BELLEVILLE, IL - An older type of hearing aid battery containing mercury is now illegal in Illinois and several other states that have banned them.

Gov. Pat Quinn signed the law last year. It took effect Monday.

The Belleville News-Democrat reports that the legislation targets what's known as a zinc-air button battery.

The U.S. banned mercury from many other batteries in the mid-1990s but not that type because manufacturers said technological limitations gave them no alternatives.

Now, there are button-sized batteries being made without mercury that function almost as well.

Kevin Greene of the Illinois Environmental Protection Agency explains that mercury doesn't break down and if it contaminates a body of water it can become even more toxic.

He says mercury can also build up in the body and cause organ damage.