Pick Your Poison
State figures on pesticide use show increasing reliance on methyl bromide alternatives.
Thursday, January 5, 2012
It was a good year for strawberries in Monterey County, and also for the pesticides that make them a nearly $1 billion crop. The quantity of pesticides applied locally to all crops rose to nearly 9 million pounds, a 12-percent increase from 2009 to 2010, according to figures released last week by the California Department of Pesticide Regulation.
After four consecutive years of declining pesticide use statewide, the rise doesn’t necessarily indicate a new trend, according to the DPR. Variable weather conditions and crop rotation cycles influence which chemicals, and how much, are applied. But while an increased use of the fungicide sulfur (which is also approved for organic farms) on wine grapes reflects an unusually cool, wet year, the DPR data also shows a noteworthy shift in less weather-dependent practices.
A 37-percent increase in the state and an 81-percent increase in Monterey County of the fumigant 1,3-dichloropropene – a near tripling in local applications – show a growing reliance on alternatives to methyl bromide, which is being phased out pursuant to an international ozone protection treaty. About three quarters of 1,3-D was applied to strawberries, followed by carrots and wine grapes.
“As availability declines, you’re going to see its use decline, and you’ll see a commensurate increase in other fumigants,” says Monterey County Agricultural Commissioner Eric Lauritzen.
The volume of methyl bromide used in the county declined by 15 percent from 2009 to 2010.
“On a statewide basis, growers are replacing methyl bromide with 1,3-D and chloropicrin,” DPR spokesperson Lea Brooks writes by email.
Chloropicrin is often applied in a blend with other fumigants, and is responsible for many of the acute symptoms, like watery eyes and itchy throats, associated with fumigant exposure. Lauritzen notes that while use has been trending upward, there were no reported incidents of faulty applications this year.
But anti-pesticide activists, including plaintiffs in a lawsuit opposing DPR’s 2010 registration of the fumigant methyl iodide, see 1,3-D and chloropicrin as less-than-ideal substitutes. They allege DPR and manufacturer Arysta LifeScience failed to adequately consider alternatives, including non-fumigant farming methods.
“A rise in the use of any fumigant is going in the wrong direction,” says Anne Katten, a work health safety specialist with Sacramento-based California Rural Legal Assistance Foundation. “We’re very much concerned that all of these fumigants are highly toxic.”
Based on its classification as a toxic air contaminant by the California Air Resources Board, 1,3-D has an additional limitation on how much can be applied per season. It’s also listed as a carcinogen under Proposition 65, the state Safe Drinking Water and Toxic Enforcement Act.
From 2001 to 2004 – the years methyl bromide faced a 70-percent reduction – 1,3-D use more than doubled in volume. It’s held relatively steady since.
Michael Marsh, directing attorney at CRLA’s Salinas outpost, thinks 1,3-D and chloropicrin would garner the same type of scrutiny methyl iodide has received if they were up for registration today. “They’ve been grandfathered in,” he says. “They’re outdated, they’re dangerous, they have not had a modern review of the associated dangers.”
Alameda County Superior Court Judge Frank Roesch will consider the merits of DPR’s scientific review of methyl iodide at a Jan. 12 hearing in Oakland.