Buried utility cables can be a source of carbon monoxide poisoning when they are ignited, according to a report from the Centers for Disease Control and Prevention.

Circumstances in which carbon monoxide releases resulted from these so-called “burnout events” are described in a report by the New York State Department of Health in this week’s Morbidity and Mortality Weekly Report.

Between 2000 and 2004, a utility company in New York City voluntarily reported 234 carbon monoxide burnout events, according to Dr. R. E. Wilburn and colleagues. Twelve of these situations resulted in injury to 37 individuals, of whom 28 required treatment at a hospital.

Evacuations of up to 810 persons were ordered during 220 events. In one case, carbon monoxide had seeped into a block of two-family homes. Other sites requiring interventions were a nursing home, a private school, a laundromat, and a medical center.

These underground fires occur when the rubber coating and insulation crack and split because of normal wear and tear, freezing and thawing, and excavation, the investigators explain. This damage is common in winter months, after road salt is spread on streets because of snow or ice storms.

Released gas travels along underground conduits, spreading into living and working spaces, or is released from manholes and drawn into buildings through ventilation systems.

“Common symptoms of carbon monoxide poisoning include headache, dizziness, weakness, nausea, vomiting, loss of muscle control, shortness of breath, chest tightness and pain, visual changes, sleepiness, fluttering of the heart, and confusion,” the investigators write.

These dangerous exposures can be prevented, they add, by installing carbon monoxide detectors in homes and businesses, sealing underground conduits at building interfaces, and preventive upkeep of the underground utility cables.

SOURCE: Morbidity and Mortality Weekly Report, October 8, 2004.