This article focuses on the environmental benefits of recycling mainly iron and steel, as well as the current status of such recycling processes. It also examines some of the economic constraints working against recycling, and offers suggestions for correcting the problem. (Author/MA)

For more than a decade, the Chinese have been using biogas digesters to produce fuel for homes in rural areas. This article discusses the design, operation, and benefits of these digesters. This means of waste treatment helps improve sanitation, produce fertilizer, and save fossil fuels. (MA)

Reviews the pollution control history of the River Thames since the time of the Roman occupation. Particular emphasis is given to the restoration policies of the last thirty years. By 1950, the waters of the Thames were nearly devoid of wildlife. Today, the river is one of the world's cleanest. (MA)

This article discusses the first U.S. exchange for industrial wastes. In its first year of operation, the exchange listed 115 waste materials for sale or wanted, some of which resulted in sales. In the future, the exchange may become a clearinghouse for recycling and polluction control technology information. (MA)

Nonpoint source pollution, water pollution not released at one specific identifiable point, now accounts for 50 percent of the nation's water pollution problem. Runoff is the primary culprit and includes the following sources: agriculture, mining, hydrologic modifications, and urban runoff. Economics, legislation, practices, and management of this…

Maximum levels of the principle water contaminants are discussed in this article. Difficulties related to establishing standards for contaminants in drinking water are identified and the possible results of high levels of these contaminants included. (MA)

A pollution-reducing and energy-saving alternative to petroleum use could be the fermentation industry and other technologies based on the use of renewable resources. Expansion of the fermentation industry could reduce our dependence on petroleum, reduce growing waste disposal problems, and help solve world food shortages. (BT)

This article identifies the cumulative effects of some environmental problems facing mankind and presents possible alternative futures. The author discusses the pervasive infiltration and detrimental effects in the biosphere of polychlorinated biphenyls, the recent increase in acid rain, the loss of tropical rain forest lands, and future energy…

A review of the environmental problems identified on Earth Day 1970 is presented. Problems on conspicuous consumption, combustion of fossil fuels, and toxic substances are discussed. (SMB)