OXLINE, the National Library of Medicine's (NLM) computerized collection of toxicology literature, has evolved since its 1972 introduction to include many diverse information resources. As we attempted to cover the literature in a field that was dispersed across a large number of journals, secondary sources were often searched and included as a "subfile" of TOXLINE, often at considerable expense to NLM. As these suppliers grew, and MEDLINE, a primary source of our bibliographic citations, grew as well, problematic duplication of citations in TOXLINE occurred. Access to TOXLINE at NLM has evolved, too, with changes in database structure, composition, cost, and methods of connection, culminating in the 1998 release of TOXLINE as a free resource available through Internet Grateful Med, and the 1999 inclusion of TOXLINE on the TOXNET Web search system.

This evolutionary process continues with a next generation TOXLINE that may best be viewed as a virtual resource on toxicology available at NLM from several different approaches. In early August 2000, TOXLINE standard bibliographic journal citations derived from MEDLINE were made accessible as part of PubMed, with a toxicology subset available as a limit. Historically, a large proportion of the standard citations in TOXLINE have come from MEDLINE, so accessing them directly in PubMed will remove the confusion about whether a MEDLINE or TOXLINE search should be performed, and will also provide to toxicology information seekers the advantages of PubMed searching, with related records, MeSH term selection, document delivery, and linking out features. We are working on providing additional toxicology-related filters that will help users focus on specific subject areas, such as reproductive toxicology or health effects of environmental exposure to toxic substances. Some of the journals that had been included in citations provided by secondary source services such as BioSciences Information Service (BIOSIS) and International Pharmaceutical Abstracts (IPA) are not included in PubMed, but each year additional journals are added to the NLM indexing process. For example, this year the following toxicology-related journals have been added to MEDLINE:

Occupational Hygiene

Toxicology in Vitro

Journal of Agricultural Safety and Health

International Journal of Environmental Health Research

Journal of Environmental Health

Some forty other toxicology-related journals are in the process of being indexed for retrieval through PubMed and this process, coupled with the expected growth of PubMed as a collection of references to biomedical journals, will provide significant standard journal resources in PubMed to searchers with toxicology questions. Some continued provision of citations from secondary sources may continue.

Other Toxicology Information Resources
What about the other toxicology information resources that over the years have become a part of TOXLINE? These can be considered in two basic categories: historical collections and research projects/technical reports. Both of these categories will continue to be available through the TOXNET Web search system as a merged set, the TOXLINE Information Collection. All the closed but still useful subfiles of the original TOXLINE will be included: for example, EMIC (Environmental Mutagen Information Center), PESTAB (Pesticide Abstracts), and PPBIB (Poisonous Plants Bibliography). In addition, several components of TOXLINE will continue to be updated on the TOXNET system. These include citations to technical reports available from the National Technical Information Service's Government Reports Announcement & Index, reports of research projects from CRISP (NIH's Computerized Research Information) and from FEDRIP (Federal Research In Progress), and industry submissions to the Environmental Protection Agency included in TSCATS (Toxic Substances Control Act Test Submissions). Some small, special collections of toxicology-related literature will also continue to be provided through the TOXNET TOXLINE Information Collection. Currently, these include the DART (Developmental and Reproductive Toxicology) component, built as a cooperative effort by NLM, the National Institute of Environmental Health Sciences (NIEHS), the Environmental Protection Agency (EPA), and the Food and Drug Administration (FDA); the CIS component from the International Labor Office; and RISKLINE, from Sweden's National Chemicals Inspectorate.

Searching the Toxicology Information Resource
What will be the easiest way to search these pieces of NLM's virtual toxicology information resources? The new NLM Gateway has just been released, providing access with one search box to PubMed, LocatorPlus, and other NLM resources. Users can search on toxicology topics and retrieve the bibliographic citations quickly from PubMed, along with other resources like monographs and consumer information. Subsequent releases of the Gateway will include DIRLINE, a Directory of Health Organizations, where relevant organizations might be located, and some of the TOXNET databases, such as HSDB or the TOXLINE Information Collection. At that time access to NLM's virtual toxicology information resource collection will be complete, with one Gateway search providing information that could include:

Standard bibliographic journal citations from PubMed

Monographs from LocatorPlus

Conference Abstracts

MEDLINEplus topics

Organizations from DIRLINE

Record(s) from HSDB

Citations to TOXLINE's research projects, technical
      reports, or historical literature

Such access to all the categories of information resources offered by NLM will provide the user with immediate awareness of the range of resources, a sampling of what is provided by each, and the means to select the most relevant resource without having to interpret definitions of distinct databases. As users become more familiar with the resources, direct access will always be possible, and easy to achieve whether through the Gateway links or through direct connection to the other NLM Web sites. For the subject area of toxicology, a disparate science encompassing many disciplines, this approach to information access is ideal. It will truly provide a Next Generation TOXLINE for all NLM users, who now include many classes of users beyond the original bounds of health professionals.

[Editor's Note: Internet Grateful Med search screens for TOXLINE will be deactivated on April 2, 2001 as described in the NLM Technical Bulletin article Internet Grateful Med to Be Retired; Reminder of NLM Gateway Availability .]

By Jeanne Goshorn
Specialized Information Services

Goshorn J. Next Generation TOXLINE. NLM Tech Bull. 2001 Jan-Feb;(318):e6.