AN INTERNATIONAL CONFERENCE many years in the making and attended by representatives of more than 150 countries is being held this week in Vienna. This U.N. Conference on Science and Technology for Development concerns an important subject, though whether it will do anything important remains to be seen.

The developing countries have only about one-tenth of the world's scientists and spend about three percent of the money budgeted for research. Most of that talent and research is concentrated in a handful of countries -- India, Mexico and Brazil, for example. The research that is done too often mirrors the spending priorities of the industrialized world. India allocates a full third of its government R&D spending to atomic energy and space -- both matters of supreme irrelevance to its tens of millions of rural poor.

But at least India has its own supply of well-trained scientists and engineers it can point in any direction it chooses.What of the vast majority of developing countries that have virtually no technical capacity at all? In a real sense, they are at the mercy of the advanced countries. They can neither control where the industrialized few put their money (heart disease, for example, rather than infectious tropical diseases) nor make wise decisions among the products and technologies offered for export.

The decisions are not theoretical. Potentially deadly industries -- like asbestos textiles, arsenic smelting, benzidine dye production and others -- that find it impossible or unprofitable to meet U.S. environmental and health standards have found new locations aborad. Pesticides, food additives and medicines whose use is prohibited in this country have at various times and under various conditions been quite legally exported. Egypt bought one potent pesticide, never registered in the United States, until it caused widespread illness and the deaths of several farmers. Another pesticide imported by Indonesia to control pests in the rice paddies killed the insects all right, but at the same time did in the fish that also lived there and that provided fertilizer for the rice and much needed food for the farmers. When it was discovered that the flame retardant TRIS used to treat children's pajamas also caused cancer, manufacturers dumped their inventories on the foreign market.