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
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
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
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.