Air in São Paulo is unfit during 70% of the year

09/08/2011 - 08h44

People in the metropolitan area of São Paulo breathed substandard air during 259 days last year.

Ozone was the number one responsible for the negative situation, said researchers heard by Folha. A toxic gas which may form from fossil fuel burned by cars, trucks and buses. Or by industrial activities.

The air in São Paulo was classified as "good" in only 106 days, according to Cetesb, State Basic Sanitation Engineering Company. The government considers the situation problematic when the air is classified as "inadequate" or "bad."

Ed Lopes/Folhapress

View from the skyline in São Paulo; people in the metropolitan area breathed substandard air during 259 days last year

The "medium" level is not seen as problematic --Cetesb says there is no great impact on people's heath. But technicians say that level affects the population.

"The World Health Organization report presenting the new air quality indexes says that even when below the limits, some effects on health can be observed", says Nelson Gouveia, doctor at USP (São Paulo University) specialized in pollution. Breathing problems usually become more intense and asthma and bronchitis worsen.

Evangelina Vormittag, of the Instituto Saúde e Sustentabilidade [Health and Sustainability Institute] says the international standards are more rigorous than Cetesb's. In the specific case of ozone, the World Health Organization standards are 40% more rigorous.

According to Cetesb, whose standards are more permissive, only 61 days in 2010 were above target - either "inadequate" or "bad".

Cetesb also classifies the air as "very bad", but it was not registered.

"We had many days with unfavorable conditions for dispersion of pollutants in 2010," says Maria Helena Martins, air quality manager at Cetesb. The winter, for instance, was extremely dry.

She says the situation in 2010 is better than in the begging of the decade. "The use of catalysts and compulsory vehicle inspection, for instance, have helped," she says.

Translated by THOMAS MUELLO