Map of life expectancy at birth from Global Education Project.

Tuesday, February 23, 2010

There's got to be a better way

As long-time readers know, I'm definitely concerned about loss of topsoil and agricultural runoff but I'm uncomfortable with no-till agriculture because it requires heavy use of herbicides. We're often told that herbicides in common use in the U.S. are safe but new information about one of the most widely used, atrazine, is disturbing. U.S. farmers use 34 million kilograms of the stuff every year.

It's been considered safe but it turns out that the studies on which that conclusion has been based are, you guessed it, largely funded by the pesticide industry and even conducted by scientists employed by the industry. Atrazine is found in drinking water in the U.S. It is now emerging that it is an endocrine disruptor that affects the sexual development of amphibians, fish and mammals.

Robust data suggestive of hormonal effects, including partial gender reassignment, come from amphibians and fish. And a review in the January Environmental Health Perspectives by Jason Rohr and Krista McCoy of the University of South Florida in Tampa includes more than a dozen papers out since atrazine’s last regulatory review. The EHP review highlights a long list of reproductive and developmental impacts in these animals. . . .

Previous EPA analyses of atrazine safety had access to four earlier reviews of animal data, Rohr notes — all funded at least in part by industry. He maintains that his is the first review that is free of industry involvement. Funding for his assessment came from the EPA, the National Science Foundation and the U.S. Department of Agriculture.

There are suggestions from epidemiological studies that atrazine may be causing birth defects in humans. We could ban atrazine -- I'm not holding my breath -- but I don't have a great deal of confidence in alternatives either. Glyphosate (Roundup©), one of the most widely used, is sold by Monsanto in conjunction with genetically modified seeds that are resistant. It's considered very safe but as usual, industry funding is largely behind that belief. It's often used with a surfactant which is toxic to fish and amphibian larvae. Since the surfactant is not considered an "active ingredient," it is unregulated. There is a great deal of evidence of toxicity of Roundup in mammals, including humans, but again, it may be the formulation, not the glyphosate per se, that does the damage. It doesn't matter, it's Roundup, not pure glyphosate, that's being sprayed all over the earth. (The Wikipedia article is as good a source as any on all this. We've known it forever -- I wrote a report that contained all this information when I was in graduate school in environmental policy in the 1980s.)

All this strikes me as nuts. I am going to continue to control weeds by tilling and mulching. Unfortunately, for large scale agriculture, that's very difficult and right now, we can't feed the world without resorting to these unpleasant alternatives.


roger said...

somebody's working on that herbicide drawback to no till farming on a large scale.

"...we can't feed the world without resorting to these unpleasant alternatives." now there's a choice for sophie occam: you can starve, or you can eat this poisonous food, the production of which is killing the planet.

we have dug a big hole.

Cervantes said...

It's great that they're working on it but it looks like their progress stalled out in 2008; there still doesn't seem to be any proof of concept or commercially available equipment. We'll see what happens.

Tilling can be greatly improved by contour plowing, use of cover crops and silt fences, mulching, and other measures to keep the topsoil in place.