> Environmental and Health Concerns > Herbicides and Pesticides

BT-The Frankenspray
by author Marianne Morris

Bacillus thuringiensis (BT) is a government-approved aerial spray for the eradication of gypsy moth larvae, sprayed over Burnaby, BC residents last May.

However, BT is also toxic to freshwater fish and the organisms on which they feed. Communities from Victoria, BC to Oregon have been opposing these aerial sprays for years, but government programs continue despite Section 35 of the Fisheries Act that says, "No person shall carry on any work or undertaking that results in the harmful alteration, disruption or destruction of fish habitat."

BT is a live microbial organism that is closely related to bacillus cereus, which causes food poisoning and bacillus anthraxis, which causes anthrax. Prior to its use the US Environmental Protection Agency did not require tests for mutagenicity (affecting rate of mutation), teratogenicity (ability to cause developmental abnormalities in a fetus) or carcinogenicity. BT also contains inert ingredients which are unidentified and could be the most toxic part of the formulation, yet the Canadian people are told it is non-toxic to humans, animals, birds or fish. BT is cumulative. It persists in water supplies and is not filtred out by conventional means. It’s been measured in the air up to 17 days after application and spores reportedly persist up to a year.

Foray 48B, which was applied over the Victoria area, has been called biological warfare. It contained sodium hydroxide, or lye, which is corrosive and can cause damage to eyes, skin, mucus membranes and the digestive system. Other ingredients have included sulfuric acid and phosphoric acid, both of them corrosive. Sulfuric acid can cause burns and loss of vision and when inhaled can cause bronchitis. Phosphoric acid irritates the skin and mucus membranes.

Government argues that world trade agreements for the lumber industry mandate the use of bacillus thuringiensis on forests infected with gypsy moth. However, entomologists insist that the spray is unnecessary. A variety of harmless techniques have been used to successfully address the problem. These include mass trapping and letting nature takes its own course!

Marianne Morris, Nelson, BC

Source: alive #213, July 2000