Researchers at the Harvard School of Public Health, showed that children exposed to mercury in the womb may suffer permanent damage to their heart function. The researchers examined more than 1,000 mothers and children living in Denmark's Faroe Islands. Residents there eat large amounts of fish, much of which is contaminated with mercury.
The children had been exposed to mercury both prenatally and after they were born. The researchers put electrodes on the heads of the children to measure electrical signals in the brain and discovered delays in brain signaling, and the higher the mother and child's mercury load at birth, the more distinct the irregularities. They also found these neurological changes led to poorer system control of heart function. The children with the most mercury in their blood were less capable of maintaining the normal variability of the heart rate necessary to secure proper oxygen supply to the body.
The researchers saw the same effects in the children when they were 7 and 14. This indicates that if a brain is exposed to mercury during development in the mother's womb, then the effect that we see during childhood is going to be a lasting effect. A brain that is affected during development will not recover, which puts the mercury question into perspective. If this was just a passing effect, it's something entirely different. But here we're talking about something that will stay with that child for a lifetime, and that will affect the child's education, academic success, financial success and whole equality of life.
A few days ago I posted a link that an EPA researcher published a report doubling the estimates of how may U.S. infants have unsafe levels of mercury in their blood. The researcher estimated that 630,000 infants were born in the 1999-2000 year with blood mercury levels higher than 5.8 parts per billion, the EPA's level of concern. This is more than double the previous estimate of 300,000 infants. The EPA removed the paper from its Web site on Thursday and was not immediately available for comment.
Journal of Pediatrics February 2004;144(2):177-83