Sunday Times 2
Chronic Kidney Disease: Food as the cause challenged
I am most grateful to the former professor of soil and water resources, Dr. C S Weeraratna for his response to my article of 1st February on North Central Region (NCR) identified as the Endemic region in the GOSL/WHO report.
What is most concerning about Dr. Weeraratna’s response are not so much the issues he raised, but the personality and the background of the individual. He clearly demonstrated that a highly learned individual in a subject that is most relevant to CKF seems completely misled and full of misconceptions. That being the case, what chance is there for ordinary people let alone the humble victim communities in the endemic region to understand and appreciate the intricacies of CKF? In fact everyone need not understand the complex issues, but those of us who are capable should do so rationally. But others should have a factual knowledge at appropriate level to prevent apportioning blame on the defenceless and ‘not guilty’ such as the farmers who were subjected to a media campaign to put the blame on them for soil pollution.
For the purpose of clarity, let me address the issues in the most relevant order as I consider, while suggesting that he and others read my article, and the GOSL/WHO report again, perhaps a several times.
1. There are 400,000 CKF patients in NCR presently. GOSL/WHO report claimed about 13 percent of a population of about two million to have chronic kidney failure of varying degree two years ago. There are 5 stages of CKF. Dr Weeraratna refers only to the end-stage patients – that will be the ones requiring dialysis or a transplant. GOSL/WHO method of reporting was absolutely correct, and so am I in my claims.
2. In the GOSL/WHO report Reference Level for cadmium in rice was given as 0.2 mg/kg (point 2 milligrams per kilogram). The relevant publication was the Joint FAO/WHO Food Standards Programme, Codex Alimentarius Commission: Report of the 33rd Session of the Codex Committee of Food Additives and Contaminants, 2001.
This study was meant for North America and the South-West Pacific region. It had relevance to Europe too. That is, to countries that had a ‘Western’ diet at that time. That was 15 years ago. Things have changed by leaps and bounds even in those countries now. Their reference levels are entirely different today. Even in those countries ‘Reference Levels’ are not the final arbiter or the determinant for food safety. It is the Ingestible Doses that matter for food related safety. As I mentioned Ingestible Doses are calculated on the basis of all the food items including water one consumes, their individual toxic level and amount.
Even 15 years ago, they gave higher value for rice but a lower value at 0.05 mg/kg for non-leafy vegetables. That was because those populations consumed much more vegetables than rice.
These values have no bearing on our diet whatsoever. For example, current rice consumption rate in UK is 90 grams per week, whereas the figure for Sri Lanka is 2110 grams per week. If we were to have Reference Level of 0.2 mg/kg, exposure period required for CKF will be much less than the current 15-20 years.
How I wish, GOSL/WHO report never gave that figure. This has even misled highly intelligent individuals such as Dr Weeraratna.
Unfortunately, the Presidential Task Force members, because they too seemingly didn’t appreciate these crucial facts, or for other reasons, without focusing on the GOSL/WHO pointer to cadmium as the reason for CKF, went on Wild-Goose-Chases, looking for mysterious agents, and most unlikely pathways to account for the amount in the body. Ignoring the most obvious route, the mouth, they ventured to look for routes such as the skin to explain for CKDu!
3. As you vouch for the claims of others that water is the source of kidney failure, could you please get those toxicologist and pharmacologist to explain, why it is that there is more cadmium in the urine of patients and the general population in the endemic region than what they intake through drinking and cooking water?
4. Rice toxic levels in the GOSL/WHO study are: 0.033 average, 0.018 median, 0.006 minimum and 0.15 mg/kg maximum. The critical limit given by European Union and the WHO is 2.52 micrograms per kilogram body weight per week. Therefore based on a national average of 2110 g of rice per week, those eating rice with average cadmium level at 0.033 will get a dose of 1.08 which is safe. In general that would be urban dwellers anywhere in the country. But those who are consuming rice at the highest toxic level will get a dose of 4.9 which is far in excess of the Reference level. Unfortunately that would be the famers with highly toxic paddy fields.
5. Currently the CKF is almost limited to NCR, but it will emerge in other regions within the next 5 years or so escalating to NCR levels in about 10 years.
6. I would be most grateful to Dr Weeraratna if he would tell us as a soil and water resource scientist, whether growing native rice as the previous government claimed in 100,000 acres with soil toxicity as given in the GOSL/WHO report, would make any difference to the rice toxic levels?
It is emotionally uncomfortable to admit that our food in particular rice might be toxic. Unfortunately it is a fact. It is not all our rice or vegetables are highly toxic, some more than others dependent on growing conditions. We need to identify those fields and conditions, then act accordingly.
We must snap out of the ‘state of denial’, then address the issues rationally as soon as possible.