A Deathless Dead End

Written by GTstaff

Monday, 17 December 2007

The host of issues surrounding Light Brown Apple Moth (LBAM) spraying—the dubiously declared emergency; the seeming lack of response to the community’s “over our dead body” decree; the governmental expense for both the state to implement the spraying and the local bodies to fight it; and the potential health hazards—all will require vigilance and community participation as this issue moves forward, particularly since, like a certain war we prefer not to dwell upon, there’s no stated end date in sight. The Ticker does not mean to diffuse the impetus for that. On the contrary: it’s important to not let the debate become clouded by overhyped or misinterpreted information. In that spirit, it’s worth noting that at least one avenue for protest—CheckMate’s purported negative health effects—still lacks substantial evidence.

A laboratory test conducted at UC Davis in October and November showed no ill health effects upon two common species of aquatic life. Using standard EPA methodology, the research team under the supervision of Dr. Inge Werner infused water with CheckMate microcapsules to see the pheromone’s effect upon freshwater fish larvae (fathead minnows, Pimephales promelas) and waterfleas (Ceriodaphnia dubia). According to the study’s report, published Nov. 28, “The ratio of microcapsule to water volume in the laboratory exposure is greater than would be expected if this product was applied directly to a surface water body.” Still, the results were of interest, since spraying patterns avoided riparian corridors and watersheds in Santa Cruz by only a few city blocks.

The study concludes that “no effects were observed for either test organism using conservative assumptions regarding dosing. Concentrations that were selected for the formulated product and the active ingredient were well above any level that would be expected based on the legal use of CheckMate LBAM-F.” (Anti-spraying groups have latched onto a column in one table that seemingly shows a 100 percent mortality rate, but the report states that a calculation error led to an exposure concentration 10,000 times higher than intended for that sample. Even scientists get to say ‘oops’ sometimes.) The negative conclusion is hardly a ringing endorsement for the safety of CheckMate, given the difference between highly controlled lab environs—the water used in the experiment was Sierra Springs—and real world ecosystems; however, the study also lends no particular help to those who assert that Checkmate is an environmental health hazard.

Activists have seized upon one detail in the report, stating that CheckMate microcapsules measure anywhere from 10 to 190 microns. A writer on Santa Cruz Indymedia links this size to a study by the American Lung Association (ALA) on particulate matter pollution, which causes damage by lodging deep within lung bronchioles. However, the maximum size considered by the ALA to be dangerous is 10 microns, coincidentally the bottom range of CheckMate capsules measured by UC Davis. Statistically speaking, the risk posed by CheckMate LBAM-F capsules at the extreme small end of the spectrum is insignificant compared to the existing particulate matter—dust, soot, ash—that naturally pervades the air.

The Ticker intends to stay abreast of any future developments or studies relating to the pheromone spray. A citizens group called the California Alliance to Stop the Spray (CASS) formed earlier this month, and is hoping to keep pressure on the government. You can visit the online resource at lbamspray.com. Another resource covering the wider region is at stopthespray.org .