Questions and Answers About Gypsy Moth Spraying |
What is Bt?
Bacillus thuringiensis (Bt) is a bacterium commonly found in nature as a normal resident of soil. It occurs in many forms, several of which are used as biological pest control agents on food crops - including organically grown foods. Bacillus thuringiensis var. kurstaki or Btk, makes a crystal which affects the Gypsy Moth larva or caterpillar. In order to work, the bacterium must be eaten by the Gypsy Moth caterpillar. Conditions needed for the Btk to be activated are found only in the stomach of moths and butterfly caterpillars. These conditions are not found in animals, birds and other desirable insects such as bees, beetles, and spiders. Nor are these conditions found in people.
Can Btk make people sick?
Btk has an excellent safety record for humans. If you eat vegetables, you probably have already ingested this bacterium. It is commonly used on commercial, and even organic, produce. The safety has been established both by laboratory research and monitoring people in the areas of the U.S., Canada and New Zealand where it has been used for more than 25 years.
People without a direct exposure to the material are unlikely to have any symptoms. However, some people working directly with Btk spray for long periods of time have had mild skin irritations or short term breathing problems. After a thorough review of the toxicity of Btk products, including both active and inert ingredients, the U.S. EPA, Health Canada, the World Health Organization, and many other groups have found it safe and effective for aerial applications when used according to label directions.
What about people with weakened immune systems and people with allergies?
Although there is not evidence that Btk will affect any given group of people, individuals with leukemia, AIDS, or any other physician-diagnosed causes of severe immune disorders, may consider leaving the spray area during the actual spraying. if you or someone in your home has one of these conditions, ask your doctor for advice about avoiding exposure before the spray project begins.
The Btk product contains residues of grains and other foods used to help the bacteria grow. If you have serious allergies to foods or food preservatives, your health care provider may consult with the manfacturer of Foray 48B (Valent Biosciences - 1.800.323.9597).
What should I do during the spraying?
Even though the spray is considered safe for humans, we recommend that people stay indoors during spraying, unless it is essential to be outdoors. If you or someone in your home has a medical problem that they believe may be made worse by the spraying, talk to your health care provider.
To avoid exposure, we recommend:
Staying indoors during and for at least 30 minutes after spraying to allow droplets to settle.
Waiting until the spray has dried before touching grass or shrubs. Cover playground equipment, sandboxes, benches, and lawn chairs before the spray or hose them off afterward.
Washing exposed skin with soap and water if direct contact with the spray droplets occur. If the material should get in your eyes, flush with water for 15 minutes.
Are there any health risks associated with the Gypsy Moth?
Gypsy moths are mainly a threat to trees and shrubs. When the number of the caterpillars has been very high, some people have had allergic reactions. The Gypsy Moth caterpillars have spiny hairs which can cause welts or a rash, lasting up to 4-5 days. Population levels of Gypsy Moth in isolated infestations such as those we have at Tuscarora, do not normally pose any health risks.
This information is from the Pesticide Exposure Safety & Tracking (PEST) Program in the State of Oregon. You can download a Btk Fact Sheet from the National Pesticide Information Center, based at Oregon State University, http://npic.orst.edu/factsheets/BTgen.pdf