Study finds "safe" mercury levels may harm adults

Reuters, Staff
Published June 11, 2003

LONDON — Low levels of mercury regarded as safe could impair brain function and memory in adults, according to American researchers. A study of 129 men and women in Brazil by researchers at Johns Hopkins University found the higher the level of mercury in their hair — a way to measure recent exposure — the more their memory and motor skills were impaired. "The study has been dismissed as too small to be conclusive, but if it is right, mercury could be reducing the mental performance of millions of people worldwide," New Scientist magazine said Wednesday. Low levels of mercury are thought to be dangerous for infants and young babies because of fears they can cause damage to the nervous system. Pregnant women are already advised not to eat fish such as tuna, shark, and king mackerel, which may contain high levels of the compound. Ellen Silbergeld, who conducted the study in Brazil, said the exposure levels to mercury among the villagers were only one-tenth of those considered dangerous for adults by the World Health Organization but still had a negative impact. Some scientists have criticized the study as too small. Silbergeld said her findings merited further research. "While the effect on each individual was small, she says, the overall impact on communities could be significant," the magazine added.