In an unprecedented action, the Environmental Protection Agency’s own scientific panel on Friday challenged the agency’s proposed public health standards governing soot and dust. The Clean Air Scientific Advisory Committee, mandated by Congress to review such proposals, asserted Friday that the standards put forward by EPA Administrator Stephen L. Johnson ignored most of the committee’s earlier recommendations and could lead to additional heart attacks, lung cancer and respiratory ailments. The Los Angeles Basin, especially the Riverside area, and the Owens Valley in the Eastern Sierra have the worst particulate pollution in the nation. The problem in urban areas is largely attributable to truck exhaust and diesel-powered vehicles; the Owens Valley has major dust storms. In December, Johnson proposed to slightly tighten the health standards that state and local governments must meet in regulating industries and other sources of pollution. But those standards, governing the smallest and most hazardous particles of soot, were substantially weaker than the scientists’ recommendations. Johnson also proposed to exempt rural areas and mining and agriculture industries from standards governing larger coarse particles, and he declined to adopt the panel’s proposed haze reduction standards. EPA officials are taking public comment on the […]