A Novel Source of Carbon Monoxide Poisoning: Explosives Used in Construction, ,

We describe an incident of carbon monoxide (CO) poisoning caused by CO migrating through soil after nearby detonation of explosive charges. Employees worked in a newly installed, unconnected manhole without incident and finished shortly before underground explosives were detonated 50 feet south of the manhole to break up rock and soil. A worker entering the manhole 45 minutes after the explosion collapsed within minutes, as did two coworkers who rescued him. One worker died, and all had elevated levels of carboxyhemoglobin. Air samples collected from the manhole 2 days after the incident showed 1,910 ppm CO; in laboratory detonations, sample explosive yielded 27 L CO per kilogram detonated. We believe the CO in this incident was released from the nearby explosion and migrated through soil and fractured rock into the manhole. The blasting and construction industries should be made aware of this previously unrecognized route of CO exposure. Additionally, confined-space procedures and training are needed to prevent future accidents. [Deitchman S, Decker J, Santis L: A novel source of carbon monoxide poisoning: Explosives used in construction. Ann Emerg Med September 1998;32:381-384.]