As many as 13 people received emergency treatment Saturday night after apparently being sickened by carbon monoxide at a church in Prince George's County, a county fire official said.
A witness described commotion and moments of confusion outside St. Bernard's Church in the Riverdale Park area as rescue equipment arrived, firefighters hooked up hoses, parishioners arrived for the 7 p.m. Mass and as many as 100 people were being evacuated.
All of those who were treated by emergency workers appeared to be conscious, said Mark E. Brady, a spokesman for the county's Fire and Emergency Medical Services Department.
Brady said a woman and two children, both about 10 years old, were taken to hospitals for treatment.
As many as 10 others were being given oxygen at the scene, at 5700 St. Bernard's Dr., near Kenilworth Avenue and Riverdale Road. They were being monitored by paramedics and were being prepared for transport to hospitals.
Brady said it was possible that they would be taken to Baltimore for treatment in a hyperbaric chamber. Such treatment, which provides oxygen at high pressures, is often recommended in severe cases of carbon monoxide poisoning. It was not clear Saturday night whether anyone had been taken for the treatment.
The source of the carbon monoxide had not been determined, but Brady said authorities were told that work had been performed earlier Saturday on the boiler at the church. Boiler or furnace problems might generate carbon monoxide.
Authorities who measured the level of carbon monoxide at the church obtained readings of about 1,300 parts per million.
That level is far above the danger threshold, Brady said. He said a normal level would be no higher than about 3 or 4 percent of that.
The church's Web site lists a Spanish Mass scheduled for 7 p.m. each Saturday, and it appeared that many of those evacuated might have arrived early.
The first call for help from the church came about 6:30 p.m., according to authorities.
Call-takers at the county's 911 center were told that someone at the church was feeling faint and dizzy.
Emergency medical services personnel who were sent to the scene, near the Riverdale Plaza shopping center, were approached by other people who said they were experiencing similar symptoms.
Additional resources were summoned, including more firefighters, the fire department hazardous materials unit, the mass casualty unit and a mobile ambulance bus, for use in transporting large numbers of patients.
Mary Windsor, a religious education teacher at the church who came upon the scene by chance, said that some people in the church had become nauseated and that others had apparently fainted.
The building was evacuated, and its utilities were shut down. As the evening went on, the levels of carbon monoxide began to decrease, Brady said.
Carbon dioxide consists of one atom of carbon and two of oxygen. Carbon monoxide, which has only one oxygen atom, often is produced when an engine or stove is operated in an enclosed or confined space where there is not enough air for complete combustion or oxidation.
It can also be produced by worn or poorly maintained combustion devices such as boilers or furnaces, according to information from a federal Web site.
Substantial amounts can also result from blocked, disconnected or leaky flues, according to the site.
Carbon monoxide bonds with the hemoglobin in the blood, which usually carries oxygen to the body's tissues. After bonding with carbon monoxide, the hemoglobin no longer provides an adequate supply of oxygen.
At high levels of exposure, according to information prepared by the Environmental Protection Agency, carbon monoxide, which is colorless and odorless, can cause death before victims recognize they are in danger.
Category: Public Health