Dioxins and furans in the air of a medium size brazilian city affected by sugarcane pre-harvesting burning - Assunção, João Vicente de; Pesquero, Celia Regina; Nardocci, Adelaide Cassia; Francisco, A P; Soares, Nilson Silva (International Symposium on Halogenated Persistent Organic Pollutants (POPs) - Dioxin 2010, 2010)