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NCP kidney disease - thinking outside the box

Chronic Kidney Disease of Unknown Origins, known as CKDU has presented itself as a baffling health problem with serious socio-economic implications. CKDU is most prevalent in the North-Central (Uthuru-Maeda) and Uva provinces. It has been investigated for at least a decade, and various theories have been presented. The use of pesticides and fertilizers, consumption of contaminated drinking water, and even the use of Aluminum cooking pots have been included in the gallery of rogues.

I have collected the published material from Sri Lanka regarding CKDU during the past year, and also looked at reports from other developing countries where similar problems have baffled the experts. A 'jury' member at a trial need not be a forensic expert, but he/she can listen to the various views that have been expressed and make suitable common-sense conclusions. I invite the reader to be a jury member at this trial. In my view there is already enough evidence to doubt that heavy metals like Cd, Pb, or As from fertilizers, or environmental toxins would be the over-arching cause of CKDU.

Diseases of unknown etiology

Given an incidence of Kidney diseases, it is natural to think of nephro-toxic substances such as arsenic, cadmium, lead, chlorocarbons etc., as causative agents. At this point a causal link is usually made to environmental factors, use of fertilizers, the quality of drinking water, fixation of toxins by plants, toxins from algae or fungi that grow abundantly in phosphate-rich rice paddies.

CKDU and other illnesses of unknown etiology that affect peasant workers is a common phenomenon in many developing countries including powerful nations like China.

China launched a massive effort to stamp out the crippling Kashin-Beck disease, fighting it since 1995, with world-renowned scientists from all over the world trying to understand it. However, while various environmental causes have been blamed, even today the cause of the illness remains unknown, with over one million people in 14 provinces affected (see Science, vol. 324, p 1378, (2009)).

CKDU in Sri Lanka

The indictment of modern fertilizers, pesticides and the environment is easily, and acceptable to the current belief system of the public at large. It is a convenient hypothesis even for the practicing scientist. Thus a hunt for environmental causes begins, and decades of research are engaged. This has been the pattern in many countries, and in the end no clear answer emerges, except in special cases like Bangladesh where the high As-contamination could be easily and unequivocally identified.

In Sri Lanka too, currently the most popular theory is to claim that the environment is polluted by the use of fertilizers containing excessive Cadmium or Arsenic. With little regard to chemistry, it is claimed that 'hard water' makes the toxins critical in the affected areas in some mysterious manner. Furthermore, one may argue that multiple nephrotoxins even at 'safe' levels may have a greater than expected nephrotoxicity, and quote well-known studies on mice. Then the researcher is confronted with a nightmare problem that can be easily politicized by lobby groups.

Hopefully, the public debate in Sri Lanka has not reach such an impasse. Although there has been some 'politicized' discussions, there is also some effort to proceed systematically by analytical chemists and medical researchers.

Dr. Shanthi Mendis, coordinator of the WHO project on CKDU is reported to have asserted that: "studies done so far on drinking water samples from Anuradhpura, Polonnaruwa and Badulla had shown that Cadmium and Lead were within normal limits. Arsenic and Cadmium had been analyzed in 118 water samples and 99 of those samples had been taken from drinking water sources believed to cause CKDU. In three of those samples, Arsenic levels were above WHO standards"

(Island - August 28, 2012).

It is even more intriguing to learn that CKDU affects males between the ages of 15-60, but hardly any females. One would have expected children (who play in the same environment), and older people to be far more susceptible to the effects of environmental toxins. Fertilizers are used equally heavily in other parts of the country. The up-country plantations use similar fertilizers in larger quantities, and yet it is not affected!

Cats, dogs and Cattle in the affected areas drink the water, and yet they are not significantly affected!

In my view, this and other reports indicate that theories based on As, Cd and Pb as nephro-toxins cannot provide an adequate answer. The three higher-level As samples reported by Dr. Mendis may well be as expected from the observed standard deviation in the sample set.

The WHO researchers as well as scientists studying CKDU are following the standard trajectory of research that has been tried out in many countries. In most cases they failed to give definitive answers to this type of problem. However, it is still necessary to follow that trajectory and examine the role of nephro-toxins before we reject it or accept it as the cause.

A possible answer

The kidneys play the key role in flushing out any toxins that we ingest. However, the kidneys cannot do this properly unless the body is supplied with at least two liters of water per day. In fact three liters (12 cups per 24 hours) might be optimal for a normal person. However, a worker sweating it out in a paddy field in the hot Uthuru-Maeda or the Uva would need even more to allow for perspiration as he toils in the sun.

The indiscriminate use of pesticides, major cause for Chronic Kidney Disease

However, it is very unlikely that such workers drink the require amount of water. A worker toiling in the middle of a paddy field is unlikely to come out of the field every couple of hours and go to a well to hydrate himself. The practice of carrying a water bottle is unheard of among Sri Lankan workers. A worker may drink a cup of tea in the morning, a cup or two of water at lunch, and then another cup or two at the end of the day, and more at dinner. To make matters worse, he might drink illicit brews ('Kassippu', containing toxins) in the evening, while the females probably do not consume Kassippu. The workers' total water consumption per day would be woefully inadequate.

Under such circumstance the worker's kidney would be severely strained, just like a car engine running without coolant. The small amounts of heavy metals that are normally flushed out would accumulate in the kidney. The liver and the thyroid would also be affected. Such workers would contract CKDU and begin to excrete raised levels of As and Cadmium in urine. Analysis of their hair or nails would show residual metal toxins, as claimed by the WHO researchers.

The reported chemical analyses of the water in the Uva or the Uthuru-Maeda provinces simply do not show the kind of alarming figures found in Bangaladesh. In any case, kidney poisons do not preferentially attack young males. It is simply that the workers are not drinking the amount of water needed by their bodies when in the field. The women, children, old folks, white-collar workers who remain near homes or offices in a non-perspiring ambiance probably drink enough water. They do not dehydrate their kidneys!

One can also predict that individuals suffering from such dehydration would begin to suffer from dry skin, itch and other consequences of dehydration before the onset of the more serious illness. Inflammation of the joints, protein-uria, etc., and CKDU would follow soon.

Plan of action

The authorities should issue re-usable water bottles to every field worker. Throw-away plastic water bottles should NOT be used as they are ultimately a pollutant and more expensive as well. Short educational sessions should be held explaining the need to drink 2-3 liters of water (8-12 cups) per day even when NOT working in a field. More water is needed when they work in a field. A group of 'Jala Vidanes' should be appointed to ensure that field workers are supplied with water.

The water may be taken from a near-by well as we do not believe that there is any special problem with the environment or the ground water in the Uthuru-Maeda or Uva. After all, the animals, household pets, old people, children and women drink the local water, and they don't seem to get CKDU. In the poisoned-arrow parable of the Buddha, it was explained that priority should be given to helping the patient stricken with the arrow, rather than finding out from where the poison came, of what wood the arrow was made of, who shot the arrow etc. Such research studies can go on in parallel with providing a simple inexpensive water bottle to each of these workers who are at risk. Other research, e.g., feeding mice with NCP water, and a reference batch of mice with Colombo water may also be very useful.

The writer was a Professor of Chemistry at the Vidyodaya University in the mid-1970s. He is currently attached to the National Research Council of Canada and the University of Montreal and teaches Physics.

 

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