RiskWorld Asks the National Library of Medicine:
What’s New, What’s the Most Popular, and What’s the Most Overlooked in Its Online Databases for Risk Professionals

Editor’s note: RiskWorld writer Carolyn Evans has delved into a national treasure trove of human health and environmental data available online at the National Library of Medicine’s TOXNET (TOXicology Data NETwork) web site. In this first article of her two-part series, she highlights what’s new, what’s the most popular, and what’s overlooked of the library’s online resources for risk analysts and other professionals. In her second article, she will highlight databases that are the most accessible and useful for the general public, including hobbyists, consumers, workers in high-risk jobs, and breast-feeding mothers.

For decades, the National Library of Medicine of the U.S. National Institutes of Health has been compiling one of the world’s most detailed collections of online databases and other resources of human health and environmental data. More than 10 million viewers accessed the library’s TOXNET (TOXicology Data NETwork) web site last year, as risk analysts, medical doctors, and other health and environmental professionals referenced the site’s vast resources at no cost. Yet even experienced users don’t realize how the depth and breadth of these online resources has expanded in recent years, says Stephanie Publicker, a technical information specialist with the Specialized Information Services division of the National Library of Medicine.

“We have so many resources – we’d like to increase awareness of just how extensive our databases are,” says Publicker, a 14-year veteran of the National Library of Medicine. “We are always adding to it. Last year, for instance, there was a spill in the Elk River in West Virginia, and there wasn’t a lot of information available about the chemicals involved. We worked with the CDC [Centers for Disease Control and Prevention] and other federal agencies to come up with the needed data and make them available online within about a week after the spill was reported.”

Publicker highlighted three databases in particular: the most-used, the newest, and the one that she thinks is the least familiar to health and environmental professionals, all of which are based on vetted research and are routinely updated.

Under the umbrella of TOXNET, the National Library of Medicine’s most popular database is the Hazardous Substances Data Bank (HSDB) at The database focuses on the toxicology of potentially hazardous chemicals and other substances. It provides information on human exposure, industrial hygiene, emergency handling procedures, environmental fate, regulatory requirements, and related areas. The database has grown over the years to include information on more than 5,000 substances that have been assessed by a scientific review panel that meets several times a year to review selected substances, add new records, and make updates as needed. A focus of attention for staff is to make sure that chemicals in the news and emerging substances are included with up-to-date content. For example, nanomaterials were added several years ago.

A typical user might be a researcher who wants to know more about permethrin. By going to HSDB, she can search for this chemical and find an overview that details permethrin’s many uses: to control mosquitoes, to preserve wood, for use on many food/feed crops, on farm animals and in barns, and in numerous indoor and outdoor residential spaces. Following the overview are scores of literature references and links to publications on the subject.

An environmental scientist who needs to know what happens to a chemical in the environment can go to HSDB and search for substances that are endocrine disrupters. By entering the term “endocrine disrupter,” he will see results showing a list of chemicals that have “endocrine disrupter” highlighted in yellow in the accompanying records. One, for example, is atrazine. Atrazine is the most-widely used herbicide in the U.S. and has been shown in several studies to be an endocrine disrupter in adult frogs.

“A real-life example of how we work together with other agencies and how we respond to what’s happening to keep HSDB current came after the January 2014 West Virginia Elk River chemical spill,” Publicker says. “HSDB staff worked in conjunction with staff from other federal agencies to create the HSDB record for 4-Methylcyclohexanemethanol (MCHM).” That record is being promptly updated as new results are available such as those from the National Toxicology Program’s series of testing.

Her next recommendation for risk analysts and other health and environmental professionals is TOXLINE at It is a lesser-known database that would likely benefit many professionals who are currently unaware of its resources, Publicker says. With more than four million references to literature on biochemical, pharmacological, physiological, and toxicological effects of drugs and other chemicals, it is a rich source of information with references from the 1840s to the present, with new ones added weekly. The database includes material from specialized journals, government reports, and meeting abstracts that would benefit researchers.

An example of someone who could make good use of the site is Michelle, a graduate student. She is aware that many studies on pesticides have been conducted and already knows that pesticides are regulated in the United States, but wants to know how much literature exists on cancer among agricultural workers since they may experience higher exposure to pesticides than the general public. By going to TOXLINE (just typing “toxline” in her browser will work) and entering “cancer agricultural workers” in the search box, she will find 68 pages of material, including “epidemiologic studies of cancer in agricultural workers” and “cancer mortality among agricultural workers from Serrana Region, state of Rio de Janeiro, Brazil,” just to name a couple.

Or take Thomas, a principal investigator, who is designing a new breast cancer study for women. He would like to perform a literature search for recent articles focused on the effects of diet on breast cancer. Thomas would like articles published since 2010. By going to TOXLINE and clicking the advanced search tab and typing “2010” in the “First Year of Publication” box, (replacing “1900”), he will be able to choose titles from 87 pages of literature with 10 entries per page, including “Do statins increase and Mediterranean diet decrease the risk of breast cancer?” If he eliminates the 2010 parameter, he can peruse 330 pages of entries, including “Omega-3 fat to reduce risk for breast cancer,” and “Adolescent diet and risk of breast cancer.”

Publicker’s final choice for the professional is the newest database, the Comparative Toxicogenomics Database (CTD) at This information is useful for medical researchers, scientists, chemists, and others.

“The CTD has over 27 million toxicogenomic relationships,” she said. “It has millions of interactions and exposure information that have the scientific data for describing the relationship between chemicals, genes, and human diseases.”

The site promotes understanding about the effects of environmental chemicals on human health by integrating data from curated scientific literature to describe chemical interactions with genes and proteins, associations between diseases and chemicals and diseases and genes and proteins, and a new data set on the exposures associated with specific chemicals.

The Comparative Toxicogenomics Database can also answer questions on topics such as which human diseases are associated with a gene or protein, which human diseases are associated with a chemical, which exposures are associated with a chemical, and which genes/proteins interact with a chemical.

Users can do lots of things on the site, such as searching chemicals by name or CAS registry number, seeing the related genes and diseases, browsing relationships among chemicals, and obtaining detailed information about them, including structure, toxicology data and related genes, diseases, pathways and references. Posted 9/8/2015

Carolyn Evans is a free-lance writer based in Knoxville, Tennessee. She is a columnist for the Knoxville News Sentinel and writes feature articles for local newspapers and magazines.