Btk and Human Health

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Resources on Bacillus thuringiensis var. kurstaki (Btk) and Human Health

Btk has been used in forestry and agriculture for over seventy years and has been shown to have an excellent safety record. Public health officials across the U.S. and Canada periodically review research on Btk and have found there is very low risk to human health. Their conclusions are reported on the websites listed below.

A physician talks about Btk treatment for gypsy moth eradication

Click on the links below for more information

Public Health – Seattle & King County website Btk and Human Health

King County Health reports that Btk is not considered toxic for people, animals, birds, fish, and other insects such as bees and ladybugs.

Washington State Dept. of Health website on “Health Information on Gypsy Moth
Control Products and Methods”

DOH concluded that Btk is not considered a human pathogen. Human infections have been looked for but not seen in several large studies of people who lived in sprayed areas.

Oregon Department of Human Health – Btk Factsheet

ODHH includes a review on the scientific literature on Btk health effects. They conclude that it is unlikely that indirect exposure to Btk will result in adverse health effects in non-target organisms, including people. 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 categorize Bacillus thuringiensis as a least toxic method of pest control.

Vancouver Island (British Columbia) Health Authority

A human health study was conducted on residents of southern Vancouver Island following a spray of Btk. This study concluded "no short-term health effects were detected in the general adult population or in hospital emergency room visits".

Information on Btk (Dr. Brad White, WSDA Pest Program Manager) PDF 112KB

General information on Btk and its use by WSDA.

U.S. Environmental Protection Agency (EPA)

Registration Eligibility Decision (RED) Fact Sheet on Btk products.