Postnatal exposure to mercury and neuropsychological development among preschooler children

Area of Science:

• Environmental Health
• Neuroscience
• Pediatrics

Background:

• Prenatal and postnatal exposure to mercury (Hg) is a public health concern.
• Assessing the impact of environmental toxins on child development is crucial for early intervention.
• High mercury levels have been observed in certain European populations, necessitating further investigation.

Purpose of the Study:

• To quantify postnatal mercury exposure in Spanish preschool children.
• To investigate the association between mercury exposure and neuropsychological development.
• To evaluate potential biases in exposure assessment and their impact on observed associations.

Main Methods:

• A cohort of 1252 Spanish children aged 4-5 years from the INMA Project was studied.
• Total mercury levels were measured in cord blood and child hair samples.
• Neuropsychological development was assessed using the McCarthy Scales of Children's Abilities (MSCA), with data analyzed using regression models.

Main Results:

• The geometric mean of hair mercury was 0.98 µg/g, considered high compared to other European countries.
• Positive associations were observed between mercury exposure and verbal, memory, and general cognitive scales of the MSCA.
• These associations were attenuated after adjusting for fish intake or accounting for measurement error in exposure data.

Conclusions:

• Despite elevated mercury levels in this Spanish cohort, no adverse effects on preschool children's neuropsychological development were detected.
• The findings suggest that potential confounding factors and measurement errors may influence the observed mercury-neurodevelopment associations.
• Further research is needed to fully understand the complex relationship between mercury exposure, diet, and child neurodevelopment.