Hazmat closes Lead-Deadwood High School for the week

LEAD, S.D. — The Lead-Deadwood School District closed its high school this week (Dec. 19-21) after a student brought mercury to school. The closure will allow the building to be cleaned and tested.

What happened?

The incident happened on Monday, Dec. 12 — the day before a winter storm closed the entire district for four days.

According to school superintendent Dr. Eric Person, the student had found elemental mercury in his home.

Not realizing the danger mercury poses, the student brought it to school to show other students.

A teacher alerted the office that a student had a suspicious substance — later determined to be the mercury.

The student and the substance were removed from the room and the principal and school nurse began tracing the students who had “direct contact,” defined as actually touching the mercury or being in very close proximity.

They also alerted those students’ families and Poison Control. Poison Control, in turn, contacted state officials, who alerted the Environmental Protection Agency (EPA).

In the course of its investigation, the school district discovered that the mercury had been in and potentially contaminated more rooms than originally believed.

How do they clean it up?

Testing and mitigation crews were brought in.

They use chemicals that render the liquid mercury inert, allowing it to be vacuumed with specialized equipment without fear of it vaporizing. Mercury vapor is considered much more dangerous to human health than liquid mercury.

The contaminated rooms are then heated and ventilated to vaporize any leftover mercury and force it out of the room.

The rooms are then tested, which takes 8 hours, during which time the mercury level must remain below a specified level.

Extending the closure

By Sunday night, Dr. Person says the district realized that the testing and clean-up would continue into the following week, disrupting classes. So the decision was made to cancel high school classes, effectively beginning students’ winter break early.

The district also realized that because more rooms were involved, more students may have been in contact. So officials contacted all families to tell them about the situation, share symptoms of mercury poisoning to look for, and provide a phone number to call with any questions.

Uses for mercury

Mercury was once widely used in the gold and silver mining industries to extract precious metals from the surrounding ore.

In the late 1800s, the element was widely used in everything from explosive detonators to electric light bulbs.

By the early 1900s, in addition to mining, it was used to make scientific instruments, vermilion, and felt. In fact, the prevalence of dementia among hat makers led to the phrase, “mad as a hatter.”