Objective: Mercury is a neurotoxin that is introduced to pregnant women from the soil, air pollutants and fish intake. Mercury in the placenta can be a biomarker for both maternal and fetal exposure. The objective of this study was to investigate how dietary patterns and environmental conditions can affect mercury concentration levels in the human placenta.
Method: Ethical consideration was granted to collect placental samples from participants at the University Hospital of the West Indies (UHWI), in November 2012 and Mandeville Regional Hospital (MRH) in July 2014. Cold vapour atomic absorption analysis was performed on the samples to determine the total mercury concentration in the placentae. The participants were interviewed on their fish intake and residence. The samples were categorized into industrial (Kingston and Mandeville) and agricultural areas (St Elizabeth, Clarendon and Trelawny).
Results: The placental mercury concentration ranged from 0.45–3.7 µg/kg, median 0.5 µg/kg. The mean maternal fish intake per week for industrial and agricultural areas was 78.4 ± 52.3 g and 86.3 ± 90 g, respectively and the mean placental mercury concentrations were 0.67 ± 0.4 µg/kg and 0.58 ± 0.2 µg/kg, respectively. There was no significant difference between fish intake and placental mercury. There was a statistically positive correlation (p = 0.04) between the mean placental mercury and the study areas. The area with the highest soil mercury of 500 ppb, had the highest mean placental mercury 1.13 ± 0.2 µg/kg.
Conclusion: The study showed that the environment can also influence placental mercury. The placental mercury levels in Jamaica were found to be below the 10 µg/kg reference level, at which fetal health could be adversely affected.