BUENOS AIRES - A house constructed of discarded materials at a cost 75 percent less than traditionally-built homes has become the star of an exposition organized this month by the Metropolitan Design Center of the Buenos Aires government.

The walls of the home are made using cardboard containers, which insulate against humidity and are resistant to fire. They are covered by bricks made from shredded plastic bottles and straw, with a mix of cement and plastic. The building's energy source includes a solar panel.

LIMA - Bakery companies in Peru are to begin using a natural enzyme of European origins in producing sweet breads for the Christmas holidays in December, replacing potassium bromate, a carcinogen that was banned in this country on Oct 10 by the Environmental Health Directorate.

The use of the new enzyme marks the baking industry's reaction to the ban, which is largely the result of an ingenious campaign by the Peruvian Consumers Association.

Potassium bromate has been used since 1914 as an additive to flour for producing bread and other baked goods because the substance adds volume to the final product. But since 1983, efforts have been under way worldwide to eliminate it.

SANTIAGO - More than 200 students participated in a unique regatta at Boca de Concón beach, on the Chilean coast, navigating the Pacific in "eco-boats" made from plastic bottles they had gathered during a clean-up day at the beach.

The initiative, which on Oct 12 drew students from three high schools, marked an effort to remove waste and raise awareness about the need to rehabilitate the marshlands of the mouth of the Aconcagua River into the bay of Concón, 150 km northwest of the capital.

The boats were made by gathering the bottles in long polyethylene sleeves, and structured like canoes, according to the design of Juan Ciorba, a professor at the University of Valparaíso's school of design.

BOGOTA - The National and Antioquia universities of Colombia are putting together the first dictionary of the country's flora, announced scientists at the eighth Latin American Botanical Congress, held in the northwestern Colombian city of Cartagena last week.

The new dictionary is to be published by year's end and will include the scientific and common names of each of the 12,000 plant species found in the country, as well as the etymological origin of the name, the history and geographic distribution of each type, making it the most complete in Latin America, say the project's organizers.

TEGUCIGALPA - The Committee for the Protection of Flora and Fauna of the Gulf of Fonseca launched a campaign to save the mangroves of this marine ecosystem, considered a biological treasure of Central America, but damaged by the shrimp industry.

"We are issuing an appeal for everyone to support us in the campaign to save the mangroves and the coastal area, because otherwise we run the risk of turning the southern region into a desert," Committee president Jorge Varela told Tierramérica.

The Gulf of Fonseca, on the Pacific coast, is shared by Honduras, Nicaragua and El Salvador. There are 78,000 hectares of mangroves there, as well as lagoons, a dry tropical forest and a wealth of biodiversity. However, shrimp production is Honduras' third leading non-traditional export.

SAN SALVADOR - Some 200 divers pulled a ton of garbage from Ilopango Lake, one of the main sources of freshwater for the Salvadoran capital and the principal means of subsistence for some 600 fisherfolk.

Plastic and aluminum containers and other rubbish were gathered by experts from a private diving school, which for the last eight years has helped with clean-up efforts in one of the country's most important water sources.

In addition to the clean-up, the minister of Environment and Natural Resources, Walter Jokisch, and representatives of the Fish Development center released 50,000 'alevín' fishes to boost the lake's population.