Carson High School students can return to classes today after the 400,000-square-foot building was cleansed of any residual mercury following what appears to be an intentional spill in the nurse's office Wednesday.
Director of Operations Mike Mitchell said a 4:30 p.m. air-quality test did not detect mercury after hours of cleaning the nurse's office, four classrooms and two hallways.
Wednesday, a missing screw-on cap allowed a little more than a teaspoon of mercury to escape from a blood pressure machine that uses the silver-colored toxic element to gauge pressure. The breach was discovered about 11:30 a.m., an hour before the high school released its students early for teacher development. Classes were canceled Thursday for cleanup. The Carson City Sheriff's Department is investigating the incident as a crime.
Eighteen students and eight staff members who were known to have visited the nurse's office were guided through a decontamination process - which included a shower with soap and water in the gym locker room - by the Carson City Fire Department. Their clothing and jewelry were confiscated for decontamination at a later date.
Mitchell said the highest levels of mercury were found in the office and surrounding hallway. Smaller levels found in four nearby classrooms and in two hallways that lead to some 10 other classrooms.
"Those classrooms were affected after school was let out when we ran our mechanical (air) system," Mitchell said. "The fact that we had an early out yesterday was very fortunate."
Over the past few years, the school district has made an effort to identify and remove hazardous materials from its premises.
"Somehow, these apparatuses had fallen through the cracks. We didn't consider medical devices. I guess we just didn't get there," Mitchell said.
It's likely each of the district's nine schools has one of these out-dated blood pressure machines, he said. Thursday, a safety manager was tasked with collecting the remainder, which will be treated as hazardous waste and disposed of accordingly.
Mitchell said, about six years ago a janitor working after school at Fritsch Elementary accidentally struck a similar machine with a broom handle, breaking the glass capsule of mercury. The mercury was quickly contained in that incident and an environmental cleanup company decontaminated the building.
"I don't know why we didn't get rid of (the machines) then," he said.
As far as the investigation in to who was responsible for unscrewing and removing the cap, Mitchell said, the nurse's office used to have a surveillance camera, but he wasn't sure if it still did.
There were no estimates available Thursday on cost of the cleanup and replacement of blood pressure machines in the district. Should investigators find who is responsible, that person could be liable for cleanup charges.
What can happen
The symptoms of mercury poisoning can include:
• impairment of peripheral vision
• disturbances in sensations - that "pins and needles" feeling as well as numbness - usually in the hands feet and sometimes around the mouth
• lack of coordination of movements, such as writing
• impairment of speech, hearing, walking
• muscle weakness
• skin rashes
• mood swing, memory loss and mental disturbances
Source: Environmental Protection Agency
Mercury in the news
• In January 2004, dozens of Pau-Wa-Lu Middle School children in Gardnerville were exposed to the element and the vapors of mercury after a classmate brought about a quarter cup to school. The mercury contaminated not only classrooms and a school bus, but the clothing and belongings of more than 50 of his classmates. The state and federal governments spent more than $100,000 on decontamination efforts; the school was closed for more than a week.
• Less than a week later, severe poisoning from long-term exposure to mercury vapor sent a Las Vegas 17-year-old to the intensive care unit for a week. EPA and Clark County officials spent weeks decontaminating the teen's home because of extremely high levels of mercury vapor. The boy had spent months playing with as much as a quart of mercury, spreading it throughout his house and back yard. The vapor very nearly killed him. A substantial amount of his family's personal property had to be destroyed because contamination levels were so high, and the family's dog experienced severe mercury poisoning.
Source: Environmental Protection Agency
- Contact reporter F.T. Norton at ftnorton@nevadaappeal.com or 881-1213.
