By Dr.C. S. Weeraratna
Former Professor of Soils and Water Resources, Rajarata University
Since the year 2000, Chronic Kidney Disease of unknown etiology (CKDU) also called Chronic Renal Failure (CRF) has been reported in several areas of Sri Lanka, mostly in the North Central Province (NCP). A large number from the Badulla and Kurunegala districts are also affected by CKDU.
Ministry of Health (MOH) initiated a research study in Oct. 2008 on CKDU to be carried out in collaboration with WHO- Colombo. The study was conducted by the National Research Programme for CKDU, to find the causal factor of CKDU and other related issues. The major finding of this study according to some news paper reports is that exposure to a combination of factors that are toxic to the kidney seems to cause this disease, and toxic factors identified up to now include arsenic, cadmium and nephrotoxic agrochemicals. However, according to the third report the study did not find high levels of cadmium exposure as reported in the previous study. The second report of the study released by WHO in October 2011 recommends that urgent action needs to be taken to implement a multisectoral strategic plan jointly with relevant ministries with short, medium and long term measures as early as possible in 2012 to minimize the growing public health risks to the population.
A seminar on CKDU, organized by the Ministry of Water Supply and Drainage was held in Anuradhapura where a report of the study on CKDU, conducted by Centre for Science and Environment (CSE) in India and Centre for Environmental Justice, Sri Lanka (CEJ) was presented by Chandra Bhushan of CSE and Hemantha Withanage of CEJ. The results of this study indicate that water samples collected from North Central Region are not contaminated with heavy metals and arsenic; nor are there any other heavy metals.
Only fluoride levels detected in the water samples were between 0.5 and 1.7 mg/l, a little above twice the desirable levels set by Sri Lanka standards. As the desirable limit for fluoride is 0.6 mg/L in Sri Lanka and levels detected in the present study are higher, fluoride at these levels over a long period of time is a possible risk factor responsible for kidney diseases.
Arsenic in Fertilizers and Pesticides:
Some are of the view that fertilizers and pesticides are the sources of arsenic, and hence, importation and use of such agrochemicals should be banned. However, before it is implemented it is necessary that that the fertilizers and pesticides which are supposed to contain arsenic are identified by appropriate tests. If the source of arsenic is fertilizers and/ or pesticides, then water in other districts such as Kandy, Nuwara Eliya , Hambantota etc. where large amounts of fertilizers and pesticides are used should also have high contents of these heavy metals, and the people in those areas should also be affected by CKDU.
Fertilizer and pesticides are not the only sources of arsenic and other heavy metals. Some organic fertilizers such as compost may also contain these heavy metals if solid waste has been used in its manufacture.
Fertilizers and Pesticides
Authors of some articles appear to be of the opinion that we need not use chemical fertilizers (Fs) and pesticides (Ps), because in the past these were not used in crop production. Use of these Fs and Ps cause environmental pollution and tend to increase cost of production. All Pesticides are toxic compounds. Toxicity is indicated by what is called LD 50 values. Those of low LD 50 values are more toxic than others. Insecticides and mosquito coils which we use to control household pests such as cockroaches also contain toxic compounds but their LD values are very high. Although Fs and Ps were not used a few decades ago, the biotic environment including the level of the fertility of the soil is not the same as was in the past. There may be a few plots cultivated without Fs and Ps using modified/different and traditional methods. If they are effective, the researchers of the Dep. of Agriculture need to make recommendations based on their findings. It is also necessary that Integrated Pest Management (IPM) methods are developed and applied so that we could give up the use of synthetic toxic chemicals to control pests.
A large number of people in the North Central Province are affected by CKDU. In order to take necessary remedial measures, the scientists are conducting studies on different aspects of CKDU. While such studies are carried out, it is extremely important that action is taken to reduce the prevalence of this lethal renal disease which is causing untold hardships to the thousands of poor people in the dry zone.There is a need for a comprehensive public health effort to effectively address the problem of CKDU. This should be taken as a National Priority with the main responsibility resting on the Ministry of Health.
From the observations and results of various studies carried out so far it could be assumed that CKDU is caused by a toxic element/s or compounds in water.
Hence, methods of detoxifying water needs to be developed. A filter has been developed by the Water Supply and Drainage Board to remove fluoride from water. Institute of Fundamental studies has developed an electro-chemical method of removing fluoride from water. The suitability of these methods needs to be tested by an appropriate authority. One way of reducing the incidence of CKDU is implementing a programme to supply good quality water to those in the affected areas.
Rainwater is the most pure form of water. It is almost free of toxic elements/compounds. A considerable portion of the rainwater that falls on the roofs of buildings can be collected in tanks in the premises itself. Water thus collected would be free of toxic substances and could be used for numerous domestic purposes including drinking.