Of greatest interest to those concerned with the environmental aspects of solid waste mana

gement is the issue of—and the need for—resource recovery and recycling. To many Americans, there is perhaps no greater symbol of our imbalance with nature and our mal-adaptation to its realities than the fact that we discard millions of tons of wastes every year which do, in act, have value. The American people realize now that trash need not be mere junk. It has the potential of becoming a significant vein or resources, a mother lode of opportunity for men of vision who can see beyond the horizon.

The American people are right. And those who serve them can no longer view solid waste management solely in terms of collection and disposal. However, something more than the magic of science and technology is required to convert all this waste back into useful resources.

In fact, in proportion to consumption, resource: recovery has been steadily losing ground in recent years in virtually every materials sector. Approximately 200 million tons of paper, iron, steel, glass, nonferrous metals, textiles, rubber and plastics flow through the economy yearly—and materials weighing roughly the same leave the economy again as waste. In spite of neighbor hood recycling projects, container recovery depots, paper drives, anti-litter campaigns, local ordinances banning the non-returnable bottle, and file emergence of valuable new technological approaches, only a trickle of the "effluence of affluence" is today being diverted from the municipal waste stream.

The principal obstacles are economic and institutional, not technological. The cost of recovering, processing and transporting wastes is so high that the resulting products simply cannot compete, economically, with virgin materials. Of course, it the true costs of such economic "externalities" as environmental impact associated with virgin materials use were reflected in production costs and if there were no subsidies to virgin materials in the form. of depletion allowances and favorable freight rates, the use of secondary materials would become muck more attractive. But they are not now. There are no economic or technical events on the horizon, short of governmental intervention, that would indicate a reversal of this trend. If allowed to continue to operate as it does now, the economic system will continue to select virgin raw materials in preference to wastes. This fact should be etched into the awareness of those who look to recycling as a way out of the solid waste management dilemma.

We can conclude from the passage that the scientific means for recycling solid waste______.

A．requires further research

B．is available now

C．remains to be developed

D．is still being experimented