11
Aug
(Beyond Pesticides, August 11, 2011) A combination of eleven different kinds of commonly used pyrethroids were tested on mice in a new study which found that, at real-world exposure levels, the insecticides can produce heightened toxicity that is equal to the sum of each insecticide’s individual effect. The mixture of similar-acting insecticides works by over-stimulating electronic channels in the mouse’s brain cells and eventually causing death. This study adds to the growing body of research on the toxicity of pesticide combinations in nature and showcases the need for policy change because the current risk assessment approach to regulating pesticides fails to look at chemical mixtures and synergistic effects. The U.S. Environmental Protection Agency (EPA) currently regulates on a chemical-by-chemical basis, but as this study demonstrates, interacting chemicals can have synergistic effects at very low levels, where a “chemical cocktail” of multiple interacting chemicals combine to have greater effects than expected. Pesticides can also have a cumulative “toxic loading” effect both in the immediate and long term. Researchers exposed mice brain cells to eleven different food-use pyrethroid insecticides either singly or in a mixture in the study entitled ”Additivity of pyrethroid actions on sodium influx in cerebrocortical neurons in primary culture.” […]
Posted in Bifenthrin, Cyfluthrin, cypermethrin, Deltamethrin, esfenvalerate, Nervous System Effects, Permethrin | No Comments »
19
Oct
(Beyond Pesticides, October 19, 2010) In addition to the ongoing investigation into the death of nearly 1,000 lobsters last fall around waters in New England and Canada, Environment Canada is now investigating the possible release of a pesticide that is not permitted for use in Canada. The pesticide, cypermethrin, is used in the U.S., including Maine, to control sea lice outbreaks in salmon farms, a practice under investigation. Cypermethrin is toxic to lobsters, and fishermen associations have been calling for the elimination of the use of pesticides in the marine environment. Fish farmers have been challenged in controlling sea lice outbreaks this summer, particularly in the upper Passamaquoddy Bay area. They have been using other chemicals to control the outbreaks, including hydrogen peroxide, Salmosan (azamethiphos), SLICE (emamectin benzoate) and Calicide (teflubenzuron). New Brunswick aquaculture organizations have maintained that fish farmers do not use cypermethrin, which is not permitted for use there. The New Brunswick Salmon Growers Association referred to the cocktail of pesticides used on salmon farms as “medicine” and referred to salmon farming techniques as “natural.” However, shoddy farming practices, such as growing too many fish per site and having too many sites in the same area, can lead […]
Posted in cypermethrin, International, Maine, Water, Wildlife/Endangered Sp. | No Comments »
18
Feb
(Beyond Pesticides, February 18, 2010) Hundreds of dead and dying lobsters just north of the Gulf of Maine were found to have been exposed to cypermethrin, a highly toxic synthetic pyrethroid pesticide registered for agricultural and residential use that some officials think may have been illegally used in fish farming. However, the chemical, which is primarily used for indoor insect control and termites, is extremely toxic to fish and aquatic organisms and part of a family of pesticides (synthetic pyrethroids) that is increasingly showing up in water bodies at toxic levels, a cause for concern according to scientists. Area fisherman are angry and concerned, however investigators are not yet certain just how this pesticide wound up in the Bay of Fundy, which is located between the Canadian provinces of Nova Scotia and New Brunswick. The first dead lobsters were discovered last fall in Grand Manan’s Seal Cove, and only a few days later fisherman found dead lobsters in two different locations in the Bay, including about 816 kilograms of dying or dead lobsters in Deer Island’s Fairhaven Harbour. This prompted an investigation by Environment Canada that began on December 22, 2009. The department looked at samples of crab, kelp, mussels […]
Posted in cypermethrin, International, Water | No Comments »
