The Minnesota Pollution Control Agency says the only mercury-detecting dog in the country died on Sunday at 14 years old.

According to a news release, Clancy served nine years with the state agency, identifying toxic vapors that humans can't see, smell or taste.

Mercury vapor can easily enter the blood stream and damage the brain, nervous system, liver and kidneys.

The labrador retriever-hound mix was part of an elite team in the Minnesota Pollution Control Agency’s Mercury-Free Zone Program.

Mercury was once used in several items found in schools such as thermometers, thermostats and laboratory reagents in chemistry labs.

Clancy and his partner, Carol Hubbard, helped remove more than 2,000 pounds of mercury from 330 schools in the state. Their work also lead to a ban on mercury in schools that was passed by the Minnesota Legislature in 2007.

Clancy retired in 2009.

“He was a great dog and the best work partner anyone could ask for,” Hubbard said in the news release. “He will be sorely missed by me, my family, and many of the people he met and helped throughout Minnesota.”