Mercury in Hair of Mothers and Infants: Influencing Factors Assessment in the Southern shores of the Caspian Sea (Iran)

Background: Mercury (Hg) is a hazardous metal responsible for environmental contamination and human intoxication. Methyl mercury bio-accumulation through food chain can be responsible for chronic mercury exposure of South Caspian Sea communities with a diet rich in fish. Uncertainties about exposure levels that could have damaging consequences for nervous system development of infants makes bio-monitoring of Hg a necessity in Southern Caspian Sea populations. Methods: Mercury concentration in the hair of 70 pairs of mothers and their breastfed infants were assessed and its relationship with influencing factors was evaluated. Results: Calculated levels of mercury exposure of both infants and mothers indicated concentrations less that the recommended levels by WHO and EPA reference. Total mean mercury concentrations in infants hair was 0.48±0.32 μg / g and for mothers was 0.19±0.09 μg / g. Correlation analysis showed that mercury concentration in the hair of infants was significantly (P=0.002, R=0.371) associated with mercury levels in the hair of their mothers. The influence of other variables such as living location, age of mothers, infants‘ sex, weight, the amount of fish and sea food consumption of mother, and the number of dental amalgam fillings, were examined as well as. Conclusion: The amount of fish and sea food consumption by mothers and the living location were the variables that significantly affected hair mercury concentrations of mothers and infants. Also the age of infants (p=0.02) and the number of dental amalgam fillings of mothers (p=0.016) significantly affected the hair mercury levels in infants. Hair