The Silent Killers? Invisible Poisons? Risk or Reality?
"The EPA registration of pesticide products containing the active ingredients chlorpyrifos, diazinon, and malathion...is likely to jeopardize the continued existence of 27 listed Pacific salmonids... We further conclude that the proposed action is likely to destroy or adversely modify critical habitat for 25 of 26 listed Pacific salmonids" National Marine Fisheries Service, 2008.

SPAWN is opposed to the use of any harmful chemicals near our sensitive creeks, especially pesticides, and will continue to educate the public of their perils and advocate to cease their use and production.

As watershed stewards we must all take steps to eliminate use of toxic chemicals, and dispose of the ones we posses in a responsible way. Marin residents can call 485-6806 to dispose of household pesticides.

Take action and make a difference for the future coho!
Step 1. Stop using chemical quick fixes to control pests. Step 2. Switch to non-toxic alternatives. Boric acid, white vinegar, and baking soda can be applied to control bugs, fight grime, and clean stains, respectively. More info at web sites below! Step 3. Spread the word! Why wait for 2025 for Marin to be pesticide free? Your voice and purchasing power will shape our local environment, so use them to promote a pesticide-free future for all our watersheds!

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Many recent instances highlight the dangers of pesticide use in the environment, from the near-extinction of brown pelicans and bald eagles in the 1970's, the aerial spraying proposed in Marin to control light brown apple moth, the continued use of herbicides on open space trails and golf courses, and the current collapse of wild salmon populations in California. Many harmful chemicals exist in our homes and workplaces, many are commonly sold at local stores.

Specifically, common chlorine bleach, the chemical diazonin of the organophosphate class of pesticides, and the chemical bifenthrin of the pyrethroid class are present in most households. Many normal chemicals like ammonia become very toxic when combined with chlorine bleach, and can disrupt or pass through septic system treatment. Diazinon is detected at levels in streams that decimate freshwater insect populations and disrupt salmon migration. It is used abundantly by farmers but was banned in stores and may still exist in the deep recesses of many garages. Pyrethroid pesticides were the residential replacement, but are very toxic to all fish and aquatic life, yet are still sold over the counter at local stores throughout Marin and California. When fish are exposed to both, the toxic effects are synergistic, meaning they are more toxic in combination than the sum of their individual effects!

If pesticide use resulted in dead fish floating down our creeks, I believe Marin citizens would halt their use immediately. Instead they are known to disrupt salmon migration, embryo development, and fry growth in ways that are difficult for environmental toxicologists like myself to measure in the field.

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PESTICIDE COMBINATIONS PRODUCE SYNERGISTIC TOXICITY FOR COHO SALMON: A new study finds that pesticides that drain into California and Northwest waterways from agricultural land may be deadlier in combination than individually. NOAA's Northwest Fisheries Science Center and researchers from Washington State University released a study in the March issue of the journalEnvironmental Health Perspectives detailing the effect. The study demonstrates that chemical exposure is "synergistic" rather than additive, meaning that when salmon were exposed to combinations of pesticides, the effects were more lethal than could be anticipated from simply adding the effects of the separate chemicals together. In other words, this kind of "pesticide cocktail" was shown to be more harmful than the sum of its parts.

"The researchers evaluated the effects of diazinon, malathion, chlorpyrifos, carbaryl, and carbofuran--which are among the most extensively used pesticides in California and the Pacific Northwest--in the brains of juvenile coho salmon," according to the study summary. They looked at how the chemicals inhibited an essential brain enzyme in salmon. In various tests of different levels of concentration and different combinations, the chemicals were shown to produce stronger effects than predicted when paired with other chemicals. The NOAA website reports that, in the study, "no salmon died when exposed to an individual pesticide, yet many died outright when exposed to combinations." The fact that these chemicals are so commonly found in the rivers and streams that provide critical salmon habitat is of great concern to the researchers. The NOAA website reports that "Mixtures of pesticides in fish habitats may pose a more important challenge to recovery efforts than previously anticipated, as testing individual pesticides to determine "safe" exposure levels may not capture the true risk to salmon."

To read the study's abstract,Click Here
To see a summary of the study on the Environmental Health Perspectives website, Click Here
For NOAA's announcement of the study, Click Here