A large birth cohort of Faroese children showed neurobehavioral deficits at age 7 years associated with developmental exposure to methylmercury. The deficits were almost entirely associated with the prenatal exposure levels. However, slight decrements in visuospatial function were associated with the current exposure at the time of examination. As also seen in clinical poisoning cases, the demonstration of these effects at age 7 years suggest that the effects of developmental neurotoxicity may be lasting.
These findings were supported by two cross-sectional studies on Madeira and in the Brazilian Amazon, where exposures were thought to have remained largely unchanged. Current mercury exposure levels were found to be associated with signs of neurotoxicity in children aged 7-12 years.
The public-health significance of neurotoxic damage is difficult to document from available health statistics. However, mercury-associated effects on, e.g., attention span, motor speed, memory, and language function, could well impact on cognitive development, education, social functions, and career. Thus, a study of subjects who had suffered excess lead exposure as children revealed that they were less educated and less successful in life than a control group.
Small differences in average performance of children may have little consequence for children with average functions, but the most impressive differences occur at the extremes of the distributions. Thus, the number of children with serious deficits may increase considerably. The latter group of children would be more likely to require special education in school, and they would be less likely to benefit from career options in society.
Learning Objectives: N/A
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.