Finding and using toxics information - Special Issue: Environmental Restoration

You take a walk around your neighborhood and notice the ever-present chemical plant with its stacks pumping foul-smelling fumes into the atmosphere and spilling green liquid into the river. You wonder: What toxic chemicals are being released in my community? Which companies are responsible? Where are they transferring their toxic waste? How can I find out about the health effects of these chemicals on my family? Can they cause cancer or interfere with my wife's capacity to bear children?

Answers to such questions and others may be found by consulting an array of computerized databases, collectively known as MEDLARS (Medical Literature Analysis and Retrieval System), available through the National Library of Medicine (NLM) in Bethesda, Maryland.

NLM's Toxicology Information Program has been providing publicly available data about toxic chemicals and their hazards for over twenty years. In this time, its computer files have expanded greatly in number, size, and scope. Whereas this information has always been and continues to be of great interest to scientists and researchers, a greater effort is being made to inform concerned citizens that they, too, can have access to this enormous store of information at a very reasonable cost. Computer files available through MEDLARS' innovative Toxicology Data Network (TOXNET) have been a boon to individuals wanting to find out more about hazardous chemicals.

The Toxic Chemicals Release Inventory (TRI) is one of the newest of these TOXNET files. This file contains data on the estimated releases of toxic chemicals to the air, water, or land, as well as amounts transferred to waste sites. In compliance with the law, industrial facilities around the country are required to report this information to the Environmental Protection Agency, which in turn provides it to NLM, the public access point for this information on computer. This file helps fulfill the U.S. Congress's wish to insure the public's right to know about environmental toxic chemicals.

TRI offers very flexible searching. You may use the file to help determine how many pounds of chlorine, for example, have been released to the air in your zip code, or in your county, city, or state, and what facility has released the greatest amount for any given year. Alternatively, you might choose to search on a company name, say ABC Chemical Products, and determine what substances they are releasing in your area, or nationwide. Listed with each company is a public contact name and phone number, should you need more information about the release. TRI can also be used if you want to find out how many pounds of certain hazardous chemicals manufactured or used outside your state are subsequently shipped into your state for disposal. These are but a few of the types of questions TRI is designed to answer.

TRI's versatility is enhanced through a statistical feature which allows you to perform a variety of functions such as adding numbers and calculating means, medians, maximums and standard deviations. One might also perform "ranging" to determine, for instance, what states release more than one million pounds of acetone into the air. In the near future, a "sort" capability will be implemented, allowing you to sort your results alphabetically or numerically. You might, for example, choose to sort the records you have retrieved alphabetically by company name.

Every database has its limitations. As helpful as the TRI data is, it contains only rather specific information related to chemical releases and transfers to waste sites. It does not contain information on the health effects of, or human exposure to, these chemicals. However, users of TRI are automatically authorized access to the entire family of NLM files, many of which do list such information and thereby supplement TRI.

The Hazardous Substances Data Bank (HSDB), for example, covers chemical toxicity, as well as emergency handling procedures, environmental fate, human exposure, detection methods, and regulatory requirements. A large part of the data in this 4,200-chemical file has been peer-reviewed by expert toxicologists and other scientists. The Registry of Toxic Effects of Chemical Substances (RTECS) is another TOXNET file of some 100,000 chemicals, covering acute and chronic effects, skin and eye irritation, carcinogenicity, mutagenicity, and reproductive consequences. TOXNET also includes files specifically dedicated to the areas of carcinogenesis, mutagenesis, and teratogenesis. Outside of TOXNET, the NLM's TOXLINE group of databases contains references, often with summaries, to journal articles dealing with hazardous chemicals and other areas of toxicology and environmental health.

Individuals may request searches on TRI and other NLM files by contacting any one of thousands of health science libraries and information centers throughout the country. Information on an online search facility in your community may be obtained from one of the seven regional medical libraries listed below. In the future, it is hoped that more public libraries will be tied into the NLM system. If you prefer to search these files on your own personal computer, you may request an application form from the address below. The cost of TRI and most other files averages $25 per hour with reduced rates during nonpeak hours. The required equipment includes a computer terminal or personal computer, a phone line, modem, and telecommunications package.

User guides and instructions are available on all NLM files. A sequence of user-friendly, menu-driven screens has been developed for TRI to allow the novice or occasional user without any computer background to search the file. This interface leads you step by step through a series of menus which ask you what kind of information you need. You may then display your results at your personal computer and printer or have the results printed in an "off-line" mode at NLM and mailed to you the next day. Similar menus are being designed for TOXNET's other files.

We encounter potentially toxic substances at home, school, the workplace, and in the general environment. Living in a totally pure, pollution-free environment is not possible, though steps are being taken to lessen our technological dependence on and exposure to hazardous chemicals. Meanwhile, there is an increasing body of information about such chemicals to help us make decisions about the nature and degree of the hazards they present and how to manage their use. The National Library of Medicine, especially through its TOXNET computer system, is an invaluable resource for this toxics information.

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