Obama administration to tighten smog limits but will satisfy few

The Environmental Protection Agency will propose tightening limits on smog-related pollution Thursday, according to individuals briefed on the decision, but the new standard will fall short of what environmentalists and public health experts had recommended. The issue of how to regulate smog, which can cause or aggravate such health problems as asthma and heart disease and is a suspect in premature death, has been a contentious one for decades. While the determination is supposed to be made solely on scientific concerns rather than economic ones, any lowered limit carries enormous economic consequences for states and cities across the nation. Communities that consistently fail to meet the standard could eventually face restrictions on certain kinds of industrial development.