The Bush administration's long-awaited and long-debated regulations for mercury emissions from power plants were finally issued in mid-March, but that hardly marked the end of the mercury issue. As news stories in recent weeks indicated, there are plentiful opportunities for continuing coverage.

The administration's cap-and-trade rules for mercury were hailed by industry groups and blasted by environmentalists. Examples of articles about the regulations included those by the Christian Science Monitor, Knight Ridder Newspapers, and the Associated Press .

A few days after the Environmental Protection Agency released the regulations, the adequacy of their scientific justification came under new scrutiny. The Washington Post reported that a study by Harvard University and the EPA itself had estimated that the health benefits of tougher rules would be 100 times as great as the EPA had stated, but top agency officials removed this finding from public documents.

Another angle that was followed involves the legal fight against EPA regulations, initially being waged by nine states -- California, Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New Mexico, New York and Vermont. These states allege that the federal rules don't properly protect children and expectant mothers and say a plan for an emissions-trading plan would create toxic "hot spots" with too much mercury. See stories by the Associated Press and the Christian Science Monitor.

Meanwhile, state legislative action has been unfolding, perhaps foreshadowing other efforts elsewhere. In New Hampshire, the Senate approved a bill with stricter mercury limits for power plants, which would also ban trading in emission credits (see the Concord Monitor's report). In Minnesota, Republican and Democratic legislators unveiled a bill to cut power plants' mercury emissions and fund related research (see the Duluth News Tribune story).

Signaling renewed congressional attention to the issue, New England senators announced plans to reintroduce legislation for stricter federal restrictions for mercury, both from power plants and from other sources (see article in The Times Argus).

Follow-up stories about the EPA's mercury regulations, such as one in the Christian Science Monitor, pointed to an expanding debate, revealing that the EPA refrained from regulating other air toxics in the mercury rules as it could have done.

Articles about a pair of new university studies on mercury and autism, a developmental disorder, indicated that reporters should be on the lookout for more such research-related news.

In one of the studies, researchers at the University of Texas Health Science Center in San Antonio reported findings suggesting that mercury, primarily emitted by power plants in Texas, may be adding to the incidence of autism in the state (see the Reuters report).

In the other study, reported by the Los Angeles Times, University of Arkansas researchers found that a protective antioxidant was abnormally low in autistic children, perhaps indicating that their bodies could have more difficulty neutralizing toxic metals such as mercury.

Mercury's impact on wildlife -- particularly contamination of fish, which poses risks for people who eat them -- continued to be spotlighted in various news accounts, such as one in The Star-Ledger of New Jersey. Columnist Tom Palmer of The Ledger in Lakeland, Fla., showed in his piece how journalists can provide valuable background and context to explain the connections between local mercury-related fish advisories and the national mercury debate.

Not all of the recent mercury-related news was tied to the issue of air emissions, however. There are also other angles to be pursued, as investigative reporters for the Mobile Register illustrated (see Mobile Register article).

The Register sponsored tests that found "mercury concentrations more than a thousand times higher than normal are widespread near roads, driveways, schoolyards, parks and churches" in a small town.

This contamination, the newspaper reported, was the apparent result of "a distinctive, salty, man-made aggregate that has been used to build up roads, driveways and parking lots."