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Air quality

Motor vehicles are responsible for the main atmospheric pollutant emissions. The city has the second worst air quality in Brazil, after only São Paulo. The use of new buses along dedicated busways has decreased pollutants as there is less idling time. SMAM (the Municipal Council of the Environment) has encouraged the use of the cleanest fuels and has played a role in monitoring pollution levels.

A partnership between SMAM, the Federal University of Rio Grande do Sul, the State Environmental Protection Foundation (FEPAM) and Petrobrás has created a network of five air monitoring stations in Porto Alegre. By utilizing a Petrobrás product called city diesel, sulphur levels in the air have dropped from 1.2 percent in 1989 to 0.5 percent. Hybrid buses which run on both diesel and electricity are also being considered for the future. Because Porto Alegre has a ready supply of natural gas, the city's taxi fleet is gradually being converted to it from gasoline.