Chinese and other Asian coal-fired electricity plants belching dangerous mercury-laced smoke are mostly to blame for mercury warnings now in every U.S. state and covering the total fish populations of 25 states, according to a startling new federal audit.

Just as alarming: Despite herculean efforts in many states to slash emissions of two acid rain producing pollutants, nitrogen oxides and sulfur dioxide, many lakes, bays and streams along the Appalachian and Pacific Coast ranges and Great Lakes can't meet federal guidelines because of pollution floating in from Canada, Mexico and nearby states.

An exhaustive new Government Accountability Office audit of Environmental Protection Agency water programs laid out the worrisome findings while presenting a vexing policy issue: They want the EPA to do more to stop pollution, but how can EPA stop foreign pollution from fouling American waters? (Read the complete report in the embedded viewer below this story.)

The easiest to handle and the area the Obama administration is focused most on is air pollution from U.S. power plants and cars. The GAO found success in some states like New York, which has cut in-state emissions 90 percent in the last two decades. The result: New York still can't meet regulations because 87 percent of the acid rain-producing pollutants are floating in "mostly from the Southeast, and Midwest United States and Canada."

The GAO said Chesapeake Bay suffers from a similar problem of pollutants flowing in from states that don't neighbor the watershed.

While acid rain pollutants spoil waters, mercury ingested by fish can harm humans, especially children, when eaten. But, said GAO, the U.S. effort is being thwarted by Asian industrial plants. GAO said that 67 percent of human-cause mercury emissions come from Asia, while only 8 percent are from North America.

A GAO map of the nation showing mercury warnings for fish shows a continuous red line from the Maine-Canada border to the Texas-Mexico line. Citing an EPA report, the GAO said that in 2010, "all 50 states reported mercury-related fish consumption advisories, and 25 states reported statewide freshwater advisories. Additionally, Alaska, Hawaii, all of the Gulf states, and most of the East Coast states, reported statewide coastal advisories."

The administration is currently negotiating mercury levels with international partners.