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Clancy, the MPCA's mercury-detecting dog

Clancy, the mercury-detecting dog, is one of the tools that the Minnesota Pollution Control Agency (MPCA) is using to check schools and other facilities for spilled and "hidden" mercury. Clancy and Carol Hubbard, his trainer and handler, are prepared to teach students and others about the dangers of mercury, how people get exposed to it, and proper handling and recycling.

Mercury-Free Zone Program is Clancy's primary assignment

The MPCA uses Clancy mostly in its statewide Mercury-Free Zone Program, which began in October 2001.

Goals of the program are to (1) reduce the risk of potential mercury exposure to students and school staff, (2) prevent releases of mercury to the environment by eliminating mercury from schools, and (3) educate students and staff about the dangers of mercury. The program will also seek to establish mercury-free zones in colleges and universities. Other types of public and industrial facilities will be added as the program matures.

The MPCA initiated the statewide program after staff found that some Minnesota schools still contain large quantities of mercury. The statewide program is an extension of a regional Mercury-Free Zone project that the agency's Lake Superior Initiative conducted in seven northeastern Minnesota counties. By September 2001, over 210 pounds of mercury and mercury-bearing equipment had been removed from 38 of the 57 schools participating in the regional project, effectively preventing about 100 pounds of elemental mercury from polluting the environment.

Why use a dog to search for mercury?

Experience in Sweden showed that use of mercury-detecting dogs is both a cost-effective way to find mercury and an excellent tool for teaching students about the dangers of mercury. The MPCA's Mercury-Free Zone Program is modeled after a successful Swedish program. In 1999, two specially trained dogs checked 1,100 schools in Sweden. As a result, about 1.4 tons of mercury were removed from these schools.

Where did the MPCA get Clancy and what do you know about him?

Members of the St. Paul Police Department Canine Unit looked at more than 200 dogs at Twin City metro area humane society facilities before they found Clancy in December 2000 at the Ramsey County Humane Society. They chose Clancy largely because he reacted to a tennis ball in the way that good detector dogs do — with enthusiasm and persistence.

Clancy is a black/chocolate Labrador retriever with a touch of hound. We think he was probably born in the spring of 1999.

How was Clancy trained to find mercury?

Patience, consistency and repetition is the key to training a dog. Over several months, officers from the St. Paul Police Department's Canine Unit taught Carol how to train Clancy to detect mercury. The police had never trained a dog to detect mercury, but they knew that it had been done in Sweden, and they already knew how to train dogs to find illegal and dangerous substances. Clancy and Carol Hubbard play hide-and-seek for hours each week. She hides mercury and he tries to find it. When he succeeds, she rewards him by playing with him with a tennis ball.

How small a volume of mercury can Clancy detect?

With his sensitive nose, Clancy can detect the vapor from as little as half a gram of mercury, the amount that is spilled when a fever thermometer is broken. Clancy can find small quantities of mercury, such as any that may have accumulated in sink U-bends, in the cracks between floorboards and tiles, and other, out-of-the-way places. He's also able to detect mercury in instruments.

Clancy's ability to detect mercury is determined largely by whether the surface area of the mercury is big enough to give off the concentration of mercury vapor to the air that he's been trained to detect. Mercury is the only metal that is a liquid at room temperature. It is the chemical processes that take place in liquid mercury that give mercury its scent. The warmer it is, the more vapor the mercury gives off and the easier it is for Clancy to smell it.

How can you confirm that Clancy's found mercury if you can't always see it?

The MPCA has a Lumex unit that can measure the concentration of mercury vapor in the air. With this machine we can confirm whether Clancy has actually found mercury. The machine is so sensitive that it can detect down to nanograms (a nanogram is one billionth of a gram).

Is Clancy's health at risk from being exposed to mercury?

Clancy may have been at greatest risk from exposure to mercury during his training. Since then, Clancy has found relatively little mercury in the schools and industrial facilities he's checked. So he's been exposed to very little liquid mercury or its vapor. A veterinarian analyzes a sample of Clancy's blood for mercury every three months. Each time his blood has been tested, the results have been below the detection limit. This is similar to the experience in Sweden, where no health problems or increased mercury contamination has been found in the blood or hair of mercury-detecting dogs.

MPCA scientists think the concentrations of mercury that Clancy will be exposed to are far too low to affect him during his lifetime. While old mercury spills pose the greatest threat of occupational mercury exposure for people, Clancy will never be exposed to these potentially high levels for extended periods. By locating spills so they can be cleaned up, Clancy is helping assure that people will not continue to breathe mercury vapor from the spills.

Whom can one contact to arrange for Clancy to inspect a school or facility?

To arrange an inspection, call Carol Hubbard at 651-757-2452 or e-mail her at carol.hubbard@pca.state.mn.us. You will be asked details about your school or facility, such as its size, address, number of employees and whether you have reason to be concerned about mercury on the premises.

Removing mercury is cheap insurance for schools

When managed correctly, mercury is not considered to be a general health threat to children in schools. However, it's not unusual for children to find mercury in a school and then spill or dump it in the school, on a bus or at home. Under some circumstances, such a spill can lead to toxic exposure levels.

Eliminating mercury is cheap insurance. By doing so, schools can avoid costly cleanups. Mercury cleanups can cost $5,000 to $250,000 and typically include short-term school closures. In the northeastern Minnesota pilot project, about $89 was spent for each pound of mercury eliminated. Cost to eliminate mercury from a building averaged about $309. (Costs do not include staff time.)

How do schools become polluted by mercury?

Schools typically have mercury-bearing thermometers and barometers in their laboratories and mercury-bearing blood pressure cuffs and fever thermometers in their nursing stations. Mercury and mercury-containing chemicals may be on lab and storeroom shelves. Mercury may have accumulated in floor drains or sink traps. There may also be mercury spills that need to be cleaned up.

Mercury pollution in schools comes mostly from broken lab and fever thermometers. Broken fluorescent tubes are another source. And, "forgotten" mercury in drawers and cabinets can give off vapor into the air or get into the waste stream.

There is no longer any reason to have mercury (other than energy-saving fluorescent lights) in schools. Effective alternatives exist for all mercury-bearing laboratory and health-care equipment.

Getting mercury out of schools helps protect everyone

Mercury is a nerve toxin that can harm humans and wildlife. It affects the brain, spinal cord, kidneys and liver. When mercury contaminates lakes and streams, bacteria can incorporate the mercury into the organic compound methylmercury. Once this very toxic substance enters the food chain, it never breaks down but accumulates in the flesh of fish. When we eat these fish, we run the risk of being poisoned by mercury. That's why it's imperative we do whatever we can to reduce mercury contamination of the environment.

Removing mercury from schools eliminates the chance that mercury from them will find its way into Minnesota's environment. In this way, the MPCA's Mercury-Free Zone Program is helping to limit mercury contamination of Minnesota's lakes and streams, the fish that live in them, and the people who eat those fish.

What does it mean when a school pledges to become a Mercury-Free Zone?

By signing the Mercury-Free Zone pledge, the school or other facility agrees to:

• inventory the mercury-bearing items in its buildings,
• turn in mercury and mercury-bearing items for recycling,
• purchase non-mercury alternatives,
• implement a phase-out plan, and,
• commit to an educational program for students, faculty and staff about mercury and other persistent bioaccumulative toxins (PBTs).

The MPCA gives pledging schools a curriculum to educate students about mercury and the dangers it poses. If funding allows, the schools also receive digital lab and fever thermometers, blood pressure cuffs and barometers.

More Information

For more information about the Mercury-Free Zone program, call Carol Hubbard at 651-757-2452 or toll free at 800-657-3864 or e-mail her at carol.hubbard@pca.state.mn.us. Or complete our online information request form.