Nanoparticles in the air decrease when drivers use more ethanol, according to a study that looked into São Paulo, Brazil.

The research found that when São Paulo drivers switched to gasoline from ethanol due to higher ethanol prices, the concentration of ultrafine particles less than 50 nanometers in diameter rose by one-third. When prices fell and drivers switched back to ethanol, the concentration of ultrafine particles also fell.

The study, published last week, was conducted by scientists from Northwestern University, the National University of Singapore and the University of São Paulo, using data from January 2011 to May 2011.

According to a news release by Northwestern University, environmental protection agencies around the world currently do not track particles of this size but studies have shown them to have negative effect on health.

Provided by Renewables Now exclusively for Essentica.