Rajarata kidney disease and the role of heavy metalsJuly 15, 2012, 7:47 pm
By Prof. O A I Ileperuma
Recently this topic has received attention of Island readers and Drs. Upali Pethiyagoda and Nalin de Silva have commented on this problem. There has been a misinterpretation of what the WHO team leader Dr. Shanthi Menids said about possible causative factors. Her statement as reported in Daily News is as follows. "According to Dr. Mendis, heavy metals could cause this condition and they have already conducted several experiments on three heavy metals, namely, cadmium, arsenic and lead. She said heavy metals are contained in soil, water and the food chain on a normal level and if it increases, it will be a threat to one’s health".
Anyone who can understand this statement will know that she never said that the WHO has evidence that these heavy metals cause the Rajarata kidney disease. Those who make a big noise about this issue should first read the above statement and try to understand it clearly. She says heavy metals COULD cause the kidney disease and nowhere has she said that these metals are present at excessive levels. She has further stated that "In soil, water and food in Sri Lanka, the heavy metals are present IN NORMAL amounts. She says if the heavy metals increase there is a threat. Therefore it is premature to come to any conclusions regarding the causative factor as heavy metals.
I have been associated with investigating the causative factors of this disease for a long time and as far as 2004, I suggested that excessive fluoride may be a causative factor. This was arrived after carefully studying the geographic distribution of this disease where without exception the victims have consumed fluoride rich water. Those who live in Anuradhapura town or the Padaviya town where people consume low fluoride water (water schemes coming from the irrigation tanks or wells situated close to irrigation canals) do not get this disease. I also showed that the use of sub-standard aluminium pots could exacerbate the fluoride intake due to the complex compounds formed by fluoride with aluminium. This research has been published and also disseminated at both local and international meetings and accepted as a possible causative factor. Presence of dental and skeletal fluorosis in patients also point out to the excessive intake of fluoride into their bodies.
The problem with the heavy metal theory is that it cannot explain why only some areas are affected. There are many other areas with similar soils and the pesticides and fertilisers used are also the same but they have not been affected by the kidney disease at issue. Notable examples are Kalpitiya, Moneragala, Bibile and the areas in the Eastern province. The arsenic theory proponents assume that hardness of water is an essential condition but there are many areas of the Matale District where the water is hard but with no reports of this disease. Even in the same NCP, why people in Anuradhapura town do not get this disease cannot be explained by the heavy metal hypothesis. Also, farmers in Nuwara Eliya who use fertilisers and pesticides much more than any other area of the country do not get this disease.
It is interesting to note that in the Mahaweli C areas which are affected such as Girandurukotte those living around the Mahaweli irrigation canals do not get this disease while those staying away from the main canals using well waters do get the disease. This correlates nicely with the fluoride content of water. While irrigation canal water has low levels of fluoride usually less than 0.5 ppm, those who use well water are exposed to much higher levels of fluoride, sometimes as high as 7 ppm. This also gives credence to my theory that fluoride is a likely causative factor.
Proponents of the arsenic theory have gone to town hanging on to the tail of a story without analysing the whole story. Once they got a forensic specialist from Spain to tell that arsenic is the cause for this disease. I personally checked with this person to know whether it was true and he categorically denied that he had ever made such a statement. He only said that this matter should be further investigated. The same WHO, in an earlier study, did not find any significant difference between the heavy metals like arsenic and cadmium in the urine of kidney patients as compared to a control population. Again some people made up a big story that what they have said about arsenic is true when they heard that arsenic was found in the urine of affected people. When the WHO publicly made that statement at a meeting where all stakeholders were present at a meeting convened by the Prime minister, WHO representative clearly indicated that they have to wait till the results of the control experiments are known. Instead these arsenic theorists through their favourite websites proudly claimed victory on the results of an unfinished experiment.
Arsenic is a ubiquitous pollutant which gets into our body through a variety of sources. Air in cities contains around one part per billion arsenic coming from the combustion of fossil fuels. These are inhaled by people and thanks to our body defence mechanisms there is a natural way of detoxification in the liver which converts arsenic to less harmful organic forms which are flushed out with urine. If we get sick due to each and every toxin that we take in, then our human lifespans will be much shorter. The body has a remarkable mechanism to detoxify small amounts of toxic materials. The toxicity becomes a problem when the body’s defence mechanisms cannot cope up with excessive amounts taken in. This is not to say that inhaling small amounts of arsenic is good for the body and if one desires to live in a 100% arsenic free environment, then that person should go and live in some other universe. In addition, medical specialists have clearly shown that none of the affected patients show characteristicexternal arsenic poisoning symptoms such as ulcers and wounds typical of such patients in Bangladesh. This also shows that arsenic has no role as a causative factor in kidney disease.
It is my opinion that the WHO instead of arbitrarily pursuing theories proposed by various groups should study this scientifically with the help of an experienced toxicologist knowledgeable about these issues. The available information about the various causative factors could then be evaluated and future experiments should be planned to confirm one or more of these factors. In this exercise, the geographic occurrence of the disease could give a clue as to the more significant factors. If necessary, animal experiments should be conducted once a particular set of conditions is established. Unfortunately, my own fluoride hypothesis was not even considered in these investigations while some totally non-scientific ideas without even an iota of scientific merit have been blindly investigated.
It certainly takes time to conclusively establish causative factor (s) because all aspects of this disease have to be investigated. There has been no agreement on the causative factor for Balkan Endemic Nephropathy affecting several Balkan countries which has received the attention of a wide variety of scientists from Europe and USA with much more sophistication and after nearly 30 years of research.
Last Updated Mar 22 2017 | 09:17 pm