Scientists to simulate chem-bio attack around Pentagon

To simulate how chemical and biological agents would flow around and into the Pentagon, scientists will release sulfur hexafluoride, SF6, a commonly used agent in airflow testing. The colorless, odorless gas is deemed so safe that it is approved by the Food and Drug Administration for injection into the body for specialized tests, according to the Pentagon.

The Environmental Protection Agency and the Virginia Department of Environmental Quality have approved the testing protocol.

The atmospheric survey, dubbed Pentagon Shield, will use standard weather sensors mounted on light poles around the Pentagon, on the building roof and in the center courtyard to measure wind speeds, direction and temperature. A 100-foot tower mounted with weather sensors will collect data from adjacent property in Arlington Cemetery, and two long-range, laser-based sensors located at the Navy Annex will measure winds around the entire Pentagon complex.

In addition, a 30-foot unmanned blimp carrying a number of scientific instruments will make night and weekend flights over the Pentagon to measure winds, says Glenn Flood, a Pentagon spokesman.

The survey data will be used to improve computer modeling that simulates atmospheric conditions around the Pentagon and eventually will contribute to the development of chemical/biological surveillance systems that can be used to protect other facilities, Flood says.

The survey is to be completed May 15, depending on weather. Personnel involved in Pentagon Shield will wear bright green safety vests, black caps and picture IDs.