Four people finishing a basement in Havre de Grace Monday afternoon were treated for carbon monoxide poisoning, fire and rescue officials reported.
One of the victims suffered exposure serious enough to warrant transport to the University of Maryland Shock Trauma Center in Baltimore.
Fire and rescue personnel responded to the 4200 block of Kevin Road, where four people were found to be exposed to high levels of carbon monoxide from a basement finishing machine, according to the Harford County Volunteer Fire & EMS Association and Deputy Chief Steve Allers of the Susquehanna Hose Company of Havre de Grace.
The level of carbon monoxide in the basement was measured at 1,000 parts per million, Allers said. Susquehanna Hose's detector begins warning of excessive carbon monoxide at about 35 parts per million, he said.
One person was sent to Shock Trauma to be treated in a hyperbaric oxygen chamber, Allers said. Two others were also sent to local hospitals. The fourth refused medical treatment. None of the injuries was life-threatening, he said.
The four victims were working for a Pennsylvania contractor, Allers said.
The Maryland Occupational Safety and Health Division is investigating the incident, the Volunteer Fire and EMS Association reported.
In addition to Susquehanna Hose, the Level Volunteer Fire Company and Aberdeen Fire Department responded, the association reported.