Tuesday in Congress, Democrats criticized the Environmental Protection Agency's decision to ignore researchers' analysis of possible health benefits from reducing mercury pollution from power plants.
"Why is the EPA suppressing the evidence that mercury pollution can be controlled better and faster?" asked Sen. John Kerry, D-Mass.
EPA officials said the study by the Harvard Center for Risk Analysis was not submitted until Feb. 22, more than a month after the deadline set for considering new data. The agency published its new regulations on mercury pollution from power plants on March 15.
The agency had received an overview of the Harvard study in early January, but it didn't include the authors' responses to peer reviewers' comments or all of the final numbers, said James Hammitt, a co-author of the study and director of the Harvard center.
EPA officials said they rejected the preliminary document as flawed.
Hammitt's study estimated the potential public health benefits from cutting mercury pollution from coal-burning power plants in half 15 years from now at $5 billion a year, compared to the EPA's estimate of up to $50 million a year. The EPA put the cost of the cleanup to utilities and users of electricity at $750 million a year in 2020.
The difference in the benefit numbers comes from Hammitt's inclusion of fewer cases of cardiovascular disease and less contaminated ocean fish in his calculations.
The EPA estimates that U.S. power plants account for 1 percent of global mercury pollution.
The government now advises that high levels of mercury in some fish, including albacore tuna, can pose a hazard for children and for pregnant or nursing women, resulting in brain and nerve damage.
EPA spokeswoman Cynthia Bergman said the agency does not believe the science on mercury is solid enough to weigh possible benefits from fewer cases of heart disease and cleaner ocean fish.
Bergman said the Harvard study assumes each pound of mercury coming from plant smokestacks will wind up in the ocean, a conclusion counter to what EPA researchers found.
Bergman acknowledged the benefits could be greater than the EPA estimated (because the agency took into account only freshwater benefits) but not 100 times greater.
Hammitt acknowledged "wide uncertainty" over calculating the benefits. "It could be ten times bigger, or ten times smaller," he said. "Part of the science underlying the subject is just not solid enough to specify things really precisely."
But Hammitt said the EPA should have provided a range of benefits, even though that might have undercut its regulatory approach of letting industry trade rights to pollute rather than insisting each plant install new pollution controls.