Medical researchers are still confounded by chronic kidney disease, the ailment that seems to affect disproportionally sugarcane workers in Central America.
Many theories have been advanced, but the latest from a professor in Colorado, is that climate change is a factor.
The professor is Richard J. Johnson of the University of Colorado Anschutz Medical Campus. He has been studying the malady for years. In a television interview reported by the university, Johnson attributed an increase of a half a degree in the average temperature in the lowlands of El Salvador since 1980 as a contributing factor to the disease.
He said that 20,000 persons may have died from kidney problems.
Costa Rica’s Guanacaste province is one place where the kidney ailment is epidemic. The problem is found all along the Pacific coast lowlands into southern México.
The disease seems to target young men who work in the sugarcane fields. One study said the ratio of men with the disease to women was three to one.
A survey of the disease said that two consistent results have emerged: First, there are clear differences in risks of chronic kidney disease according to type of industry and occupation. Workers in the sugarcane cultivation, mining, and fishing or shipping industries have higher prevalence rates, whereas areas in which coffee growing and services dominate show no evidence of excess disease. Second, persons living at low altitudes are more likely to have chronic kidney diesase than those living at higher elevations.
A July study said that the mortality rate in Guanacaste among men increased from 4.4 to 38.5 per 100,000 since 1970. That is much higher than the rate for the rest of Costa Rica, which is 2.6 to 8.4 per 100,000.
Yet another study said that researchers examined workers in seven sugar cane
industry job categories: cane cutter, seeder, seed cutter, agrichemical applicator, irrigator, driver, and factory worker.
Of these, cane cutters had the greater risk of kidney injury during the harvest, according to the researchers.
Johnson, in his report, said that as the temperature increases, as it is expected to do, more workers will experience kidney problems.
The prevalence of the disease is measured by urine and blood samples that can check the efficiency of the kidneys.
The most prominent theory so far is that dehydration and the physical strain of hard work in hot weather results in stress on the kidneys. Hence, the concern voiced by Johnson.
There also has been a suggestion that heavy metals, pesticides and cheap alcohol are contributors. But recent research seems to rule out these factors.
Other researchers have said that sugarcane workers who do their job at higher elevations do not experience high rates of kidney problems.
The same research said that subsistence farmers who grow crops at low elevations also do not appear to have the kidney problems.
Some researchers even have suggested genetic predispostions to the disease.
The same problems are showing up in Sri Lanka, India and Egypt.
The topic has been studied heavily. An online research site that lists academic articles reported this month that some 44 major reports are available.
Still other researchers are urging that more attention be shown to heat stress.
Some sugarcane producers already are giving their workers lectures, providing shade for rest periods and also giving sugarcane cutters fluids to drink while on the job.