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Books show how chemicals act in environment No excuse for another silent spring 
In 1961, Rachel Carson published Silent Spring, astounding the world with the news that DDT and other pesticides were present at dangerous levels in birds. Thirty-six years later, chemists understand the behavior of such toxic substances and are not surprised when they find traces in animals, water, soil and air."Now we are in an era where it is possible to predict how chemicals will behave in our environment and use the knowledge to avoid using the nasty ones," says Trent's environmental modelling centre senior research chair Don Mackay. Up to now, that knowledge has been scattered through thousands of scientific abstracts. Between the 12 chemicals banned by Canada and the 10 million that exist in the world, there is a huge grey area of others. Mackay has pinpointed 700 "priority" organic -- not metallic -- chemicals such as PCBs and dioxins that are produced in large amounts, persist the longest and accumulate in fish, birds and mammals. For the past six years, he has worked with two University of Toronto senior research associates, Kuo Chung Ma and Wan Ying Shiu, to pull together all pertinent information about these 700. Since 1991, they have published five handbooks listing different chemical families with models of how industries, governments, researchers and students can predict the behavior of some of the world's most toxic. "The general aim is to assist society to use chemicals safely," says Mackay, "and to select chemicals which will not persist and cause adverse effects in preference to those which are troublesome. "This approach is warmly embraced by more enlightened industry which seeks to profit from chemical synthesis and sale. It is not desirable to go to the expense of producing chemicals, only to have them banned or severely regulated." The handbooks are Mackay's signal to other chemists to be environmentally responsible. In a world that depends on chemicals to maintain the food supply, disinfect, preserve, produce clothing and plastics, these books are his way of saying to chemists "you should know what you're doing." He has a captive audience among the 11 chemical industries and the Natural Sciences and Engineering Research Council representatives that have funded the Environmental Modelling Centre for five years. "In the past, we've done many stupid things," says Mackay. "We have used chemicals unwisely, such as PCBs. Some chemicals just have to be banned and some have to controlled very tightly because they're quite nasty but they're also very valuable to us." These five illustrated handbooks bring together for the first time data that makes it possible to determine where a chemical goes -- whether it goes into the air, soil, water, fish, birds and/or animals -- .how long it stays there, and how fast it travels. Each handbook presents exhaustive data on different chemical families: PCBs, dioxins, volatiles organic chemicals, oxygen, nitrogen and sulphur-containing compounds and, finally, pesticides. At about $100 each, the 600- to 1,000-page handbooks are not cheap. By next year, Mackay and his co-authors hope to finish revising the volumes for a CD-ROM version that could be available for as little as $300. Users don't have to wait for the CD to take advantage of an electronic version. Predictive models are posted on the Trent Web site on the Environmental Modelling Centre Web page and already, notes Mackay, industries, governments and consultants and university researchers around the world are downloading the models at a rate of six per day. |
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Last updated: September 26, 1997