Mercury concentration in the milk of mothers living near the southern coast of the Caspian Sea during different stages of lactation period

Abstract

The aim of this study was to determine mercury levels and changes during lactation in colostrum, transitional milk, and mature milk (1 month and 2 months post partum). The mercury mean concentration in milk samples collected from 18 women was 90 ± 20 and 100 ± 30 ng L⁻¹ for colostrum and transitional milk, respectively. Also, mean concentration of 160 ± 70 and 140 ± 50 ng L⁻¹ for mature milk 1 month and up to 2 months post partum were found. The concentration of mercury did not decline during the lactation period. Mercury daily intake was estimated when the infants were fed human milk only. The intakes ranged from 0.0 to 80 and from 0.0 to 70 ng kg⁻¹ body weight day⁻¹ for colostrum and transitional milk, respectively. For mature milk at the first month and up to 2 months the intakes were estimated from 1 to 200 and from 0.0 to 270 ng kg⁻¹ body weight day⁻¹. Significant difference was found between mothers without amalgam-filled teeth and mothers with one to five amalgam-filled teeth. Fruit and vegetable consumption showed negative correlation with the mercury concentration in human milk.

Keywords:

• mercury
• human milk
• Iranian women
• fish consumption
• vegetable consumption