It would be pretty hard to avoid the news about sugar: it's bad for us. Diets high in sugar contribute mightily to the nation's burgeoning problems of obesity and diabetes and may even be a factor in dementia. But sugar in its crop form is also proving to be deadly. The cause and effect, however, is as murky as a cloudy day in the rainforest.
Will Shorr has written a remarkable, hands-on article in the Guardian, examining the high rates of chronic kidney disease (CKD) among the workers who grow and harvest sugar cane in Central America. CKD is the second leading killer of men in El Salvador.
Why are sugar cane workers succumbing to kidney disease? Is it the working conditions? Is it the pesticides? Is it the diet of the workers? Fingers are pointing in a number of directions, and by the time the truth is sorted out, we may well find a toxic trail that includes of all three factors.
Nicaragua Sugar Estates, one of Central America's largest plantations, has conducted its own internal studies, one of which identified one potential factor in the disease: "strenuous labour with exposure to high environmental temperatures without an adequate hydration program." .Nonetheless, a company spokesman denies the connection: "We're convinced that we have nothing to do with kidney disease. Our productive practices do not generate and are not causal factors for CKD."
But researchers in the US have connected CKD to heat stress and dehydration. A standard day for an El Salvadorian sugar worker lasts between four and five hours, with double shifts during the summer planting season, when temperatures top out at 104 degrees.
Shorr quotes Héctor García, a 33 year old with stage-two kidney failure: "It's very hot; we suffer. People sometimes collapse. More often they vomit, especially when the heat is worse. They do two shifts to earn more money." Another worker, 40 years old and close to death with stage five CKD, reported the same symptoms, compounded by the limited resources in his home: "When I come home, I feel surrendered. Sick. Headache. I can't shower because the water [from the roof-mounted tank] is too hot." The image of the hand-rigged shower, full of very hot water, epitomizes the wretched living conditions of the workers.
Compounding the problem, most CKD sufferers do not even know they are ill: the disease is asymptomatic until its last, most deadly stages. Even when they feel unwell, many workers go into denial - they feel helpless, as they cannot afford the medication or the recommended diet of fresh vegetables and chicken breast. Dialysis - the last hope of the ill - is often avoided, because most of the workers who go on it end up dead anyway, so it appears to their co-workers that dialysis causes the death.
Researchers have found rates of CKD in cane cutters and seed cutters - the most strenuous jobs - to be higher than in pesticide applicators, who have greater exposure to agrochemicals. This seems to indicate that the pesticides are not a significant factor. But this conclusion may be premature.
Five chemicals are used in the cultivation of sugar cane: amine, terbutryn, pendimethalin, 2,4-D and atrazine. Shorr sent the chemical recipe for the yellow potion he observed being sprayed on the crops to Professor Andrew Watterson of the University of Stirling - an authority on agrochemicals and health. They were all herbicides, he noted. Watterson came up with a litany of potential problems:
Atrazine can cause kidney damage at high levels; acute exposure to 2.4-D can cause chronic kidney damage; pendimethalin is "harmful through skin contact and inhalation"; in lab tests, long-term feeding of terbutryn to rats caused kidney damage. None of them are acutely toxic, but this combination, plus the tropical climate, could worsen their effects.
On the prevention side, sprayers are supposed to avoid contact with skin; to wear face shields, respiratory protection, rubber boots and specialist coveralls. We can only surmise that such protective equipment, while technically useful, would be difficult to use in 100 degree weather. On the other hand, assuming the sprayers are protected, other workers do not wear protection and may thus experience greater exposures to the chemicals.
Sugar in the Diet?
Shorr concludes his article with a shocking new study that points in yet another direction. Richard Johnson, of the University of Colorado's Division of Renal Diseases and Hypertension, thinks the problem might have its genesis in a mechanism that his team discovered in rats. Johnson speculates that if dehydrated workers with already sugary kidneys are rehydrating with soft drinks or fruit juice, they may experience a potentially explosive fructose load. He adds that "it's not proven, so we don't want to get ahead of the gun here [rather unfortunate metaphor]." The research has not as-yet been published. But Johnson goes on to say that the experimental data is quite compelling, and it "could explain what's going on."
It would truly be ironic if the cane field workers were dying from kidney failure in part because they use sugary soft drinks to rehydrate. "Buy the world a Coke" indeed!
While it is too early to draw definitive conclusions, the Guardian article identifies at least three converging factors in the high CKD rates among field workers: extremely high heat compounded by hydration problems; a mix of potentially harmful pesticides; and an unhealthy diet too full of sweetened beverages. Add the impoverished living conditions of the workers - and marginal medical care - and you have all the makings of an abbreviated lifespan.
The US gets 23% of the its raw sugar from Central America; the European Union spends more than €4.7m on this import. Sugar is El Salvador's second-biggest export. This is big business. With so much money at stake, the dying workers are little more than collateral damage. It appears that what they really need is an ample supply of clear, cool water, but such a simple remedy, alas, is nowhere in sight.