Look at glyphosate dispassionately



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The grapevine whispered to me that at a recent meeting in Parliament, when the Minister of Plantation Industries was presenting his case for lifting the current ban on glyphosate, you had remarked that this weed killer is a ‘poison’ and the ban should not be lifted.


Perhaps you were suddenly reminded of what you learnt at the Medical College, the wise words of Bombastus Paracelsus, the founder of the science of pharmacology, uttered some 500 years ago, that all substances are poisons. Unfortunately, you, at the spur of the moment, forgot the rest of what he said, that is: "....there is nothing which is not a poison and it is the dosage that differentiates a poison and remedy"! I am surprised that you who are usually articulate in your arguments, made such a remark. You ought to have studied this matter thoroughly, before making such a remark. Ideally you should have appointed an expert committee of competent, unbiased professionals (scientists and medical specialist) to give the government a decision on the matter. That never happened, and the ban appears to have happened at the behest of a Buddhist monk, who is also a politician! Although glyphosate was banned on the myth that it was a factor in the causation of CKDu, the Presidential Task Force on the subject has hitherto failed to investigate and report on this matter of urgent national interest.


Let me help you with a few pieces of vital information that should enable you to make an evidence-based decision on the matter:


1. Glyphosate was partially banned during the latter part of the previous regime, and totally in June 2015 under the new government. It is evident that a certain research paper published in a fee-levying journal as a hypothesis (the word hypothesis was prominently displayed near the title of this paper) by some local scientists, was instrumental in making this decision. I need not tell you that any ‘muck ‘can be published in such journals so long as the fee, usually two to three thousand dollars is paid. The paper surmises that glyphosate complexing in the hard water prevalent in the CKDu affected areas with metals, including heavy metals, enabling the complexes to remain in the water for long periods, hence entering the kidneys, bypassing the liver, is probably a causal factor! What a hypothesis! Highly reputed chemists including several professors of chemistry of the Peradeniya University and many others have ’torn this hypothesis to bits’, stating that its chemistry is totally flawed, and such a course of events is highly untenable! No other researcher or research publication has supported this hypothesis, to our knowledge.


2. You would know that there were two WHO related studies on the CKDu in Sri Lanka, one in 2013 led by Prof. Shanthi Mendis and the other, in fact, an International Consultation of 54 scientists held in Colombo last April. I was a participant in the latter. In none of these was glyphosate implicated in the etiology of CKDu. In the 2013 study, it was concluded that cadmium (Cd) levels in the urine of CKDu patients were significantly higher than in the control subjects, and Cd may be a causative factor, and co-exposure to cadmium and arsenic is known to produce additive effects. . It is further stated that some pesticide residue levels were above reference levels in CKDu patients and some of them are known to be nephrotoxic, and may aggravate the causation of the disease. In the case of glyphosate, 3.5 % of the CKDu patients had residues of it in the urine above reference level. For some unknown reason, this report failed to state the glyphosate residue status of the control subjects, who were from a non-CKDu area (Hambantota). On re-analysis of the raw data (available at the National Science Foundation) it was revealed that there was double the number (7.0%) of subjects with glyphosate residue levels above reference limit in the control area! In fact, there were significantly more subjects with above reference limits of several other pesticides too in the control group! (Please see the Table attached) Why did the WHO not reveal this fact? Had it been done then, probably glyphosate would not have been banned today. What a blow to the poor farmers highly dependent on glyphosate for their weed management!


3. In the final Report of the WHO International Consultation held here last April, it is stated that the "evidence of this association" ( of pesticides with CKDU ) "was considered inconclusive" , and that " longitudinal well-designed studies that include healthy individuals in endemic and non-endemic areas, with bio banks, will be needed to assess the possible role of agrochemicals in the causation and progression of CKDu". Hon Minister, need we say more!


4. You would know that concern about glyphosate arose, particularly in Europe and the U.S, following a report by the International Agency for Research on Cancer (IARC) that glyphosate was probably carcinogenic and not because of any evidence linking it to CKDu or nephrotoxicity. That decision led to shifting glyphosate from Class 3 to Class 2a of the carcinogenicity classification of substances. There had been various criticisms of this decision. Over 20 internationally highly reputed scientific organizations, such as the Royal Society of Great Britain and several Nobel Laureates were critical of this decision. I need not tell you that there are numerous day to day used materials such as processed meat and alcohol etc. which are, in fact, in Class 1 of this classification. Interestingly, in a court case filed against the re-classification of glyphosate, the leader of the IARC team admitted that he refrained from divulging critical information to his IARC team from a wide study conducted in the U.S on glyphosate, where he himself was a senior member of that team. When cross examined, he further confessed that had that information been known by his teammates, the IARC decision could have been different!


5. More importantly, the Joint Meeting of Pesticide Residues comprising experts from the WHO and FAO last year, following the IARC report, declared that there is no evidence of carcinogenicity or genotoxicity linking glyphosate and CKDu.


6. Glyphosate use in Europe and the U.S is far more intense and it has been reported that, for example, over 40% of the Europeans have some glyphosate residue traces in their urine. In Malta this figure is over 90%. However, none of these countries have banned glyphosate. No other country in the world other than Sri Lanka has done so. Following the IARC report there has been widespread concern about glyphosate, and EU reconsidered all evidence on the chemical before its use was re-authorised for 8 more years. The permissible glyphosate limit in the U.S, as per its Environmental Protection Agency is 600 parts per billion (ppb) in drinking water. In the EU it is lower, being 200 ppb. Our residue levels are nowhere near those, being only less than one ppb in the water, soil and many crops that had been measured by the Office of the Registrar of Pesticides. In fact, even in studies of the proponents of the glyphosate-CKDu hypothesis, referred to above, the levels in the water were 0.7 to 3.5 ppb. Japan is very concerned about pesticide residues in items of food imported, and for tea it is 1.0 ppm. Our tea has not reached this level, despite glyphosate being used for nearly a decade.


7. Most importantly, it is now becoming exceedingly evident that the etiology of CKDu is tied up with the drinking water, in that those who drank water from dug wells or deep wells contact the disease, but not those who drank river, reservoir or spring water. It is generally believed that hard water and ionicity (dissolved salts) are the likely cause. This is elegantly demonstrated in a study at Ginnoruwa, Girandurukotte. Of two villages in Ginnoruwa, Badulupura located on the highlands and Sarabumi on the lowlands, people from the former catch the disease, but not those from the latter. The Badulupura people drink water from dug wells, whereas those from Sarabumi do not; they drink river or reservoir water. However, both groups of people have paddy fields in the lowlands , and largely consume their own paddy. Before the Mahaweli settlements took place, the indigenous people of the Rajarata exclusively drank tank or river water, and there was no CKDu. It was only with the expansion of settlements and population did the need for dug wells arise.


8. It is a fact that the tea industry is suffering huge losses as a result of poor weed management in the absence of glyphosate or an effective and cost competitive alternative. The loss for 2015 was reported to be some Rs 6 billion. On the other hand, the Rajarata farmers are silently suffering with their weed control costs skyrocketing, on the misguided notion that glyphosate is a cause for CKDu. When explained that there in no such evidence they were aghast! Rice cultivation can manage without glyphosate at a cost, 20% more water being needed for post-plant weed control by inundation. On the other hand, the control of the highly competitive and noxious weeds such as Kalanduru (Cyperus ) in upland crops such as maize and pulses needs glyphosate. It cannot be done by ploughing or harrowing because of its regeneration habit.


"Kalanduru" infesting a young maize crop despite harrowing; glyphosate effectively kills it! (See picture)


Given all these facts we urge the Hon Minister to look at the issue dispassionately. This is as important to farmers as the SAITM issue to the medical students of this country. Ideally, we urge you to appoint an independent, unbiased team of scientists to give you a factual report on the matter.


Dr Parakrama Waidyanatha


 
 
 
 
 
 
 
 
 
 
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