Hair mercury concentrations of children and mothers in Korea: implication for exposure and evaluation

Abstract

Background: Mercury is a global pollutant that affects neurodevelopment of children.

Objective: The objectives were to measure and evaluate mercury concentration of children and mothers, and its association with exposure.

Methods: A cross-sectional assessment was done using questionnaires and hair mercury were analysed by Cold Vapor Atomic Absorption Spectrometry in the National Institute for Minamata Disease in Japan.

Results: A total of 112 children and 111 mothers were included; mean age was 34 months and 32 years, respectively. 17.9% of children and 34.2% of mothers had concentrations greater than 1 parts per million (ppm) as reference level. Body weight at birth, feeding methods, maternal age, and maternal education level were significantly different in each group (p<.05). Mean maternal hair mercury level (0.91 ppm) was higher than children (0.74 ppm), and has a positive correlation between them (p<.05). 68.1% of children, 75% of pregnant period, 63.4% of lactating period, and 78.6% of last six months have been consuming fish. With multiple regression analysis, hair mercury levels in children aged less than 6 months had a linear relationship with body weight at birth, gestational weeks, feeding methods (breast- or bottle- feeding) and maternal educational level. While children aged over 6 months significantly differed with gender, frequency of fish servings per week, and frequency of maternal fish consumption in lactation period. And hair mercury levels had inverse linear relationship with maternal monthly income in this age group. Maternal mercury levels had linear relationship with maternal age.

Conclusion: Mercury levels in children may be affected by their mothers due to similar dietary patterns. Further long-term large-scale and follow-up studies are needed.