In November 1997, a report was released by the Commission for Environmental Cooperation (CEC) that assesses the current state of science on the transboundary impacts of ground-level ozone pollution. Ground-level ozone, a major component of smog, is recognized as an important public health concern in many parts of the world. Long believed to be a primarily local, urban problem, it has become increasingly evident in recent years that ozone smog is a regional phenomenon, subject to long-range windborne transport across state and national borders. To investigate the regional nature of ozone pollution, a number of data collection programs, data analyses, and modeling efforts have been initiated and carried out both cooperatively and independently in the United States and Canada. These initiatives have helped to demonstrate that the transport of ground-level ozone and its precursors occurs over distances of many hundreds of kilometers in the eastern United States and Canada. Moreover, depending on prevailing weather conditions, ozone can travel across the border in either direction so that both nations are at times the recipient of, and at other times a contributor to, their neighbor’s air pollution problem.

The transboundary ozone transport report is the result of a collaborative effort between the CEC, the Eastern Canada Transboundary Smog Issue Group (ECTSIG), and the Northeast States for Coordinated Air Use Management (NESCAUM).

Click here for more information on the CEC report and how to obtain a copy.