Scientists warn of time bomb


By Cyril Wimalasurendre

An algal bloom in the Southern‚ÄąProvince (File Photo)

KANDY – Former Director General of Agriculture Dr. Sarath Amarasiri addressing a seminar on "Alleged toxic Elements and their inference on the Kidney disease in Sri Lanka" claimed that many reservoirs in the North Central Province had very high levels of phosphorous which could cause algal blooms.

The seminar attended by scientists and administrators was held at the Department of Agriculture recently.

Dr. Amarasiri said that according to the National Water Supply and Drainage Board (NWSDB) Nachchaduwa Wewa, Tissawewa, Nuwara Wewa, Kala Wewa, Parakrama Samudra, Minneriya Wewa were among the major reservoirs that contain high levels of phosphorus.

The Department of Agriculture had analysed the water in some of these reservoirs in 1965 but at that time there was no phosphate pollution in them.

Dr. Amarasiri said that it would appear that excessive fertiliser application on the vegetable farms of the up-country was probably a cause of the problem.

The excessive phosphate through erosion and runoff entered the streams feeding the Mahaweli River which fed many of the reservoirs, he said.

The vegetable growers in Nuwara Eliya and Bandarawela areas added five to ten times the Department Agriculture (DOA) recommended fertiliser quantities. Soil analysis by the Department of Agriculture (DOA) had revealed that over 70 percent of those farms had excess phosphate in the soil and any further addition of phosphate would not increase crop yields, the former DG Agriculture said.

Such addition was not only wasteful but harmful to the environment. Furthermore the soil in over 50 percent of the farms exceeded the so-called environmental critical value of 60 ppm phosphorus, beyond which the element was easily lost to lakes and reservoirs. In some farms the soil phosphorus value was over 400 ppm, he said.

Prof. Ananda Kulasooriya of the Institute of Fundamental Studies (IFS) pointed out that the IFS had carried out a survey of algal growth in 61 reservoirs and that many of the algae identified had the capability of secreting toxins which were highly poisonous to humans.

Prof. Dhammika Menike of the Faculty of medicine, University of Peradeniya claimed that some of those toxins could damage the livers and kidneys of humans.

It was also observed at the seminar that Cadmium (Cd) was a usual contaminant in phosphate fertiliser and Cd had been noticed in the Rajarata Kidney disease (CKDU) in that the affected patients had significantly more Cd in the urine than that of unaffected people in the same area. That was according to the findings in the WHO report on CKDU that was published some time back, scientists said.

The general consensus among the participants of the seminar was that the government must act swiftly to avoid a further catastrophe in the North Central Province.

The politicians and the public should be educated on the matter. Immediate action should be taken to educate the workers and the upcountry farmers on judicious use of fertiliser, scientists said.

Action must also taken to ensure that fertiliser was applied on the basis of soil analytical data and requisite legislation and regulations should be established in that regard, they said.

It was pointed out that fertiliser companies had suspended the sale of individual fertilisers such as urea, muriate of potash and superphosphate and sold only mixtures.

That compelled farmers to add phosphate even though the soil was already replete with phosphorus worsening the current pollution problems, the scientists said, stressing that government should step in to avert a disaster.

Dr. Parakrama Vaidynatha also contributed to the seminar in his capacity as an organiser.

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