The question of whether mercury, used as a preservative in some vaccines, causes or contributes to disorders such as autism, hyperactivity and attention-deficit disorder continues to be debated. But even the possibility that mercury in vaccines might cause harm is reason enough to ban it, particularly in light of the fact that other preservatives are available.
If Gov. Matt Blunt signs a bill approved by the Missouri Legislature in the just-ended session, Missouri will become the third state in the nation -- California and Iowa are the other two -- to restrict the use of thimerosal, the most commonly used vaccine preservative that is 50 percent mercury by weight.
The bill is only a partial victory for advocates of a complete ban on mercury in vaccines. But it is a step closer. And the debate this year over the reasons for seeking the ban have done much to educate legislators about the issue.
The Southeast Missourian also has played a role in informing readers -- and lawmakers -- about the thimerosal issue. In-depth stories by reporters Callie Miller Clark and Bob Miller have explored the medical data regarding mercury in vaccines and have documented the impact disorders possibly triggered by thimerosal have had on families in our coverage area.
Now that the groundwork has been laid in Jefferson City, renewed efforts to ban mercury from all vaccines administered in Missouri are likely in future legislative sessions. This is a cause that deserves to be pursued.