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Copyright Issues

For copyrighted sources, diligent efforts were made by the editors/compilers of this product to obey all copyright laws. Most of the information in the encyclopedia is either from public-domain government documents or has been summarized in properly attributed short quotes, summaries, or paraphrases governed by fair use conventions.

In some cases, large blocks of text were copied from public-domain government products such as the National Library of Medicine's Hazardous Substances Databank and from the Agency for Toxic Substances and Disease Registry toxicological profile documents.

Regardless of whether the source was public domain or not, every effort was made to properly attribute all quotes and summaries of information from other documents. Hundreds of sources have been referenced by numbers in brackets at the end of the line or paragraph of text. The full citations are found in the References Entry (98KB PDF) References, Numerical Order section (page 6). There are also embedded references in sections copied from other public-domain government databases.

In some cases, longer quotes (longer than would be supported by fair use conventions) were used from copyrighted sources after obtaining written copyright permission from the publisher. One major publisher of environmental toxicology information (Lewis Publishers, and Imprint of CRC Press) gave us written permission to copy text at will as long as no figures or tables were reproduced and as long as the text was properly attributed regarding the source. However, other publishers were more restrictive and their information was used only after written copyright permission was obtained.

Those who might desire to reuse or re-publish any copyrighted information herein are cautioned that other types of independent re-distributions of some of this information may require additional copyright permission from some of the original copyrighted sources. In other words, the written copyright permissions obtained for our current distribution of this document in this current format and setting may not automatically convey to all possible non-National Park Service or for-profit re-distribution uses. It is up to each such potential user to independently obey copyright laws for each the many potential applications of information use. The U.S. government is not responsible for liability from any copyright misuse of the information herein by other users.

Last Updated: November 13, 2012