Almost 6,000 people will die prematurely from respiratory illness due to emissions from power plants owned by eight utility companies that the Clinton administration sued for violating the Clean Air Act, according to a private report released yesterday. In addition to the deaths, the report predicted that the pollution would lead to 140,000 asthma attacks and 14,000 cases of acute bronchitis. Residents of the Midwest and the South will be hit hardest, and the nation’s overall productivity will suffer as well, because Americans will miss an estimated 1.2 million days of work per year due to related health problems. The energy industry pooh-poohed the study, with one spokesperson calling it the “45 millionth” of its kind and questioning the science behind it. The report, which was prepared by Abt Associates and paid for by the Rockefeller Family Fund, comes as the Bush administration is lobbying to change the Clean Air Act in ways that environmentalists say would weaken it.