Fish Consumption Advice for Alaskans
Human Biomonitoring (Mercury Levels in Human Hair or Blood) Human biomonitoring is an important tool to assess actual human exposures to contaminants by measuring contaminant levels present in blood, urine, hair, fat, or other matrices. Biomonitoring data reduce scientific uncertainty relative to a standard risk assessment, which estimates human exposure to the contaminant from sources such as air, food, or water using a series of exposure assumptions and theoretical calculations. In Alaska, public health officials often use biomonitoring data to optimize their risk interpretations and health advice regarding environmental exposures to contaminants. 16
To assess mercury exposure in Alaska, DPH launched a Statewide Maternal Hair Mercury Biomonitoring Program in July 2002. This ongoing program originally offered free, confidential hair mercury testing to all pregnant women in Alaska. Eligibility has since been expanded to include all Alaskan women of childbearing age (aged 15–45 years).
Through December 31, 2006, hair samples were analyzed from 359 women from 51 Alaskan communities.17 Participants included 201 pregnant women and 158 non-pregnant women of childbearing age. The 359 participants had a median hair mercury level of 0.53 parts per million (ppm) (Figure 1), with a maximum of 7.82 ppm. All hair mercury levels were well below 14 ppm. The World Health Organization’s (WHO) analysis of two large epidemiological studies determined that no adverse health effects occurred to the fetus when maternal hair mercury levels were less than 14 ppm. 18
Figure 1. Hair Mercury Concentrations of Women who Participated in the Alaska Mercury Biomonitoring Program, July 2002 – December 2006 (n=359)
Number of Samples
Total Mercury (ppm)
To provide a margin of safety, DPH conducts follow-up investigations on all hair mercury levels above 5 ppm. Follow-up investigations were conducted for the three women whose hair samples exceeded 5 ppm. All three women lived in the Yukon-Kuskokwim Delta or the Aleutian Islands and consumed large amounts of marine mammal livers and/or kidneys, which were determined to be the primary source of their mercury exposure. DPH informed the women of ways to reduce their mercury exposure if they chose to do so, by eating traditional foods that contain less mercury.