It's High Time to Take On Chemical Toxicity

THERE has been widespread concern about chemical pollution for decades. Efforts to counter that pollution through monitoring and regulation have grown apace. Yet there still is substantial risk because we don't know what we are doing by introducing many thousands of synthetic chemicals into the environment. It's time to put a higher priority on finding out what the dangers really are. A good place to start would be to take very seriously the recent report on neurotoxins - chemicals that attack the nervous system - issued by the congressional Office of Technology Assessment (OTA). Although this focuses on the situation as it affects the United States, OTA's warning has global relevance.

Synthetic chemicals are not necessarily dangerous just because they are synthetic. Many of them contribute substantially to human welfare. The danger lies in a general ignorance of which chemicals are poisonous and which are not. This is in spite of the wide knowledge chemists have of poisons. OTA's point is that this knowledge is weak when it comes to understanding the potential of various chemicals to affect the nervous system.

The report notes: ``More than 65,000 chemicals are in the US Environmental Protection Agency's (EPA) inventory of toxic chemicals; and the agency annually receives approximately 1,500 notices of intent to manufacture new substances. Since few of these chemicals have been tested to determine if they adversely affect the nervous system, no precise figures are available on the total number of chemicals in existence that are potentially neurotoxic to humans.''

Some neurotoxins such as mercury, lead, or various pesticides are well known. They also are reasonably well regulated, although the study points out that regulation could be tighter in many cases. And in some cases, obviously needed regulation is shamefully neglected, as when the United States allows companies to export chemicals banned at home. This is an unconscionable imposition on importing nations. Moreover, the poisons may come back to the US in the form of residues on imported foods.

OTA's main conclusion is that, even when there is a will to understand a chemical's toxicity and to regulate that chemical if necessary, potential neurotoxicity often is neglected. There is a tendency to assume that tests for general toxic effects will pick up neurological risks as well.

But, as the study points out, nervous-system effects can be subtle and can involve much lower doses than more obvious poisoning. The study finds that ``in general, Federal research programs are not adequately addressing neurotoxicity concerns.''

Part of the problem is that old bugaboo, lack of adequate funding. Even EPA's relatively large in-house research is underfunded, with no money available to support outside research in this field. There also are problems of perspective among the relevant federal agencies and research workers. The report notes that concerns about cancer have dominated discussions of toxic risks. Yet, it observes, neurotoxicity ``may pose an equal or greater threat to public health.''

Here is an urgent research challenge. Meeting it mainly requires a change of perspective by Congress and the administration. They should act on this seminal report. It would be a mistake to let it gather dust as just another warning about chemical pollution.

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