1. AIR POLLUTION
EPA explains why it didn't tighten acid-rain standards
Responding to a challenge from environmental groups, U.S. EPA yesterday defended its decision to not set a more stringent air standard for pollutants that contribute to acid rain. EPA last April opted not to tighten its secondary National Ambient Air Quality Standards for nitrogen oxides (NOx) and sulfur dioxides (SO2), which are designed to address environmental "welfare" such as aquatic ecosystems under the Clean Air Act.