Sunday Times 2
Chronic Kidney Disease: The proof is in the food they eat
‘Forgive them, for they do not know what they have done’
Chronic Kidney Failure in the North Central Province (NCP), unlike the usual causes of kidney disease, diabetes or blood pressure, was first established about twenty years ago. Even today many in the medical and scientific community are uncertain as to the cause of it. This is so in part due to the multiple possible factors associated with the condition, but it does not explain in totality why we haven’t been able to find the cause yet.
There are about 400,000 people in the NCP with varying degrees of kidney failure. About six months ago, the minister in charge told Parliament that 13 people died of the condition every day. The toll is expected to increase in the coming years.
Why only NCP?
At present, the disease is confined almost to the NCP. That is because agricultural practices in the NCP are different to those of other parts of the country. Much of the agriculture is based on irrigation with water derived from the hill country via the Mahaweli. Hill country water is used by direct application, following storage in reservoirs followed by storage in Yodha Wewas (Giant Tanks) and other tanks.
From hill country, the water brings fertiliser nutrients as well as fertiliser, and weedicide and pesticide related agents to the NCP. The farmers are well aware that the more water they use, the better their crops are.
Sadly, both the farmer and the agriculturists are unaware of a far more crucial factor — fertiliser-related toxic elements such as cadmium, arsenic and lead. These come to the paddy fields more from irrigated water than from direct application of fertiliser. This is so because it takes 2,000-5,000 litres of water to harvest one kilogram of rice. Although the concentration is low and within International Reference standards, once the water is in the paddy fields, the total amount of any toxic agent in the entire volume of water becomes available to produce one kilogram of rice. This applies to nutrients as well as all the toxic agents. This is how apparently clean water from hill country gets translated into possible toxic doses in our diet from rice.
Hill country water is not the only source of toxic agents other than fertiliser or other agrochemicals. Another is the nutrient rich sediments from reservoirs. In the past, when we were unaware of fertiliser toxic agents, it was most reasonable and logical to use reservoir silt in chena fields or home gardens. Then the de-silted material was dumped on the reservoir bund so that it would wash into the paddy fields – and chena farmers and home vegetable growers, unaware of the toxicity of the soil, would take the stuff away to feed their vegetable plots. Little did they realise they were growing toxic vegetables. One cannot blame the farmers for not knowing what they were doing, but agriculturists and relevant officials may consider it an insult to their intelligence if one were to hold them responsible for this practice. But isn’t that exactly what it is? Today the need for de-silting is not only to improve holding capacity and outlet clearance, but for a far more important issue of preventing the toxic elements from getting into the soil, hence the food chain. It is sheer disbelief, even today the practice is similar, or where there is modification, the silt is dumped in jungles or remote locations. Should anyone be surprised that our pastures and weeds have toxic agents in them according to the GOSL/WHO report?
In the past, the reservoirs were de-silted for the purpose of regaining the water capacity, and clear the blocked sluice gates. Today, the need for de-silting is different. It is carried out not only for the purposes of the past, but more importantly to remove the toxic agents and prevent them from entering the food chain. For that reason the disposal has to be far more thoughtfully done. It cannot be dumped on the reservoir bank. It cannot be used as compost or to enrich any agricultural soil.
It is said some vegetable growers have two plots, one for personal consumption and the other for sale. They do not use fertiliser in the personal consumption plot, because they believe fertiliser is toxic. They could very well be correct on that score; hence they use fertiliser on the ‘for sale’ plot only. The irony is, in their ‘personal’ plot many use compost from the reservoir silt, oblivious to the fact that silt compost is far more toxic than fertiliser! Why on earth didn’t someone point this out? This fact should have become known to the responsible offices, at least when GOSL/WHO report stated that CKF prevalence was highest amongst the chena farmers.
Sowing the seeds and reaping disease: Mahaweli water brings toxic substances to NCP paddy fields
Diet is the cause
Chronic kidney failure in the NCP is not one of occupation as suggested by members of the Presidential Task Force, and others, but it is one of diet. The fact that the prevalence is high among the farmer community is one of coincidence, and it can be explained.
The GOSL/WHO report established that most food items — rice, vegetables and yams — had varying levels of arsenic, cadmium, lead, and some weedicide and pesticide related chemicals. Calculation of amount of these agents getting into the body through the diet shows that those who consume food with high toxic levels of cadmium get a sufficient dose to cause kidney failure. It is only for cadmium there are safety or reference levels decided by the WHO or the European Union for diet to prevent kidney failure. Since some of our diet cadmium levels are above those safety levels we can most confidently conclude that cadmium is the agent that causes chronic kidney failure in NCP.
CKF and chena farmer
Although almost every Sri Lankan eats similar food, there are some variations between communities. For example, paddy farmers consume mostly rice while chena farmers at times substitute rice for yams such as manioc and sweet potato. The urban communities while having a more varied diet eat pulses with bread and wheat flour instead of rice. They also eat dhosa, noodles and other food items which are likely to be less toxic. Despite the differences in their diets, if the toxicity of the food items is similarly toxic or not toxic, we wouldn’t be able to explain diet as the cause of kidney failure. This is what some scientists have done. They did not even consider the toxic levels of food items, but simply compared the quantity and type of food, and declared, ‘there is no difference in the diets; hence diet is not the cause of kidney failure.’
The toxic levels of food items are different and depend on where they are grown. For example, a paddy farmer cultivating a highly toxic soil reaps highly toxic rice. This applies to chena fields or vegetable plots too. Root vegetables or yams such as manioc and sweet potato are the most toxic produce. Rural people, farmers consume more yams than urban people, often having yams for breakfast almost daily. The consumption of yams is high among chena farmers who grow them. This is why there is high incidence of kidney failure among chena farmers. This is not because of their occupation, but because of their diet.
This does not mean that occupational activity does not expose them to toxic agents; it is just that the most dominant factor by far is the diet, and there is enough cadmium in some food items to give one a critical dose.
Why cadmium, not others
Cadmium is a well-established element known to cause chronic kidney failure. Other fertiliser-related toxic elements such as arsenic and lead are not known to cause chronic kidney failure, but they are nonetheless harmful agents that cause other health problems. Through their harmful effects, they may even accelerate kidney failure. Those agents too must be avoided. Likewise weedicide and pesticide must be used with care, and thoughtfully. It is unlikely that any of these agents are completely harmless. However, none of the weedicide or pesticide products is known to cause kidney failure by itself or in combination with other agriculture related chemicals or elements. Much attention has been drawn to glyphosate, a weedicide constituent, but there is no proof of it as a kidney-failure-causing agent.
We must treat all agriculture related agents with much thought, and they must be of good quality. For example the fertiliser related heavy metals — arsenic, cadmium and lead — are impurities naturally found in phosphate fertiliser. They don’t serve any useful purpose. On the contrary, they could be dangerous and harmful to the health, indeed the very life.
Since farmers eat what they grow, those who have toxic fields or vegetable plots, produce toxic food, hence have a toxic diet and most likely persistently get a dose of cadmium sufficient to cause kidney failure. Others who have cleaner soils reap safer produce, hence escape being a victim. Non farmers buy their rice and vegetable in the market place or shops; hence end up having a diet whose toxicity lies between the two extremes because market place or shops get food produce from all parts of the country. Thus their diets would not cause kidney failure, or take a longer period for them to get affected.
Some paddy fields are more toxic than others
All the paddy fields that use fertiliser are likely to be toxic but of varying degrees. Those get irrigation water from hill country will have a higher soil toxic level, but the paddy field soil toxic levels will vary dependent on the proportion and volume of hill country water they receive. Although most of the CKF victims were initially and to a good extent even now are from near the water bodies, downside of Wewas, this demography will change over time as a result of those receiving a low or moderate toxic dose reaching a Critical Dose over a period time, and also due to the diminishing of potential victims as a result of already being a victim.
Chronic kidney faiure will emerge in other parts of the country also. That is because our paddy field soil fertiliser related toxic elements such as arsenic, cadmium and lead levels in Hambantota, a region not known to have kidney failure, is lower but not too dissimilar to NCP according to the GOSL/WHO report published in 2013. Hence our most urgent attention must be drawn to the soil quality everywhere in the country to avoid an island wide tragedy similar to NCP.
‘Forgive them for they did not know what they have done’
Much of what has happened in the NCP is a tragic consequence of well-meaning and well-intentioned action by many of us. No one could have foreseen this tragedy. Gamini Dissanayake’s dream and vision of harnessing the waters of the hill country to provide electricity literally to brighten the lives of many throughout the country, and to use electricity for a national industrial drive, his vision of self-sufficiency in rice and national food security, creating livelihood opportunities and uplifting lives of rural poor have all been achieved through Mahaweli. What a tragedy it is, the marvel of Mahaweli has become a conduit for the transportation of agricultural toxins from the hill country contributing to kidney failure in the NCP.
If Gamini Dissanayake were to be alive today, unlike the leaders who failed to admit to a problem and take appropriate action, he would have acted at the earliest indication of something not being right to remedy the ills.
It is not Mahaweli per se that caused this tragic issue to get out of control. It is the leaders, politicians and administrators who failed to recognise the problem, and some scientists who took a walk on the wild side ignoring the glaring facts. It is they who should carry the lions share of the responsibility. Those who mismanaged silting of Wewas and disposed of the silt in the most irresponsible manner, and failed to implement and guide people to avoid toxic exposure to silt compost; politicians, officials and some fertiliser dealers who may have breached the regulations and standards; those who attempted to deny the facts, or blame others; Officials who failed to promote interim but simple measures such as cooking rice in excess water and draining off the excess, and eating polished rice: all these people must examine their conscience.
In the words of Buddha, ‘Chethna han bikkawe kamman waddami’, (essence of the words are, it is the intention that matters). I doubt very much some of the above would qualify. Those who don’t please step aside, let those who wish to solve this issue do so without hindrance. Many, it appears were under duress. Now that those shackles are no more, please do what you always wanted to do, ‘do good’.
Chronic kidney failure can be stopped. It must be done in earnest.
(Dr Kamal Gammampila is a Biomedical Research Scientist at the National Institute for Health Research, Imperial College, London. He can be contacted at gamma120@yahoo.com)