Notes
This project has been funded at least in part with Federal funds from the U.S. Environmental Protection Agency under Contract No. 68–02–3948. The conclusions reached and scientific views expressed in this review are solely those of the authors. The content of this publication does not necessarily reflect the views or policies of the U.S. Environmental Protection Agency, nor does mention of trade names, commercial products, or organizations, imply endorsement by the U.S. Government.