The Nation - News from Nov. 2, 1988

The United States signed a supplemental treaty aimed at limiting emissions of nitrogen oxides, air pollutants that help cause acid rain and smog, the Environmental Protection Agency said. Administrator Lee M. Thomas signed the protocol to the existing treaty on long-range transboundary air pollution in Sofia, Bulgaria, the agency said. During talks on the agreement, the United States sought a 20% credit for reductions already made that other countries had not yet undertaken. As a compromise, the agreement requires participants to limit emissions in the 1990s but permits each to choose as its ceiling the emission level of any year through 1987. The annual average from 1987.