The US Environmental Protection Agency says that WHO safety limits for
mercury are five times too high. The conclusion comes from a study that
reanalysed data on human exposure to the metal.
Most human exposure to mercury comes from seafood, and a recent study
indicated that the metal affects the neurological development of fetuses
(This Week, 22 November 1997, p 4).
The EPA recommends a maximum level of 0.1 micrograms per kilogram of body
weight—which could be reached by eating just one can of tuna per week.
But electricity generating companies, whose plants emit mercury, argue that
the EPA’s conclusions rely too heavily on a few instances of acute exposure.
