Sri Lanka Partially Bans Glyphosate for Deadly Kidney Disease Epidemic
metal-chelating activity causes bioaccumulation of toxic metals in the body,
resulting in an estimated 400 000 cases in Sri Lanka
and 20 000 deaths Dr Eva
Sri Lanka is set to partially ban glyphosate-based herbicide use
following a new peer-reviewed
study linking it to a fatal chronic kidney disease epidemic badly affecting the
country . Kidney problems have been further documented in other global
regions, prompting an earlier complete ban by
El Salvador late last year . A complete ban was
initially proposed, but due to plantation sector representatives claiming a
shortage of agricultural workers that would not sufficiently manage weeds
without glyphosate, the government has now limited the ban to disease endemic
areas . Even Brazil, one of the largest growers of
glyphosate-tolerant genetically modified (GM) crops has now filed a law suit by
Federal Prosecutors to ban glyphosate along with 8 other dangerous pesticides
. It is becoming increasingly difficult for government regulators and glyphosate producers to justify the use of
this herbicide when other nations are banning the chemical outright in order to
protect their citizens.
can impact human health in a number of ways, one of which is through its potent
metal chelating abilities. Indeed, glyphosate was originally patented by
Stauffer Chemical Co. in 1964 (U.S. Patent No. 3,160,632)  for this very function.
Chelating mineral ions can lead to nutritional depletion in plants and animals,
which has already been shown to cause health problems in both. In the case of
this kidney disease epidemic, its chelation of metals such as arsenic in the
water supplies is now though to lead to their bioaccumulation in the body,
resulting in kidney failure and even death, as proposed
in a new study  by Channa Jayasumana (Rajarata University, Sri Lanka),
Sarath Gunatilake (California State University, USA) and Priyantha Senanayake
(Hela Suwaya Organization, Sri Lanka) published in the International
Journal of Environmental Research and Public Health. Glyphosate has also been linked to many other health problems
including cancers (see  Glyphosate and Cancer, SiS 62), infertility (see  Glyphosate/Roundup
& Human Male Infertility, SiS 62),
along with neurotoxicity, reproductive problems, birth defects, and other
problems (see  Ban
GMOs Now, special ISIS report).
Starting in the mid-1990s, this Chronic Kidney Disease of unknown aetiology
(CKDu) was discovered among the rice paddy farmers in the North Central
Province (NCP) of Sri Lanka. Over the next two decades, the disease spread
rapidly to the other farming areas. The prevalence of the disease is estimated
at 15 %  affecting a total of 400 000 patients with an estimated death toll
of around 20 000 . The Sri Lankan Ministry of Health have since defined
CKDu with the following criteria:
(1) No past history of, or current treatment for diabetes
mellitus or chronic and/or severe hypertension, snake bites, urological disease
of known aetiology or glomerulonephritis.
(2) Normal glycosylated haemoglobin levels (HbA1C ˂ 6.5%).
(3) Blood pressure ˂160/100
mmHg untreated or ˂140/90 mmHg on up to two antihypertensive agents.
disease seems to progress slowly, with tubular interstitial nephritis (inflammation
of the spaces between renal tubules) associated with mononuclear cell
infiltration (infiltration of immune cells – indicative of inflammatory
lesions), glomerular sclerosis (hardening or scarring of the renal glomeruli) and
tubular atrophy . It is further characterized by tubular proteinurea
(excess, unabsorbed protein buildup), usually alpha-1 and beta-2
microglobulinuria proteins, and high urine Neutrophil Gelatinase-associated
lipocalin (NGal) levels (>300 ng/mg creatinine).
CKDu previously linked to hard water, arsenic and unidentified
Different groups including members of the World Health
Organisation have already researched the disease and acknowledged a
multifactorial cause, with the main causative factors being exposure to
arsenic, cadmium and pesticides. Consumption of hard water, low water intake
and exposure to high temperatures resulting in significant dehydration, are
among the other factors. However, as the authors of the new study state, “whatever
hypothesis that is propounded should be able to answer the questions as to why
CKDu is confined to certain geographical areas of Sri Lanka and why there was
no CKDu in Sri Lanka prior to the 1990s.”
The authors first present a well-documented, statistically
significant correlation between water hardness and CKDu. Ninety six percent of
the CKDu patients had consumed hard or very hard water for at least five years,
which is also clearly illustrated by the maps of Sri Lankan regions showing
those most affected by the disease to reside in hard water regions (see figure
1). They also noted further observations in the affected regions:
The number of villagers who complain that the ground water hardness in CKDu
endemic area has increased steadily over the last two decades.
Certain shallow wells (2–5 m), previously used for
drinking purposes are now abandoned due to high hardness and bad taste.
There are a few natural springs located in the CKDu endemic area where water is
not hard. People who consume water from these sources have been determined to
be free from the disease.
Individuals who drink treated water from large water supply schemes (especially
in the two cities of Anuradhapura and Polonnaruwa), while living in the same
endemic areas, do not have the disease.
In the adjoining farming areas of the Northern Province of Sri Lanka, where the
ground water hardness level is known also to be hard
or very hard, there have not been any significant number of CKDu cases reported.
Figure 1 Map of Sri Lanka
correlating prevalence of CKDu disease by region (left), with regions of hard or
very hard water
evidence has shown that CKDu patients accumulated
arsenic in their bodies, with toxic levels of arsenic in urine, hair and
nail samples, while healthy people in CDUk endemic regions also show signs of
high arsenic levels, suggesting that hard water is linked to CKDu onset .
It has been further suggested that the arsenic originates from tainted
agrochemicals including pesticides and fertilizers, though the source has not
yet been fully determined.
CKDu caused by ‘compound X’ – now discovered to be glyphosate
The study reveals that a previously unknown factor, referred to by
the authors as ‘compound X’, originates from agrochemicals and that compound X,
when combined with hard water containing toxic levels of calcium and magnesium,
causes serious kidney damage. In support of the hypothesis that compound X
derives from agrochemicals and is indeed glyphosate, are the observations that
CKDu emerged in the 1990s, which fits with the massive influx of agrochemicals
in Sri Lanka since the 1970s following changes in economic policies. Further,
low concentrations can lead to bioaccumulation of a toxic substance, which would
explain the 12-15 year lag time before symptoms emerge. This coincides with the
shifting age of patients, with prevalence of disease increasing in younger
people in recent years, suggesting a cumulative
nature of the toxin. In addition, regions of Sri Lanka that have restricted
agrochemical use, as in the North where the concern of political, violent
conflict meant that governments wanted to prevent people from using agrochemicals to make explosives, high levels of
CKDu do not exist. These areas also have hard water, showing that hard water
alone is not sufficient to cause CDKu. The authors used these observations to describe
the expected properties of compound X listed below:
A compound made of recently (2–3 decades) introduced chemicals to the CKDu endemic area
(b) Ability to form stable complexes with hard water
(c) Ability to capture and retain arsenic and nephrotoxic metals
and act as a “carrier” in delivering these toxins to the kidney
(d) Possible multiple routes of exposure: ingestion, dermal and
(e) Not having a significant first pass effect when complexed with
hard water (a phenomenon of drug metabolism, usually by the liver, whereby the
concentration of a drug is greatly reduced before it reaches the systemic
(f) Presenting difficulties in identification when using conventional
is further implicated by the fact that it is by far the most commonly used
herbicide in Sri Lanka, with quantities of glyphosate use exceeding all other
forms metal complexes that bioaccumulate in the body
was first used as a descaling agent to clean out calcium and other mineral
deposits from pipes and boilers, aided by the chemical’s high water solubility.
Descaling agents bind to metals, making the water soluble and removable. Its
stability in water depends on a number of factors, including phosphate which
competes with glyphosate for soil absorption. Further, its
binding to metals can cause the formation of strong complexes that affect its
biodegradability, with glyphosate degradation time increasing to 7-22 years in
particular conditions such as pH. In water above pH 6.5, glyphosate turns into
a dianion (an anion with a -2 negative charge), suggesting it forms metal
complexes in alkaline conditions, increasing its solubility and thus leaching
deep into soils [14,15]. Alkaline conditions are known to reduce the weed
killing capacity of glyphosate, with glyphosate-metal complexes being stable in
basic but not acidic conditions. The effects of pH are also important in
understanding the stability of the lattice structure in the acidic conditions
of the kidney, as will be explained below.
using nuclear magnetic resonance (NMR) techniques show glyphosate to interact
with calcium, magnesium and other metals, and that these complexes become more
stable with time [16, 17]. Further, the paddy farming soil in regions endemic
for CKDu are rich in metals including calcium, magnesium, iron, nickel,
chromium and cobalt. Ferric irons alter soil
absorption of glyphosate and its metabolite, AMPA (α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic
acid). This problem is confounded by the application of triple phosphate (TSP)
fertiliser to paddy fields, which have been found to be contaminated with
certain metal ions as well as high levels of arsenic. This leaves people highly
vulnerable to exposure of stable, toxic glyphosate-metal complexes through
their drinking water. Glyphosate exposure also occurs
through the skin, farmers are found to have glyphosate in urine following spraying.
Glyphosate can mix with sweat in hot and humid climates before being absorbed through
the skin. Further, Sri Lankan farmers do not often wear protective gear
to prevent respiratory exposure. Arsenic and cadmium also commonly contaminate
rice, vegetables and tobacco leaves which are often chewed along with betel
leaves by Sri Lankans. This transdermal and respiratory exposure therefore
provides an additional opportunity for glyphosate to bind to nephrotoxic metals
consumed in foods and bioaccumulate in the body.
on previously published studies on how glyphosate forms metal complexes and
matrices [14-17], the authors propose the formation
of stable glyphosate metal lattices, which can explain how glyphosate, hard
water, arsenic and other nephrotoxic metals cause kidney disease in Sri Lanka,
as well as the increase in water hardness over the years. This proposed
glyphosate metal lattice, as shown in figure 2, is based on previous NMR
studies showing the ability of hard water ions to bind to both the phosphonate
and carboxyl functional groups of the glyphosate molecule to form complexes.
is worth noting that glyphosate’s causative role in CKDu has previously eluded
researchers due to its chemical properties including its ionic character, high
polarity, high solubility in water, low volatility, insolubility in organic
solvents and strong complexion behaviour, which make it very difficult to
detect in the lab.
Figure 2 Proposed glyphosate/heavy metal
of glyphosate’s role in kidney disease
glyphosate metal lattice hypothesis is supported by the observation that people
who drink natural spring water do not suffer the disease, with these waters
being devoid of magnesium and calcium, making the water unable to retain
glyphosate. It also explains why regions with hard water but low levels of
herbicide and chemical fertilizer are free of CKDu. Further, CKDu patients show
accumulation of metals (As and Cd) in the hair and nail samples, but low levels
of urinary excretion of metals (compared with control subjects in the same regions),
suggesting the kidney is unable to properly rid these chemicals from the body. Urine
from control as well as CKDu patients in endemic areas also show presence of
glyphosate and heavy metals, providing evidence of the presence of components
of the glyphosate metal lattice in their bodies. Evidence from El Salvador also
points to toxic heavy metals as a culprit in the disease that largely affects
poor, agricultural workers in the nation.
lattice is proposed to accumulate in the kidney where the acidic conditions
caused by the daily secretion of acids such as ammonium, cause the breakdown of
the lattice. Ammonium sulphate is already used by agriculturalists as a buffer
to release glyphosate from metal ions in hard water conditions, suggesting the
same mechanism may underlie the effects seen in the kidney proximal tubules in
CKDu patients. The lattice breakdown can then release glyphosate and its
metabolite AMPA as well arsenic, which may damage the
glomeruli. Other heavy metals can then be partially reabsorbed by the kidneys
resulting in further tubular damage. Nephrotoxicity of heavy metals is already
well known, with long-term exposure causing oxidative stress, nitrosative stress
(cell damage caused by reactive nitrogen oxygen species acting together with
reactive oxygen species), apoptosis and necrosis in the glomerular and proximal
tubular cells [18-21]. Glomerular sclerosis (hardening and inflammation of the
kidneys), glomerular collapse and tubular interstitial damage are the result of
these pathological mechanisms. Glyphosate alone has also been shown in numerous
studies to cause kidney toxicity. Nile Talapia exposed to glyphosate show
changes in proximal tubular cells . Exposed juvenile African catfish
develop haematopoietic cell death, as well as kidney histopathological changes
including dilatation of Bowman’s space (a region of the kidney involved in the
first filtration of the blood to form urine) as well as degenerated tubules .
Mammalian studies have found increased serum creatinine, blood urea and reduced
kidney weight of rats who were fed with glyphosate exposed maize . Oral
exposure increases blood urea levels and leads to renal dysfunction in rats 
while dairy cows suffer similar symptoms . See  Ban GMOs Now, ISIS special report,
for a comprehensive summary of glyphosate toxicity to health and the
on the effects of glyphosate and hard water metals
combined would provide crucial insight into this hypothesis, though there is no
publication on this matter despite the known association of glyphosate with
described alternative pathways of glyphosate-induced kidney damage
studies have noted alternative mechanisms by which glyphosate can cause kidney
damage. Indeed, glyphosate can induce toxicity through a number of mechanisms including the disruption of cytochrome P450 and aromatase
pathways that may be responsible for the genotoxic and teratogenic effects seen
under glyphosate exposure. A recent review  explains how glyphosate has
been patented as an antibiotic and shown to kill beneficial gut bacteria in
poultry, leading to dysbiosis (microbial imbalance). This may go on to promote
the growth of pathogenic bacteria such C.difficile which produce
excessive amounts of p-Cresol sulphate, a toxic phenol that is associated with
chronic kidney disease and can induce activation of inflammatory cytokines and
chemokines, with inflammation playing a key role in kidney disease. Glyhosate
also induces a switch from aerobic to anaerobic respiration in E. coli
and other gut bacterial species, causing the increased production of indole, a
derivative of the aromatic amino acid tryptophan, whose breakdown also requires
cytpchrome P450. Tryptophan, an aromatic amino acid whose production depends on
the shikimate pathway that glyphosate inhibits, contains an indole ring.
Therefore, disruption of trypophan synthesis by gut microbes may well lead to
the accumulation of indole in the body. Indole is an important signalling
molecule for many bacteria, and along with p-Cresol, is associated with kidney
National governments are beginning to take long overdue steps to
protect their citizens from glyphosate, the most commonly used herbicide in the
world. Its links to diseases in both humans, crops and livestock can no longer be
ignored. Other worldwide governments need to follow the examples of both El
Salvador and Sri Lanka in protecting their citizens from a highly toxic
to be banned in Sri Lanka, GMWatch.com, accessed 24th March 2014. http://www.gmwatch.org/index.php/news/archive/2014/15350-glyphosate-to-be-banned-in-sri-lanka
Salvador Government Bans Roundup over Deadly Kidney Disease.
Sustainablepulse.com, accessed 27th February 2014 http://sustainablepulse.com/2013/09/19/el-salvador-government-bans-roundup-over-deadly-kidney-disease/#.Uw94kfl_uSo
Federal Public Prosecutor Requests Total Ban of Glyphosate Herbicides. SustainablePulse.com,
accessed 26th March 2o14. http://sustainablepulse.com/2014/03/26/brazils-federal-public-prosecutor-requests-total-ban-glyphosate-herbicides/#.UzL_A_l_vTE
Fon TA, Uhing EH, “Aminomethylenephosphinic acids, salts thereof, and process
for their production”, U.S. Patent No. 3,160,632, 8 Dec 1964.
C, Gunatilake S, Senanayake P. 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 2014, 11, 2125-2147; doi:10.3390/ijerph110202125
MW. Glyphosate and Cancer. Science in Society, to appear. 2014
MW. Glyphosate/Roundup and Human Male Infertility. Science in Society, to
MA, Paranagama PA, Dahanayake KS, Wijewardena KC, Amarasinghe
MD, Fonseka SI. Possible link of chronic arsenic toxicity to chronic kidney
disease of unknown etiology in Sri Lanka. JNSR 2013, 3, 64–73.
Mendis S, Maheepala P, Mehta FR. CKDu National Research Project Team. Chronic
kidney disease of uncertain aetiology: Prevalence and causative factors in a
developing country. BMC Nephrology 2013, 14,
Komiya, T, Ratnatunga N, Senevirathna ST, Harada KH, Hitomi, T, Gobe G, Muso E,
Abeysekera T, Koizumi A. Tubulointerstitial damage as the major pathological
lesion in endemic chronic kidney disease among farmers in North Central
Province of Sri Lanka. Environmental Health and Preventive Medicine 2012, 17, 213–221.
Paranagama PA, Dahanayake KS, Wijewardena KC, Amarasinghe MD, Fonseka SI.
Possible link of chronic arsenic toxicity to chronic kidney disease of unknown
etiology in Sri Lanka. JNSR 2013, 3, 64–73.
& Hoggard PE. Metal complexes of glyphosate. J. Agric. Food Chem.
1988, 38, 1326–1329
Vereecken H. Mobility
and leaching of glyphosate: A review. Pest Management Science 2005, 61,
Thelen, KD, Jackson
EP, Penner D. The basis for the hardwater antagonism of glyphosate activity. Weed
Science 1995, 42, 541–548
Caetano M, Ramalho
T, Botrel D, da Cunha E, de Mello W. Understanding the inactivation process of
organophosphorus herbicides: A dft study of glyphosate metallic complexes with
Zn2+, Ca2+, Mg2+, Cu2+, Co3+, Fe3+, Cr3+, and Al3+. International Journal of
Quantum Chemistry 2012, 112, 2752–2762.
Sabolic I. Common
mechanisms in nephropathy induced by toxic metals. Nephron Physiology
2006, 104, 107–114.
Madden EF &
Fowler, B.A. Mechanisms of nephrotoxicity from metal combinations: A review. Drug
and Chemical Toxicology 2000, 23, 1–12.
Therond P. Oxidative
stress and damages to biomolecules (lipids, proteins, DNA). Annales
Pharmaceutiques Françaises 2006, 64, 383–389
W.; Upatham, E.S.; Kruatrachue, M.; Sahaphong, S.; Vichasri-Grams, S.;
Pokethitiyook, P. Biochemical and histopathological effects of glyphosate
herbicide on Nile tilapia (Oreochromis niloticus). Environmental Toxicology
2003, 18, 260–267.
Histopathological effect of glyphosate on Juvenile African Catfish (Clarias
gariepinus). American-Eurasian Journal of Agricultural & Environmental
Sciences 2008, 4, 362–367.
Cellier, D.; de Vendomois, J. New analysis of a rat feeding study with a
genetically modified maize reveals signs of hepatorenal toxicity. Archives
of Environmental Contamination and Toxicology 2007, 52, 596–602.
Tizhe EV, Ibrahim
ND, Fatihu MY, Igbokwe IO, George BD, Ambali SF, Shallangwa JM. Serum
biochemical assessment of hepatic and renal functions of rats during oral
exposure to glyphosate with zinc. Comparative Clinical Pathology 2013,
Krüger M, Schrödl
W, Neuhaus J, Shehata AA. Field investigations of glyphosate in urine of Danish
dairy cows. Journal of Environmental & Analytical Toxicology 2013,
Samsel A &
Seneff S. Glyphosate’s Suppression of Cytochrome P450 Enzymes and Amino
Acid Biosynthesis by the Gut Microbiome: Pathways to Modern Diseases. Entropy
2013, 15, 1416-1463; doi:10.3390/e15041416.
Rory Short Comment left 9th April 2014 18:06:38 I think the producers of glyphosate should be charged with crimes against not only humanity but also the biosphere.
John Wilson Comment left 9th April 2014 18:06:46 Might kidney damage be occurring at a slower rate worldwide by the same process. What are the trends in kidney disease globally?
As glyphosate is present in drinking water, food and in the atmosphere we all have traces of glyphosate in our bodies. If glyphosate forms strong nephrotoxic compounds with a range of metals then surely these molecules will be gradually accumulating in nearly everybody - but faster in people who drink hard water and eat food with toxic fertilizer residues.
The first imperative should be to stop all non-agricultural use of glyphosate herbicides.ie. Using it to manage amenity land by local authorities and others. This use of glyphosate does not even have the justification that it is being used to produce food. My local authority, Newcastle City Council, use it extensively on public land.
Dr S K Weragoda Comment left 7th May 2014 08:08:59 I am working on the same issue for three years time. My test results of well water over 1,400 wells through out the country coincide the distribution of CKDu patients will with Fluoride and hardness.
Impact of Fluoride on kidney also well established.
We need to have a national discussion soon as possible to collect all the data and conclude all the relevant causes fro the issue.
My simple idea is that the Compound X would be multifunctional.
Sanjeewa Warnakulasuriya Comment left 12th August 2014 04:04:52 Hi, I'm a resident in Australia and we have been doing charity work to the effected communities with kidny failures. Our next project is to donate a reverse osmosis water purification unit to an identified area in Anuradhapura district.
My question is to Dr S. K. Weragoda and others who have done extencive research on this matter.
Please let me know, donating a water purification plant is the best thing to do or is there any thing else that can be done to benefit wider community. Thanks. Sanjeewa Warnakulasuriya.