Public health benefits of hair-mercury analysis and dietary advice in lowering methylmercury exposure in pregnant women

Scand J Public Health. 2017 Jun;45(4):444-451. doi: 10.1177/1403494816689310. Epub 2017 Apr 6.


Aims: To evaluate whether a public health intervention using focused dietary advice combined with a hair-mercury analysis can lower neurotoxic methylmercury exposure among pregnant women without decreasing their overall intake of seafood.

Methods: A total of 146 pregnant women were consecutively recruited from the antenatal clinic at a Danish university hospital at their initial ultrasound scan. Dietary advice was provided on avoiding methylmercury exposure from large predatory fish and a hair sample from each participant was analysed for mercury, with the results being communicated shortly thereafter to the women. A dietary questionnaire was filled in. Follow-up three months later included a dietary questionnaire and a repeat hair-mercury analysis.

Results: In the follow-up group, 22% of the women had hair-mercury concentrations above a safe limit of 0.58 µg/g at enrolment, decreasing to 8% three months later. Average hair-mercury concentrations decreased by 21%. However, the total seafood intake remained at the same level after three months.

Conclusions: Increased exposure to methylmercury among pregnant women is an important public health concern in Denmark. The observed lowering of hair-mercury concentrations associated with dietary advice corresponds to a substantial public health benefit that probably makes such an intervention highly profitable.

Keywords: Intervention; cost–benefit evaluation; intervention; methylmercury; pregnant women; prenatal exposure; seafood diet.

MeSH terms

  • Adult
  • Cost-Benefit Analysis
  • Denmark
  • Diet / psychology*
  • Diet / statistics & numerical data
  • Diet Surveys
  • Directive Counseling*
  • Environmental Exposure / analysis
  • Environmental Exposure / prevention & control*
  • Female
  • Follow-Up Studies
  • Food Contamination
  • Hair / chemistry*
  • Health Promotion / methods*
  • Humans
  • Mercury / analysis*
  • Methylmercury Compounds / analysis*
  • Pregnancy
  • Public Health
  • Seafood / statistics & numerical data


  • Methylmercury Compounds
  • Mercury