Sled Dogs and Sniffers Help Study Mercury

Scientists are using dog hair to study mercury contamination in the environment and to assess how levels of the contaminant in food supplies may affect human populations.

“The foods sled dogs are eating are scraps left over from people in the villages,” said Peter Bowers, an archaeologist at Northern Land Use Research, an Alaskan consulting firm, who contributed to a study published in the journal Science of the Total Environment in October.

Sled dogs eat a diet rich in fish, similar to that partaken by Alaska’s indigenous population.  Scientists hope to use data from sled dog populations to find out how much mercury humans are eating and determine where contaminants enter the food chain. Fish accumulate varying levels of mercury depending on their habitat and diet.  Scientists hope that mercury levels in dog hair from different husky populations will provide information on mercury levels in the native fish they eat.

The study included samples of hair collected from dogs in five regions of Alaska as well as from a sample collected from sled dog remains dating back to 780 A.D.  Another study also included samples collected from dogs living in the states of New York and Alaska who were fed a commercially-prepared diet.

The highest levels of mercury were detected in modern dogs living in a village near the Bering Sea. The lowest levels of mercury were detected in the archaeological group and modern dogs in New York who were fed a commercial diet.  Dogs fed a commercial diets or who ate native diets but lived in areas farthest from the sea had the lowest levels of the modern day Alaskan group.

Salmon eat mercury-contaminated plankton and algae. The metal accumulates in their bodies and is passed on when a dog or other animal eats them.

The study focused on mercury levels in sled dog fur because people don’t often want to participate in research studies.  Hair analyses are used because collecting hair samples is far less invasive than testing organs or blood, and hair samples provide a good indicator of mercury levels in an organism.

Interested in getting your dog’s hair tested for mercury levels?  You can do it here:  HairAnalysisLab (Though I am more than a little concerned about a laboratory group that can’t spell the word ‘analysis’ correctly….) 

Another way dogs help us study mercury in the environment is by working as detection dogs.  Clancy, a Labrador retriever mix employed by the Minnesota Pollution Control Agency (MPCA), has been trained to sniff out mercury in schools and laboratories.

In the last five years, Clancy (who was adopted from the humane society) has helped rid schools of more than 1,500 pounds of mercury.  He and his handler are tested for mercury every 3 to 12 months.  

Because they could potentially be exposed to high levels of the toxin, they have their blood tested instead of their hair as this provides for a greater level of short-term accuracy in detection.

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