Studies of the volatile organic compounds precursors of ozone in Sao Paulo city

Ozone is the main problem of air pollution in the city of Sao Paulo. This study, which was carried out in the Brazilian Basic Sanitation Engineering Company (CETESB, acronym in Portuguese) monitoring station of air quality, focused on the elucidation of the main volatile organic compounds ozone precursors in Sao Paulo atmosphere. Thirty-six samples were collected in August and September 2006, when the consumption of ethanol was about 50%, 69 species of volatile organic compounds were quantified, the ten major urban pollutants compounds in the formation of O(3) were: 1-butene (6.8%), ethylene (6.5%), formaldehyde (6.1%), acetaldehyde (5.5%), toluene (4.8%), 1-ethyl-4-methylbenzene (3.7%), trans-2-pentene (3.7%), propylene (3.7%), trans-2-butene (3.5%), and 1-methylcyclopentene (3.5%). The most abundant classes of air concentration were: alkanes (45%), alkenes (26%), aromatics (14%), aldehydes (13%), and alkadyenes (2%).