Sunday, June 13, 2010

Happenings: Salt Tastes Better than Dichloropropene

Ventura strawberry farmers—or the people who represent them—delight in playing the role of victim. They lament the fact that Claritans fill water with chlorides and then send it downstream. There, hapless growers are forced to irrigate their strawberries with water too salty to abide. So while choride is common, natural, and essential to life, farm interests talk about it like it’s pretty sinister stuff[1].

“Increasing the salt content of water applied to crops is like slowly applying poison.”
-Ventura County Agricultural Water Quality Coalition, FAQ[2]

“In recent years, thanks to rapid growth in the population of the Santa Clarita Valley, the water released by those treatment plants has become laden with chlorides and other salts. The chloride levels have risen so high that they have begun poisoning some of Ventura County’s most important crops, including strawberries, avocados and nursery stock, all of which are particularly salt-sensitive.”
-Farm Bureau of Ventura County[3]

“It’s the obligation of the upstream dischargers to comply with (the standard) and protect their downstream neighbors from the consequences of their contamination.”
-John Krist, CEO of Farm Bureau, in an article in The Signal[4]

Instead of relatively benign salt, conventional strawberry farmers prefer bathing their fields with hundreds of tons of halogenated hydrocarbons, organophosphates, and other pesticides, herbicides, and fumigants. Many of these chemicals just aren’t found in nature and many aren’t very well-studied. We know they do wonders killing fungus and nematodes, but many are also suspected or confirmed toxins, carcinogens, or endocrine disruptors.
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At pesticideinfo.org , one can view how pesticides are applied by crop type, county, and year. You can easily produce a table like the one below, which documents pesticide use by Ventura County strawberry growers in 2008, the most recent year available:



Click on the table for the full list of pesticides used[5]. Note: “A PAN Bad Actor” is a chemical that the Pesticide Action Network has identified as being one or more of the following: carcinogen; reproductive or developmental toxin; neurotoxin; groundwater contaminant; or acutely toxic according to the World Health Organization

Chloropicrin, a devastating chemical weapon from World War I, is used as a fumigant for strawberry fields. It sterilizes the soil, killing organisms that might harm strawberry plants (it also kills many organisms that are harmless or beneficial). Over one-million pounds of chloropicrin were used on Ventura County strawberries in 2008, applied at about 122 pounds per acre. The good news is that chloropicrin decays within a few days of use. The bad news: its breakdown releases chlorides[6]. Chloropicrin is 65% chlorine by weight, and it releases chlorides within minutes or hours of being applied[7]. Thus, application of 1,011,790 pounds of chloropicrin adds over 650,000 pounds of chlorides to strawberry fields every year. I was unable to find a study documenting whether these chlorides might damage crops, but it seems well worth investigating.

Nearly 750,000 pounds of dichloropropene was also used in 2008. Strawberry farmers, eager as they seem to protect water quality, may be unaware that the California Pesticides Database lists dichloropropene as a “highly toxic groundwater contaminant”. Fields are treated with methyl bromide as well. Unfortunately, the chemical depletes the ozone layer, so it may be replaced with metyhyl iodide, which has made the news recently because it is profoundly toxic and carcinogenic[8]. In addition to all of these chemicals, literally tons of fenhexamid, thiram, malathion, boscalid, chlorpyrifos, and bifenazate are used in Ventura strawberry fields.

There is evidence that high levels of chlorides are bad for strawberries—a fact I’m not disputing. But where is the concern over chemicals far more toxic to humans than chloride? It is absolutely disgusting for agricultural interests to call chlorides “pollution” and “contamination” while they fill their fields and bathe their berries with chemicals far more deserving of those labels. While these pesticides don’t flow upstream, many are persistent in the environment and can affect us indirectly. There haven’t been comprehensive experiments to establish the levels of chlorides that harm strawberries, much less experiments that look at how spraying chemical pesticides, herbicides, fumigants, and fertilizers might affect chloride sensitivity.

The voice of Ventura County agriculture has driven the Regional Water Quality Control Board to set a low chloride tolerance. But if it were up to me, I’d rather have millions of pounds of salt added to water than millions of pounds of synthetic pesticides sprayed in the soil, leached into water, and filling the air. Perhaps having water too salty for strawberries wouldn't be so bad after all.
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[1]Of course, the amount of chloride is key; to quote Paracelsus, "Poison is in everything, and there is no thing without poison. Only the dose makes a thing not a poison."
[2] http://www.vcawqc.org/FAQs.html
[3]
http://www.farmbureauvc.com/water_quality.html
[4]
http://www.the-signal.com/section/36/article/29901/
[5]
http://www.pesticideinfo.org/DCo.jsp?cok=56&sk=1016
[6] http://extoxnet.orst.edu/pips/chloropi.htm

[7] http://www.ars.usda.gov/is/np/mba/july96/wilhel1.htm and http://pubs.acs.org/doi/abs/10.1021/bk-1997-0652.ch008

[8] http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2010/06/12/EDT11DTF3O.DTL

2 comments:

Anonymous said...

really?

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