The use of home and garden pesticides in Eastsound increases the contamination of local clams above federal food safety standards, according to a study recently released by Kwiáht director Russel Barsh.

Barsh released the findings after the showing Hedrick Smith’s documentary “Poisoned Waters” at Orcas Center, and Barsh said it got the audience’s attention.

Kwiáht researchers tested 99 uncultivated clams dug from Fishing Bay, Crescent Beach, Buck Bay and White Beach for locally sold pesticides and for PCBs. All of the clams bore traces of these contaminants, but the clams from Fishing Bay were as much as ten times more contaminated with pesticides.

Pyrethroids (synthetic derivatives of pyrethrins) are the active ingredients in most of the pesticides sold for home or garden use in San Juan County. These compounds are much more toxic to insects than to people, but they can accumulate in marine animals and fish to levels that pose a threat to food safety.

The researchers recommend that the outdoor use of pesticides in Eastsound be reduced through consumer education and by taking the most toxic and persistent products off local store shelves.

“Our rankings of locally sold products are available from stores, and from our education partner, the San Juan Nature Institute,” Barsh said.

Local high school and university students participated in the study as laboratory assistants, including Eliana Blaine of Orcas, Jen Reeve of Lopez, and Claire Daniel of San Juan Island. They are co-authors of the report that released, with Barsh and supervising analytical chemist Dr. Jack Bell. The study was made possible by grants from the Orcas Island Community Foundation and The Russell Family Foundation.

The authors of the report note that while no cultivated shellfish were tested, clams and oysters sold by shellfish farms are likely to be less contaminated because they are grown above the sediment and harvested when still very young.