Comparing Heavy Metal Concentrations in Human Hair and River Otter Fur

Students at the Ocean Research College Academy (ORCA) have been video monitoring river otters (Lontra canadensis) in the Snohomish River estuary system for the past three years, as well as collecting and dissecting over 200 scat samples to determine diet composition. These mammals feed opportunistically on crab, sculpin, and even bird. Because of their high trophic level standing, it was hypothesized that otters were most likely to reflect bioaccumulation of heavy metals and other elements, as well as the health of their ecosystem, which could be seen through concentrations in their fur. Fur samples were collected non-invasively by a designed brush system under a fence and elementally analyzed using the ICP-MS at the Everett Environmental Lab. Human hair was also analyzed for this study, accounting for and comparing age, gender, diet, and hair products that may contribute to concentrations. If people who consume seafood, such as crab, show similar concentration to rivers otters, a common source of bioaccumulation could be assumed. Preliminary data suggests that river otters have an average zinc concentration of 605.185 mg/kg in ppb, parts per billion, and the ratio of magnesium to iron is 1 : 3.46, respectively. A preliminary human hair survey suggests that women have an average zinc concentration of 371.826 mg/kg with a high of 733.900 mg/kg, whereas men had an average zinc concentration of 207.579 mg/kg with a high of 238.855 mg/kg. As expected, men had an average higher iron concentration than women by sevenfold, 241.464 mg/kg compared to women at 34.51 mg/kg