Bacillus popillaeDutky andPopillia japonicaNewman have been used in commercial production of milky disease spore dust for 26 years. The overall health of the people who produce the spore dust has not been adversely affected by prolonged exposure to this insect pathogen, and findings of recent clinical and physical examinations of personnel were within normal ranges for sex and age. In addition, antibodies toB. popilliaeandP. japonicawere not detected in their sera.