Mercury ban worries scientists

Scientists are warning officials negotiating a global treaty on mercury that banning the deadly chemical completely would be dangerous for public health because of the chemical's use in vaccines.

The ban option is one of several proposals on the table for a meeting later this month in Nairobi, but a final treaty isn't expected until 2013.

A large number of vaccines - including for diseases such as tetanus, measles and meningitis - contain mercury compounds, which prevent contamination.

David Wood, a World Health Organization vaccines expert, says not being able to use mercury "is not a viable option."

Most of the concerns about mercury center on emissions from burning coal, gold mining, and people eating fish tainted with the chemical.