The authors analyzed the biological diversity of sanitary indicative microorganisms of the genus Staphylococcus in man and environmental objects in an area adjacent to a gas industrial enterprise. The species diversity of staphylococci was found to increase upon technogenic chemical exposure, which was recorded in both ambient air and bacterial carriers. The rise in the biological diversity was shown to occur with the increased number of rare species which adequate assessment required the use of the Shennon index. Whether the index of biological species diversity of staphylococci during microbiological monitoring of natural ecological systems is discussed in the paper.