In March, the Environmental Protection Agency, acting under
court order, proposed the first national standard for emissions
of mercury, sulfur dioxide and other pollutants from coal-fired
power plants. The standards, which have yet to be made final,
are expected to lead to the closings of dozens of aging coal
plants and require expensive clean-up technology to be installed
at newer plants; industry groups and Republicans in Congress
have vowed to fight them. One of those leading the charge
against the rules is Representative Joe Barton of Texas, who
found himself under fire on Tuesday by public health advocates
for comments sharply questioning the public health benefit of
controlling mercury, particulate matter and other emissions from
power plants. At a Congressional hearing in April, Mr. Barton
suggested that an E.P.A. estimate that the pollution control
rules would prevent 17,000 premature deaths a year had been
“pulled out of thin air.” The numbers must be exaggerated, Mr.
Barton said, because “to cause p