?

Glyphosate residues have been found in many different fruits and vegetables, and have even been detected in harvested foodstuffs which were planted several months after the glyphosate application (5).

The authorities responsible for approving glyphosate and other pesticides have set so-called 'safe limits' for the amounts of the pesticides which can be present in the environment and the human food chain. Their assumption is that at these levels the pesticides will not cause harm. The defined limits are extrapolated from animal studies. Each time it turns out that the 'safe limits' have been exceeded, the amounts allowed are raised, apparently arbitrarily.

There are absolutely no scientific grounds for defining what might be a safe limit for human consumption. The only way they could be established realistically would be for all the animal studies to be repeated using humans as the guinea pigs. When new medicines are being researched, the process starts with animal studies in the laboratory, and then moves on to human trials before a medicine is passed for production. Why should poisons which are destined to permeate our soils, water and air, and to enter our food chain, be accepted without this vital second stage of research?

Of course, detailed human testing of the kind that has been done on animals would be unacceptable on ethical grounds. But by allowing the use of pesticides without human trials, everyone exposed to the pesticides, whether knowingly, unknowingly, willingly or unwillingly, has become the human guinea pig for their safety or otherwise. The results in practice show that a great deal of harm is being done.

Scientific evidence against pesticides ridiculed and/or suppressed

Energetic attempts have been made to discredit scientists who have systematically tried to show that pesticides pose risks to human health. Specially virulent attacks were aimed at Gilles-Eric Séralini and his team, who have vigorously rebutted the criticisms and continue to work on identifying the extent of the health risks involved. Under pressure from agrochemical lobbyists, a study they published was retracted by journal editors in 2013, despite the authors standing by their results. The study was republished in 2014.

Complex factors in pesticide use not taken into account

In practice, the effects of GBHs have been shown as more complex and more dangerous than those revealed in the laboratory experiments (1), (6), (7). The European Union regulators have come under fire for allegedly basing approval for glyphosate and Roundup on outdated, industry-sponsored tests while ignoring or suppressing scientific studies revealing the damage caused by Roundup and glyphosate, and for delaying the review of the herbicide, due in 2012, until 2015 (8). In 2013, the US Environmental Protection Agency (EPA) which issues the permits for pesticides, raised the levels of glyphosate permissible in oilseed and food crops - despite the fact that there is no proof that any level of herbicide is safe.

Empirical evidence

Scientific evidence takes a long time to accumulate. Practical experience revealed problems very many years ago. In the United Kingdom, for instance, medical specialists were commenting privately on the high incidence among farmers of myalgic encephalomyelitis (M.E., a chronically debilitating disease) back in the 1980s. There was speculation that this might be because of the heavy use of organophosphates, including glyphosate herbicides. In the 1990s, evidence was already accumulating about the harmful effects of glyphosate in practice (9).

My own first experience of glyphosate happened in around 2000, when I picked up a piece of litter from a flower bed in my street in London. I noticed that there was a stickiness on the leaves of the plants I touched, but thought nothing of it, until an hour later, when my hand swelled up and became excruciatingly painful. This hampered my afternoon's work with patients very badly. I contacted my local Council, who told me they had sprayed the flower bed with a herbicide which was "safe enough to drink": Roundup.

It is now known that ingesting Roundup can cause serious problems, including gastrointestinal corrosion, inability to swallow (dysphagia), epigastric pain, kidney and liver impairment, kidney failure, breathing difficulties, reduced consciousness, heart abnormalities and even death (10). These effects are known through observation of what happens when people ingest glyphosate, whether deliberately or unwittingly, or through environmental exposure. Obviously, no 'scientific studies' have been done on humans: it would be unacceptable to give humans poisons to eat or drink in order to see how much would do them harm, and how long it would take. Animal lovers would argue that it is equally unacceptable to perform these painful and destructive experiments on any living creature.

Glyphosate actions and reactions

Glyphosate kills weeds by inhibiting the shikimic acid pathway: shikimic acid is part of a process vital for plant survival. It was thought that this mechanism did not exist in humans (11). However, it is now recognized that the shikimate pathway exists in humans in the regulation of bacteria in the gut, and these gut bacteria are vital for the human immune system (12). Most people are now aware that it is the suppression of vital gut bacteria by the overuse of antibiotics which has led to the rise of the so-called 'superbugs'. Understanding that herbicides can also disrupt vital gut activity is an important step towards understanding how harmful herbicides can be to human health.

Glyphosate use proliferating

Glyphosate has been heavily promoted since its introduction in the 1970s by Agrochemical firm Monsanto, who still market it in the herbicide Roundup (Croatian Cidokor), which was banned in Europe in October 2016. The US patent for glyphosate expired in 2000, allowing other companies to produce GBHs, such as Syngenta, who make Touchdown (Croatian Ouragan). Monsanto had meanwhile broadened the market for GBHs by introducing Glyphosate-tolerant (Roundup Ready) genetically engineered crops in 1996. Roundup is now produced in several different formulations and increasing concentrations.

Independent review of glyphosate safety urgently needed

There is more than enough evidence to suggest that there is an urgent need to review the safety of glyphosate in particular and pesticides in general, without basing the review on material submitted by the agrochemical companies, and without allowing intervention by those companies.

1) the risks of glyphosate were underestimated when the product was launched as a herbicide;

2) largely unpublished studies submitted by the agrochemical companies were a poor scientific basis for asserting that glyphosate was 'safe';

3) the process of granting approval for glyphosate as a herbicide was therefore flawed;

4) there has been no long-term scientific study of the effects of glyphosate in the field under different conditions;

5) there is no scientific proof that any level of pesticide ingestion is safe for humans;

6) there is no scientific proof that pesticide use does not harm the environment or wildlife.

BAN PESTICIDES APPROVED UNDER THE CURRENT SYSTEM!

It is highly debatable whether chemical pesticides are needed at all. At the very least, a new, independent and more stringent approval system should be put in place. The use of pesticides which have been approved under the current system should be suspended pending objective assessments which take into account all the available evidence of possible harm to humans and the natural environment. Pesticide use in the environment should be reconsidered. Alternative methods of controlling unwanted vegetation and insects should be investigated and put to use.

SCIENTIFIC BASIS FOR WORRIES ABOUT GLYPHOSATE

Below is a brief summary of some of the scientific evidence relating to the main areas of concern. Most of the references lead to other papers and studies, and of course much more can be found by searching for 'Glyphosate problems' on the Internet, especially through the archives of relevant scientific journals.

GLYPHOSATE AND HUMAN HEALTH CONCERNS

Cancers. Clear laboratory and epidemiological evidence that glyphosate is potentially carcinogenic has been suppressed over many years (13). Glyphosate has been implicated in a number of cancers in humans, including non-Hodgkin lymphoma  (14, 15, 16) and multiple myeloma (17). Glyphosate has been shown to affect human oestrogen receptors, and to cause proliferation in human hormone-dependent breast cancer (18). Apart from consumers or potential consumers, there is particular concern for those who handle pesticides (19).

Birth defects and endocrine disruption. Birth defects have been found in humans (8 (20). Glyphosate has been shown to be an endocrine disruptor in human placenta cells (21, 22, 23). A study on three generations of aquatic snails showed that by the third generation glyphosate had adverse effects on the snails' reproduction and development, which could also have implications for humans (24). Glyphosate has been implicated in the malformations in piglets born in Denmark (25): these findings apparently contradict the assertion "Glyphosate does not cause mutations" in the Reregistration Eligibility Decision (RED) issued by the United States Environmental Protection Agency in September 1993 (26).

DNA damage. A study on human-derived buccal epithelial cells (taken from inside the mouth) showed that glyphosate and Roundup had cytotoxic and DNA-damaging properties (27).

Genotoxic effects. Glyphosate was shown to cause clastogenic and cytotoxic effects in bone marrow cells in mice, resulting in chromosomal damage (28).

Male infertility. In vitro it has been shown that glyphosate and Roundup cause damage to rats' testicular cells (29). Male reproductive functions in rats have been shown to be disrupted by low doses of Roundup (30).

Disruption of the gut bacteria. Glyphosate fed to rats is largely taken up in the gastrointestinal tract (31). It causes depletion of essential minerals and amino acids in dairy cows (32). In humans, glyphosate has been shown to disrupt bacteria in the gut (12).

Possible consequences of gut bacteria disruption include: 

     Crohn's disease (12)

     digestive problems (12)

     obesity (12)

     depression (12)

     Alzheimer's disease (12)

     Parkinson's disease (12) Glyphosate has been strongly linked to Parkinson's disease in humans (33)

     liver conditions (12)

     autism (12) (34)

     cancer (12)

     Coeliac disease (15)

     gluten intolerance (15)

Immune system disruption. A study of 258 dairy cows on 14 farms in Germany showed that animals with a high concentration of glyphosate in their urine revealed changes reflecting an adverse influence on their immune system. (32)

Damage to stomach, liver, kidney, brain, pancreas and spleen. A study on rats showed widespread damage to multiple organs from glyphosate, but also that zinc supplementation beforehand mitigated some of the effects (35).

Kidney damage (15) (4)

Thyroid disease (15)

Neurotoxicity. Roundup has been shown to cause oxidative damage and neurotoxicity in rats (36)

GLYPHOSATE AND THE ENVIRONMENT

Damage in soil and crops. Long-term studies have shown that glyphosate has many unpredicted and unwanted effects on the soil and plants. In Canada, glyphosate was found to be a factor in Fusarium infection (a highly damaging fungus) in wheat and barley (37). Field studies conducted over ten years from 1997-2007 on glyphosate-resistant soybean and maize showed that glyphosate application increased the frequency of root-colonizing Fusarium, interfered with microbial groups and functions, and could even serve as a nutrient for plant-destructive fungi (38). Glyphosate was found to have various negative effects, including toxicity to beneficial bacteria such as nitrogen-fixing rhizbia, and possible contamination of groundwater (5).

Damage to plants and trees. Glyphosate weakens plant defences against diseases, with glyphosate-treated crops showing increased disease severity (39). Glyphosate has been found to be damaging to plant growth (40). It can also cause serious damage to trees (41).

Weed resistance. Application of glyphosate-based herbicides has been shown to give rise to resistant weeds (42).

Earthworms. Laboratory tests have shown that glyphosate and another herbicide, 2,4-D, cause significant harm to earthworms (43).

Bees. The damage done to bee colonies, therefore pollination and honey production, through neonicotinoids and pyrethroids has been long established (44). A link between harm to bees and glyphosate has taken longer. A study on the effects of giving bees equivalent doses of glyphosate to those which they might get in the fields showed that their learning functions were impaired, giving rise to the possibility that traces of glyphosate brought into hives by forager bees could accumulate and have a damaging effect on colony performance (45).

In July 2014, s district judge in Yucatán, Mexico, ruled that "co-existence between honey production and GMO [Roundup-ready] soybeans is not possible". The judge's verdict was given on the basis of scientific evidence presented in Court, and resulted in Monsanto's permit for commercial planting of Roundup ready soybeans in Yucatán to be revoked. In March 2014, the Second District Court decreed: "The government secretariats of SAGARP [the Ministry of Agriculture] and SEMARNAT [the Ministry of the Environment] must guarantee that no genetically engineered (GE) soy will be grown in the state of Campeche starting from the 7th March 2014".

Insects. It has long been accepted that glyphosate-based herbicides could and probably would cause harm to insects and birds through damage to their food sources and habitats. This has been proved beyond doubt in the case of the Monarch butterfly (Danaus piexippus), which has shown a sharp decline in numbers which has been directly linked to the destruction of their milkweed breeding habitats (46, 47). 

Aquatic ecotoxicity : this document sets out the technical considerations for estimating the toxicity of glyphosate and glyphosate-based herbicides.

Water contamination. It was admitted in the 1993 EPA re-registration document that glyphosate has the potential to contaminate surface water (26, p 37). It has been shown to be capable of reaching groundwater (48). A Mexican study of 23 groundwater sites in agricultural and natural protected areas showed that glyphosate was detected in all the samples, including the natural protected areas where the researchers had not expected to find it. It was found in greater concentration during the dry season, which was as expected (49). An Austrian study showed significant residues of glyphosate and its metabolite AMPA in surface waters and waste water-treatment plants (50). Great concern has been expressed about the persistence of glyphosate in seawater, especially in relation to the Great Barrier Reef (51).

Fish 

Liver damage. A study has established that glyphosate causes moderate to severe liver damage in neotropical fish, Piaractus mesopotamicus, which "may affect the detoxification and/or tissue repair processes and contribute to fish death". (52).

DNA damage and oxidative stress have been found in freshwater fish Channa punctatus through exposure to sub-lethal doses of a glyphosate-based herbicide. (53).

Fish and aquatic invertebrates

Studies showed that under certain conditions a glyphosate-based herbicide could be toxic to aquatic invertebrates, including midge larvae and mayfly nymphs, and freshwater fish, including rainbow trout and bluegills. (54).

To sum up

The amount of glyphosate used across the world is enormous and apparently ever-increasing. From 1974 to 2014, over 1.6 billion kilograms of glyphosate as an active ingredient were applied in the United States, representing 19% of the estimated global use of glyphosate, which amounted to some 8.6 billion kilograms (55). Glyphosate's effects are all-pervasive, its damage impossible to calculate. 

Scientists are proving how and why glyphosate-based herbicides are damaging to human health and the environment. They should not have to do this. Clearly, the studies from which these herbicides were deemed to be safe were inadequate, to say the least. "Safe poison" is an oxymoron. There is every reason to ban glyphosate-based herbicides, in favour of farming and gardening practices which sustain good health in the soil, air and water on which we depend for our vital nutrition.

References

1) Buffin, D., Jewell, T., 2001.Health and environmental impacts of glyphosate: The implications of increased use of glyphosate in association with genetically modified crops. Pub. Friends of the Earth UK. 117 references

2) Krüger, M., Schledorn, P., Schrödl, W., Hoppe, H-W., Lutz, W., Shehata, A.A., 2014. Detection of Glyphosate Residues in Animals and Humans. Journal of Environmental and Anayltical Toxicology 4: 210. 30 references

3) Watts, M., 2009. Glyphosate.  Resport for the Pesticide Action Network Asia and the Pacific. 295 references

4) Jayasumana, C., Gunatilake, S., Senanayake, P., 2014. Glyphosate, Hard Water and Nephrotoxic Metals: Are They the Culprits Behind the Epidemic of Chronic Kidney Disease of Unknown Etiology in Sri Lanka? International Journal of Environmental Research and Public Health. 109 references

5) Cox, C., 1995. Glyphosate, Part 2: Human Exposure and Ecological Effects. Journal of Pesticide Reform 15 (4) 78 references

6) Julius, H., 2002.The Glyphosate threat 1: environmental issues. Pub. Friends of the Earth, available on The Rivermouth Action Group Inc. website. 98 references

7) Julius, H., 2002.The Glyphosate threat 2: health issues. Pub. Friends of the Earth, available on the Rivermouth Action Group Inc. website. 16 references

8) Antoniou, M., Ezz El-Din Mostafa Habib, M., Howard, C. V., Jennings, R.C., Leifert, C., Nodari, R.O., Robinson, C., Fagan, J.. June 2011. Roundup and birth defects. Is the public being kept in the dark?  Pub. Earth Open Source. 358 references

9) Pesticide Action Network, 1996. Glyphosate fact sheet. Pesticide News 33: 28-29. 11 references

10) Bradberry, S.M., Proudfoot, A.T., Vale, J.A., 2004. Glyphosate poisoning. Toxicological Reviews 23 (3) 159-167. 51 references 

11) Cotton, S., 2014 Soundbite molecules - glyphosate. Royal Society of Chemistry online magazine.

13) Ho, M.W., 2014. Glyphosate and Cancer. Institute of Science in Society Report 26.3.2014. 34 references