Child neurodevelopment in a Bolivian mining city
María Ruiz-Castell1, Pamela Paco, Flavia-Laura Barbieri
1Centre for Research in Environmental Epidemiology (CREAL), Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain. mruiz@creal.cat
Insights
Children near mining sites showed no neurodevelopment issues. Surprisingly, low prenatal lead exposure was linked to better infant development scores, despite environmental contamination.
Area of Science:
- Environmental health
- Pediatric neurodevelopment
- Toxicology
Background:
- Children living near mining industries may face risks from environmental contaminants.
- Prenatal exposure to trace elements can impact infant neurodevelopment.
- Assessing neurodevelopmental outcomes in vulnerable populations is crucial.
Purpose of the Study:
- To evaluate the neurodevelopment of infants exposed prenatally to mining-related trace elements.
- To determine the association between maternal blood trace element levels and infant neurodevelopmental outcomes.
- To investigate potential risks in children residing in a contaminated mining area.
Main Methods:
- Prospective cohort study in Oruro, Bolivia, recruiting pregnant women.
- Maternal blood trace element levels (including lead and antimony) measured pre-delivery.
- Infant neurodevelopment assessed using the Bayley Scales of Infant Development (BSID) at 10.5–12.5 months.
- Socioeconomic status and medical history collected via questionnaires.
Main Results:
- Maternal blood lead levels were low (geometric mean 1.76 μg/dL), comparable to non-contaminated areas.
- Antimony levels were relatively elevated (geometric mean 1.03 μg/dL).
- No significant mental or psychomotor abnormalities were detected in infants based on BSID scores.
- A positive association was observed between low maternal blood lead levels and higher infant BSID performance.
Conclusions:
- Women in the studied mining area showed low overall exposure to most trace elements, including lead.
- Infant neurodevelopmental outcomes were not adversely affected at the observed exposure levels.
- Unexpectedly, low-level prenatal lead exposure correlated with enhanced infant cognitive and psychomotor development.
Abstract:
This study evaluates the neurodevelopment of children living near contaminated mining industries during their first year of life. Participants from the city of Oruro (Bolivia) were prospectively recruited during pregnancy. Follow-up occurred between May 2007 and November 2009. Information about the socioeconomic status and medical history of the pregnant women were collected using questionnaires. Neurodevelopment was evaluated for 246 children using the Bayley Scales of Infant Development (BSID) at 10.5-12.5 months of age. Exposure to trace elements (Pb, As, Cd, Sb, Cs, Zn, Fe, Cu, Se, Rb, and Sr) during prenatal life was evaluated by testing maternal blood concentrations before delivery. Almost all measured levels were lower than the control limits. The blood lead concentration of pregnant women was low, considering the contaminated environmental context. The geometric mean was 1.76 μg/dL (95% CI: 1.68-1.84), a level comparable with those observed in non-contaminated areas. The only element found to be relatively elevated was antimony, with a geometric mean of 1.03 μg/dL (95% CI: 0.96-1.11). Our results suggest that women from this mining area were not highly exposed. The Bayley Scales of Infant Development (BSID) did not reveal mental or psychomotor abnormalities. Surprisingly, at the observed low levels, lead was positively associated with the children's BSID performance.
