Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. 
Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. What was studied?
This study investigated the effects of early (during lactation) and recent (during follow-up) exposure to mercury and lead on the neurodevelopment of children. Specifically, it focused on children who had elevated mercury levels and/or developmental delays during infancy. The research analyzed how these exposures influenced the children’s neurodevelopmental performance at the age of 5-8 years, using various cognitive and visual-motor integration tests.
Who was studied?
The study followed a subgroup of 82 children from a previous study involving 944 lactating mothers and their infants. These children were specifically selected based on their elevated mercury levels in hair or signs of developmental delays during infancy. The children underwent testing between 2017-2018, with exposure data gathered during their early lactation period (2011–2013).
Most important findings
The study found significant associations between early exposure to mercury and lead and the children’s neurodevelopmental outcomes. Higher urinary mercury levels during infancy were linked to lower scores on the Test of Non-Verbal Intelligence (TONI) and Beery Visual-Motor Integration (VMI) tests, which assess nonverbal IQ and visual-motor coordination, respectively. Elevated methylmercury levels in mothers’ blood were associated with lower child IQ scores. Interestingly, higher methylmercury levels in hair samples from both mothers and children were linked to better visual-motor scores, though these associations might be influenced by confounding factors, including fish consumption. Furthermore, exposure to lead during lactation showed marginal effects on visual-motor skills, suggesting potential neurodevelopmental risks, though the evidence was less robust than for mercury exposure.
Key implications
The findings underscore the importance of monitoring mercury and lead exposure during early life, especially during the lactation period, as it can have lasting effects on neurodevelopment. The results highlight the potential risks of exposure even at low levels, which may not be detectable through standard neurodevelopmental screening tools. For the HTMC program, these findings suggest the need for stringent regulations and thresholds for mercury and lead levels in food products, especially those intended for children or lactating mothers. Additionally, the study emphasizes the value of biomarkers, such as urinary porphyrins, for tracking mercury exposure, which could enhance monitoring and certification processes. The interaction between metal exposure and factors like diet should also be considered in future regulatory frameworks to ensure a comprehensive approach to food safety.
Citation
Al-Saleh, I., Moncari, L., Jomaa, A., Elkhatib, R., Al-Rouqi, R., Eltabache, C., Al-Rajudi, T., Alnuwaysir, H., Nester, M., & Aldhalaan, H. (2020). Effects of early and recent mercury and lead exposure on the neurodevelopment of children with elevated mercury and/or developmental delays during lactation: A follow-up study. International Journal of Hygiene and Environmental Health, 230, 113629. https://doi.org/10.1016/j.ijheh.2020.113629
Mercury (Hg) is a neurotoxic heavy metal found in various consumer products and environmental sources, making it a major public health concern. Its regulation is critical to protect vulnerable populations from long-term health effects, such as neurological impairment and cardiovascular disease. The HMTC program ensures that products meet the highest standards for mercury safety.
Lead is a neurotoxic heavy metal with no safe exposure level. It contaminates food, consumer goods and drinking water, causing cognitive deficits, birth defects and cardiovascular disease. HMTC’s rigorous lead testing applies ALARA principles to protect infants and consumers and to prepare brands for tightening regulations.
