Thousands of people in the Asian island nation of Sri Lanka have been struck by a mysterious and deadly form of kidney disease.
A new study points to a likely cause: pesticides and fertilizers.
Tucked away in Sri Lanka’s North Central Province is the village of Halmillawetiya. A pebbled path connects small houses of brick and mud set among coconut palms and other tropical trees.
Sampath Kumarasinghe, 21, lives here with his widowed mother and extended family.
As Kumarasinghe sits on his porch, his mother, P. Dingirimenike, sits close by, talking and cutting areca nuts, which people chew like tobacco. The sounds of a radio waft from the house.
Kumarasinghe tells visitors he’s doing fine.
But you can tell he isn’t fine.
Despite the brutal heat, he’s wearing a wool hat. He speaks softly, and his movements are slow for someone his age.
Like most people here, Kumarasinghe is a rice farmer, but recently he hasn’t had the strength to work on his farm.
Kumarasinghe’s kidneys are failing. They are no longer filtering waste from his bloodstream.
“My body is weak,” he said.
He is being kept alive by dialysis, a procedure he receives twice a week at a regional hospital. He is hoping to get a kidney transplant.
A Disease of “Unknown Etiology”
Kumarasinghe is one of thousands of people in the North Central Province suffering from chronic kidney disease. According to the Sri Lankan Ministry of Health, 15 percent of the population here is affected.
The public hospital in the provincial capital of Anuradhapura treats at least 2,000 chronic kidney disease patients every month.
No one knows the exact death toll, but health officials say that in Anuradhapura district alone, about 150 people die from the disease every year.
The disease first came to the attention of physicians at the hospital about 20 years ago, says Dr. Rajeewa Dassanayake, the hospital’s kidney specialist.
“They started noticing that there (were) a number of deaths due to kidney disease,” he said. “And the physicians at the time noticed that this was not happening in the rest of the country.”
Dassanayake says these patients didn’t fit the typical profile. They didn’t have diabetes or high blood pressure, the common causes of chronic kidney disease worldwide.
To distinguish this illness from the more common form of chronic kidney disease, the Sri Lankan government labeled it CKDu — chronic kidney disease of unknown etiology (i.e. of unknown cause).
“Unfortunately, for CKDu, there’s still no specific treatment,” Dassanayake said.
And there has been no known way to prevent it.
The Search for Answers
Four years ago, the World Health Organization (WHO) and the government of Sri Lanka launched a joint investigation into the causes of the disease.
Scientists looked for clues by testing people and the environment. They took blood, urine and tissue samples. They tested the region’s food, water and air.
The results of those analyses were released this summer, in a one-page press release.
The culprits appeared to be two toxic metals, cadmium and arsenic, which previous studies suggest can harm the kidney.
Palitha Mahipala, an official with the Sri Lankan Ministry of Health, says that people in the North Central Province showed relatively high levels of the metals in their blood and urine.
Although the levels were generally within what is considered the safe range, Mahipala says that continuous exposure to those levels may have damaged kidneys.
“Probably the chronic exposure would have been the reason for this,” he said.
But if arsenic and cadmium are to blame, where are they coming from?
The new study blames farm chemicals, which may be slowly poisoning the population by contaminating food and air.
Cadmium is found in some fertilizers. Arsenic is an active ingredient in some pesticides, although it is illegal to use arsenic-based pesticides in Sri Lanka.
Farm chemicals are so cheap here, thanks to government subsidies, that farmers tend to put far too much on their fields, thereby increasing the amounts of contaminants in the environment.
Companies that import and sell pesticides and herbicides contest the government’s conclusion. They point out that the government and WHO have not yet released their full study.
“We believe the evidence is not scientific enough to say that the pesticide is the main reason for this chronic kidney disease,” said Senarath Kiriwaththuduwage, research and development manager at Crop Life Sri Lanka, an industry trade association. “These findings are not published in reputed scientific journals.”
Some doctors and scientists familiar with the study agree that more research needs to be done, but many believe that farm chemicals are at least partly to blame for CKDu
